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| author | Anas Nashif <anas.nashif@intel.com> | 2012-10-30 12:57:26 -0700 |
|---|---|---|
| committer | Anas Nashif <anas.nashif@intel.com> | 2012-10-30 12:57:26 -0700 |
| commit | 1a78a62555be32868418fe52f8e330c9d0f95d5a (patch) | |
| tree | d3765a80e7d3b9640ec2e930743630cd6b9fce2b /doc/html/mpi | |
| download | boost-1a78a62555be32868418fe52f8e330c9d0f95d5a.tar.gz boost-1a78a62555be32868418fe52f8e330c9d0f95d5a.tar.bz2 boost-1a78a62555be32868418fe52f8e330c9d0f95d5a.zip | |
Imported Upstream version 1.49.0upstream/1.49.0
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| -rwxr-xr-x | doc/html/mpi/acknowledge.html | 53 | ||||
| -rwxr-xr-x | doc/html/mpi/design.html | 77 | ||||
| -rwxr-xr-x | doc/html/mpi/getting_started.html | 253 | ||||
| -rwxr-xr-x | doc/html/mpi/history.html | 67 | ||||
| -rwxr-xr-x | doc/html/mpi/performance.html | 102 | ||||
| -rwxr-xr-x | doc/html/mpi/python.html | 290 | ||||
| -rwxr-xr-x | doc/html/mpi/reference.html | 464 | ||||
| -rwxr-xr-x | doc/html/mpi/tutorial.html | 3616 |
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diff --git a/doc/html/mpi/acknowledge.html b/doc/html/mpi/acknowledge.html new file mode 100755 index 0000000000..4752acb1fc --- /dev/null +++ b/doc/html/mpi/acknowledge.html @@ -0,0 +1,53 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Acknowledgments</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../mpi.html" title="Chapter 17. Boost.MPI"> +<link rel="prev" href="history.html" title="Revision History"> +<link rel="next" href="../program_options.html" title="Chapter 18. Boost.Program_options"> +</head> +<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> +<table cellpadding="2" width="100%"><tr> +<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../boost.png"></td> +<td align="center"><a href="../../../index.html">Home</a></td> +<td align="center"><a href="../../../libs/libraries.htm">Libraries</a></td> +<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> +<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> +<td align="center"><a href="../../../more/index.htm">More</a></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="history.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../mpi.html"><img src="../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../program_options.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +<div class="section"> +<div class="titlepage"><div><div><h2 class="title" style="clear: both"> +<a name="mpi.acknowledge"></a>Acknowledgments</h2></div></div></div> +<p> + Boost.MPI was developed with support from Zurcher Kantonalbank. Daniel Egloff + and Michael Gauckler contributed many ideas to Boost.MPI's design, particularly + in the design of its abstractions for MPI data types and the novel skeleton/context + mechanism for large data structures. Prabhanjan (Anju) Kambadur developed the + predecessor to Boost.MPI that proved the usefulness of the Serialization library + in an MPI setting and the performance benefits of specialization in a C++ abstraction + layer for MPI. Jeremy Siek managed the formal review of Boost.MPI. + </p> +</div> +<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> +<td align="left"></td> +<td align="right"><div class="copyright-footer">Copyright © 2005-2007 Douglas Gregor, + Matthias Troyer, Trustees of Indiana University<p> + Distributed under the Boost Software License, Version 1.0. (See accompanying + file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top"> + http://www.boost.org/LICENSE_1_0.txt </a>) + </p> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="history.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../mpi.html"><img src="../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../program_options.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/mpi/design.html b/doc/html/mpi/design.html new file mode 100755 index 0000000000..df5eaacfac --- /dev/null +++ b/doc/html/mpi/design.html @@ -0,0 +1,77 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Design Philosophy</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../mpi.html" title="Chapter 17. Boost.MPI"> +<link rel="prev" href="python.html" title="Python Bindings"> +<link rel="next" href="performance.html" title="Performance Evaluation"> +</head> +<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> +<table cellpadding="2" width="100%"><tr> +<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../boost.png"></td> +<td align="center"><a href="../../../index.html">Home</a></td> +<td align="center"><a href="../../../libs/libraries.htm">Libraries</a></td> +<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> +<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> +<td align="center"><a href="../../../more/index.htm">More</a></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="python.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../mpi.html"><img src="../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="performance.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +<div class="section"> +<div class="titlepage"><div><div><h2 class="title" style="clear: both"> +<a name="mpi.design"></a>Design Philosophy</h2></div></div></div> +<p> + The design philosophy of the Parallel MPI library is very simple: be both convenient + and efficient. MPI is a library built for high-performance applications, but + it's FORTRAN-centric, performance-minded design makes it rather inflexible + from the C++ point of view: passing a string from one process to another is + inconvenient, requiring several messages and explicit buffering; passing a + container of strings from one process to another requires an extra level of + manual bookkeeping; and passing a map from strings to containers of strings + is positively infuriating. The Parallel MPI library allows all of these data + types to be passed using the same simple <code class="computeroutput"><span class="identifier">send</span><span class="special">()</span></code> and <code class="computeroutput"><span class="identifier">recv</span><span class="special">()</span></code> primitives. Likewise, collective operations + such as <code class="computeroutput"><a class="link" href="../boost/mpi/reduce.html" title="Function reduce">reduce()</a></code> allow arbitrary data types + and function objects, much like the C++ Standard Library would. + </p> +<p> + The higher-level abstractions provided for convenience must not have an impact + on the performance of the application. For instance, sending an integer via + <code class="computeroutput"><span class="identifier">send</span></code> must be as efficient as + a call to <code class="computeroutput"><span class="identifier">MPI_Send</span></code>, which means + that it must be implemented by a simple call to <code class="computeroutput"><span class="identifier">MPI_Send</span></code>; + likewise, an integer <code class="computeroutput"><a class="link" href="../boost/mpi/reduce.html" title="Function reduce">reduce()</a></code> using <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">plus</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span></code> must + be implemented with a call to <code class="computeroutput"><span class="identifier">MPI_Reduce</span></code> + on integers using the <code class="computeroutput"><span class="identifier">MPI_SUM</span></code> + operation: anything less will impact performance. In essence, this is the "don't + pay for what you don't use" principle: if the user is not transmitting + strings, s/he should not pay the overhead associated with strings. + </p> +<p> + Sometimes, achieving maximal performance means foregoing convenient abstractions + and implementing certain functionality using lower-level primitives. For this + reason, it is always possible to extract enough information from the abstractions + in Boost.MPI to minimize the amount of effort required to interface between + Boost.MPI and the C MPI library. + </p> +</div> +<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> +<td align="left"></td> +<td align="right"><div class="copyright-footer">Copyright © 2005-2007 Douglas Gregor, + Matthias Troyer, Trustees of Indiana University<p> + Distributed under the Boost Software License, Version 1.0. (See accompanying + file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top"> + http://www.boost.org/LICENSE_1_0.txt </a>) + </p> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="python.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../mpi.html"><img src="../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="performance.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/mpi/getting_started.html b/doc/html/mpi/getting_started.html new file mode 100755 index 0000000000..5269a69858 --- /dev/null +++ b/doc/html/mpi/getting_started.html @@ -0,0 +1,253 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Getting started</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../mpi.html" title="Chapter 17. Boost.MPI"> +<link rel="prev" href="../mpi.html" title="Chapter 17. Boost.MPI"> +<link rel="next" href="tutorial.html" title="Tutorial"> +</head> +<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> +<table cellpadding="2" width="100%"><tr> +<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../boost.png"></td> +<td align="center"><a href="../../../index.html">Home</a></td> +<td align="center"><a href="../../../libs/libraries.htm">Libraries</a></td> +<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> +<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> +<td align="center"><a href="../../../more/index.htm">More</a></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="../mpi.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../mpi.html"><img src="../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="tutorial.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +<div class="section"> +<div class="titlepage"><div><div><h2 class="title" style="clear: both"> +<a name="mpi.getting_started"></a>Getting started</h2></div></div></div> +<div class="toc"><dl> +<dt><span class="section"><a href="getting_started.html#mpi.mpi_impl">MPI Implementation</a></span></dt> +<dt><span class="section"><a href="getting_started.html#mpi.config">Configure and Build</a></span></dt> +<dt><span class="section"><a href="getting_started.html#mpi.installation">Installing and Using Boost.MPI</a></span></dt> +<dt><span class="section"><a href="getting_started.html#mpi.testing">Testing Boost.MPI</a></span></dt> +</dl></div> +<p> + Getting started with Boost.MPI requires a working MPI implementation, a recent + version of Boost, and some configuration information. + </p> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="mpi.mpi_impl"></a>MPI Implementation</h3></div></div></div> +<p> + To get started with Boost.MPI, you will first need a working MPI implementation. + There are many conforming <a href="http://www-unix.mcs.anl.gov/mpi/implementations.html" target="_top">MPI + implementations</a> available. Boost.MPI should work with any of the + implementations, although it has only been tested extensively with: + </p> +<div class="itemizedlist"><ul class="itemizedlist" type="disc"> +<li class="listitem"> + <a href="http://www.open-mpi.org" target="_top">Open MPI 1.0.x</a> + </li> +<li class="listitem"> + <a href="http://www.lam-mpi.org" target="_top">LAM/MPI 7.x</a> + </li> +<li class="listitem"> + <a href="http://www-unix.mcs.anl.gov/mpi/mpich/" target="_top">MPICH 1.2.x</a> + </li> +</ul></div> +<p> + You can test your implementation using the following simple program, which + passes a message from one processor to another. Each processor prints a message + to standard output. + </p> +<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">mpi</span><span class="special">.</span><span class="identifier">h</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span> + +<span class="keyword">int</span> <span class="identifier">main</span><span class="special">(</span><span class="keyword">int</span> <span class="identifier">argc</span><span class="special">,</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">argv</span><span class="special">[])</span> +<span class="special">{</span> + <span class="identifier">MPI_Init</span><span class="special">(&</span><span class="identifier">argc</span><span class="special">,</span> <span class="special">&</span><span class="identifier">argv</span><span class="special">);</span> + + <span class="keyword">int</span> <span class="identifier">rank</span><span class="special">;</span> + <span class="identifier">MPI_Comm_rank</span><span class="special">(</span><span class="identifier">MPI_COMM_WORLD</span><span class="special">,</span> <span class="special">&</span><span class="identifier">rank</span><span class="special">);</span> + <span class="keyword">if</span> <span class="special">(</span><span class="identifier">rank</span> <span class="special">==</span> <span class="number">0</span><span class="special">)</span> <span class="special">{</span> + <span class="keyword">int</span> <span class="identifier">value</span> <span class="special">=</span> <span class="number">17</span><span class="special">;</span> + <span class="keyword">int</span> <span class="identifier">result</span> <span class="special">=</span> <span class="identifier">MPI_Send</span><span class="special">(&</span><span class="identifier">value</span><span class="special">,</span> <span class="number">1</span><span class="special">,</span> <span class="identifier">MPI_INT</span><span class="special">,</span> <span class="number">1</span><span class="special">,</span> <span class="number">0</span><span class="special">,</span> <span class="identifier">MPI_COMM_WORLD</span><span class="special">);</span> + <span class="keyword">if</span> <span class="special">(</span><span class="identifier">result</span> <span class="special">==</span> <span class="identifier">MPI_SUCCESS</span><span class="special">)</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"Rank 0 OK!"</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> + <span class="special">}</span> <span class="keyword">else</span> <span class="keyword">if</span> <span class="special">(</span><span class="identifier">rank</span> <span class="special">==</span> <span class="number">1</span><span class="special">)</span> <span class="special">{</span> + <span class="keyword">int</span> <span class="identifier">value</span><span class="special">;</span> + <span class="keyword">int</span> <span class="identifier">result</span> <span class="special">=</span> <span class="identifier">MPI_Recv</span><span class="special">(&</span><span class="identifier">value</span><span class="special">,</span> <span class="number">1</span><span class="special">,</span> <span class="identifier">MPI_INT</span><span class="special">,</span> <span class="number">0</span><span class="special">,</span> <span class="number">0</span><span class="special">,</span> <span class="identifier">MPI_COMM_WORLD</span><span class="special">,</span> + <span class="identifier">MPI_STATUS_IGNORE</span><span class="special">);</span> + <span class="keyword">if</span> <span class="special">(</span><span class="identifier">result</span> <span class="special">==</span> <span class="identifier">MPI_SUCCESS</span> <span class="special">&&</span> <span class="identifier">value</span> <span class="special">==</span> <span class="number">17</span><span class="special">)</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"Rank 1 OK!"</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> + <span class="special">}</span> + <span class="identifier">MPI_Finalize</span><span class="special">();</span> + <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> +<span class="special">}</span> +</pre> +<p> + You should compile and run this program on two processors. To do this, consult + the documentation for your MPI implementation. With <a href="http://www.lam-mpi.org/" target="_top">LAM/MPI</a>, + for instance, you compile with the <code class="computeroutput"><span class="identifier">mpiCC</span></code> + or <code class="computeroutput"><span class="identifier">mpic</span><span class="special">++</span></code> + compiler, boot the LAM/MPI daemon, and run your program via <code class="computeroutput"><span class="identifier">mpirun</span></code>. For instance, if your program is + called <code class="computeroutput"><span class="identifier">mpi</span><span class="special">-</span><span class="identifier">test</span><span class="special">.</span><span class="identifier">cpp</span></code>, + use the following commands: + </p> +<pre class="programlisting">mpiCC -o mpi-test mpi-test.cpp +lamboot +mpirun -np 2 ./mpi-test +lamhalt +</pre> +<p> + When you run this program, you will see both <code class="computeroutput"><span class="identifier">Rank</span> + <span class="number">0</span> <span class="identifier">OK</span><span class="special">!</span></code> and <code class="computeroutput"><span class="identifier">Rank</span> + <span class="number">1</span> <span class="identifier">OK</span><span class="special">!</span></code> printed to the screen. However, they may + be printed in any order and may even overlap each other. The following output + is perfectly legitimate for this MPI program: + </p> +<pre class="programlisting">Rank Rank 1 OK! +0 OK! +</pre> +<p> + If your output looks something like the above, your MPI implementation appears + to be working with a C++ compiler and we're ready to move on. + </p> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="mpi.config"></a>Configure and Build</h3></div></div></div> +<p> + Boost.MPI uses version 2 of the <a href="http://www.boost.org/doc/html/bbv2.html" target="_top">Boost.Build</a> + system for configuring and building the library binary. You will need a very + new version of <a href="http://www.boost.org/tools/build/jam_src/index.html" target="_top">Boost.Jam</a> + (3.1.12 or later). If you already have Boost.Jam, run <code class="computeroutput"><span class="identifier">bjam</span> + <span class="special">-</span><span class="identifier">v</span></code> + to determine what version you are using. + </p> +<p> + Information about building Boost.Jam is <a href="http://www.boost.org/tools/build/jam_src/index.html#building_bjam" target="_top">available + here</a>. However, most users need only run <code class="computeroutput"><span class="identifier">build</span><span class="special">.</span><span class="identifier">sh</span></code> in + the <code class="computeroutput"><span class="identifier">tools</span><span class="special">/</span><span class="identifier">build</span><span class="special">/</span><span class="identifier">jam_src</span></code> subdirectory of Boost. Then, copy + the resulting <code class="computeroutput"><span class="identifier">bjam</span></code> executable + some place convenient. + </p> +<p> + For many users using <a href="http://www.lam-mpi.org/" target="_top">LAM/MPI</a>, + <a href="http://www-unix.mcs.anl.gov/mpi/mpich/" target="_top">MPICH</a>, or <a href="http://www.open-mpi.org" target="_top">OpenMPI</a>, configuration is almost automatic. + If you don't already have a file <code class="computeroutput"><span class="identifier">user</span><span class="special">-</span><span class="identifier">config</span><span class="special">.</span><span class="identifier">jam</span></code> in + your home directory, copy <code class="computeroutput"><span class="identifier">tools</span><span class="special">/</span><span class="identifier">build</span><span class="special">/</span><span class="identifier">v2</span><span class="special">/</span><span class="identifier">user</span><span class="special">-</span><span class="identifier">config</span><span class="special">.</span><span class="identifier">jam</span></code> there. + For many users, MPI support can be enabled simply by adding the following + line to your user-config.jam file, which is used to configure Boost.Build + version 2. + </p> +<pre class="programlisting"><span class="keyword">using</span> <span class="identifier">mpi</span> <span class="special">;</span> +</pre> +<p> + This should auto-detect MPI settings based on the MPI wrapper compiler in + your path, e.g., <code class="computeroutput"><span class="identifier">mpic</span><span class="special">++</span></code>. + If the wrapper compiler is not in your path, see below. + </p> +<p> + To actually build the MPI library, go into the top-level Boost directory + and execute the command: + </p> +<pre class="programlisting">bjam --with-mpi +</pre> +<p> + If your MPI wrapper compiler has a different name from the default, you can + pass the name of the wrapper compiler as the first argument to the mpi module: + </p> +<pre class="programlisting"><span class="keyword">using</span> <span class="identifier">mpi</span> <span class="special">:</span> <span class="special">/</span><span class="identifier">opt</span><span class="special">/</span><span class="identifier">mpich2</span><span class="special">-</span><span class="number">1.0</span><span class="special">.</span><span class="number">4</span><span class="special">/</span><span class="identifier">bin</span><span class="special">/</span><span class="identifier">mpiCC</span> <span class="special">;</span> +</pre> +<p> + If your MPI implementation does not have a wrapper compiler, or the MPI auto-detection + code does not work with your MPI's wrapper compiler, you can pass MPI-related + options explicitly via the second parameter to the <code class="computeroutput"><span class="identifier">mpi</span></code> + module: + </p> +<pre class="programlisting"><span class="keyword">using</span> <span class="identifier">mpi</span> <span class="special">:</span> <span class="special">:</span> <span class="special"><</span><span class="identifier">find</span><span class="special">-</span><span class="identifier">shared</span><span class="special">-</span><span class="identifier">library</span><span class="special">></span><span class="identifier">lammpio</span> <span class="special"><</span><span class="identifier">find</span><span class="special">-</span><span class="identifier">shared</span><span class="special">-</span><span class="identifier">library</span><span class="special">></span><span class="identifier">lammpi</span><span class="special">++</span> + <span class="special"><</span><span class="identifier">find</span><span class="special">-</span><span class="identifier">shared</span><span class="special">-</span><span class="identifier">library</span><span class="special">></span><span class="identifier">mpi</span> <span class="special"><</span><span class="identifier">find</span><span class="special">-</span><span class="identifier">shared</span><span class="special">-</span><span class="identifier">library</span><span class="special">></span><span class="identifier">lam</span> + <span class="special"><</span><span class="identifier">find</span><span class="special">-</span><span class="identifier">shared</span><span class="special">-</span><span class="identifier">library</span><span class="special">></span><span class="identifier">dl</span> <span class="special">;</span> +</pre> +<p> + To see the results of MPI auto-detection, pass <code class="computeroutput"><span class="special">--</span><span class="identifier">debug</span><span class="special">-</span><span class="identifier">configuration</span></code> on the bjam command line. + </p> +<p> + The (optional) fourth argument configures Boost.MPI for running regression + tests. These parameters specify the executable used to launch jobs (default: + "mpirun") followed by any necessary arguments to this to run tests + and tell the program to expect the number of processors to follow (default: + "-np"). With the default parameters, for instance, the test harness + will execute, e.g., + </p> +<pre class="programlisting">mpirun -np 4 all_gather_test +</pre> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="mpi.installation"></a>Installing and Using Boost.MPI</h3></div></div></div> +<p> + Installation of Boost.MPI can be performed in the build step by specifying + <code class="computeroutput"><span class="identifier">install</span></code> on the command line + and (optionally) providing an installation location, e.g., + </p> +<pre class="programlisting">bjam --with-mpi install +</pre> +<p> + This command will install libraries into a default system location. To change + the path where libraries will be installed, add the option <code class="computeroutput"><span class="special">--</span><span class="identifier">prefix</span><span class="special">=</span><span class="identifier">PATH</span></code>. + </p> +<p> + To build applications based on Boost.MPI, compile and link them as you normally + would for MPI programs, but remember to link against the <code class="computeroutput"><span class="identifier">boost_mpi</span></code> + and <code class="computeroutput"><span class="identifier">boost_serialization</span></code> libraries, + e.g., + </p> +<pre class="programlisting">mpic++ -I/path/to/boost/mpi my_application.cpp -Llibdir \ + -lboost_mpi-gcc-mt-1_35 -lboost_serialization-gcc-d-1_35.a +</pre> +</div> +<p> + If you plan to use the <a class="link" href="python.html" title="Python Bindings">Python bindings</a> for + Boost.MPI in conjunction with the C++ Boost.MPI, you will also need to link + against the boost_mpi_python library, e.g., by adding <code class="computeroutput"><span class="special">-</span><span class="identifier">lboost_mpi_python</span><span class="special">-</span><span class="identifier">gcc</span><span class="special">-</span><span class="identifier">mt</span><span class="special">-</span><span class="number">1</span><span class="identifier">_35</span></code> + to your link command. This step will only be necessary if you intend to <a class="link" href="python.html#mpi.python_user_data" title="Transmitting User-Defined Data">register C++ types</a> or use the <a class="link" href="python.html#mpi.python_skeleton_content" title="Skeleton/Content Mechanism">skeleton/content + mechanism</a> from within Python. + </p> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="mpi.testing"></a>Testing Boost.MPI</h3></div></div></div> +<p> + If you would like to verify that Boost.MPI is working properly with your + compiler, platform, and MPI implementation, a self-contained test suite is + available. To use this test suite, you will need to first configure Boost.Build + for your MPI environment and then run <code class="computeroutput"><span class="identifier">bjam</span></code> + in <code class="computeroutput"><span class="identifier">libs</span><span class="special">/</span><span class="identifier">mpi</span><span class="special">/</span><span class="identifier">test</span></code> + (possibly with some extra options). For <a href="http://www.lam-mpi.org/" target="_top">LAM/MPI</a>, + you will need to run <code class="computeroutput"><span class="identifier">lamboot</span></code> + before running <code class="computeroutput"><span class="identifier">bjam</span></code>. For + <a href="http://www-unix.mcs.anl.gov/mpi/mpich/" target="_top">MPICH</a>, you may + need to create a machine file and pass <code class="computeroutput"><span class="special">-</span><span class="identifier">sMPIRUN_FLAGS</span><span class="special">=</span><span class="string">"-machinefile <filename>"</span></code> to + Boost.Jam; see the section on <a class="link" href="getting_started.html#mpi.config" title="Configure and Build">configuration</a> + for more information. If testing succeeds, <code class="computeroutput"><span class="identifier">bjam</span></code> + will exit without errors. + </p> +</div> +</div> +<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> +<td align="left"></td> +<td align="right"><div class="copyright-footer">Copyright © 2005-2007 Douglas Gregor, + Matthias Troyer, Trustees of Indiana University<p> + Distributed under the Boost Software License, Version 1.0. (See accompanying + file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top"> + http://www.boost.org/LICENSE_1_0.txt </a>) + </p> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="../mpi.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../mpi.html"><img src="../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="tutorial.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/mpi/history.html b/doc/html/mpi/history.html new file mode 100755 index 0000000000..973d5043e0 --- /dev/null +++ b/doc/html/mpi/history.html @@ -0,0 +1,67 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Revision History</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../mpi.html" title="Chapter 17. Boost.MPI"> +<link rel="prev" href="performance.html" title="Performance Evaluation"> +<link rel="next" href="acknowledge.html" title="Acknowledgments"> +</head> +<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> +<table cellpadding="2" width="100%"><tr> +<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../boost.png"></td> +<td align="center"><a href="../../../index.html">Home</a></td> +<td align="center"><a href="../../../libs/libraries.htm">Libraries</a></td> +<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> +<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> +<td align="center"><a href="../../../more/index.htm">More</a></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="performance.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../mpi.html"><img src="../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="acknowledge.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +<div class="section"> +<div class="titlepage"><div><div><h2 class="title" style="clear: both"> +<a name="mpi.history"></a>Revision History</h2></div></div></div> +<div class="itemizedlist"><ul class="itemizedlist" type="disc"> +<li class="listitem"> + <span class="bold"><strong>Boost 1.36.0</strong></span>: + <div class="itemizedlist"><ul class="itemizedlist" type="circle"><li class="listitem"> + Support for non-blocking operations in Python, from Andreas Klöckner + </li></ul></div> + </li> +<li class="listitem"> + <span class="bold"><strong>Boost 1.35.0</strong></span>: Initial release, containing + the following post-review changes + <div class="itemizedlist"><ul class="itemizedlist" type="circle"> +<li class="listitem"> + Support for arrays in all collective operations + </li> +<li class="listitem"> + Support default-construction of <code class="computeroutput"><a class="link" href="../boost/mpi/environment.html" title="Class environment">environment</a></code> + </li> +</ul></div> + </li> +<li class="listitem"> + <span class="bold"><strong>2006-09-21</strong></span>: Boost.MPI accepted into Boost. + </li> +</ul></div> +</div> +<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> +<td align="left"></td> +<td align="right"><div class="copyright-footer">Copyright © 2005-2007 Douglas Gregor, + Matthias Troyer, Trustees of Indiana University<p> + Distributed under the Boost Software License, Version 1.0. (See accompanying + file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top"> + http://www.boost.org/LICENSE_1_0.txt </a>) + </p> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="performance.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../mpi.html"><img src="../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="acknowledge.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/mpi/performance.html b/doc/html/mpi/performance.html new file mode 100755 index 0000000000..0df335dba4 --- /dev/null +++ b/doc/html/mpi/performance.html @@ -0,0 +1,102 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Performance Evaluation</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../mpi.html" title="Chapter 17. Boost.MPI"> +<link rel="prev" href="design.html" title="Design Philosophy"> +<link rel="next" href="history.html" title="Revision History"> +</head> +<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> +<table cellpadding="2" width="100%"><tr> +<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../boost.png"></td> +<td align="center"><a href="../../../index.html">Home</a></td> +<td align="center"><a href="../../../libs/libraries.htm">Libraries</a></td> +<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> +<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> +<td align="center"><a href="../../../more/index.htm">More</a></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="design.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../mpi.html"><img src="../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="history.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +<div class="section"> +<div class="titlepage"><div><div><h2 class="title" style="clear: both"> +<a name="mpi.performance"></a>Performance Evaluation</h2></div></div></div> +<p> + Message-passing performance is crucial in high-performance distributed computing. + To evaluate the performance of Boost.MPI, we modified the standard <a href="http://www.scl.ameslab.gov/netpipe/" target="_top">NetPIPE</a> + benchmark (version 3.6.2) to use Boost.MPI and compared its performance against + raw MPI. We ran five different variants of the NetPIPE benchmark: + </p> +<div class="orderedlist"><ol class="orderedlist" type="1"> +<li class="listitem"> + MPI: The unmodified NetPIPE benchmark. + </li> +<li class="listitem"> + Boost.MPI: NetPIPE modified to use Boost.MPI calls for communication. + </li> +<li class="listitem"> + MPI (Datatypes): NetPIPE modified to use a derived datatype (which itself + contains a single <code class="computeroutput"><span class="identifier">MPI_BYTE</span></code>) + rathan than a fundamental datatype. + </li> +<li class="listitem"> + Boost.MPI (Datatypes): NetPIPE modified to use a user-defined type <code class="computeroutput"><span class="identifier">Char</span></code> in place of the fundamental <code class="computeroutput"><span class="keyword">char</span></code> type. The <code class="computeroutput"><span class="identifier">Char</span></code> + type contains a single <code class="computeroutput"><span class="keyword">char</span></code>, + a <code class="computeroutput"><span class="identifier">serialize</span><span class="special">()</span></code> + method to make it serializable, and specializes <code class="computeroutput"><a class="link" href="../boost/mpi/is_mpi_datatype.html" title="Struct template is_mpi_datatype">is_mpi_datatype</a></code> + to force Boost.MPI to build a derived MPI data type for it. + </li> +<li class="listitem"> + Boost.MPI (Serialized): NetPIPE modified to use a user-defined type <code class="computeroutput"><span class="identifier">Char</span></code> in place of the fundamental <code class="computeroutput"><span class="keyword">char</span></code> type. This <code class="computeroutput"><span class="identifier">Char</span></code> + type contains a single <code class="computeroutput"><span class="keyword">char</span></code> + and is serializable. Unlike the Datatypes case, <code class="computeroutput"><a class="link" href="../boost/mpi/is_mpi_datatype.html" title="Struct template is_mpi_datatype">is_mpi_datatype</a></code> + is <span class="bold"><strong>not</strong></span> specialized, forcing Boost.MPI + to perform many, many serialization calls. + </li> +</ol></div> +<p> + The actual tests were performed on the Odin cluster in the <a href="http://www.cs.indiana.edu/" target="_top">Department + of Computer Science</a> at <a href="http://www.iub.edu" target="_top">Indiana University</a>, + which contains 128 nodes connected via Infiniband. Each node contains 4GB memory + and two AMD Opteron processors. The NetPIPE benchmarks were compiled with Intel's + C++ Compiler, version 9.0, Boost 1.35.0 (prerelease), and <a href="http://www.open-mpi.org/" target="_top">Open + MPI</a> version 1.1. The NetPIPE results follow: + </p> +<p> + <span class="inlinemediaobject"><img src="../../../libs/mpi/doc/netpipe.png" alt="netpipe"></span> + </p> +<p> + There are a some observations we can make about these NetPIPE results. First + of all, the top two plots show that Boost.MPI performs on par with MPI for + fundamental types. The next two plots show that Boost.MPI performs on par with + MPI for derived data types, even though Boost.MPI provides a much more abstract, + completely transparent approach to building derived data types than raw MPI. + Overall performance for derived data types is significantly worse than for + fundamental data types, but the bottleneck is in the underlying MPI implementation + itself. Finally, when forcing Boost.MPI to serialize characters individually, + performance suffers greatly. This particular instance is the worst possible + case for Boost.MPI, because we are serializing millions of individual characters. + Overall, the additional abstraction provided by Boost.MPI does not impair its + performance. + </p> +</div> +<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> +<td align="left"></td> +<td align="right"><div class="copyright-footer">Copyright © 2005-2007 Douglas Gregor, + Matthias Troyer, Trustees of Indiana University<p> + Distributed under the Boost Software License, Version 1.0. (See accompanying + file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top"> + http://www.boost.org/LICENSE_1_0.txt </a>) + </p> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="design.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../mpi.html"><img src="../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="history.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/mpi/python.html b/doc/html/mpi/python.html new file mode 100755 index 0000000000..cc27546939 --- /dev/null +++ b/doc/html/mpi/python.html @@ -0,0 +1,290 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Python Bindings</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../mpi.html" title="Chapter 17. Boost.MPI"> +<link rel="prev" href="../boost/mpi/timer.html" title="Class timer"> +<link rel="next" href="design.html" title="Design Philosophy"> +</head> +<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> +<table cellpadding="2" width="100%"><tr> +<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../boost.png"></td> +<td align="center"><a href="../../../index.html">Home</a></td> +<td align="center"><a href="../../../libs/libraries.htm">Libraries</a></td> +<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> +<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> +<td align="center"><a href="../../../more/index.htm">More</a></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="../boost/mpi/timer.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../mpi.html"><img src="../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="design.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +<div class="section"> +<div class="titlepage"><div><div><h2 class="title" style="clear: both"> +<a name="mpi.python"></a>Python Bindings</h2></div></div></div> +<div class="toc"><dl> +<dt><span class="section"><a href="python.html#mpi.python_quickstart">Quickstart</a></span></dt> +<dt><span class="section"><a href="python.html#mpi.python_user_data">Transmitting User-Defined Data</a></span></dt> +<dt><span class="section"><a href="python.html#mpi.python_collectives">Collectives</a></span></dt> +<dt><span class="section"><a href="python.html#mpi.python_skeleton_content">Skeleton/Content Mechanism</a></span></dt> +<dt><span class="section"><a href="python.html#mpi.python_compatbility">C++/Python MPI Compatibility</a></span></dt> +<dt><span class="section"><a href="python.html#mpi.pythonref">Reference</a></span></dt> +</dl></div> +<p> + Boost.MPI provides an alternative MPI interface from the <a href="http://www.python.org" target="_top">Python</a> + programming language via the <code class="computeroutput"><span class="identifier">boost</span><span class="special">.</span><span class="identifier">mpi</span></code> module. + The Boost.MPI Python bindings, built on top of the C++ Boost.MPI using the + <a href="http://www.boost.org/libs/python/doc" target="_top">Boost.Python</a> library, + provide nearly all of the functionality of Boost.MPI within a dynamic, object-oriented + language. + </p> +<p> + The Boost.MPI Python module can be built and installed from the <code class="computeroutput"><span class="identifier">libs</span><span class="special">/</span><span class="identifier">mpi</span><span class="special">/</span><span class="identifier">build</span></code> directory. + Just follow the <a class="link" href="getting_started.html#mpi.config" title="Configure and Build">configuration</a> and <a class="link" href="getting_started.html#mpi.installation" title="Installing and Using Boost.MPI">installation</a> + instructions for the C++ Boost.MPI. Once you have installed the Python module, + be sure that the installation location is in your <code class="computeroutput"><span class="identifier">PYTHONPATH</span></code>. + </p> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="mpi.python_quickstart"></a>Quickstart</h3></div></div></div> +<p> + Getting started with the Boost.MPI Python module is as easy as importing + <code class="computeroutput"><span class="identifier">boost</span><span class="special">.</span><span class="identifier">mpi</span></code>. Our first "Hello, World!" + program is just two lines long: + </p> +<pre class="programlisting"><span class="keyword">import</span> <span class="identifier">boost</span><span class="special">.</span><span class="identifier">mpi</span> <span class="keyword">as</span> <span class="identifier">mpi</span> +<span class="keyword">print</span> <span class="string">"I am process %d of %d."</span> <span class="special">%</span> <span class="special">(</span><span class="identifier">mpi</span><span class="special">.</span><span class="identifier">rank</span><span class="special">,</span> <span class="identifier">mpi</span><span class="special">.</span><span class="identifier">size</span><span class="special">)</span> +</pre> +<p> + Go ahead and run this program with several processes. Be sure to invoke the + <code class="computeroutput"><span class="identifier">python</span></code> interpreter from + <code class="computeroutput"><span class="identifier">mpirun</span></code>, e.g., + </p> +<pre class="programlisting">mpirun -np 5 python hello_world.py +</pre> +<p> + This will return output such as: + </p> +<pre class="programlisting">I am process 1 of 5. +I am process 3 of 5. +I am process 2 of 5. +I am process 4 of 5. +I am process 0 of 5. +</pre> +<p> + Point-to-point operations in Boost.MPI have nearly the same syntax in Python + as in C++. We can write a simple two-process Python program that prints "Hello, + world!" by transmitting Python strings: + </p> +<pre class="programlisting"><span class="keyword">import</span> <span class="identifier">boost</span><span class="special">.</span><span class="identifier">mpi</span> <span class="keyword">as</span> <span class="identifier">mpi</span> + +<span class="keyword">if</span> <span class="identifier">mpi</span><span class="special">.</span><span class="identifier">world</span><span class="special">.</span><span class="identifier">rank</span> <span class="special">==</span> <span class="number">0</span><span class="special">:</span> + <span class="identifier">mpi</span><span class="special">.</span><span class="identifier">world</span><span class="special">.</span><span class="identifier">send</span><span class="special">(</span><span class="number">1</span><span class="special">,</span> <span class="number">0</span><span class="special">,</span> <span class="string">'Hello'</span><span class="special">)</span> + <span class="identifier">msg</span> <span class="special">=</span> <span class="identifier">mpi</span><span class="special">.</span><span class="identifier">world</span><span class="special">.</span><span class="identifier">recv</span><span class="special">(</span><span class="number">1</span><span class="special">,</span> <span class="number">1</span><span class="special">)</span> + <span class="keyword">print</span> <span class="identifier">msg</span><span class="special">,</span><span class="string">'!'</span> +<span class="keyword">else</span><span class="special">:</span> + <span class="identifier">msg</span> <span class="special">=</span> <span class="identifier">mpi</span><span class="special">.</span><span class="identifier">world</span><span class="special">.</span><span class="identifier">recv</span><span class="special">(</span><span class="number">0</span><span class="special">,</span> <span class="number">0</span><span class="special">)</span> + <span class="keyword">print</span> <span class="special">(</span><span class="identifier">msg</span> <span class="special">+</span> <span class="string">', '</span><span class="special">),</span> + <span class="identifier">mpi</span><span class="special">.</span><span class="identifier">world</span><span class="special">.</span><span class="identifier">send</span><span class="special">(</span><span class="number">0</span><span class="special">,</span> <span class="number">1</span><span class="special">,</span> <span class="string">'world'</span><span class="special">)</span> +</pre> +<p> + There are only a few notable differences between this Python code and the + example <a class="link" href="tutorial.html#mpi.point_to_point" title="Point-to-Point communication">in the C++ tutorial</a>. First + of all, we don't need to write any initialization code in Python: just loading + the <code class="computeroutput"><span class="identifier">boost</span><span class="special">.</span><span class="identifier">mpi</span></code> module makes the appropriate <code class="computeroutput"><span class="identifier">MPI_Init</span></code> and <code class="computeroutput"><span class="identifier">MPI_Finalize</span></code> + calls. Second, we're passing Python objects from one process to another through + MPI. Any Python object that can be pickled can be transmitted; the next section + will describe in more detail how the Boost.MPI Python layer transmits objects. + Finally, when we receive objects with <code class="computeroutput"><span class="identifier">recv</span></code>, + we don't need to specify the type because transmission of Python objects + is polymorphic. + </p> +<p> + When experimenting with Boost.MPI in Python, don't forget that help is always + available via <code class="computeroutput"><span class="identifier">pydoc</span></code>: just + pass the name of the module or module entity on the command line (e.g., + <code class="computeroutput"><span class="identifier">pydoc</span> <span class="identifier">boost</span><span class="special">.</span><span class="identifier">mpi</span><span class="special">.</span><span class="identifier">communicator</span></code>) to receive complete reference + documentation. When in doubt, try it! + </p> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="mpi.python_user_data"></a>Transmitting User-Defined Data</h3></div></div></div> +<p> + Boost.MPI can transmit user-defined data in several different ways. Most + importantly, it can transmit arbitrary <a href="http://www.python.org" target="_top">Python</a> + objects by pickling them at the sender and unpickling them at the receiver, + allowing arbitrarily complex Python data structures to interoperate with + MPI. + </p> +<p> + Boost.MPI also supports efficient serialization and transmission of C++ objects + (that have been exposed to Python) through its C++ interface. Any C++ type + that provides (de-)serialization routines that meet the requirements of the + Boost.Serialization library is eligible for this optimization, but the type + must be registered in advance. To register a C++ type, invoke the C++ function + <code class="computeroutput"><a class="link" href="../boost/mpi/python/register_serialized.html" title="Function template register_serialized">register_serialized</a></code>. + If your C++ types come from other Python modules (they probably will!), those + modules will need to link against the <code class="computeroutput"><span class="identifier">boost_mpi</span></code> + and <code class="computeroutput"><span class="identifier">boost_mpi_python</span></code> libraries + as described in the <a class="link" href="getting_started.html#mpi.installation" title="Installing and Using Boost.MPI">installation section</a>. + Note that you do <span class="bold"><strong>not</strong></span> need to link against + the Boost.MPI Python extension module. + </p> +<p> + Finally, Boost.MPI supports separation of the structure of an object from + the data it stores, allowing the two pieces to be transmitted separately. + This "skeleton/content" mechanism, described in more detail in + a later section, is a communication optimization suitable for problems with + fixed data structures whose internal data changes frequently. + </p> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="mpi.python_collectives"></a>Collectives</h3></div></div></div> +<p> + Boost.MPI supports all of the MPI collectives (<code class="computeroutput"><span class="identifier">scatter</span></code>, + <code class="computeroutput"><span class="identifier">reduce</span></code>, <code class="computeroutput"><span class="identifier">scan</span></code>, + <code class="computeroutput"><span class="identifier">broadcast</span></code>, etc.) for any + type of data that can be transmitted with the point-to-point communication + operations. For the MPI collectives that require a user-specified operation + (e.g., <code class="computeroutput"><span class="identifier">reduce</span></code> and <code class="computeroutput"><span class="identifier">scan</span></code>), the operation can be an arbitrary + Python function. For instance, one could concatenate strings with <code class="computeroutput"><span class="identifier">all_reduce</span></code>: + </p> +<pre class="programlisting"><span class="identifier">mpi</span><span class="special">.</span><span class="identifier">all_reduce</span><span class="special">(</span><span class="identifier">my_string</span><span class="special">,</span> <span class="keyword">lambda</span> <span class="identifier">x</span><span class="special">,</span><span class="identifier">y</span><span class="special">:</span> <span class="identifier">x</span> <span class="special">+</span> <span class="identifier">y</span><span class="special">)</span> +</pre> +<p> + The following module-level functions implement MPI collectives: all_gather + Gather the values from all processes. all_reduce Combine the results from + all processes. all_to_all Every process sends data to every other process. + broadcast Broadcast data from one process to all other processes. gather + Gather the values from all processes to the root. reduce Combine the results + from all processes to the root. scan Prefix reduction of the values from + all processes. scatter Scatter the values stored at the root to all processes. + </p> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="mpi.python_skeleton_content"></a>Skeleton/Content Mechanism</h3></div></div></div> +<p> + Boost.MPI provides a skeleton/content mechanism that allows the transfer + of large data structures to be split into two separate stages, with the skeleton + (or, "shape") of the data structure sent first and the content + (or, "data") of the data structure sent later, potentially several + times, so long as the structure has not changed since the skeleton was transferred. + The skeleton/content mechanism can improve performance when the data structure + is large and its shape is fixed, because while the skeleton requires serialization + (it has an unknown size), the content transfer is fixed-size and can be done + without extra copies. + </p> +<p> + To use the skeleton/content mechanism from Python, you must first register + the type of your data structure with the skeleton/content mechanism <span class="bold"><strong>from C++</strong></span>. The registration function is <code class="computeroutput"><a class="link" href="../boost/mpi/python/register_skeleton_and_c_id778072.html" title="Function template register_skeleton_and_content">register_skeleton_and_content</a></code> + and resides in the <code class="computeroutput"><a class="link" href="reference.html#header.boost.mpi.python_hpp" title="Header <boost/mpi/python.hpp>"><boost/mpi/python.hpp></a></code> + header. + </p> +<p> + Once you have registered your C++ data structures, you can extract the skeleton + for an instance of that data structure with <code class="computeroutput"><span class="identifier">skeleton</span><span class="special">()</span></code>. The resulting <code class="computeroutput"><span class="identifier">skeleton_proxy</span></code> + can be transmitted via the normal send routine, e.g., + </p> +<pre class="programlisting"><span class="identifier">mpi</span><span class="special">.</span><span class="identifier">world</span><span class="special">.</span><span class="identifier">send</span><span class="special">(</span><span class="number">1</span><span class="special">,</span> <span class="number">0</span><span class="special">,</span> <span class="identifier">skeleton</span><span class="special">(</span><span class="identifier">my_data_structure</span><span class="special">))</span> +</pre> +<p> + <code class="computeroutput"><span class="identifier">skeleton_proxy</span></code> objects can + be received on the other end via <code class="computeroutput"><span class="identifier">recv</span><span class="special">()</span></code>, which stores a newly-created instance + of your data structure with the same "shape" as the sender in its + <code class="computeroutput"><span class="error">"</span><span class="identifier">object</span></code> + attribute: + </p> +<pre class="programlisting"><span class="identifier">shape</span> <span class="special">=</span> <span class="identifier">mpi</span><span class="special">.</span><span class="identifier">world</span><span class="special">.</span><span class="identifier">recv</span><span class="special">(</span><span class="number">0</span><span class="special">,</span> <span class="number">0</span><span class="special">)</span> +<span class="identifier">my_data_structure</span> <span class="special">=</span> <span class="identifier">shape</span><span class="special">.</span><span class="identifier">object</span> +</pre> +<p> + Once the skeleton has been transmitted, the content (accessed via <code class="computeroutput"><span class="identifier">get_content</span></code>) can be transmitted in much + the same way. Note, however, that the receiver also specifies <code class="computeroutput"><span class="identifier">get_content</span><span class="special">(</span><span class="identifier">my_data_structure</span><span class="special">)</span></code> + in its call to receive: + </p> +<pre class="programlisting"><span class="keyword">if</span> <span class="identifier">mpi</span><span class="special">.</span><span class="identifier">rank</span> <span class="special">==</span> <span class="number">0</span><span class="special">:</span> + <span class="identifier">mpi</span><span class="special">.</span><span class="identifier">world</span><span class="special">.</span><span class="identifier">send</span><span class="special">(</span><span class="number">1</span><span class="special">,</span> <span class="number">0</span><span class="special">,</span> <span class="identifier">get_content</span><span class="special">(</span><span class="identifier">my_data_structure</span><span class="special">))</span> +<span class="keyword">else</span><span class="special">:</span> + <span class="identifier">mpi</span><span class="special">.</span><span class="identifier">world</span><span class="special">.</span><span class="identifier">recv</span><span class="special">(</span><span class="number">0</span><span class="special">,</span> <span class="number">0</span><span class="special">,</span> <span class="identifier">get_content</span><span class="special">(</span><span class="identifier">my_data_structure</span><span class="special">))</span> +</pre> +<p> + Of course, this transmission of content can occur repeatedly, if the values + in the data structure--but not its shape--changes. + </p> +<p> + The skeleton/content mechanism is a structured way to exploit the interaction + between custom-built MPI datatypes and <code class="computeroutput"><span class="identifier">MPI_BOTTOM</span></code>, + to eliminate extra buffer copies. + </p> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="mpi.python_compatbility"></a>C++/Python MPI Compatibility</h3></div></div></div> +<p> + Boost.MPI is a C++ library whose facilities have been exposed to Python via + the Boost.Python library. Since the Boost.MPI Python bindings are build directly + on top of the C++ library, and nearly every feature of C++ library is available + in Python, hybrid C++/Python programs using Boost.MPI can interact, e.g., + sending a value from Python but receiving that value in C++ (or vice versa). + However, doing so requires some care. Because Python objects are dynamically + typed, Boost.MPI transfers type information along with the serialized form + of the object, so that the object can be received even when its type is not + known. This mechanism differs from its C++ counterpart, where the static + types of transmitted values are always known. + </p> +<p> + The only way to communicate between the C++ and Python views on Boost.MPI + is to traffic entirely in Python objects. For Python, this is the normal + state of affairs, so nothing will change. For C++, this means sending and + receiving values of type <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">python</span><span class="special">::</span><span class="identifier">object</span></code>, + from the <a href="http://www.boost.org/libs/python/doc" target="_top">Boost.Python</a> + library. For instance, say we want to transmit an integer value from Python: + </p> +<pre class="programlisting"><span class="identifier">comm</span><span class="special">.</span><span class="identifier">send</span><span class="special">(</span><span class="number">1</span><span class="special">,</span> <span class="number">0</span><span class="special">,</span> <span class="number">17</span><span class="special">)</span> +</pre> +<p> + In C++, we would receive that value into a Python object and then <code class="computeroutput"><span class="identifier">extract</span></code> an integer value: + </p> +<pre class="programlisting"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">python</span><span class="special">::</span><span class="identifier">object</span> <span class="identifier">value</span><span class="special">;</span> +<span class="identifier">comm</span><span class="special">.</span><span class="identifier">recv</span><span class="special">(</span><span class="number">0</span><span class="special">,</span> <span class="number">0</span><span class="special">,</span> <span class="identifier">value</span><span class="special">);</span> +<span class="keyword">int</span> <span class="identifier">int_value</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">python</span><span class="special">::</span><span class="identifier">extract</span><span class="special"><</span><span class="keyword">int</span><span class="special">>(</span><span class="identifier">value</span><span class="special">);</span> +</pre> +<p> + In the future, Boost.MPI will be extended to allow improved interoperability + with the C++ Boost.MPI and the C MPI bindings. + </p> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="mpi.pythonref"></a>Reference</h3></div></div></div> +<p> + The Boost.MPI Python module, <code class="computeroutput"><span class="identifier">boost</span><span class="special">.</span><span class="identifier">mpi</span></code>, has + its own <a href="../boost.mpi.html" target="_top">reference documentation</a>, which + is also available using <code class="computeroutput"><span class="identifier">pydoc</span></code> + (from the command line) or <code class="computeroutput"><span class="identifier">help</span><span class="special">(</span><span class="identifier">boost</span><span class="special">.</span><span class="identifier">mpi</span><span class="special">)</span></code> + (from the Python interpreter). + </p> +</div> +</div> +<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> +<td align="left"></td> +<td align="right"><div class="copyright-footer">Copyright © 2005-2007 Douglas Gregor, + Matthias Troyer, Trustees of Indiana University<p> + Distributed under the Boost Software License, Version 1.0. (See accompanying + file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top"> + http://www.boost.org/LICENSE_1_0.txt </a>) + </p> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="../boost/mpi/timer.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../mpi.html"><img src="../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="design.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/mpi/reference.html b/doc/html/mpi/reference.html new file mode 100755 index 0000000000..9f8a4ef85d --- /dev/null +++ b/doc/html/mpi/reference.html @@ -0,0 +1,464 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Reference</title> +<link rel="stylesheet" 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class="titlepage"><div><div><h3 class="title"> +<a name="header.boost.mpi_hpp"></a>Header <<a href="../../../boost/mpi.hpp" target="_top">boost/mpi.hpp</a>></h3></div></div></div> +<p>This file is a top-level convenience header that includes all of the Boost.MPI library headers. Users concerned about compile time may wish to include only specific headers from the Boost.MPI library. </p> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="header.boost.mpi.allocator_hpp"></a>Header <<a href="../../../boost/mpi/allocator.hpp" target="_top">boost/mpi/allocator.hpp</a>></h3></div></div></div> +<p>This header provides an STL-compliant allocator that uses the MPI-2 memory allocation facilities. </p> +<pre class="synopsis"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> + <span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">{</span> + <span class="keyword">template</span><span class="special"><</span><span class="special">></span> <span class="keyword">class</span> <a class="link" href="../boost/mpi/allocator_void_id764381.html" title="Class allocator<void>">allocator</a><span class="special"><</span><span class="keyword">void</span><span class="special">></span><span class="special">;</span> + + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">class</span> <a class="link" href="../boost/mpi/allocator.html" title="Class template allocator">allocator</a><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T1<span class="special">,</span> <span class="keyword">typename</span> T2<span class="special">></span> + <span class="keyword">bool</span> <a class="link" href="../boost/mpi/operator___id765997.html" title="Function template operator=="><span class="keyword">operator</span><span class="special">==</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/allocator.html" title="Class template allocator">allocator</a><span class="special"><</span> <span class="identifier">T1</span> <span class="special">></span> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <a class="link" href="../boost/mpi/allocator.html" title="Class template allocator">allocator</a><span class="special"><</span> <span class="identifier">T2</span> <span class="special">></span> <span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T1<span class="special">,</span> <span class="keyword">typename</span> T2<span class="special">></span> + <span class="keyword">bool</span> <a class="link" href="../boost/mpi/operator___id766049.html" title="Function template operator!="><span class="keyword">operator</span><span class="special">!=</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/allocator.html" title="Class template allocator">allocator</a><span class="special"><</span> <span class="identifier">T1</span> <span class="special">></span> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <a class="link" href="../boost/mpi/allocator.html" title="Class template allocator">allocator</a><span class="special"><</span> <span class="identifier">T2</span> <span class="special">></span> <span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="special">}</span> +<span class="special">}</span></pre> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="header.boost.mpi.collectives_hpp"></a>Header <<a href="../../../boost/mpi/collectives.hpp" target="_top">boost/mpi/collectives.hpp</a>></h3></div></div></div> +<p>This header contains MPI collective operations, which implement various parallel algorithms that require the coordination of all processes within a communicator. The header <code class="computeroutput">collectives_fwd.hpp</code> provides forward declarations for each of these operations. To include only specific collective algorithms, use the headers <code class="computeroutput">boost/mpi/collectives/algorithm_name.hpp</code>. </p> +<pre class="synopsis"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> + <span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">{</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/all_gather.html" title="Function all_gather"><span class="identifier">all_gather</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">&</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span> <span class="identifier">T</span> <span class="special">></span> <span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">void</span> <a class="link" href="../boost/mpi/all_gather.html" title="Function all_gather"><span class="identifier">all_gather</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">&</span><span class="special">,</span> <span class="identifier">T</span> <span class="special">*</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/all_gather.html" title="Function all_gather"><span class="identifier">all_gather</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">*</span><span class="special">,</span> <span class="keyword">int</span><span class="special">,</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span> <span class="identifier">T</span> <span class="special">></span> <span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/all_gather.html" title="Function all_gather"><span class="identifier">all_gather</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">*</span><span class="special">,</span> <span class="keyword">int</span><span class="special">,</span> <span class="identifier">T</span> <span class="special">*</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">,</span> <span class="keyword">typename</span> Op<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/all_reduce.html" title="Function all_reduce"><span class="identifier">all_reduce</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">&</span><span class="special">,</span> <span class="identifier">T</span> <span class="special">&</span><span class="special">,</span> <span class="identifier">Op</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">,</span> <span class="keyword">typename</span> Op<span class="special">></span> + <span class="identifier">T</span> <a class="link" href="../boost/mpi/all_reduce.html" title="Function all_reduce"><span class="identifier">all_reduce</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">&</span><span class="special">,</span> <span class="identifier">Op</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">,</span> <span class="keyword">typename</span> Op<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/all_reduce.html" title="Function all_reduce"><span class="identifier">all_reduce</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">*</span><span class="special">,</span> <span class="keyword">int</span><span class="special">,</span> <span class="identifier">T</span> <span class="special">*</span><span class="special">,</span> <span class="identifier">Op</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/all_to_all.html" title="Function all_to_all"><span class="identifier">all_to_all</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span> <span class="identifier">T</span> <span class="special">></span> <span class="special">&</span><span class="special">,</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span> <span class="identifier">T</span> <span class="special">></span> <span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">void</span> <a class="link" href="../boost/mpi/all_to_all.html" title="Function all_to_all"><span class="identifier">all_to_all</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">*</span><span class="special">,</span> <span class="identifier">T</span> <span class="special">*</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/all_to_all.html" title="Function all_to_all"><span class="identifier">all_to_all</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span> <span class="identifier">T</span> <span class="special">></span> <span class="special">&</span><span class="special">,</span> <span class="keyword">int</span><span class="special">,</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span> <span class="identifier">T</span> <span class="special">></span> <span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/all_to_all.html" title="Function all_to_all"><span class="identifier">all_to_all</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">*</span><span class="special">,</span> <span class="keyword">int</span><span class="special">,</span> <span class="identifier">T</span> <span class="special">*</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">void</span> <a class="link" href="../boost/mpi/broadcast.html" title="Function broadcast"><span class="identifier">broadcast</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="identifier">T</span> <span class="special">&</span><span class="special">,</span> <span class="keyword">int</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">void</span> <a class="link" href="../boost/mpi/broadcast.html" title="Function broadcast"><span class="identifier">broadcast</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="identifier">T</span> <span class="special">*</span><span class="special">,</span> <span class="keyword">int</span><span class="special">,</span> <span class="keyword">int</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/broadcast.html" title="Function broadcast"><span class="identifier">broadcast</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <a class="link" href="../boost/mpi/skeleton_proxy.html" title="Struct template skeleton_proxy">skeleton_proxy</a><span class="special"><</span> <span class="identifier">T</span> <span class="special">></span> <span class="special">&</span><span class="special">,</span> <span class="keyword">int</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/broadcast.html" title="Function broadcast"><span class="identifier">broadcast</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <a class="link" href="../boost/mpi/skeleton_proxy.html" title="Struct template skeleton_proxy">skeleton_proxy</a><span class="special"><</span> <span class="identifier">T</span> <span class="special">></span> <span class="special">&</span><span class="special">,</span> <span class="keyword">int</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/gather.html" title="Function gather"><span class="identifier">gather</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">&</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span> <span class="identifier">T</span> <span class="special">></span> <span class="special">&</span><span class="special">,</span> <span class="keyword">int</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/gather.html" title="Function gather"><span class="identifier">gather</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">&</span><span class="special">,</span> <span class="identifier">T</span> <span class="special">*</span><span class="special">,</span> <span class="keyword">int</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">void</span> <a class="link" href="../boost/mpi/gather.html" title="Function gather"><span class="identifier">gather</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">&</span><span class="special">,</span> <span class="keyword">int</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/gather.html" title="Function gather"><span class="identifier">gather</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">*</span><span class="special">,</span> <span class="keyword">int</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span> <span class="identifier">T</span> <span class="special">></span> <span class="special">&</span><span class="special">,</span> + <span class="keyword">int</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/gather.html" title="Function gather"><span class="identifier">gather</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">*</span><span class="special">,</span> <span class="keyword">int</span><span class="special">,</span> <span class="identifier">T</span> <span class="special">*</span><span class="special">,</span> <span class="keyword">int</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/gather.html" title="Function gather"><span class="identifier">gather</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">*</span><span class="special">,</span> <span class="keyword">int</span><span class="special">,</span> <span class="keyword">int</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/scatter.html" title="Function scatter"><span class="identifier">scatter</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span> <span class="identifier">T</span> <span class="special">></span> <span class="special">&</span><span class="special">,</span> <span class="identifier">T</span> <span class="special">&</span><span class="special">,</span> <span class="keyword">int</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/scatter.html" title="Function scatter"><span class="identifier">scatter</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">*</span><span class="special">,</span> <span class="identifier">T</span> <span class="special">&</span><span class="special">,</span> <span class="keyword">int</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">void</span> <a class="link" href="../boost/mpi/scatter.html" title="Function scatter"><span class="identifier">scatter</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="identifier">T</span> <span class="special">&</span><span class="special">,</span> <span class="keyword">int</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/scatter.html" title="Function scatter"><span class="identifier">scatter</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span> <span class="identifier">T</span> <span class="special">></span> <span class="special">&</span><span class="special">,</span> <span class="identifier">T</span> <span class="special">*</span><span class="special">,</span> <span class="keyword">int</span><span class="special">,</span> + <span class="keyword">int</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/scatter.html" title="Function scatter"><span class="identifier">scatter</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">*</span><span class="special">,</span> <span class="identifier">T</span> <span class="special">*</span><span class="special">,</span> <span class="keyword">int</span><span class="special">,</span> <span class="keyword">int</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">void</span> <a class="link" href="../boost/mpi/scatter.html" title="Function scatter"><span class="identifier">scatter</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="identifier">T</span> <span class="special">*</span><span class="special">,</span> <span class="keyword">int</span><span class="special">,</span> <span class="keyword">int</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">,</span> <span class="keyword">typename</span> Op<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/reduce.html" title="Function reduce"><span class="identifier">reduce</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">&</span><span class="special">,</span> <span class="identifier">T</span> <span class="special">&</span><span class="special">,</span> <span class="identifier">Op</span><span class="special">,</span> <span class="keyword">int</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">,</span> <span class="keyword">typename</span> Op<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/reduce.html" title="Function reduce"><span class="identifier">reduce</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">&</span><span class="special">,</span> <span class="identifier">Op</span><span class="special">,</span> <span class="keyword">int</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">,</span> <span class="keyword">typename</span> Op<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/reduce.html" title="Function reduce"><span class="identifier">reduce</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">*</span><span class="special">,</span> <span class="keyword">int</span><span class="special">,</span> <span class="identifier">T</span> <span class="special">*</span><span class="special">,</span> <span class="identifier">Op</span><span class="special">,</span> <span class="keyword">int</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">,</span> <span class="keyword">typename</span> Op<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/reduce.html" title="Function reduce"><span class="identifier">reduce</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">*</span><span class="special">,</span> <span class="keyword">int</span><span class="special">,</span> <span class="identifier">Op</span><span class="special">,</span> <span class="keyword">int</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">,</span> <span class="keyword">typename</span> Op<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/scan.html" title="Function scan"><span class="identifier">scan</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">&</span><span class="special">,</span> <span class="identifier">T</span> <span class="special">&</span><span class="special">,</span> <span class="identifier">Op</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">,</span> <span class="keyword">typename</span> Op<span class="special">></span> + <span class="identifier">T</span> <a class="link" href="../boost/mpi/scan.html" title="Function scan"><span class="identifier">scan</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">&</span><span class="special">,</span> <span class="identifier">Op</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">,</span> <span class="keyword">typename</span> Op<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/scan.html" title="Function scan"><span class="identifier">scan</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">*</span><span class="special">,</span> <span class="keyword">int</span><span class="special">,</span> <span class="identifier">T</span> <span class="special">*</span><span class="special">,</span> <span class="identifier">Op</span><span class="special">)</span><span class="special">;</span> + <span class="special">}</span> +<span class="special">}</span></pre> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="header.boost.mpi.collectives_fwd_hpp"></a>Header <<a href="../../../boost/mpi/collectives_fwd.hpp" target="_top">boost/mpi/collectives_fwd.hpp</a>></h3></div></div></div> +<p>This header provides forward declarations for all of the collective operations contained in the header <code class="computeroutput">collectives.hpp</code>. </p> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="header.boost.mpi.communicator_hpp"></a>Header <<a href="../../../boost/mpi/communicator.hpp" target="_top">boost/mpi/communicator.hpp</a>></h3></div></div></div> +<p>This header defines the <code class="computeroutput">communicator</code> class, which is the basis of all communication within Boost.MPI, and provides point-to-point communication operations. </p> +<pre class="synopsis"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> + <span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">{</span> + <span class="keyword">class</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a><span class="special">;</span> + + <span class="keyword">enum</span> <a class="link" href="../boost/mpi/comm_create_kind.html" title="Type comm_create_kind">comm_create_kind</a><span class="special">;</span> + + <span class="keyword">const</span> <span class="keyword">int</span> <a class="link" href="../boost/mpi/any_source.html" title="Global any_source">any_source</a><span class="special">;</span> <span class="comment">// A constant representing "any process.". </span> + <span class="keyword">const</span> <span class="keyword">int</span> <a class="link" href="../boost/mpi/any_tag.html" title="Global any_tag">any_tag</a><span class="special">;</span> <span class="comment">// A constant representing "any tag.". </span> + <span class="identifier">BOOST_MPI_DECL</span> <span class="keyword">bool</span> <a class="link" href="../boost/mpi/operator___id768574.html" title="Function operator=="><span class="keyword">operator</span><span class="special">==</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">bool</span> <a class="link" href="../boost/mpi/operator___id768622.html" title="Function operator!="><span class="keyword">operator</span><span class="special">!=</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a> <span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="special">}</span> +<span class="special">}</span></pre> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="header.boost.mpi.config_hpp"></a>Header <<a href="../../../boost/mpi/config.hpp" target="_top">boost/mpi/config.hpp</a>></h3></div></div></div> +<p>This header provides MPI configuration details that expose the capabilities of the underlying MPI implementation, and provides auto-linking support on Windows. </p> +<pre class="synopsis"> + +<a class="link" href="../MPICH_IGNORE_CXX_SEEK.html" title="Macro MPICH_IGNORE_CXX_SEEK">MPICH_IGNORE_CXX_SEEK</a> +<a class="link" href="../BOOST_MPI_HAS_MEMORY_ALLOCATION.html" title="Macro BOOST_MPI_HAS_MEMORY_ALLOCATION">BOOST_MPI_HAS_MEMORY_ALLOCATION</a> +<a class="link" href="../BOOST_MPI_HAS_NOARG_INITIALIZATION.html" title="Macro BOOST_MPI_HAS_NOARG_INITIALIZATION">BOOST_MPI_HAS_NOARG_INITIALIZATION</a> +<a class="link" href="../BOOST_MPI_CALLING_CONVENTION.html" title="Macro BOOST_MPI_CALLING_CONVENTION">BOOST_MPI_CALLING_CONVENTION</a> +<a class="link" href="../BOOST_MPI_DECL.html" title="Macro BOOST_MPI_DECL">BOOST_MPI_DECL</a></pre> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="header.boost.mpi.datatype_hpp"></a>Header <<a href="../../../boost/mpi/datatype.hpp" target="_top">boost/mpi/datatype.hpp</a>></h3></div></div></div> +<p>This header provides the mapping from C++ types to MPI data types. </p> +<pre class="synopsis"> + +<a class="link" href="../BOOST_IS_MPI_DATATYPE.html" title="Macro BOOST_IS_MPI_DATATYPE">BOOST_IS_MPI_DATATYPE</a>(T)</pre> +<pre class="synopsis"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> + <span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">{</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/mpi/is_mpi_integer_datatype.html" title="Struct template is_mpi_integer_datatype">is_mpi_integer_datatype</a><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/mpi/is_mpi_floating_point_d_id767983.html" title="Struct template is_mpi_floating_point_datatype">is_mpi_floating_point_datatype</a><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/mpi/is_mpi_logical_datatype.html" title="Struct template is_mpi_logical_datatype">is_mpi_logical_datatype</a><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/mpi/is_mpi_complex_datatype.html" title="Struct template is_mpi_complex_datatype">is_mpi_complex_datatype</a><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/mpi/is_mpi_byte_datatype.html" title="Struct template is_mpi_byte_datatype">is_mpi_byte_datatype</a><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/mpi/is_mpi_builtin_datatype.html" title="Struct template is_mpi_builtin_datatype">is_mpi_builtin_datatype</a><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/mpi/is_mpi_datatype.html" title="Struct template is_mpi_datatype">is_mpi_datatype</a><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="identifier">MPI_Datatype</span> <a class="link" href="../boost/mpi/get_mpi_datatype_id770338.html" title="Function template get_mpi_datatype"><span class="identifier">get_mpi_datatype</span></a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">T</span> <span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="special">}</span> +<span class="special">}</span></pre> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="header.boost.mpi.datatype_fwd_hpp"></a>Header <<a href="../../../boost/mpi/datatype_fwd.hpp" target="_top">boost/mpi/datatype_fwd.hpp</a>></h3></div></div></div> +<p>This header provides forward declarations for the contents of the header <code class="computeroutput">datatype.hpp</code>. It is expected to be used primarily by user-defined C++ classes that need to specialize <code class="computeroutput">is_mpi_datatype</code>. </p> +<pre class="synopsis"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> + <span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">{</span> + <span class="keyword">struct</span> <a class="link" href="../boost/mpi/packed.html" title="Struct packed">packed</a><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="identifier">MPI_Datatype</span> <a name="boost.mpi.get_mpi_datatype_id770454"></a><span class="identifier">get_mpi_datatype</span><span class="special">(</span><span class="special">)</span><span class="special">;</span> + <span class="special">}</span> +<span class="special">}</span></pre> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="header.boost.mpi.environment_hpp"></a>Header <<a href="../../../boost/mpi/environment.hpp" target="_top">boost/mpi/environment.hpp</a>></h3></div></div></div> +<p>This header provides the <code class="computeroutput">environment</code> class, which provides routines to initialize, finalization, and query the status of the Boost MPI environment. </p> +<pre class="synopsis"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> + <span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">{</span> + <span class="keyword">class</span> <a class="link" href="../boost/mpi/environment.html" title="Class environment">environment</a><span class="special">;</span> + <span class="special">}</span> +<span class="special">}</span></pre> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="header.boost.mpi.exception_hpp"></a>Header <<a href="../../../boost/mpi/exception.hpp" target="_top">boost/mpi/exception.hpp</a>></h3></div></div></div> +<p>This header provides exception classes that report MPI errors to the user and macros that translate MPI error codes into Boost.MPI exceptions. </p> +<pre class="synopsis"> + +<a class="link" href="../BOOST_MPI_CHECK_RESULT.html" title="Macro BOOST_MPI_CHECK_RESULT">BOOST_MPI_CHECK_RESULT</a>(MPIFunc, Args)</pre> +<pre class="synopsis"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> + <span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">{</span> + <span class="keyword">class</span> <a class="link" href="../boost/mpi/exception.html" title="Class exception">exception</a><span class="special">;</span> + <span class="special">}</span> +<span class="special">}</span></pre> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="header.boost.mpi.graph_communicator_hpp"></a>Header <<a href="../../../boost/mpi/graph_communicator.hpp" target="_top">boost/mpi/graph_communicator.hpp</a>></h3></div></div></div> +<p>This header defines facilities to support MPI communicators with graph topologies, using the graph interface defined by the Boost Graph Library. One can construct a communicator whose topology is described by any graph meeting the requirements of the Boost Graph Library's graph concepts. Likewise, any communicator that has a graph topology can be viewed as a graph by the Boost Graph Library, permitting one to use the BGL's graph algorithms on the process topology. </p> +<pre class="synopsis"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> + <span class="keyword">template</span><span class="special"><</span><span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/graph_traits_mpi_graph__id770177.html" title="Struct graph_traits<mpi::graph_communicator>">graph_traits</a><span class="special"><</span><span class="identifier">mpi</span><span class="special">::</span><span class="identifier">graph_communicator</span><span class="special">></span><span class="special">;</span> + <span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">{</span> + <span class="keyword">class</span> <a class="link" href="../boost/mpi/graph_communicator.html" title="Class graph_communicator">graph_communicator</a><span class="special">;</span> + + <span class="comment">// Returns the source vertex from an edge in the graph topology of a communicator. </span> + <span class="keyword">int</span> <a name="boost.mpi.source"></a><span class="identifier">source</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">pair</span><span class="special"><</span> <span class="keyword">int</span><span class="special">,</span> <span class="keyword">int</span> <span class="special">></span> <span class="special">&</span> edge<span class="special">,</span> <span class="keyword">const</span> <a class="link" href="../boost/mpi/graph_communicator.html" title="Class graph_communicator">graph_communicator</a> <span class="special">&</span><span class="special">)</span><span class="special">;</span> + + <span class="comment">// Returns the target vertex from an edge in the graph topology of a communicator. </span> + <span class="keyword">int</span> <a name="boost.mpi.target"></a><span class="identifier">target</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">pair</span><span class="special"><</span> <span class="keyword">int</span><span class="special">,</span> <span class="keyword">int</span> <span class="special">></span> <span class="special">&</span> edge<span class="special">,</span> <span class="keyword">const</span> <a class="link" href="../boost/mpi/graph_communicator.html" title="Class graph_communicator">graph_communicator</a> <span class="special">&</span><span class="special">)</span><span class="special">;</span> + + <span class="comment">// Returns an iterator range containing all of the edges outgoing from the given vertex in a graph topology of a communicator. </span> + <span class="emphasis"><em><span class="identifier">unspecified</span></em></span> <a name="boost.mpi.out_edges"></a><span class="identifier">out_edges</span><span class="special">(</span><span class="keyword">int</span> vertex<span class="special">,</span> <span class="keyword">const</span> <a class="link" href="../boost/mpi/graph_communicator.html" title="Class graph_communicator">graph_communicator</a> <span class="special">&</span> comm<span class="special">)</span><span class="special">;</span> + + <span class="comment">// Returns the out-degree of a vertex in the graph topology of a communicator. </span> + <span class="keyword">int</span> <a name="boost.mpi.out_degree"></a><span class="identifier">out_degree</span><span class="special">(</span><span class="keyword">int</span> vertex<span class="special">,</span> <span class="keyword">const</span> <a class="link" href="../boost/mpi/graph_communicator.html" title="Class graph_communicator">graph_communicator</a> <span class="special">&</span> comm<span class="special">)</span><span class="special">;</span> + + <span class="comment">// Returns an iterator range containing all of the neighbors of the given vertex in the communicator's graph topology. </span> + <span class="emphasis"><em><span class="identifier">unspecified</span></em></span> <a name="boost.mpi.adjacent_vertices"></a><span class="identifier">adjacent_vertices</span><span class="special">(</span><span class="keyword">int</span> vertex<span class="special">,</span> <span class="keyword">const</span> <a class="link" href="../boost/mpi/graph_communicator.html" title="Class graph_communicator">graph_communicator</a> <span class="special">&</span> comm<span class="special">)</span><span class="special">;</span> + + <span class="comment">// Returns an iterator range that contains all of the vertices with the communicator's graph topology, i.e., all of the process ranks in the communicator. </span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">pair</span><span class="special"><</span> <span class="identifier">counting_iterator</span><span class="special"><</span> <span class="keyword">int</span> <span class="special">></span><span class="special">,</span> <span class="identifier">counting_iterator</span><span class="special"><</span> <span class="keyword">int</span> <span class="special">></span> <span class="special">></span> + <a name="boost.mpi.vertices"></a><span class="identifier">vertices</span><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/graph_communicator.html" title="Class graph_communicator">graph_communicator</a> <span class="special">&</span> comm<span class="special">)</span><span class="special">;</span> + + <span class="comment">// Returns the number of vertices within the graph topology of the communicator, i.e., the number of processes in the communicator. </span> + <span class="keyword">int</span> <a name="boost.mpi.num_vertices"></a><span class="identifier">num_vertices</span><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/graph_communicator.html" title="Class graph_communicator">graph_communicator</a> <span class="special">&</span> comm<span class="special">)</span><span class="special">;</span> + + <span class="comment">// Returns an iterator range that contains all of the edges with the communicator's graph topology. </span> + <span class="emphasis"><em><span class="identifier">unspecified</span></em></span> <a name="boost.mpi.edges"></a><span class="identifier">edges</span><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/graph_communicator.html" title="Class graph_communicator">graph_communicator</a> <span class="special">&</span> comm<span class="special">)</span><span class="special">;</span> + + <span class="comment">// Returns the number of edges in the communicator's graph topology. </span> + <span class="keyword">int</span> <a name="boost.mpi.num_edges"></a><span class="identifier">num_edges</span><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/graph_communicator.html" title="Class graph_communicator">graph_communicator</a> <span class="special">&</span> comm<span class="special">)</span><span class="special">;</span> + <span class="identifier">identity_property_map</span> <a class="link" href="../boost/mpi/get_id772292.html" title="Function get"><span class="identifier">get</span></a><span class="special">(</span><span class="identifier">vertex_index_t</span><span class="special">,</span> <span class="keyword">const</span> <a class="link" href="../boost/mpi/graph_communicator.html" title="Class graph_communicator">graph_communicator</a> <span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">int</span> <a class="link" href="../boost/mpi/get_id772322.html" title="Function get"><span class="identifier">get</span></a><span class="special">(</span><span class="identifier">vertex_index_t</span><span class="special">,</span> <span class="keyword">const</span> <a class="link" href="../boost/mpi/graph_communicator.html" title="Class graph_communicator">graph_communicator</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">int</span><span class="special">)</span><span class="special">;</span> + <span class="special">}</span> +<span class="special">}</span></pre> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="header.boost.mpi.group_hpp"></a>Header <<a href="../../../boost/mpi/group.hpp" target="_top">boost/mpi/group.hpp</a>></h3></div></div></div> +<p>This header defines the <code class="computeroutput">group</code> class, which allows one to manipulate and query groups of processes. </p> +<pre class="synopsis"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> + <span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">{</span> + <span class="keyword">class</span> <a class="link" href="../boost/mpi/group.html" title="Class group">group</a><span class="special">;</span> + <span class="identifier">BOOST_MPI_DECL</span> <span class="keyword">bool</span> <a class="link" href="../boost/mpi/operator___id771575.html" title="Function operator=="><span class="keyword">operator</span><span class="special">==</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/group.html" title="Class group">group</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <a class="link" href="../boost/mpi/group.html" title="Class group">group</a> <span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">bool</span> <a class="link" href="../boost/mpi/operator___id771621.html" title="Function operator!="><span class="keyword">operator</span><span class="special">!=</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/group.html" title="Class group">group</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <a class="link" href="../boost/mpi/group.html" title="Class group">group</a> <span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="identifier">BOOST_MPI_DECL</span> <a class="link" href="../boost/mpi/group.html" title="Class group">group</a> <a class="link" href="../boost/mpi/operator_id771668.html" title="Function operator|"><span class="keyword">operator</span><span class="special">|</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/group.html" title="Class group">group</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <a class="link" href="../boost/mpi/group.html" title="Class group">group</a> <span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="identifier">BOOST_MPI_DECL</span> <a class="link" href="../boost/mpi/group.html" title="Class group">group</a> <a class="link" href="../boost/mpi/operator__id770818.html" title="Function operator&"><span class="keyword">operator</span><span class="special">&</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/group.html" title="Class group">group</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <a class="link" href="../boost/mpi/group.html" title="Class group">group</a> <span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="identifier">BOOST_MPI_DECL</span> <a class="link" href="../boost/mpi/group.html" title="Class group">group</a> <a class="link" href="../boost/mpi/operator-_id770872.html" title="Function operator-"><span class="keyword">operator</span><span class="special">-</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="../boost/mpi/group.html" title="Class group">group</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <a class="link" href="../boost/mpi/group.html" title="Class group">group</a> <span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="special">}</span> +<span class="special">}</span></pre> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="header.boost.mpi.intercommunicator_hpp"></a>Header <<a href="../../../boost/mpi/intercommunicator.hpp" target="_top">boost/mpi/intercommunicator.hpp</a>></h3></div></div></div> +<p>This header defines the <code class="computeroutput">intercommunicator</code> class, which permits communication between different process groups. </p> +<pre class="synopsis"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> + <span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">{</span> + <span class="keyword">class</span> <a class="link" href="../boost/mpi/intercommunicator.html" title="Class intercommunicator">intercommunicator</a><span class="special">;</span> + <span class="special">}</span> +<span class="special">}</span></pre> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="header.boost.mpi.nonblocking_hpp"></a>Header <<a href="../../../boost/mpi/nonblocking.hpp" target="_top">boost/mpi/nonblocking.hpp</a>></h3></div></div></div> +<p>This header defines operations for completing non-blocking communication requests. </p> +<pre class="synopsis"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> + <span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">{</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <a class="link" href="../ForwardIterator.html" title="Concept ForwardIterator">ForwardIterator</a><span class="special">></span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">pair</span><span class="special"><</span> <a class="link" href="../boost/mpi/status.html" title="Class status">status</a><span class="special">,</span> <span class="identifier">ForwardIterator</span> <span class="special">></span> + <a class="link" href="../boost/mpi/wait_any.html" title="Function template wait_any"><span class="identifier">wait_any</span></a><span class="special">(</span><span class="identifier">ForwardIterator</span><span class="special">,</span> <span class="identifier">ForwardIterator</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <a class="link" href="../ForwardIterator.html" title="Concept ForwardIterator">ForwardIterator</a><span class="special">></span> + <span class="identifier">optional</span><span class="special"><</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">pair</span><span class="special"><</span> <a class="link" href="../boost/mpi/status.html" title="Class status">status</a><span class="special">,</span> <span class="identifier">ForwardIterator</span> <span class="special">></span> <span class="special">></span> + <a class="link" href="../boost/mpi/test_any.html" title="Function template test_any"><span class="identifier">test_any</span></a><span class="special">(</span><span class="identifier">ForwardIterator</span><span class="special">,</span> <span class="identifier">ForwardIterator</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <a class="link" href="../ForwardIterator.html" title="Concept ForwardIterator">ForwardIterator</a><span class="special">,</span> <span class="keyword">typename</span> <a class="link" href="../OutputIterator.html" title="Concept OutputIterator">OutputIterator</a><span class="special">></span> + <span class="identifier">OutputIterator</span> + <a class="link" href="../boost/mpi/wait_all.html" title="Function wait_all"><span class="identifier">wait_all</span></a><span class="special">(</span><span class="identifier">ForwardIterator</span><span class="special">,</span> <span class="identifier">ForwardIterator</span><span class="special">,</span> <span class="identifier">OutputIterator</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <a class="link" href="../ForwardIterator.html" title="Concept ForwardIterator">ForwardIterator</a><span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/wait_all.html" title="Function wait_all"><span class="identifier">wait_all</span></a><span class="special">(</span><span class="identifier">ForwardIterator</span><span class="special">,</span> <span class="identifier">ForwardIterator</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <a class="link" href="../ForwardIterator.html" title="Concept ForwardIterator">ForwardIterator</a><span class="special">,</span> <span class="keyword">typename</span> <a class="link" href="../OutputIterator.html" title="Concept OutputIterator">OutputIterator</a><span class="special">></span> + <span class="identifier">optional</span><span class="special"><</span> <span class="identifier">OutputIterator</span> <span class="special">></span> + <a class="link" href="../boost/mpi/test_all.html" title="Function test_all"><span class="identifier">test_all</span></a><span class="special">(</span><span class="identifier">ForwardIterator</span><span class="special">,</span> <span class="identifier">ForwardIterator</span><span class="special">,</span> <span class="identifier">OutputIterator</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <a class="link" href="../ForwardIterator.html" title="Concept ForwardIterator">ForwardIterator</a><span class="special">></span> + <span class="keyword">bool</span> <a class="link" href="../boost/mpi/test_all.html" title="Function test_all"><span class="identifier">test_all</span></a><span class="special">(</span><span class="identifier">ForwardIterator</span><span class="special">,</span> <span class="identifier">ForwardIterator</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <a class="link" href="../BidirectionalIterator.html" title="Concept BidirectionalIterator">BidirectionalIterator</a><span class="special">,</span> <span class="keyword">typename</span> <a class="link" href="../OutputIterator.html" title="Concept OutputIterator">OutputIterator</a><span class="special">></span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">pair</span><span class="special"><</span> <span class="identifier">OutputIterator</span><span class="special">,</span> <span class="identifier">BidirectionalIterator</span> <span class="special">></span> + <a class="link" href="../boost/mpi/wait_some.html" title="Function wait_some"><span class="identifier">wait_some</span></a><span class="special">(</span><span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="identifier">OutputIterator</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <a class="link" href="../BidirectionalIterator.html" title="Concept BidirectionalIterator">BidirectionalIterator</a><span class="special">></span> + <span class="identifier">BidirectionalIterator</span> + <a class="link" href="../boost/mpi/wait_some.html" title="Function wait_some"><span class="identifier">wait_some</span></a><span class="special">(</span><span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="identifier">BidirectionalIterator</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <a class="link" href="../BidirectionalIterator.html" title="Concept BidirectionalIterator">BidirectionalIterator</a><span class="special">,</span> <span class="keyword">typename</span> <a class="link" href="../OutputIterator.html" title="Concept OutputIterator">OutputIterator</a><span class="special">></span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">pair</span><span class="special"><</span> <span class="identifier">OutputIterator</span><span class="special">,</span> <span class="identifier">BidirectionalIterator</span> <span class="special">></span> + <a class="link" href="../boost/mpi/test_some.html" title="Function test_some"><span class="identifier">test_some</span></a><span class="special">(</span><span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="identifier">OutputIterator</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <a class="link" href="../BidirectionalIterator.html" title="Concept BidirectionalIterator">BidirectionalIterator</a><span class="special">></span> + <span class="identifier">BidirectionalIterator</span> + <a class="link" href="../boost/mpi/test_some.html" title="Function test_some"><span class="identifier">test_some</span></a><span class="special">(</span><span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="identifier">BidirectionalIterator</span><span class="special">)</span><span class="special">;</span> + <span class="special">}</span> +<span class="special">}</span></pre> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="header.boost.mpi.operations_hpp"></a>Header <<a href="../../../boost/mpi/operations.hpp" target="_top">boost/mpi/operations.hpp</a>></h3></div></div></div> +<p>This header provides a mapping from function objects to <code class="computeroutput">MPI_Op</code> constants used in MPI collective operations. It also provides several new function object types not present in the standard <code class="computeroutput"></code> <functional> header that have direct mappings to <code class="computeroutput">MPI_Op</code>. </p> +<pre class="synopsis"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> + <span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">{</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> Op<span class="special">,</span> <span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/mpi/is_commutative.html" title="Struct template is_commutative">is_commutative</a><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/mpi/maximum.html" title="Struct template maximum">maximum</a><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/mpi/minimum.html" title="Struct template minimum">minimum</a><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/mpi/bitwise_and.html" title="Struct template bitwise_and">bitwise_and</a><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/mpi/bitwise_or.html" title="Struct template bitwise_or">bitwise_or</a><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/mpi/logical_xor.html" title="Struct template logical_xor">logical_xor</a><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/mpi/bitwise_xor.html" title="Struct template bitwise_xor">bitwise_xor</a><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> Op<span class="special">,</span> <span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/mpi/is_mpi_op.html" title="Struct template is_mpi_op">is_mpi_op</a><span class="special">;</span> + <span class="special">}</span> +<span class="special">}</span></pre> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="header.boost.mpi.packed_iarchive_hpp"></a>Header <<a href="../../../boost/mpi/packed_iarchive.hpp" target="_top">boost/mpi/packed_iarchive.hpp</a>></h3></div></div></div> +<p>This header provides the facilities for packing Serializable data types into a buffer using <code class="computeroutput">MPI_Pack</code>. The buffers can then be transmitted via MPI and then be unpacked either via the facilities in <code class="computeroutput">packed_oarchive.hpp</code> or <code class="computeroutput">MPI_Unpack</code>. </p> +<pre class="synopsis"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> + <span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">{</span> + <span class="keyword">class</span> <a class="link" href="../boost/mpi/packed_iarchive.html" title="Class packed_iarchive">packed_iarchive</a><span class="special">;</span> + + <span class="keyword">typedef</span> <span class="identifier">packed_iprimitive</span> <a name="boost.mpi.iprimitive"></a><span class="identifier">iprimitive</span><span class="special">;</span> + <span class="special">}</span> +<span class="special">}</span></pre> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="header.boost.mpi.packed_oarchive_hpp"></a>Header <<a href="../../../boost/mpi/packed_oarchive.hpp" target="_top">boost/mpi/packed_oarchive.hpp</a>></h3></div></div></div> +<p>This header provides the facilities for unpacking Serializable data types from a buffer using <code class="computeroutput">MPI_Unpack</code>. The buffers are typically received via MPI and have been packed either by via the facilities in <code class="computeroutput">packed_iarchive.hpp</code> or <code class="computeroutput">MPI_Pack</code>. </p> +<pre class="synopsis"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> + <span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">{</span> + <span class="keyword">class</span> <a class="link" href="../boost/mpi/packed_oarchive.html" title="Class packed_oarchive">packed_oarchive</a><span class="special">;</span> + + <span class="keyword">typedef</span> <span class="identifier">packed_oprimitive</span> <a name="boost.mpi.oprimitive"></a><span class="identifier">oprimitive</span><span class="special">;</span> + <span class="special">}</span> +<span class="special">}</span></pre> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="header.boost.mpi.python_hpp"></a>Header <<a href="../../../boost/mpi/python.hpp" target="_top">boost/mpi/python.hpp</a>></h3></div></div></div> +<p>This header interacts with the Python bindings for Boost.MPI. The routines in this header can be used to register user-defined and library-defined data types with Boost.MPI for efficient (de-)serialization and separate transmission of skeletons and content. </p> +<pre class="synopsis"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> + <span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">{</span> + <span class="keyword">namespace</span> <span class="identifier">python</span> <span class="special">{</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/python/register_serialized.html" title="Function template register_serialized"><span class="identifier">register_serialized</span></a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">T</span> <span class="special">&</span> <span class="special">=</span> <span class="identifier">T</span><span class="special">(</span><span class="special">)</span><span class="special">,</span> <span class="identifier">PyTypeObject</span> <span class="special">*</span> <span class="special">=</span> <span class="number">0</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> + <span class="keyword">void</span> <a class="link" href="../boost/mpi/python/register_skeleton_and_c_id778072.html" title="Function template register_skeleton_and_content"><span class="identifier">register_skeleton_and_content</span></a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">T</span> <span class="special">&</span> <span class="special">=</span> <span class="identifier">T</span><span class="special">(</span><span class="special">)</span><span class="special">,</span> + <span class="identifier">PyTypeObject</span> <span class="special">*</span> <span class="special">=</span> <span class="number">0</span><span class="special">)</span><span class="special">;</span> + <span class="special">}</span> + <span class="special">}</span> +<span class="special">}</span></pre> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="header.boost.mpi.request_hpp"></a>Header <<a href="../../../boost/mpi/request.hpp" target="_top">boost/mpi/request.hpp</a>></h3></div></div></div> +<p>This header defines the class <code class="computeroutput">request</code>, which contains a request for non-blocking communication. </p> +<pre class="synopsis"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> + <span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">{</span> + <span class="keyword">class</span> <a class="link" href="../boost/mpi/request.html" title="Class request">request</a><span class="special">;</span> + <span class="special">}</span> +<span class="special">}</span></pre> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="header.boost.mpi.skeleton_and_content_hpp"></a>Header <<a href="../../../boost/mpi/skeleton_and_content.hpp" target="_top">boost/mpi/skeleton_and_content.hpp</a>></h3></div></div></div> +<p>This header provides facilities that allow the structure of data types (called the "skeleton") to be transmitted and received separately from the content stored in those data types. These facilities are useful when the data in a stable data structure (e.g., a mesh or a graph) will need to be transmitted repeatedly. In this case, transmitting the skeleton only once saves both communication effort (it need not be sent again) and local computation (serialization need only be performed once for the content). </p> +<pre class="synopsis"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> + <span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">{</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/mpi/skeleton_proxy.html" title="Struct template skeleton_proxy">skeleton_proxy</a><span class="special">;</span> + + <span class="keyword">class</span> <a class="link" href="../boost/mpi/content.html" title="Class content">content</a><span class="special">;</span> + <span class="keyword">class</span> <a class="link" href="../boost/mpi/packed_skeleton_iarchive.html" title="Class packed_skeleton_iarchive">packed_skeleton_iarchive</a><span class="special">;</span> + <span class="keyword">class</span> <a class="link" href="../boost/mpi/packed_skeleton_oarchive.html" title="Class packed_skeleton_oarchive">packed_skeleton_oarchive</a><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">const</span> <a class="link" href="../boost/mpi/skeleton_proxy.html" title="Struct template skeleton_proxy">skeleton_proxy</a><span class="special"><</span> <span class="identifier">T</span> <span class="special">></span> <a class="link" href="../boost/mpi/skeleton.html" title="Function template skeleton"><span class="identifier">skeleton</span></a><span class="special">(</span><span class="identifier">T</span> <span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">const</span> <a class="link" href="../boost/mpi/content.html" title="Class content">content</a> <a class="link" href="../boost/mpi/get_content.html" title="Function template get_content"><span class="identifier">get_content</span></a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">T</span> <span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="special">}</span> +<span class="special">}</span></pre> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="header.boost.mpi.skeleton_and_content_fwd_hpp"></a>Header <<a href="../../../boost/mpi/skeleton_and_content_fwd.hpp" target="_top">boost/mpi/skeleton_and_content_fwd.hpp</a>></h3></div></div></div> +<p>This header contains all of the forward declarations required to use transmit skeletons of data structures and the content of data structures separately. To actually transmit skeletons or content, include the header <code class="computeroutput">boost/mpi/skeleton_and_content.hpp</code>. </p> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="header.boost.mpi.status_hpp"></a>Header <<a href="../../../boost/mpi/status.hpp" target="_top">boost/mpi/status.hpp</a>></h3></div></div></div> +<p>This header defines the class <code class="computeroutput">status</code>, which reports on the results of point-to-point communication. </p> +<pre class="synopsis"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> + <span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">{</span> + <span class="keyword">class</span> <a class="link" href="../boost/mpi/status.html" title="Class status">status</a><span class="special">;</span> + <span class="special">}</span> +<span class="special">}</span></pre> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="header.boost.mpi.timer_hpp"></a>Header <<a href="../../../boost/mpi/timer.hpp" target="_top">boost/mpi/timer.hpp</a>></h3></div></div></div> +<p>This header provides the <code class="computeroutput">timer</code> class, which provides access to the MPI timers. </p> +<pre class="synopsis"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> + <span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">{</span> + <span class="keyword">class</span> <a class="link" href="../boost/mpi/timer.html" title="Class timer">timer</a><span class="special">;</span> + <span class="special">}</span> +<span class="special">}</span></pre> +</div> +</div> +<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> +<td align="left"></td> +<td align="right"><div class="copyright-footer">Copyright © 2005-2007 Douglas Gregor, + Matthias Troyer, Trustees of Indiana University<p> + Distributed under the Boost Software License, Version 1.0. (See accompanying + file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top"> + http://www.boost.org/LICENSE_1_0.txt </a>) + </p> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="tutorial.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../mpi.html"><img src="../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../boost/mpi/allocator_void_id764381.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/mpi/tutorial.html b/doc/html/mpi/tutorial.html new file mode 100755 index 0000000000..d16bb24e75 --- /dev/null +++ b/doc/html/mpi/tutorial.html @@ -0,0 +1,3616 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Tutorial</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../mpi.html" title="Chapter 17. Boost.MPI"> +<link rel="prev" href="getting_started.html" title="Getting started"> +<link rel="next" href="reference.html" title="Reference"> +</head> +<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> +<table cellpadding="2" width="100%"><tr> +<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../boost.png"></td> +<td align="center"><a href="../../../index.html">Home</a></td> +<td align="center"><a href="../../../libs/libraries.htm">Libraries</a></td> +<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> +<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> +<td align="center"><a href="../../../more/index.htm">More</a></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="getting_started.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../mpi.html"><img src="../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="reference.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +<div class="section"> +<div class="titlepage"><div><div><h2 class="title" style="clear: both"> +<a name="mpi.tutorial"></a>Tutorial</h2></div></div></div> +<div class="toc"><dl> +<dt><span class="section"><a href="tutorial.html#mpi.point_to_point">Point-to-Point communication</a></span></dt> +<dt><span class="section"><a href="tutorial.html#mpi.collectives">Collective operations</a></span></dt> +<dt><span class="section"><a href="tutorial.html#mpi.communicators">Managing communicators</a></span></dt> +<dt><span class="section"><a href="tutorial.html#mpi.skeleton_and_content">Separating structure from content</a></span></dt> +<dt><span class="section"><a href="tutorial.html#mpi.performance_optimizations">Performance optimizations</a></span></dt> +<dt><span class="section"><a href="tutorial.html#mpi.c_mapping">Mapping from C MPI to Boost.MPI</a></span></dt> +</dl></div> +<p> + A Boost.MPI program consists of many cooperating processes (possibly running + on different computers) that communicate among themselves by passing messages. + Boost.MPI is a library (as is the lower-level MPI), not a language, so the + first step in a Boost.MPI is to create an <code class="computeroutput"><a class="link" href="../boost/mpi/environment.html" title="Class environment">mpi::environment</a></code> + object that initializes the MPI environment and enables communication among + the processes. The <code class="computeroutput"><a class="link" href="../boost/mpi/environment.html" title="Class environment">mpi::environment</a></code> + object is initialized with the program arguments (which it may modify) in your + main program. The creation of this object initializes MPI, and its destruction + will finalize MPI. In the vast majority of Boost.MPI programs, an instance + of <code class="computeroutput"><a class="link" href="../boost/mpi/environment.html" title="Class environment">mpi::environment</a></code> will + be declared in <code class="computeroutput"><span class="identifier">main</span></code> at the + very beginning of the program. + </p> +<p> + Communication with MPI always occurs over a <span class="bold"><strong>communicator</strong></span>, + which can be created be simply default-constructing an object of type <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html" title="Class communicator">mpi::communicator</a></code>. This communicator + can then be queried to determine how many processes are running (the "size" + of the communicator) and to give a unique number to each process, from zero + to the size of the communicator (i.e., the "rank" of the process): + </p> +<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">mpi</span><span class="special">/</span><span class="identifier">environment</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">mpi</span><span class="special">/</span><span class="identifier">communicator</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span> +<span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">mpi</span><span class="special">;</span> + +<span class="keyword">int</span> <span class="identifier">main</span><span class="special">(</span><span class="keyword">int</span> <span class="identifier">argc</span><span class="special">,</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">argv</span><span class="special">[])</span> +<span class="special">{</span> + <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">environment</span> <span class="identifier">env</span><span class="special">(</span><span class="identifier">argc</span><span class="special">,</span> <span class="identifier">argv</span><span class="special">);</span> + <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">communicator</span> <span class="identifier">world</span><span class="special">;</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"I am process "</span> <span class="special"><<</span> <span class="identifier">world</span><span class="special">.</span><span class="identifier">rank</span><span class="special">()</span> <span class="special"><<</span> <span class="string">" of "</span> <span class="special"><<</span> <span class="identifier">world</span><span class="special">.</span><span class="identifier">size</span><span class="special">()</span> + <span class="special"><<</span> <span class="string">"."</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> + <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> +<span class="special">}</span> +</pre> +<p> + If you run this program with 7 processes, for instance, you will receive output + such as: + </p> +<pre class="programlisting">I am process 5 of 7. +I am process 0 of 7. +I am process 1 of 7. +I am process 6 of 7. +I am process 2 of 7. +I am process 4 of 7. +I am process 3 of 7. +</pre> +<p> + Of course, the processes can execute in a different order each time, so the + ranks might not be strictly increasing. More interestingly, the text could + come out completely garbled, because one process can start writing "I + am a process" before another process has finished writing "of 7.". + </p> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="mpi.point_to_point"></a>Point-to-Point communication</h3></div></div></div> +<div class="toc"><dl> +<dt><span class="section"><a href="tutorial.html#mpi.nonblocking">Non-blocking communication</a></span></dt> +<dt><span class="section"><a href="tutorial.html#mpi.user_data_types">User-defined data types</a></span></dt> +</dl></div> +<p> + As a message passing library, MPI's primary purpose is to routine messages + from one process to another, i.e., point-to-point. MPI contains routines + that can send messages, receive messages, and query whether messages are + available. Each message has a source process, a target process, a tag, and + a payload containing arbitrary data. The source and target processes are + the ranks of the sender and receiver of the message, respectively. Tags are + integers that allow the receiver to distinguish between different messages + coming from the same sender. + </p> +<p> + The following program uses two MPI processes to write "Hello, world!" + to the screen (<code class="computeroutput"><span class="identifier">hello_world</span><span class="special">.</span><span class="identifier">cpp</span></code>): + </p> +<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">mpi</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">string</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">serialization</span><span class="special">/</span><span class="identifier">string</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> +<span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">mpi</span><span class="special">;</span> + +<span class="keyword">int</span> <span class="identifier">main</span><span class="special">(</span><span class="keyword">int</span> <span class="identifier">argc</span><span class="special">,</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">argv</span><span class="special">[])</span> +<span class="special">{</span> + <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">environment</span> <span class="identifier">env</span><span class="special">(</span><span class="identifier">argc</span><span class="special">,</span> <span class="identifier">argv</span><span class="special">);</span> + <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">communicator</span> <span class="identifier">world</span><span class="special">;</span> + + <span class="keyword">if</span> <span class="special">(</span><span class="identifier">world</span><span class="special">.</span><span class="identifier">rank</span><span class="special">()</span> <span class="special">==</span> <span class="number">0</span><span class="special">)</span> <span class="special">{</span> + <span class="identifier">world</span><span class="special">.</span><span class="identifier">send</span><span class="special">(</span><span class="number">1</span><span class="special">,</span> <span class="number">0</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">(</span><span class="string">"Hello"</span><span class="special">));</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">msg</span><span class="special">;</span> + <span class="identifier">world</span><span class="special">.</span><span class="identifier">recv</span><span class="special">(</span><span class="number">1</span><span class="special">,</span> <span class="number">1</span><span class="special">,</span> <span class="identifier">msg</span><span class="special">);</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">msg</span> <span class="special"><<</span> <span class="string">"!"</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> + <span class="special">}</span> <span class="keyword">else</span> <span class="special">{</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">msg</span><span class="special">;</span> + <span class="identifier">world</span><span class="special">.</span><span class="identifier">recv</span><span class="special">(</span><span class="number">0</span><span class="special">,</span> <span class="number">0</span><span class="special">,</span> <span class="identifier">msg</span><span class="special">);</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">msg</span> <span class="special"><<</span> <span class="string">", "</span><span class="special">;</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span><span class="special">.</span><span class="identifier">flush</span><span class="special">();</span> + <span class="identifier">world</span><span class="special">.</span><span class="identifier">send</span><span class="special">(</span><span class="number">0</span><span class="special">,</span> <span class="number">1</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">(</span><span class="string">"world"</span><span class="special">));</span> + <span class="special">}</span> + + <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> +<span class="special">}</span> +</pre> +<p> + The first processor (rank 0) passes the message "Hello" to the + second processor (rank 1) using tag 0. The second processor prints the string + it receives, along with a comma, then passes the message "world" + back to processor 0 with a different tag. The first processor then writes + this message with the "!" and exits. All sends are accomplished + with the <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html#id766471-bb">communicator::send</a></code> + method and all receives use a corresponding <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html#id766808-bb">communicator::recv</a></code> + call. + </p> +<div class="section"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="mpi.nonblocking"></a>Non-blocking communication</h4></div></div></div> +<p> + The default MPI communication operations--<code class="computeroutput"><span class="identifier">send</span></code> + and <code class="computeroutput"><span class="identifier">recv</span></code>--may have to wait + until the entire transmission is completed before they can return. Sometimes + this <span class="bold"><strong>blocking</strong></span> behavior has a negative + impact on performance, because the sender could be performing useful computation + while it is waiting for the transmission to occur. More important, however, + are the cases where several communication operations must occur simultaneously, + e.g., a process will both send and receive at the same time. + </p> +<p> + Let's revisit our "Hello, world!" program from the previous section. + The core of this program transmits two messages: + </p> +<pre class="programlisting"><span class="keyword">if</span> <span class="special">(</span><span class="identifier">world</span><span class="special">.</span><span class="identifier">rank</span><span class="special">()</span> <span class="special">==</span> <span class="number">0</span><span class="special">)</span> <span class="special">{</span> + <span class="identifier">world</span><span class="special">.</span><span class="identifier">send</span><span class="special">(</span><span class="number">1</span><span class="special">,</span> <span class="number">0</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">(</span><span class="string">"Hello"</span><span class="special">));</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">msg</span><span class="special">;</span> + <span class="identifier">world</span><span class="special">.</span><span class="identifier">recv</span><span class="special">(</span><span class="number">1</span><span class="special">,</span> <span class="number">1</span><span class="special">,</span> <span class="identifier">msg</span><span class="special">);</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">msg</span> <span class="special"><<</span> <span class="string">"!"</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> +<span class="special">}</span> <span class="keyword">else</span> <span class="special">{</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">msg</span><span class="special">;</span> + <span class="identifier">world</span><span class="special">.</span><span class="identifier">recv</span><span class="special">(</span><span class="number">0</span><span class="special">,</span> <span class="number">0</span><span class="special">,</span> <span class="identifier">msg</span><span class="special">);</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">msg</span> <span class="special"><<</span> <span class="string">", "</span><span class="special">;</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span><span class="special">.</span><span class="identifier">flush</span><span class="special">();</span> + <span class="identifier">world</span><span class="special">.</span><span class="identifier">send</span><span class="special">(</span><span class="number">0</span><span class="special">,</span> <span class="number">1</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">(</span><span class="string">"world"</span><span class="special">));</span> +<span class="special">}</span> +</pre> +<p> + The first process passes a message to the second process, then prepares + to receive a message. The second process does the send and receive in the + opposite order. However, this sequence of events is just that--a <span class="bold"><strong>sequence</strong></span>--meaning that there is essentially no parallelism. + We can use non-blocking communication to ensure that the two messages are + transmitted simultaneously (<code class="computeroutput"><span class="identifier">hello_world_nonblocking</span><span class="special">.</span><span class="identifier">cpp</span></code>): + </p> +<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">mpi</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">string</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">serialization</span><span class="special">/</span><span class="identifier">string</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> +<span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">mpi</span><span class="special">;</span> + +<span class="keyword">int</span> <span class="identifier">main</span><span class="special">(</span><span class="keyword">int</span> <span class="identifier">argc</span><span class="special">,</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">argv</span><span class="special">[])</span> +<span class="special">{</span> + <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">environment</span> <span class="identifier">env</span><span class="special">(</span><span class="identifier">argc</span><span class="special">,</span> <span class="identifier">argv</span><span class="special">);</span> + <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">communicator</span> <span class="identifier">world</span><span class="special">;</span> + + <span class="keyword">if</span> <span class="special">(</span><span class="identifier">world</span><span class="special">.</span><span class="identifier">rank</span><span class="special">()</span> <span class="special">==</span> <span class="number">0</span><span class="special">)</span> <span class="special">{</span> + <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">request</span> <span class="identifier">reqs</span><span class="special">[</span><span class="number">2</span><span class="special">];</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">msg</span><span class="special">,</span> <span class="identifier">out_msg</span> <span class="special">=</span> <span class="string">"Hello"</span><span class="special">;</span> + <span class="identifier">reqs</span><span class="special">[</span><span class="number">0</span><span class="special">]</span> <span class="special">=</span> <span class="identifier">world</span><span class="special">.</span><span class="identifier">isend</span><span class="special">(</span><span class="number">1</span><span class="special">,</span> <span class="number">0</span><span class="special">,</span> <span class="identifier">out_msg</span><span class="special">);</span> + <span class="identifier">reqs</span><span class="special">[</span><span class="number">1</span><span class="special">]</span> <span class="special">=</span> <span class="identifier">world</span><span class="special">.</span><span class="identifier">irecv</span><span class="special">(</span><span class="number">1</span><span class="special">,</span> <span class="number">1</span><span class="special">,</span> <span class="identifier">msg</span><span class="special">);</span> + <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">wait_all</span><span class="special">(</span><span class="identifier">reqs</span><span class="special">,</span> <span class="identifier">reqs</span> <span class="special">+</span> <span class="number">2</span><span class="special">);</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">msg</span> <span class="special"><<</span> <span class="string">"!"</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> + <span class="special">}</span> <span class="keyword">else</span> <span class="special">{</span> + <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">request</span> <span class="identifier">reqs</span><span class="special">[</span><span class="number">2</span><span class="special">];</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">msg</span><span class="special">,</span> <span class="identifier">out_msg</span> <span class="special">=</span> <span class="string">"world"</span><span class="special">;</span> + <span class="identifier">reqs</span><span class="special">[</span><span class="number">0</span><span class="special">]</span> <span class="special">=</span> <span class="identifier">world</span><span class="special">.</span><span class="identifier">isend</span><span class="special">(</span><span class="number">0</span><span class="special">,</span> <span class="number">1</span><span class="special">,</span> <span class="identifier">out_msg</span><span class="special">);</span> + <span class="identifier">reqs</span><span class="special">[</span><span class="number">1</span><span class="special">]</span> <span class="special">=</span> <span class="identifier">world</span><span class="special">.</span><span class="identifier">irecv</span><span class="special">(</span><span class="number">0</span><span class="special">,</span> <span class="number">0</span><span class="special">,</span> <span class="identifier">msg</span><span class="special">);</span> + <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">wait_all</span><span class="special">(</span><span class="identifier">reqs</span><span class="special">,</span> <span class="identifier">reqs</span> <span class="special">+</span> <span class="number">2</span><span class="special">);</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">msg</span> <span class="special"><<</span> <span class="string">", "</span><span class="special">;</span> + <span class="special">}</span> + + <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> +<span class="special">}</span> +</pre> +<p> + We have replaced calls to the <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html#id766471-bb">communicator::send</a></code> + and <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html#id766808-bb">communicator::recv</a></code> + members with similar calls to their non-blocking counterparts, <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html#id769273-bb">communicator::isend</a></code> + and <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html#id769634-bb">communicator::irecv</a></code>. + The prefix <span class="bold"><strong>i</strong></span> indicates that the operations + return immediately with a <code class="computeroutput"><a class="link" href="../boost/mpi/request.html" title="Class request">mpi::request</a></code> + object, which allows one to query the status of a communication request + (see the <code class="computeroutput"><a class="link" href="../boost/mpi/request.html#id774877-bb">test</a></code> + method) or wait until it has completed (see the <code class="computeroutput"><a class="link" href="../boost/mpi/request.html#id774859-bb">wait</a></code> + method). Multiple requests can be completed at the same time with the + <code class="computeroutput"><a class="link" href="../boost/mpi/wait_all.html" title="Function wait_all">wait_all</a></code> operation. + </p> +<p> + If you run this program multiple times, you may see some strange results: + namely, some runs will produce: + </p> +<pre class="programlisting"><span class="identifier">Hello</span><span class="special">,</span> <span class="identifier">world</span><span class="special">!</span> +</pre> +<p> + while others will produce: + </p> +<pre class="programlisting"><span class="identifier">world</span><span class="special">!</span> +<span class="identifier">Hello</span><span class="special">,</span> +</pre> +<p> + or even some garbled version of the letters in "Hello" and "world". + This indicates that there is some parallelism in the program, because after + both messages are (simultaneously) transmitted, both processes will concurrent + execute their print statements. For both performance and correctness, non-blocking + communication operations are critical to many parallel applications using + MPI. + </p> +</div> +<div class="section"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="mpi.user_data_types"></a>User-defined data types</h4></div></div></div> +<p> + The inclusion of <code class="computeroutput"><span class="identifier">boost</span><span class="special">/</span><span class="identifier">serialization</span><span class="special">/</span><span class="identifier">string</span><span class="special">.</span><span class="identifier">hpp</span></code> + in the previous examples is very important: it makes values of type <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span></code> serializable, so that they can + be be transmitted using Boost.MPI. In general, built-in C++ types (<code class="computeroutput"><span class="keyword">int</span></code>s, <code class="computeroutput"><span class="keyword">float</span></code>s, + characters, etc.) can be transmitted over MPI directly, while user-defined + and library-defined types will need to first be serialized (packed) into + a format that is amenable to transmission. Boost.MPI relies on the <a href="http://www.boost.org/libs/serialization/doc" target="_top">Boost.Serialization</a> + library to serialize and deserialize data types. + </p> +<p> + For types defined by the standard library (such as <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span></code> + or <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span></code>) and some types in Boost (such + as <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">variant</span></code>), the <a href="http://www.boost.org/libs/serialization/doc" target="_top">Boost.Serialization</a> + library already contains all of the required serialization code. In these + cases, you need only include the appropriate header from the <code class="computeroutput"><span class="identifier">boost</span><span class="special">/</span><span class="identifier">serialization</span></code> directory. + </p> +<p> + For types that do not already have a serialization header, you will first + need to implement serialization code before the types can be transmitted + using Boost.MPI. Consider a simple class <code class="computeroutput"><span class="identifier">gps_position</span></code> + that contains members <code class="computeroutput"><span class="identifier">degrees</span></code>, + <code class="computeroutput"><span class="identifier">minutes</span></code>, and <code class="computeroutput"><span class="identifier">seconds</span></code>. This class is made serializable + by making it a friend of <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">serialization</span><span class="special">::</span><span class="identifier">access</span></code> + and introducing the templated <code class="computeroutput"><span class="identifier">serialize</span><span class="special">()</span></code> function, as follows: + </p> +<pre class="programlisting"><span class="keyword">class</span> <span class="identifier">gps_position</span> +<span class="special">{</span> +<span class="keyword">private</span><span class="special">:</span> + <span class="keyword">friend</span> <span class="keyword">class</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">serialization</span><span class="special">::</span><span class="identifier">access</span><span class="special">;</span> + + <span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">Archive</span><span class="special">></span> + <span class="keyword">void</span> <span class="identifier">serialize</span><span class="special">(</span><span class="identifier">Archive</span> <span class="special">&</span> <span class="identifier">ar</span><span class="special">,</span> <span class="keyword">const</span> <span class="keyword">unsigned</span> <span class="keyword">int</span> <span class="identifier">version</span><span class="special">)</span> + <span class="special">{</span> + <span class="identifier">ar</span> <span class="special">&</span> <span class="identifier">degrees</span><span class="special">;</span> + <span class="identifier">ar</span> <span class="special">&</span> <span class="identifier">minutes</span><span class="special">;</span> + <span class="identifier">ar</span> <span class="special">&</span> <span class="identifier">seconds</span><span class="special">;</span> + <span class="special">}</span> + + <span class="keyword">int</span> <span class="identifier">degrees</span><span class="special">;</span> + <span class="keyword">int</span> <span class="identifier">minutes</span><span class="special">;</span> + <span class="keyword">float</span> <span class="identifier">seconds</span><span class="special">;</span> +<span class="keyword">public</span><span class="special">:</span> + <span class="identifier">gps_position</span><span class="special">(){};</span> + <span class="identifier">gps_position</span><span class="special">(</span><span class="keyword">int</span> <span class="identifier">d</span><span class="special">,</span> <span class="keyword">int</span> <span class="identifier">m</span><span class="special">,</span> <span class="keyword">float</span> <span class="identifier">s</span><span class="special">)</span> <span class="special">:</span> + <span class="identifier">degrees</span><span class="special">(</span><span class="identifier">d</span><span class="special">),</span> <span class="identifier">minutes</span><span class="special">(</span><span class="identifier">m</span><span class="special">),</span> <span class="identifier">seconds</span><span class="special">(</span><span class="identifier">s</span><span class="special">)</span> + <span class="special">{}</span> +<span class="special">};</span> +</pre> +<p> + Complete information about making types serializable is beyond the scope + of this tutorial. For more information, please see the <a href="http://www.boost.org/libs/serialization/doc" target="_top">Boost.Serialization</a> + library tutorial from which the above example was extracted. One important + side benefit of making types serializable for Boost.MPI is that they become + serializable for any other usage, such as storing the objects to disk to + manipulated them in XML. + </p> +<p> + Some serializable types, like <code class="computeroutput"><span class="identifier">gps_position</span></code> + above, have a fixed amount of data stored at fixed field positions. When + this is the case, Boost.MPI can optimize their serialization and transmission + to avoid extraneous copy operations. To enable this optimization, users + should specialize the type trait <code class="computeroutput"><a class="link" href="../boost/mpi/is_mpi_datatype.html" title="Struct template is_mpi_datatype">is_mpi_datatype</a></code>, e.g.: + </p> +<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">{</span> + <span class="keyword">template</span> <span class="special"><></span> + <span class="keyword">struct</span> <span class="identifier">is_mpi_datatype</span><span class="special"><</span><span class="identifier">gps_position</span><span class="special">></span> <span class="special">:</span> <span class="identifier">mpl</span><span class="special">::</span><span class="identifier">true_</span> <span class="special">{</span> <span class="special">};</span> +<span class="special">}</span> <span class="special">}</span> +</pre> +<p> + For non-template types we have defined a macro to simplify declaring a + type as an MPI datatype + </p> +<pre class="programlisting"><span class="identifier">BOOST_IS_MPI_DATATYPE</span><span class="special">(</span><span class="identifier">gps_position</span><span class="special">)</span> +</pre> +<p> + For composite traits, the specialization of <code class="computeroutput"><a class="link" href="../boost/mpi/is_mpi_datatype.html" title="Struct template is_mpi_datatype">is_mpi_datatype</a></code> may depend + on <code class="computeroutput"><span class="identifier">is_mpi_datatype</span></code> itself. + For instance, a <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">array</span></code> object is fixed only when the type + of the parameter it stores is fixed: + </p> +<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">{</span> + <span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">T</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">N</span><span class="special">></span> + <span class="keyword">struct</span> <span class="identifier">is_mpi_datatype</span><span class="special"><</span><span class="identifier">array</span><span class="special"><</span><span class="identifier">T</span><span class="special">,</span> <span class="identifier">N</span><span class="special">></span> <span class="special">></span> + <span class="special">:</span> <span class="keyword">public</span> <span class="identifier">is_mpi_datatype</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="special">{</span> <span class="special">};</span> +<span class="special">}</span> <span class="special">}</span> +</pre> +<p> + The redundant copy elimination optimization can only be applied when the + shape of the data type is completely fixed. Variable-length types (e.g., + strings, linked lists) and types that store pointers cannot use the optimiation, + but Boost.MPI will be unable to detect this error at compile time. Attempting + to perform this optimization when it is not correct will likely result + in segmentation faults and other strange program behavior. + </p> +<p> + Boost.MPI can transmit any user-defined data type from one process to another. + Built-in types can be transmitted without any extra effort; library-defined + types require the inclusion of a serialization header; and user-defined + types will require the addition of serialization code. Fixed data types + can be optimized for transmission using the <code class="computeroutput"><a class="link" href="../boost/mpi/is_mpi_datatype.html" title="Struct template is_mpi_datatype">is_mpi_datatype</a></code> type trait. + </p> +</div> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="mpi.collectives"></a>Collective operations</h3></div></div></div> +<div class="toc"><dl> +<dt><span class="section"><a href="tutorial.html#mpi.broadcast">Broadcast</a></span></dt> +<dt><span class="section"><a href="tutorial.html#mpi.gather">Gather</a></span></dt> +<dt><span class="section"><a href="tutorial.html#mpi.reduce">Reduce</a></span></dt> +</dl></div> +<p> + <a class="link" href="tutorial.html#mpi.point_to_point" title="Point-to-Point communication">Point-to-point operations</a> are the + core message passing primitives in Boost.MPI. However, many message-passing + applications also require higher-level communication algorithms that combine + or summarize the data stored on many different processes. These algorithms + support many common tasks such as "broadcast this value to all processes", + "compute the sum of the values on all processors" or "find + the global minimum." + </p> +<div class="section"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="mpi.broadcast"></a>Broadcast</h4></div></div></div> +<p> + The <code class="computeroutput"><a class="link" href="../boost/mpi/broadcast.html" title="Function broadcast">broadcast</a></code> + algorithm is by far the simplest collective operation. It broadcasts a + value from a single process to all other processes within a <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a></code>. For instance, + the following program broadcasts "Hello, World!" from process + 0 to every other process. (<code class="computeroutput"><span class="identifier">hello_world_broadcast</span><span class="special">.</span><span class="identifier">cpp</span></code>) + </p> +<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">mpi</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">string</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">serialization</span><span class="special">/</span><span class="identifier">string</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> +<span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">mpi</span><span class="special">;</span> + +<span class="keyword">int</span> <span class="identifier">main</span><span class="special">(</span><span class="keyword">int</span> <span class="identifier">argc</span><span class="special">,</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">argv</span><span class="special">[])</span> +<span class="special">{</span> + <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">environment</span> <span class="identifier">env</span><span class="special">(</span><span class="identifier">argc</span><span class="special">,</span> <span class="identifier">argv</span><span class="special">);</span> + <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">communicator</span> <span class="identifier">world</span><span class="special">;</span> + + <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">value</span><span class="special">;</span> + <span class="keyword">if</span> <span class="special">(</span><span class="identifier">world</span><span class="special">.</span><span class="identifier">rank</span><span class="special">()</span> <span class="special">==</span> <span class="number">0</span><span class="special">)</span> <span class="special">{</span> + <span class="identifier">value</span> <span class="special">=</span> <span class="string">"Hello, World!"</span><span class="special">;</span> + <span class="special">}</span> + + <span class="identifier">broadcast</span><span class="special">(</span><span class="identifier">world</span><span class="special">,</span> <span class="identifier">value</span><span class="special">,</span> <span class="number">0</span><span class="special">);</span> + + <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"Process #"</span> <span class="special"><<</span> <span class="identifier">world</span><span class="special">.</span><span class="identifier">rank</span><span class="special">()</span> <span class="special"><<</span> <span class="string">" says "</span> <span class="special"><<</span> <span class="identifier">value</span> + <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> + <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> +<span class="special">}</span> +</pre> +<p> + Running this program with seven processes will produce a result such as: + </p> +<pre class="programlisting">Process #0 says Hello, World! +Process #2 says Hello, World! +Process #1 says Hello, World! +Process #4 says Hello, World! +Process #3 says Hello, World! +Process #5 says Hello, World! +Process #6 says Hello, World! +</pre> +</div> +<div class="section"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="mpi.gather"></a>Gather</h4></div></div></div> +<p> + The <code class="computeroutput"><a class="link" href="../boost/mpi/gather.html" title="Function gather">gather</a></code> + collective gathers the values produced by every process in a communicator + into a vector of values on the "root" process (specified by an + argument to <code class="computeroutput"><span class="identifier">gather</span></code>). The + /i/th element in the vector will correspond to the value gathered fro mthe + /i/th process. For instance, in the following program each process computes + its own random number. All of these random numbers are gathered at process + 0 (the "root" in this case), which prints out the values that + correspond to each processor. (<code class="computeroutput"><span class="identifier">random_gather</span><span class="special">.</span><span class="identifier">cpp</span></code>) + </p> +<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">mpi</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">vector</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">cstdlib</span><span class="special">></span> +<span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">mpi</span><span class="special">;</span> + +<span class="keyword">int</span> <span class="identifier">main</span><span class="special">(</span><span class="keyword">int</span> <span class="identifier">argc</span><span class="special">,</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">argv</span><span class="special">[])</span> +<span class="special">{</span> + <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">environment</span> <span class="identifier">env</span><span class="special">(</span><span class="identifier">argc</span><span class="special">,</span> <span class="identifier">argv</span><span class="special">);</span> + <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">communicator</span> <span class="identifier">world</span><span class="special">;</span> + + <span class="identifier">std</span><span class="special">::</span><span class="identifier">srand</span><span class="special">(</span><span class="identifier">time</span><span class="special">(</span><span class="number">0</span><span class="special">)</span> <span class="special">+</span> <span class="identifier">world</span><span class="special">.</span><span class="identifier">rank</span><span class="special">());</span> + <span class="keyword">int</span> <span class="identifier">my_number</span> <span class="special">=</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">rand</span><span class="special">();</span> + <span class="keyword">if</span> <span class="special">(</span><span class="identifier">world</span><span class="special">.</span><span class="identifier">rank</span><span class="special">()</span> <span class="special">==</span> <span class="number">0</span><span class="special">)</span> <span class="special">{</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="identifier">all_numbers</span><span class="special">;</span> + <span class="identifier">gather</span><span class="special">(</span><span class="identifier">world</span><span class="special">,</span> <span class="identifier">my_number</span><span class="special">,</span> <span class="identifier">all_numbers</span><span class="special">,</span> <span class="number">0</span><span class="special">);</span> + <span class="keyword">for</span> <span class="special">(</span><span class="keyword">int</span> <span class="identifier">proc</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> <span class="identifier">proc</span> <span class="special"><</span> <span class="identifier">world</span><span class="special">.</span><span class="identifier">size</span><span class="special">();</span> <span class="special">++</span><span class="identifier">proc</span><span class="special">)</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"Process #"</span> <span class="special"><<</span> <span class="identifier">proc</span> <span class="special"><<</span> <span class="string">" thought of "</span> + <span class="special"><<</span> <span class="identifier">all_numbers</span><span class="special">[</span><span class="identifier">proc</span><span class="special">]</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> + <span class="special">}</span> <span class="keyword">else</span> <span class="special">{</span> + <span class="identifier">gather</span><span class="special">(</span><span class="identifier">world</span><span class="special">,</span> <span class="identifier">my_number</span><span class="special">,</span> <span class="number">0</span><span class="special">);</span> + <span class="special">}</span> + + <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> +<span class="special">}</span> +</pre> +<p> + Executing this program with seven processes will result in output such + as the following. Although the random values will change from one run to + the next, the order of the processes in the output will remain the same + because only process 0 writes to <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span></code>. + </p> +<pre class="programlisting">Process #0 thought of 332199874 +Process #1 thought of 20145617 +Process #2 thought of 1862420122 +Process #3 thought of 480422940 +Process #4 thought of 1253380219 +Process #5 thought of 949458815 +Process #6 thought of 650073868 +</pre> +<p> + The <code class="computeroutput"><span class="identifier">gather</span></code> operation collects + values from every process into a vector at one process. If instead the + values from every process need to be collected into identical vectors on + every process, use the <code class="computeroutput"><a class="link" href="../boost/mpi/all_gather.html" title="Function all_gather">all_gather</a></code> algorithm, + which is semantically equivalent to calling <code class="computeroutput"><span class="identifier">gather</span></code> + followed by a <code class="computeroutput"><span class="identifier">broadcast</span></code> + of the resulting vector. + </p> +</div> +<div class="section"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="mpi.reduce"></a>Reduce</h4></div></div></div> +<p> + The <code class="computeroutput"><a class="link" href="../boost/mpi/reduce.html" title="Function reduce">reduce</a></code> + collective summarizes the values from each process into a single value + at the user-specified "root" process. The Boost.MPI <code class="computeroutput"><span class="identifier">reduce</span></code> operation is similar in spirit + to the STL <a href="http://www.sgi.com/tech/stl/accumulate.html" target="_top"><code class="computeroutput"><span class="identifier">accumulate</span></code></a> operation, because + it takes a sequence of values (one per process) and combines them via a + function object. For instance, we can randomly generate values in each + process and the compute the minimum value over all processes via a call + to <code class="computeroutput"><a class="link" href="../boost/mpi/reduce.html" title="Function reduce">reduce</a></code> + (<code class="computeroutput"><span class="identifier">random_min</span><span class="special">.</span><span class="identifier">cpp</span></code>):: + </p> +<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">mpi</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">cstdlib</span><span class="special">></span> +<span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">mpi</span><span class="special">;</span> + +<span class="keyword">int</span> <span class="identifier">main</span><span class="special">(</span><span class="keyword">int</span> <span class="identifier">argc</span><span class="special">,</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">argv</span><span class="special">[])</span> +<span class="special">{</span> + <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">environment</span> <span class="identifier">env</span><span class="special">(</span><span class="identifier">argc</span><span class="special">,</span> <span class="identifier">argv</span><span class="special">);</span> + <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">communicator</span> <span class="identifier">world</span><span class="special">;</span> + + <span class="identifier">std</span><span class="special">::</span><span class="identifier">srand</span><span class="special">(</span><span class="identifier">time</span><span class="special">(</span><span class="number">0</span><span class="special">)</span> <span class="special">+</span> <span class="identifier">world</span><span class="special">.</span><span class="identifier">rank</span><span class="special">());</span> + <span class="keyword">int</span> <span class="identifier">my_number</span> <span class="special">=</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">rand</span><span class="special">();</span> + + <span class="keyword">if</span> <span class="special">(</span><span class="identifier">world</span><span class="special">.</span><span class="identifier">rank</span><span class="special">()</span> <span class="special">==</span> <span class="number">0</span><span class="special">)</span> <span class="special">{</span> + <span class="keyword">int</span> <span class="identifier">minimum</span><span class="special">;</span> + <span class="identifier">reduce</span><span class="special">(</span><span class="identifier">world</span><span class="special">,</span> <span class="identifier">my_number</span><span class="special">,</span> <span class="identifier">minimum</span><span class="special">,</span> <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">minimum</span><span class="special"><</span><span class="keyword">int</span><span class="special">>(),</span> <span class="number">0</span><span class="special">);</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"The minimum value is "</span> <span class="special"><<</span> <span class="identifier">minimum</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> + <span class="special">}</span> <span class="keyword">else</span> <span class="special">{</span> + <span class="identifier">reduce</span><span class="special">(</span><span class="identifier">world</span><span class="special">,</span> <span class="identifier">my_number</span><span class="special">,</span> <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">minimum</span><span class="special"><</span><span class="keyword">int</span><span class="special">>(),</span> <span class="number">0</span><span class="special">);</span> + <span class="special">}</span> + + <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> +<span class="special">}</span> +</pre> +<p> + The use of <code class="computeroutput"><span class="identifier">mpi</span><span class="special">::</span><span class="identifier">minimum</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span></code> + indicates that the minimum value should be computed. <code class="computeroutput"><span class="identifier">mpi</span><span class="special">::</span><span class="identifier">minimum</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span></code> is a binary function object that compares + its two parameters via <code class="computeroutput"><span class="special"><</span></code> + and returns the smaller value. Any associative binary function or function + object will work. For instance, to concatenate strings with <code class="computeroutput"><span class="identifier">reduce</span></code> one could use the function object + <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">plus</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">></span></code> + (<code class="computeroutput"><span class="identifier">string_cat</span><span class="special">.</span><span class="identifier">cpp</span></code>): + </p> +<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">mpi</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">string</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">functional</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">serialization</span><span class="special">/</span><span class="identifier">string</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> +<span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">mpi</span><span class="special">;</span> + +<span class="keyword">int</span> <span class="identifier">main</span><span class="special">(</span><span class="keyword">int</span> <span class="identifier">argc</span><span class="special">,</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">argv</span><span class="special">[])</span> +<span class="special">{</span> + <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">environment</span> <span class="identifier">env</span><span class="special">(</span><span class="identifier">argc</span><span class="special">,</span> <span class="identifier">argv</span><span class="special">);</span> + <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">communicator</span> <span class="identifier">world</span><span class="special">;</span> + + <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">names</span><span class="special">[</span><span class="number">10</span><span class="special">]</span> <span class="special">=</span> <span class="special">{</span> <span class="string">"zero "</span><span class="special">,</span> <span class="string">"one "</span><span class="special">,</span> <span class="string">"two "</span><span class="special">,</span> <span class="string">"three "</span><span class="special">,</span> + <span class="string">"four "</span><span class="special">,</span> <span class="string">"five "</span><span class="special">,</span> <span class="string">"six "</span><span class="special">,</span> <span class="string">"seven "</span><span class="special">,</span> + <span class="string">"eight "</span><span class="special">,</span> <span class="string">"nine "</span> <span class="special">};</span> + + <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">result</span><span class="special">;</span> + <span class="identifier">reduce</span><span class="special">(</span><span class="identifier">world</span><span class="special">,</span> + <span class="identifier">world</span><span class="special">.</span><span class="identifier">rank</span><span class="special">()</span> <span class="special"><</span> <span class="number">10</span><span class="special">?</span> <span class="identifier">names</span><span class="special">[</span><span class="identifier">world</span><span class="special">.</span><span class="identifier">rank</span><span class="special">()]</span> + <span class="special">:</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">(</span><span class="string">"many "</span><span class="special">),</span> + <span class="identifier">result</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">plus</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">>(),</span> <span class="number">0</span><span class="special">);</span> + + <span class="keyword">if</span> <span class="special">(</span><span class="identifier">world</span><span class="special">.</span><span class="identifier">rank</span><span class="special">()</span> <span class="special">==</span> <span class="number">0</span><span class="special">)</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"The result is "</span> <span class="special"><<</span> <span class="identifier">result</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> + + <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> +<span class="special">}</span> +</pre> +<p> + In this example, we compute a string for each process and then perform + a reduction that concatenates all of the strings together into one, long + string. Executing this program with seven processors yields the following + output: + </p> +<pre class="programlisting">The result is zero one two three four five six +</pre> +<p> + Any kind of binary function objects can be used with <code class="computeroutput"><span class="identifier">reduce</span></code>. + For instance, and there are many such function objects in the C++ standard + <code class="computeroutput"><span class="special"><</span><span class="identifier">functional</span><span class="special">></span></code> header and the Boost.MPI header <code class="computeroutput"><span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">mpi</span><span class="special">/</span><span class="identifier">operations</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code>. Or, you can create your own function + object. Function objects used with <code class="computeroutput"><span class="identifier">reduce</span></code> + must be associative, i.e. <code class="computeroutput"><span class="identifier">f</span><span class="special">(</span><span class="identifier">x</span><span class="special">,</span> + <span class="identifier">f</span><span class="special">(</span><span class="identifier">y</span><span class="special">,</span> <span class="identifier">z</span><span class="special">))</span></code> must be equivalent to <code class="computeroutput"><span class="identifier">f</span><span class="special">(</span><span class="identifier">f</span><span class="special">(</span><span class="identifier">x</span><span class="special">,</span> <span class="identifier">y</span><span class="special">),</span> <span class="identifier">z</span><span class="special">)</span></code>. If they are also commutative (i..e, + <code class="computeroutput"><span class="identifier">f</span><span class="special">(</span><span class="identifier">x</span><span class="special">,</span> <span class="identifier">y</span><span class="special">)</span> <span class="special">==</span> <span class="identifier">f</span><span class="special">(</span><span class="identifier">y</span><span class="special">,</span> + <span class="identifier">x</span><span class="special">)</span></code>), + Boost.MPI can use a more efficient implementation of <code class="computeroutput"><span class="identifier">reduce</span></code>. + To state that a function object is commutative, you will need to specialize + the class <code class="computeroutput"><a class="link" href="../boost/mpi/is_commutative.html" title="Struct template is_commutative">is_commutative</a></code>. + For instance, we could modify the previous example by telling Boost.MPI + that string concatenation is commutative: + </p> +<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">{</span> + + <span class="keyword">template</span><span class="special"><></span> + <span class="keyword">struct</span> <span class="identifier">is_commutative</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">plus</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">>,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">></span> + <span class="special">:</span> <span class="identifier">mpl</span><span class="special">::</span><span class="identifier">true_</span> <span class="special">{</span> <span class="special">};</span> + +<span class="special">}</span> <span class="special">}</span> <span class="comment">// end namespace boost::mpi</span> +</pre> +<p> + By adding this code prior to <code class="computeroutput"><span class="identifier">main</span><span class="special">()</span></code>, Boost.MPI will assume that string concatenation + is commutative and employ a different parallel algorithm for the <code class="computeroutput"><span class="identifier">reduce</span></code> operation. Using this algorithm, + the program outputs the following when run with seven processes: + </p> +<pre class="programlisting">The result is zero one four five six two three +</pre> +<p> + Note how the numbers in the resulting string are in a different order: + this is a direct result of Boost.MPI reordering operations. The result + in this case differed from the non-commutative result because string concatenation + is not commutative: <code class="computeroutput"><span class="identifier">f</span><span class="special">(</span><span class="string">"x"</span><span class="special">,</span> + <span class="string">"y"</span><span class="special">)</span></code> + is not the same as <code class="computeroutput"><span class="identifier">f</span><span class="special">(</span><span class="string">"y"</span><span class="special">,</span> + <span class="string">"x"</span><span class="special">)</span></code>, + because argument order matters. For truly commutative operations (e.g., + integer addition), the more efficient commutative algorithm will produce + the same result as the non-commutative algorithm. Boost.MPI also performs + direct mappings from function objects in <code class="computeroutput"><span class="special"><</span><span class="identifier">functional</span><span class="special">></span></code> + to <code class="computeroutput"><span class="identifier">MPI_Op</span></code> values predefined + by MPI (e.g., <code class="computeroutput"><span class="identifier">MPI_SUM</span></code>, + <code class="computeroutput"><span class="identifier">MPI_MAX</span></code>); if you have your + own function objects that can take advantage of this mapping, see the class + template <code class="computeroutput"><a class="link" href="../boost/mpi/is_mpi_op.html" title="Struct template is_mpi_op">is_mpi_op</a></code>. + </p> +<p> + Like <a class="link" href="tutorial.html#mpi.gather" title="Gather"><code class="computeroutput"><span class="identifier">gather</span></code></a>, + <code class="computeroutput"><span class="identifier">reduce</span></code> has an "all" + variant called <code class="computeroutput"><a class="link" href="../boost/mpi/all_reduce.html" title="Function all_reduce">all_reduce</a></code> that performs + the reduction operation and broadcasts the result to all processes. This + variant is useful, for instance, in establishing global minimum or maximum + values. + </p> +</div> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="mpi.communicators"></a>Managing communicators</h3></div></div></div> +<p> + Communication with Boost.MPI always occurs over a communicator. A communicator + contains a set of processes that can send messages among themselves and perform + collective operations. There can be many communicators within a single program, + each of which contains its own isolated communication space that acts independently + of the other communicators. + </p> +<p> + When the MPI environment is initialized, only the "world" communicator + (called <code class="computeroutput"><span class="identifier">MPI_COMM_WORLD</span></code> in + the MPI C and Fortran bindings) is available. The "world" communicator, + accessed by default-constructing a <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html" title="Class communicator">mpi::communicator</a></code> + object, contains all of the MPI processes present when the program begins + execution. Other communicators can then be constructed by duplicating or + building subsets of the "world" communicator. For instance, in + the following program we split the processes into two groups: one for processes + generating data and the other for processes that will collect the data. (<code class="computeroutput"><span class="identifier">generate_collect</span><span class="special">.</span><span class="identifier">cpp</span></code>) + </p> +<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">mpi</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">cstdlib</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">serialization</span><span class="special">/</span><span class="identifier">vector</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> +<span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">mpi</span><span class="special">;</span> + +<span class="keyword">enum</span> <span class="identifier">message_tags</span> <span class="special">{</span><span class="identifier">msg_data_packet</span><span class="special">,</span> <span class="identifier">msg_broadcast_data</span><span class="special">,</span> <span class="identifier">msg_finished</span><span class="special">};</span> + +<span class="keyword">void</span> <span class="identifier">generate_data</span><span class="special">(</span><span class="identifier">mpi</span><span class="special">::</span><span class="identifier">communicator</span> <span class="identifier">local</span><span class="special">,</span> <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">communicator</span> <span class="identifier">world</span><span class="special">);</span> +<span class="keyword">void</span> <span class="identifier">collect_data</span><span class="special">(</span><span class="identifier">mpi</span><span class="special">::</span><span class="identifier">communicator</span> <span class="identifier">local</span><span class="special">,</span> <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">communicator</span> <span class="identifier">world</span><span class="special">);</span> + +<span class="keyword">int</span> <span class="identifier">main</span><span class="special">(</span><span class="keyword">int</span> <span class="identifier">argc</span><span class="special">,</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">argv</span><span class="special">[])</span> +<span class="special">{</span> + <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">environment</span> <span class="identifier">env</span><span class="special">(</span><span class="identifier">argc</span><span class="special">,</span> <span class="identifier">argv</span><span class="special">);</span> + <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">communicator</span> <span class="identifier">world</span><span class="special">;</span> + + <span class="keyword">bool</span> <span class="identifier">is_generator</span> <span class="special">=</span> <span class="identifier">world</span><span class="special">.</span><span class="identifier">rank</span><span class="special">()</span> <span class="special"><</span> <span class="number">2</span> <span class="special">*</span> <span class="identifier">world</span><span class="special">.</span><span class="identifier">size</span><span class="special">()</span> <span class="special">/</span> <span class="number">3</span><span class="special">;</span> + <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">communicator</span> <span class="identifier">local</span> <span class="special">=</span> <span class="identifier">world</span><span class="special">.</span><span class="identifier">split</span><span class="special">(</span><span class="identifier">is_generator</span><span class="special">?</span> <span class="number">0</span> <span class="special">:</span> <span class="number">1</span><span class="special">);</span> + <span class="keyword">if</span> <span class="special">(</span><span class="identifier">is_generator</span><span class="special">)</span> <span class="identifier">generate_data</span><span class="special">(</span><span class="identifier">local</span><span class="special">,</span> <span class="identifier">world</span><span class="special">);</span> + <span class="keyword">else</span> <span class="identifier">collect_data</span><span class="special">(</span><span class="identifier">local</span><span class="special">,</span> <span class="identifier">world</span><span class="special">);</span> + + <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> +<span class="special">}</span> +</pre> +<p> + When communicators are split in this way, their processes retain membership + in both the original communicator (which is not altered by the split) and + the new communicator. However, the ranks of the processes may be different + from one communicator to the next, because the rank values within a communicator + are always contiguous values starting at zero. In the example above, the + first two thirds of the processes become "generators" and the remaining + processes become "collectors". The ranks of the "collectors" + in the <code class="computeroutput"><span class="identifier">world</span></code> communicator + will be 2/3 <code class="computeroutput"><span class="identifier">world</span><span class="special">.</span><span class="identifier">size</span><span class="special">()</span></code> + and greater, whereas the ranks of the same collector processes in the <code class="computeroutput"><span class="identifier">local</span></code> communicator will start at zero. + The following excerpt from <code class="computeroutput"><span class="identifier">collect_data</span><span class="special">()</span></code> (in <code class="computeroutput"><span class="identifier">generate_collect</span><span class="special">.</span><span class="identifier">cpp</span></code>) illustrates + how to manage multiple communicators: + </p> +<pre class="programlisting"><span class="identifier">mpi</span><span class="special">::</span><span class="identifier">status</span> <span class="identifier">msg</span> <span class="special">=</span> <span class="identifier">world</span><span class="special">.</span><span class="identifier">probe</span><span class="special">();</span> +<span class="keyword">if</span> <span class="special">(</span><span class="identifier">msg</span><span class="special">.</span><span class="identifier">tag</span><span class="special">()</span> <span class="special">==</span> <span class="identifier">msg_data_packet</span><span class="special">)</span> <span class="special">{</span> + <span class="comment">// Receive the packet of data</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="identifier">data</span><span class="special">;</span> + <span class="identifier">world</span><span class="special">.</span><span class="identifier">recv</span><span class="special">(</span><span class="identifier">msg</span><span class="special">.</span><span class="identifier">source</span><span class="special">(),</span> <span class="identifier">msg</span><span class="special">.</span><span class="identifier">tag</span><span class="special">(),</span> <span class="identifier">data</span><span class="special">);</span> + + <span class="comment">// Tell each of the collectors that we'll be broadcasting some data</span> + <span class="keyword">for</span> <span class="special">(</span><span class="keyword">int</span> <span class="identifier">dest</span> <span class="special">=</span> <span class="number">1</span><span class="special">;</span> <span class="identifier">dest</span> <span class="special"><</span> <span class="identifier">local</span><span class="special">.</span><span class="identifier">size</span><span class="special">();</span> <span class="special">++</span><span class="identifier">dest</span><span class="special">)</span> + <span class="identifier">local</span><span class="special">.</span><span class="identifier">send</span><span class="special">(</span><span class="identifier">dest</span><span class="special">,</span> <span class="identifier">msg_broadcast_data</span><span class="special">,</span> <span class="identifier">msg</span><span class="special">.</span><span class="identifier">source</span><span class="special">());</span> + + <span class="comment">// Broadcast the actual data.</span> + <span class="identifier">broadcast</span><span class="special">(</span><span class="identifier">local</span><span class="special">,</span> <span class="identifier">data</span><span class="special">,</span> <span class="number">0</span><span class="special">);</span> +<span class="special">}</span> +</pre> +<p> + The code in this except is executed by the "master" collector, + e.g., the node with rank 2/3 <code class="computeroutput"><span class="identifier">world</span><span class="special">.</span><span class="identifier">size</span><span class="special">()</span></code> + in the <code class="computeroutput"><span class="identifier">world</span></code> communicator + and rank 0 in the <code class="computeroutput"><span class="identifier">local</span></code> (collector) + communicator. It receives a message from a generator via the <code class="computeroutput"><span class="identifier">world</span></code> communicator, then broadcasts the + message to each of the collectors via the <code class="computeroutput"><span class="identifier">local</span></code> + communicator. + </p> +<p> + For more control in the creation of communicators for subgroups of processes, + the Boost.MPI <code class="computeroutput"><a class="link" href="../boost/mpi/group.html" title="Class group">group</a></code> + provides facilities to compute the union (<code class="computeroutput"><span class="special">|</span></code>), + intersection (<code class="computeroutput"><span class="special">&</span></code>), and difference + (<code class="computeroutput"><span class="special">-</span></code>) of two groups, generate + arbitrary subgroups, etc. + </p> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="mpi.skeleton_and_content"></a>Separating structure from content</h3></div></div></div> +<p> + When communicating data types over MPI that are not fundamental to MPI (such + as strings, lists, and user-defined data types), Boost.MPI must first serialize + these data types into a buffer and then communicate them; the receiver then + copies the results into a buffer before deserializing into an object on the + other end. For some data types, this overhead can be eliminated by using + <code class="computeroutput"><a class="link" href="../boost/mpi/is_mpi_datatype.html" title="Struct template is_mpi_datatype">is_mpi_datatype</a></code>. + However, variable-length data types such as strings and lists cannot be MPI + data types. + </p> +<p> + Boost.MPI supports a second technique for improving performance by separating + the structure of these variable-length data structures from the content stored + in the data structures. This feature is only beneficial when the shape of + the data structure remains the same but the content of the data structure + will need to be communicated several times. For instance, in a finite element + analysis the structure of the mesh may be fixed at the beginning of computation + but the various variables on the cells of the mesh (temperature, stress, + etc.) will be communicated many times within the iterative analysis process. + In this case, Boost.MPI allows one to first send the "skeleton" + of the mesh once, then transmit the "content" multiple times. Since + the content need not contain any information about the structure of the data + type, it can be transmitted without creating separate communication buffers. + </p> +<p> + To illustrate the use of skeletons and content, we will take a somewhat more + limited example wherein a master process generates random number sequences + into a list and transmits them to several slave processes. The length of + the list will be fixed at program startup, so the content of the list (i.e., + the current sequence of numbers) can be transmitted efficiently. The complete + example is available in <code class="computeroutput"><span class="identifier">example</span><span class="special">/</span><span class="identifier">random_content</span><span class="special">.</span><span class="identifier">cpp</span></code>. We + being with the master process (rank 0), which builds a list, communicates + its structure via a <code class="computeroutput"><a class="link" href="../boost/mpi/skeleton.html" title="Function template skeleton">skeleton</a></code>, then repeatedly + generates random number sequences to be broadcast to the slave processes + via <code class="computeroutput"><a class="link" href="../boost/mpi/content.html" title="Class content">content</a></code>: + </p> +<pre class="programlisting"><span class="comment">// Generate the list and broadcast its structure</span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">list</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="identifier">l</span><span class="special">(</span><span class="identifier">list_len</span><span class="special">);</span> +<span class="identifier">broadcast</span><span class="special">(</span><span class="identifier">world</span><span class="special">,</span> <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">skeleton</span><span class="special">(</span><span class="identifier">l</span><span class="special">),</span> <span class="number">0</span><span class="special">);</span> + +<span class="comment">// Generate content several times and broadcast out that content</span> +<span class="identifier">mpi</span><span class="special">::</span><span class="identifier">content</span> <span class="identifier">c</span> <span class="special">=</span> <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">get_content</span><span class="special">(</span><span class="identifier">l</span><span class="special">);</span> +<span class="keyword">for</span> <span class="special">(</span><span class="keyword">int</span> <span class="identifier">i</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> <span class="identifier">i</span> <span class="special"><</span> <span class="identifier">iterations</span><span class="special">;</span> <span class="special">++</span><span class="identifier">i</span><span class="special">)</span> <span class="special">{</span> + <span class="comment">// Generate new random values</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">generate</span><span class="special">(</span><span class="identifier">l</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(),</span> <span class="identifier">l</span><span class="special">.</span><span class="identifier">end</span><span class="special">(),</span> <span class="special">&</span><span class="identifier">random</span><span class="special">);</span> + + <span class="comment">// Broadcast the new content of l</span> + <span class="identifier">broadcast</span><span class="special">(</span><span class="identifier">world</span><span class="special">,</span> <span class="identifier">c</span><span class="special">,</span> <span class="number">0</span><span class="special">);</span> +<span class="special">}</span> + +<span class="comment">// Notify the slaves that we're done by sending all zeroes</span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">fill</span><span class="special">(</span><span class="identifier">l</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(),</span> <span class="identifier">l</span><span class="special">.</span><span class="identifier">end</span><span class="special">(),</span> <span class="number">0</span><span class="special">);</span> +<span class="identifier">broadcast</span><span class="special">(</span><span class="identifier">world</span><span class="special">,</span> <span class="identifier">c</span><span class="special">,</span> <span class="number">0</span><span class="special">);</span> +</pre> +<p> + The slave processes have a very similar structure to the master. They receive + (via the <code class="computeroutput"><a class="link" href="../boost/mpi/broadcast.html" title="Function broadcast">broadcast()</a></code> call) the skeleton of the + data structure, then use it to build their own lists of integers. In each + iteration, they receive via another <code class="computeroutput"><span class="identifier">broadcast</span><span class="special">()</span></code> the new content in the data structure and + compute some property of the data: + </p> +<pre class="programlisting"><span class="comment">// Receive the content and build up our own list</span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">list</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="identifier">l</span><span class="special">;</span> +<span class="identifier">broadcast</span><span class="special">(</span><span class="identifier">world</span><span class="special">,</span> <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">skeleton</span><span class="special">(</span><span class="identifier">l</span><span class="special">),</span> <span class="number">0</span><span class="special">);</span> + +<span class="identifier">mpi</span><span class="special">::</span><span class="identifier">content</span> <span class="identifier">c</span> <span class="special">=</span> <span class="identifier">mpi</span><span class="special">::</span><span class="identifier">get_content</span><span class="special">(</span><span class="identifier">l</span><span class="special">);</span> +<span class="keyword">int</span> <span class="identifier">i</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> +<span class="keyword">do</span> <span class="special">{</span> + <span class="identifier">broadcast</span><span class="special">(</span><span class="identifier">world</span><span class="special">,</span> <span class="identifier">c</span><span class="special">,</span> <span class="number">0</span><span class="special">);</span> + + <span class="keyword">if</span> <span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">find_if</span> + <span class="special">(</span><span class="identifier">l</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(),</span> <span class="identifier">l</span><span class="special">.</span><span class="identifier">end</span><span class="special">(),</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">bind1st</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">not_equal_to</span><span class="special"><</span><span class="keyword">int</span><span class="special">>(),</span> <span class="number">0</span><span class="special">))</span> <span class="special">==</span> <span class="identifier">l</span><span class="special">.</span><span class="identifier">end</span><span class="special">())</span> + <span class="keyword">break</span><span class="special">;</span> + + <span class="comment">// Compute some property of the data.</span> + + <span class="special">++</span><span class="identifier">i</span><span class="special">;</span> +<span class="special">}</span> <span class="keyword">while</span> <span class="special">(</span><span class="keyword">true</span><span class="special">);</span> +</pre> +<p> + The skeletons and content of any Serializable data type can be transmitted + either via the <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html#id766471-bb">send</a></code> and <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html#id766808-bb">recv</a></code> members of the <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a></code> + class (for point-to-point communicators) or broadcast via the <code class="computeroutput"><a class="link" href="../boost/mpi/broadcast.html" title="Function broadcast">broadcast()</a></code> collective. When separating + a data structure into a skeleton and content, be careful not to modify the + data structure (either on the sender side or the receiver side) without transmitting + the skeleton again. Boost.MPI can not detect these accidental modifications + to the data structure, which will likely result in incorrect data being transmitted + or unstable programs. + </p> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="mpi.performance_optimizations"></a>Performance optimizations</h3></div></div></div> +<div class="toc"><dl> +<dt><span class="section"><a href="tutorial.html#mpi.serialization_optimizations">Serialization optimizations</a></span></dt> +<dt><span class="section"><a href="tutorial.html#mpi.homogeneous_machines">Homogeneous machines</a></span></dt> +</dl></div> +<div class="section"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="mpi.serialization_optimizations"></a>Serialization optimizations</h4></div></div></div> +<p> + To obtain optimal performance for small fixed-length data types not containing + any pointers it is very important to mark them using the type traits of + Boost.MPI and Boost.Serialization. + </p> +<p> + It was alredy discussed that fixed length types containing no pointers + can be using as <code class="computeroutput"><a class="link" href="../boost/mpi/is_mpi_datatype.html" title="Struct template is_mpi_datatype">is_mpi_datatype</a></code>, e.g.: + </p> +<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">mpi</span> <span class="special">{</span> + <span class="keyword">template</span> <span class="special"><></span> + <span class="keyword">struct</span> <span class="identifier">is_mpi_datatype</span><span class="special"><</span><span class="identifier">gps_position</span><span class="special">></span> <span class="special">:</span> <span class="identifier">mpl</span><span class="special">::</span><span class="identifier">true_</span> <span class="special">{</span> <span class="special">};</span> +<span class="special">}</span> <span class="special">}</span> +</pre> +<p> + or the equivalent macro + </p> +<pre class="programlisting"><span class="identifier">BOOST_IS_MPI_DATATYPE</span><span class="special">(</span><span class="identifier">gps_position</span><span class="special">)</span> +</pre> +<p> + In addition it can give a substantial performance gain to turn off tracking + and versioning for these types, if no pointers to these types are used, + by using the traits classes or helper macros of Boost.Serialization: + </p> +<pre class="programlisting"><span class="identifier">BOOST_CLASS_TRACKING</span><span class="special">(</span><span class="identifier">gps_position</span><span class="special">,</span><span class="identifier">track_never</span><span class="special">)</span> +<span class="identifier">BOOST_CLASS_IMPLEMENTATION</span><span class="special">(</span><span class="identifier">gps_position</span><span class="special">,</span><span class="identifier">object_serializable</span><span class="special">)</span> +</pre> +</div> +<div class="section"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="mpi.homogeneous_machines"></a>Homogeneous machines</h4></div></div></div> +<p> + More optimizations are possible on homogeneous machines, by avoiding MPI_Pack/MPI_Unpack + calls but using direct bitwise copy. This feature can be enabled by defining + the macro BOOST_MPI_HOMOGENEOUS when building Boost.MPI and when building + the application. + </p> +<p> + In addition all classes need to be marked both as is_mpi_datatype and as + is_bitwise_serializable, by using the helper macro of Boost.Serialization: + </p> +<pre class="programlisting"><span class="identifier">BOOST_IS_BITWISE_SERIALIZABLE</span><span class="special">(</span><span class="identifier">gps_position</span><span class="special">)</span> +</pre> +<p> + Usually it is safe to serialize a class for which is_mpi_datatype is true + by using binary copy of the bits. The exception are classes for which some + members should be skipped for serialization. + </p> +</div> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="mpi.c_mapping"></a>Mapping from C MPI to Boost.MPI</h3></div></div></div> +<p> + This section provides tables that map from the functions and constants of + the standard C MPI to their Boost.MPI equivalents. It will be most useful + for users that are already familiar with the C or Fortran interfaces to MPI, + or for porting existing parallel programs to Boost.MPI. + </p> +<div class="table"> +<a name="mpi.tutorial.c_mapping.t0"></a><p class="title"><b>Table 17.1. Point-to-point communication</b></p> +<div class="table-contents"><table class="table" summary="Point-to-point communication"> +<colgroup> +<col> +<col> +</colgroup> +<thead><tr> +<th> + <p> + C Function/Constant + </p> + </th> +<th> + <p> + Boost.MPI Equivalent + </p> + </th> +</tr></thead> +<tbody> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_ANY_SOURCE</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><span class="identifier">any_source</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_ANY_TAG</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><span class="identifier">any_tag</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node40.html#Node40" target="_top"><code class="computeroutput"><span class="identifier">MPI_Bsend</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node51.html#Node51" target="_top"><code class="computeroutput"><span class="identifier">MPI_Bsend_init</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node42.html#Node42" target="_top"><code class="computeroutput"><span class="identifier">MPI_Buffer_attach</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node42.html#Node42" target="_top"><code class="computeroutput"><span class="identifier">MPI_Buffer_detach</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node50.html#Node50" target="_top"><code class="computeroutput"><span class="identifier">MPI_Cancel</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/request.html#id774915-bb">request::cancel</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node35.html#Node35" target="_top"><code class="computeroutput"><span class="identifier">MPI_Get_count</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/status.html#id775775-bb">status::count</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node46.html#Node46" target="_top"><code class="computeroutput"><span class="identifier">MPI_Ibsend</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node50.html#Node50" target="_top"><code class="computeroutput"><span class="identifier">MPI_Iprobe</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html#id763306-bb">communicator::iprobe</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node46.html#Node46" target="_top"><code class="computeroutput"><span class="identifier">MPI_Irsend</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node46.html#Node46" target="_top"><code class="computeroutput"><span class="identifier">MPI_Isend</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html#id769273-bb">communicator::isend</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node46.html#Node46" target="_top"><code class="computeroutput"><span class="identifier">MPI_Issend</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node46.html#Node46" target="_top"><code class="computeroutput"><span class="identifier">MPI_Irecv</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html#id769273-bb">communicator::irecv</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node50.html#Node50" target="_top"><code class="computeroutput"><span class="identifier">MPI_Probe</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html#id763232-bb">communicator::probe</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node53.html#Node53" target="_top"><code class="computeroutput"><span class="identifier">MPI_PROC_NULL</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node34.html#Node34" target="_top"><code class="computeroutput"><span class="identifier">MPI_Recv</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html#id766808-bb">communicator::recv</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node51.html#Node51" target="_top"><code class="computeroutput"><span class="identifier">MPI_Recv_init</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node47.html#Node47" target="_top"><code class="computeroutput"><span class="identifier">MPI_Request_free</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node40.html#Node40" target="_top"><code class="computeroutput"><span class="identifier">MPI_Rsend</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node51.html#Node51" target="_top"><code class="computeroutput"><span class="identifier">MPI_Rsend_init</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node31.html#Node31" target="_top"><code class="computeroutput"><span class="identifier">MPI_Send</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html#id766471-bb">communicator::send</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node52.html#Node52" target="_top"><code class="computeroutput"><span class="identifier">MPI_Sendrecv</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node52.html#Node52" target="_top"><code class="computeroutput"><span class="identifier">MPI_Sendrecv_replace</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node51.html#Node51" target="_top"><code class="computeroutput"><span class="identifier">MPI_Send_init</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node40.html#Node40" target="_top"><code class="computeroutput"><span class="identifier">MPI_Ssend</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node51.html#Node51" target="_top"><code class="computeroutput"><span class="identifier">MPI_Ssend_init</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node51.html#Node51" target="_top"><code class="computeroutput"><span class="identifier">MPI_Start</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node51.html#Node51" target="_top"><code class="computeroutput"><span class="identifier">MPI_Startall</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node47.html#Node47" target="_top"><code class="computeroutput"><span class="identifier">MPI_Test</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/request.html#id774859-bb">request::test</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node47.html#Node47" target="_top"><code class="computeroutput"><span class="identifier">MPI_Testall</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/test_all.html" title="Function test_all">test_all</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node47.html#Node47" target="_top"><code class="computeroutput"><span class="identifier">MPI_Testany</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/test_any.html" title="Function template test_any">test_any</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node47.html#Node47" target="_top"><code class="computeroutput"><span class="identifier">MPI_Testsome</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/test_some.html" title="Function test_some">test_some</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node50.html#Node50" target="_top"><code class="computeroutput"><span class="identifier">MPI_Test_cancelled</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/status.html#id775762-bb">status::cancelled</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node47.html#Node47" target="_top"><code class="computeroutput"><span class="identifier">MPI_Wait</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/request.html#id774859-bb">request::wait</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node47.html#Node47" target="_top"><code class="computeroutput"><span class="identifier">MPI_Waitall</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/wait_all.html" title="Function wait_all">wait_all</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node47.html#Node47" target="_top"><code class="computeroutput"><span class="identifier">MPI_Waitany</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/wait_any.html" title="Function template wait_any">wait_any</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node47.html#Node47" target="_top"><code class="computeroutput"><span class="identifier">MPI_Waitsome</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/wait_some.html" title="Function wait_some">wait_some</a></code> + </p> + </td> +</tr> +</tbody> +</table></div> +</div> +<br class="table-break"><p> + Boost.MPI automatically maps C and C++ data types to their MPI equivalents. + The following table illustrates the mappings between C++ types and MPI datatype + constants. + </p> +<div class="table"> +<a name="mpi.tutorial.c_mapping.t1"></a><p class="title"><b>Table 17.2. Datatypes</b></p> +<div class="table-contents"><table class="table" summary="Datatypes"> +<colgroup> +<col> +<col> +</colgroup> +<thead><tr> +<th> + <p> + C Constant + </p> + </th> +<th> + <p> + Boost.MPI Equivalent + </p> + </th> +</tr></thead> +<tbody> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_CHAR</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><span class="keyword">signed</span> <span class="keyword">char</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_SHORT</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><span class="keyword">signed</span> <span class="keyword">short</span> + <span class="keyword">int</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_INT</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><span class="keyword">signed</span> <span class="keyword">int</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_LONG</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><span class="keyword">signed</span> <span class="keyword">long</span> + <span class="keyword">int</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_UNSIGNED_CHAR</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><span class="keyword">unsigned</span> <span class="keyword">char</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_UNSIGNED_SHORT</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><span class="keyword">unsigned</span> <span class="keyword">short</span> + <span class="keyword">int</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_UNSIGNED_INT</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><span class="keyword">unsigned</span> <span class="keyword">int</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_UNSIGNED_LONG</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><span class="keyword">unsigned</span> <span class="keyword">long</span> + <span class="keyword">int</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_FLOAT</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><span class="keyword">float</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_DOUBLE</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><span class="keyword">double</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_LONG_DOUBLE</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><span class="keyword">long</span> <span class="keyword">double</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_BYTE</span></code> + </p> + </td> +<td> + <p> + unused + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_PACKED</span></code> + </p> + </td> +<td> + <p> + used internally for <a class="link" href="tutorial.html#mpi.user_data_types" title="User-defined data types">serialized + data types</a> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_LONG_LONG_INT</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><span class="keyword">long</span> <span class="keyword">long</span> + <span class="keyword">int</span></code>, if supported by compiler + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_UNSIGNED_LONG_LONG_INT</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><span class="keyword">unsigned</span> <span class="keyword">long</span> + <span class="keyword">long</span> <span class="keyword">int</span></code>, + if supported by compiler + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_FLOAT_INT</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">pair</span><span class="special"><</span><span class="keyword">float</span><span class="special">,</span> + <span class="keyword">int</span><span class="special">></span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_DOUBLE_INT</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">pair</span><span class="special"><</span><span class="keyword">double</span><span class="special">,</span> + <span class="keyword">int</span><span class="special">></span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_LONG_INT</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">pair</span><span class="special"><</span><span class="keyword">long</span><span class="special">,</span> + <span class="keyword">int</span><span class="special">></span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_2INT</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">pair</span><span class="special"><</span><span class="keyword">int</span><span class="special">,</span> <span class="keyword">int</span><span class="special">></span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_SHORT_INT</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">pair</span><span class="special"><</span><span class="keyword">short</span><span class="special">,</span> + <span class="keyword">int</span><span class="special">></span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_LONG_DOUBLE_INT</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">pair</span><span class="special"><</span><span class="keyword">long</span> <span class="keyword">double</span><span class="special">,</span> <span class="keyword">int</span><span class="special">></span></code> + </p> + </td> +</tr> +</tbody> +</table></div> +</div> +<br class="table-break"><p> + Boost.MPI does not provide direct wrappers to the MPI derived datatypes functionality. + Instead, Boost.MPI relies on the <a href="http://www.boost.org/libs/serialization/doc" target="_top">Boost.Serialization</a> + library to construct MPI datatypes for user-defined classe. The section on + <a class="link" href="tutorial.html#mpi.user_data_types" title="User-defined data types">user-defined data types</a> describes + this mechanism, which is used for types that marked as "MPI datatypes" + using <code class="computeroutput"><a class="link" href="../boost/mpi/is_mpi_datatype.html" title="Struct template is_mpi_datatype">is_mpi_datatype</a></code>. + </p> +<p> + The derived datatypes table that follows describes which C++ types correspond + to the functionality of the C MPI's datatype constructor. Boost.MPI may not + actually use the C MPI function listed when building datatypes of a certain + form. Since the actual datatypes built by Boost.MPI are typically hidden + from the user, many of these operations are called internally by Boost.MPI. + </p> +<div class="table"> +<a name="mpi.tutorial.c_mapping.t2"></a><p class="title"><b>Table 17.3. Derived datatypes</b></p> +<div class="table-contents"><table class="table" summary="Derived datatypes"> +<colgroup> +<col> +<col> +</colgroup> +<thead><tr> +<th> + <p> + C Function/Constant + </p> + </th> +<th> + <p> + Boost.MPI Equivalent + </p> + </th> +</tr></thead> +<tbody> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node56.html#Node56" target="_top"><code class="computeroutput"><span class="identifier">MPI_Address</span></code></a> + </p> + </td> +<td> + <p> + used automatically in Boost.MPI + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node58.html#Node58" target="_top"><code class="computeroutput"><span class="identifier">MPI_Type_commit</span></code></a> + </p> + </td> +<td> + <p> + used automatically in Boost.MPI + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node55.html#Node55" target="_top"><code class="computeroutput"><span class="identifier">MPI_Type_contiguous</span></code></a> + </p> + </td> +<td> + <p> + arrays + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node56.html#Node56" target="_top"><code class="computeroutput"><span class="identifier">MPI_Type_extent</span></code></a> + </p> + </td> +<td> + <p> + used automatically in Boost.MPI + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node58.html#Node58" target="_top"><code class="computeroutput"><span class="identifier">MPI_Type_free</span></code></a> + </p> + </td> +<td> + <p> + used automatically in Boost.MPI + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node55.html#Node55" target="_top"><code class="computeroutput"><span class="identifier">MPI_Type_hindexed</span></code></a> + </p> + </td> +<td> + <p> + any type used as a subobject + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node55.html#Node55" target="_top"><code class="computeroutput"><span class="identifier">MPI_Type_hvector</span></code></a> + </p> + </td> +<td> + <p> + unused + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node55.html#Node55" target="_top"><code class="computeroutput"><span class="identifier">MPI_Type_indexed</span></code></a> + </p> + </td> +<td> + <p> + any type used as a subobject + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node57.html#Node57" target="_top"><code class="computeroutput"><span class="identifier">MPI_Type_lb</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node56.html#Node56" target="_top"><code class="computeroutput"><span class="identifier">MPI_Type_size</span></code></a> + </p> + </td> +<td> + <p> + used automatically in Boost.MPI + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node55.html#Node55" target="_top"><code class="computeroutput"><span class="identifier">MPI_Type_struct</span></code></a> + </p> + </td> +<td> + <p> + user-defined classes and structs + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node57.html#Node57" target="_top"><code class="computeroutput"><span class="identifier">MPI_Type_ub</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node55.html#Node55" target="_top"><code class="computeroutput"><span class="identifier">MPI_Type_vector</span></code></a> + </p> + </td> +<td> + <p> + used automatically in Boost.MPI + </p> + </td> +</tr> +</tbody> +</table></div> +</div> +<br class="table-break"><p> + MPI's packing facilities store values into a contiguous buffer, which can + later be transmitted via MPI and unpacked into separate values via MPI's + unpacking facilities. As with datatypes, Boost.MPI provides an abstract interface + to MPI's packing and unpacking facilities. In particular, the two archive + classes <code class="computeroutput"><a class="link" href="../boost/mpi/packed_oarchive.html" title="Class packed_oarchive">packed_oarchive</a></code> + and <code class="computeroutput"><a class="link" href="../boost/mpi/packed_iarchive.html" title="Class packed_iarchive">packed_iarchive</a></code> + can be used to pack or unpack a contiguous buffer using MPI's facilities. + </p> +<div class="table"> +<a name="mpi.tutorial.c_mapping.t3"></a><p class="title"><b>Table 17.4. Packing and unpacking</b></p> +<div class="table-contents"><table class="table" summary="Packing and unpacking"> +<colgroup> +<col> +<col> +</colgroup> +<thead><tr> +<th> + <p> + C Function + </p> + </th> +<th> + <p> + Boost.MPI Equivalent + </p> + </th> +</tr></thead> +<tbody> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node62.html#Node62" target="_top"><code class="computeroutput"><span class="identifier">MPI_Pack</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/packed_oarchive.html" title="Class packed_oarchive">packed_oarchive</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node62.html#Node62" target="_top"><code class="computeroutput"><span class="identifier">MPI_Pack_size</span></code></a> + </p> + </td> +<td> + <p> + used internally by Boost.MPI + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node62.html#Node62" target="_top"><code class="computeroutput"><span class="identifier">MPI_Unpack</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/packed_iarchive.html" title="Class packed_iarchive">packed_iarchive</a></code> + </p> + </td> +</tr> +</tbody> +</table></div> +</div> +<br class="table-break"><p> + Boost.MPI supports a one-to-one mapping for most of the MPI collectives. + For each collective provided by Boost.MPI, the underlying C MPI collective + will be invoked when it is possible (and efficient) to do so. + </p> +<div class="table"> +<a name="mpi.tutorial.c_mapping.t4"></a><p class="title"><b>Table 17.5. Collectives</b></p> +<div class="table-contents"><table class="table" summary="Collectives"> +<colgroup> +<col> +<col> +</colgroup> +<thead><tr> +<th> + <p> + C Function + </p> + </th> +<th> + <p> + Boost.MPI Equivalent + </p> + </th> +</tr></thead> +<tbody> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node73.html#Node73" target="_top"><code class="computeroutput"><span class="identifier">MPI_Allgather</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/all_gather.html" title="Function all_gather">all_gather</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node73.html#Node73" target="_top"><code class="computeroutput"><span class="identifier">MPI_Allgatherv</span></code></a> + </p> + </td> +<td> + <p> + most uses supported by <code class="computeroutput"><a class="link" href="../boost/mpi/all_gather.html" title="Function all_gather">all_gather</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node82.html#Node82" target="_top"><code class="computeroutput"><span class="identifier">MPI_Allreduce</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/all_reduce.html" title="Function all_reduce">all_reduce</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node75.html#Node75" target="_top"><code class="computeroutput"><span class="identifier">MPI_Alltoall</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/all_to_all.html" title="Function all_to_all">all_to_all</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node75.html#Node75" target="_top"><code class="computeroutput"><span class="identifier">MPI_Alltoallv</span></code></a> + </p> + </td> +<td> + <p> + most uses supported by <code class="computeroutput"><a class="link" href="../boost/mpi/all_to_all.html" title="Function all_to_all">all_to_all</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node66.html#Node66" target="_top"><code class="computeroutput"><span class="identifier">MPI_Barrier</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html#id763388-bb">communicator::barrier</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node67.html#Node67" target="_top"><code class="computeroutput"><span class="identifier">MPI_Bcast</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/broadcast.html" title="Function broadcast">broadcast</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node69.html#Node69" target="_top"><code class="computeroutput"><span class="identifier">MPI_Gather</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/gather.html" title="Function gather">gather</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node69.html#Node69" target="_top"><code class="computeroutput"><span class="identifier">MPI_Gatherv</span></code></a> + </p> + </td> +<td> + <p> + most uses supported by <code class="computeroutput"><a class="link" href="../boost/mpi/gather.html" title="Function gather">gather</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node77.html#Node77" target="_top"><code class="computeroutput"><span class="identifier">MPI_Reduce</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/reduce.html" title="Function reduce">reduce</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node83.html#Node83" target="_top"><code class="computeroutput"><span class="identifier">MPI_Reduce_scatter</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node84.html#Node84" target="_top"><code class="computeroutput"><span class="identifier">MPI_Scan</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/scan.html" title="Function scan">scan</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node71.html#Node71" target="_top"><code class="computeroutput"><span class="identifier">MPI_Scatter</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/scatter.html" title="Function scatter">scatter</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node71.html#Node71" target="_top"><code class="computeroutput"><span class="identifier">MPI_Scatterv</span></code></a> + </p> + </td> +<td> + <p> + most uses supported by <code class="computeroutput"><a class="link" href="../boost/mpi/scatter.html" title="Function scatter">scatter</a></code> + </p> + </td> +</tr> +</tbody> +</table></div> +</div> +<br class="table-break"><p> + Boost.MPI uses function objects to specify how reductions should occur in + its equivalents to <code class="computeroutput"><span class="identifier">MPI_Allreduce</span></code>, + <code class="computeroutput"><span class="identifier">MPI_Reduce</span></code>, and <code class="computeroutput"><span class="identifier">MPI_Scan</span></code>. The following table illustrates + how <a href="http://www.mpi-forum.org/docs/mpi-11-html/node78.html#Node78" target="_top">predefined</a> + and <a href="http://www.mpi-forum.org/docs/mpi-11-html/node80.html#Node80" target="_top">user-defined</a> + reduction operations can be mapped between the C MPI and Boost.MPI. + </p> +<div class="table"> +<a name="mpi.tutorial.c_mapping.t5"></a><p class="title"><b>Table 17.6. Reduction operations</b></p> +<div class="table-contents"><table class="table" summary="Reduction operations"> +<colgroup> +<col> +<col> +</colgroup> +<thead><tr> +<th> + <p> + C Constant + </p> + </th> +<th> + <p> + Boost.MPI Equivalent + </p> + </th> +</tr></thead> +<tbody> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_BAND</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/bitwise_and.html" title="Struct template bitwise_and">bitwise_and</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_BOR</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/bitwise_or.html" title="Struct template bitwise_or">bitwise_or</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_BXOR</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/bitwise_xor.html" title="Struct template bitwise_xor">bitwise_xor</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_LAND</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">logical_and</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_LOR</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">logical_or</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_LXOR</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/logical_xor.html" title="Struct template logical_xor">logical_xor</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_MAX</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/maximum.html" title="Struct template maximum">maximum</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_MAXLOC</span></code> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_MIN</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/minimum.html" title="Struct template minimum">minimum</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_MINLOC</span></code> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_Op_create</span></code> + </p> + </td> +<td> + <p> + used internally by Boost.MPI + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_Op_free</span></code> + </p> + </td> +<td> + <p> + used internally by Boost.MPI + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_PROD</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">multiplies</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_SUM</span></code> + </p> + </td> +<td> + <p> + <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">plus</span></code> + </p> + </td> +</tr> +</tbody> +</table></div> +</div> +<br class="table-break"><p> + MPI defines several special communicators, including <code class="computeroutput"><span class="identifier">MPI_COMM_WORLD</span></code> + (including all processes that the local process can communicate with), <code class="computeroutput"><span class="identifier">MPI_COMM_SELF</span></code> (including only the local + process), and <code class="computeroutput"><span class="identifier">MPI_COMM_EMPTY</span></code> + (including no processes). These special communicators are all instances of + the <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a></code> + class in Boost.MPI. + </p> +<div class="table"> +<a name="mpi.tutorial.c_mapping.t6"></a><p class="title"><b>Table 17.7. Predefined communicators</b></p> +<div class="table-contents"><table class="table" summary="Predefined communicators"> +<colgroup> +<col> +<col> +</colgroup> +<thead><tr> +<th> + <p> + C Constant + </p> + </th> +<th> + <p> + Boost.MPI Equivalent + </p> + </th> +</tr></thead> +<tbody> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_COMM_WORLD</span></code> + </p> + </td> +<td> + <p> + a default-constructed <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_COMM_SELF</span></code> + </p> + </td> +<td> + <p> + a <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a></code> + that contains only the current process + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_COMM_EMPTY</span></code> + </p> + </td> +<td> + <p> + a <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a></code> + that evaluates false + </p> + </td> +</tr> +</tbody> +</table></div> +</div> +<br class="table-break"><p> + Boost.MPI supports groups of processes through its <code class="computeroutput"><a class="link" href="../boost/mpi/group.html" title="Class group">group</a></code> class. + </p> +<div class="table"> +<a name="mpi.tutorial.c_mapping.t7"></a><p class="title"><b>Table 17.8. Group operations and constants</b></p> +<div class="table-contents"><table class="table" summary="Group operations and constants"> +<colgroup> +<col> +<col> +</colgroup> +<thead><tr> +<th> + <p> + C Function/Constant + </p> + </th> +<th> + <p> + Boost.MPI Equivalent + </p> + </th> +</tr></thead> +<tbody> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_GROUP_EMPTY</span></code> + </p> + </td> +<td> + <p> + a default-constructed <code class="computeroutput"><a class="link" href="../boost/mpi/group.html" title="Class group">group</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node97.html#Node97" target="_top"><code class="computeroutput"><span class="identifier">MPI_Group_size</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/group.html#id772431-bb">group::size</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node97.html#Node97" target="_top"><code class="computeroutput"><span class="identifier">MPI_Group_rank</span></code></a> + </p> + </td> +<td> + <p> + memberref boost::mpi::group::rank <code class="computeroutput"><span class="identifier">group</span><span class="special">::</span><span class="identifier">rank</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node97.html#Node97" target="_top"><code class="computeroutput"><span class="identifier">MPI_Group_translate_ranks</span></code></a> + </p> + </td> +<td> + <p> + memberref boost::mpi::group::translate_ranks <code class="computeroutput"><span class="identifier">group</span><span class="special">::</span><span class="identifier">translate_ranks</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node97.html#Node97" target="_top"><code class="computeroutput"><span class="identifier">MPI_Group_compare</span></code></a> + </p> + </td> +<td> + <p> + operators <code class="computeroutput"><span class="special">==</span></code> and + <code class="computeroutput"><span class="special">!=</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_IDENT</span></code> + </p> + </td> +<td> + <p> + operators <code class="computeroutput"><span class="special">==</span></code> and + <code class="computeroutput"><span class="special">!=</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_SIMILAR</span></code> + </p> + </td> +<td> + <p> + operators <code class="computeroutput"><span class="special">==</span></code> and + <code class="computeroutput"><span class="special">!=</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_UNEQUAL</span></code> + </p> + </td> +<td> + <p> + operators <code class="computeroutput"><span class="special">==</span></code> and + <code class="computeroutput"><span class="special">!=</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node98.html#Node98" target="_top"><code class="computeroutput"><span class="identifier">MPI_Comm_group</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html#id767691-bb">communicator::group</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node98.html#Node98" target="_top"><code class="computeroutput"><span class="identifier">MPI_Group_union</span></code></a> + </p> + </td> +<td> + <p> + operator <code class="computeroutput"><span class="special">|</span></code> for groups + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node98.html#Node98" target="_top"><code class="computeroutput"><span class="identifier">MPI_Group_intersection</span></code></a> + </p> + </td> +<td> + <p> + operator <code class="computeroutput"><span class="special">&</span></code> for + groups + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node98.html#Node98" target="_top"><code class="computeroutput"><span class="identifier">MPI_Group_difference</span></code></a> + </p> + </td> +<td> + <p> + operator <code class="computeroutput"><span class="special">-</span></code> for groups + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node98.html#Node98" target="_top"><code class="computeroutput"><span class="identifier">MPI_Group_incl</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/group.html#id772499-bb">group::include</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node98.html#Node98" target="_top"><code class="computeroutput"><span class="identifier">MPI_Group_excl</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/group.html#id772499-bb">group::exclude</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node98.html#Node98" target="_top"><code class="computeroutput"><span class="identifier">MPI_Group_range_incl</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node98.html#Node98" target="_top"><code class="computeroutput"><span class="identifier">MPI_Group_range_excl</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node99.html#Node99" target="_top"><code class="computeroutput"><span class="identifier">MPI_Group_free</span></code></a> + </p> + </td> +<td> + <p> + used automatically in Boost.MPI + </p> + </td> +</tr> +</tbody> +</table></div> +</div> +<br class="table-break"><p> + Boost.MPI provides manipulation of communicators through the <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a></code> class. + </p> +<div class="table"> +<a name="mpi.tutorial.c_mapping.t8"></a><p class="title"><b>Table 17.9. Communicator operations</b></p> +<div class="table-contents"><table class="table" summary="Communicator operations"> +<colgroup> +<col> +<col> +</colgroup> +<thead><tr> +<th> + <p> + C Function + </p> + </th> +<th> + <p> + Boost.MPI Equivalent + </p> + </th> +</tr></thead> +<tbody> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node101.html#Node101" target="_top"><code class="computeroutput"><span class="identifier">MPI_Comm_size</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html#id767666-bb">communicator::size</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node101.html#Node101" target="_top"><code class="computeroutput"><span class="identifier">MPI_Comm_rank</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html#id767640-bb">communicator::rank</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node101.html#Node101" target="_top"><code class="computeroutput"><span class="identifier">MPI_Comm_compare</span></code></a> + </p> + </td> +<td> + <p> + operators <code class="computeroutput"><span class="special">==</span></code> and + <code class="computeroutput"><span class="special">!=</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node102.html#Node102" target="_top"><code class="computeroutput"><span class="identifier">MPI_Comm_dup</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a></code> + class constructor using <code class="computeroutput"><span class="identifier">comm_duplicate</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node102.html#Node102" target="_top"><code class="computeroutput"><span class="identifier">MPI_Comm_create</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html" title="Class communicator">communicator</a></code> + constructor + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node102.html#Node102" target="_top"><code class="computeroutput"><span class="identifier">MPI_Comm_split</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html#id762930-bb">communicator::split</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node103.html#Node103" target="_top"><code class="computeroutput"><span class="identifier">MPI_Comm_free</span></code></a> + </p> + </td> +<td> + <p> + used automatically in Boost.MPI + </p> + </td> +</tr> +</tbody> +</table></div> +</div> +<br class="table-break"><p> + Boost.MPI currently provides support for inter-communicators via the <code class="computeroutput"><a class="link" href="../boost/mpi/intercommunicator.html" title="Class intercommunicator">intercommunicator</a></code> + class. + </p> +<div class="table"> +<a name="mpi.tutorial.c_mapping.t9"></a><p class="title"><b>Table 17.10. Inter-communicator operations</b></p> +<div class="table-contents"><table class="table" summary="Inter-communicator operations"> +<colgroup> +<col> +<col> +</colgroup> +<thead><tr> +<th> + <p> + C Function + </p> + </th> +<th> + <p> + Boost.MPI Equivalent + </p> + </th> +</tr></thead> +<tbody> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node112.html#Node112" target="_top"><code class="computeroutput"><span class="identifier">MPI_Comm_test_inter</span></code></a> + </p> + </td> +<td> + <p> + use <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html#id768127-bb">communicator::as_intercommunicator</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node112.html#Node112" target="_top"><code class="computeroutput"><span class="identifier">MPI_Comm_remote_size</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/intercommunicator.html#id771022-bb">boost::mpi::intercommunicator::remote_size</a></code> + <code class="computeroutput"><span class="identifier">intercommunicator</span><span class="special">::</span><span class="identifier">remote_size</span></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node112.html#Node112" target="_top"><code class="computeroutput"><span class="identifier">MPI_Comm_remote_group</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/intercommunicator.html#id771034-bb">intercommunicator::remote_group</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node113.html#Node113" target="_top"><code class="computeroutput"><span class="identifier">MPI_Intercomm_create</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/intercommunicator.html" title="Class intercommunicator">intercommunicator</a></code> + constructor + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node113.html#Node113" target="_top"><code class="computeroutput"><span class="identifier">MPI_Intercomm_merge</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/intercommunicator.html#id771048-bb">intercommunicator::merge</a></code> + </p> + </td> +</tr> +</tbody> +</table></div> +</div> +<br class="table-break"><p> + Boost.MPI currently provides no support for attribute caching. + </p> +<div class="table"> +<a name="mpi.tutorial.c_mapping.t10"></a><p class="title"><b>Table 17.11. Attributes and caching</b></p> +<div class="table-contents"><table class="table" summary="Attributes and caching"> +<colgroup> +<col> +<col> +</colgroup> +<thead><tr> +<th> + <p> + C Function/Constant + </p> + </th> +<th> + <p> + Boost.MPI Equivalent + </p> + </th> +</tr></thead> +<tbody> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_NULL_COPY_FN</span></code> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_NULL_DELETE_FN</span></code> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_KEYVAL_INVALID</span></code> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node119.html#Node119" target="_top"><code class="computeroutput"><span class="identifier">MPI_Keyval_create</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node119.html#Node119" target="_top"><code class="computeroutput"><span class="identifier">MPI_Copy_function</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node119.html#Node119" target="_top"><code class="computeroutput"><span class="identifier">MPI_Delete_function</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node119.html#Node119" target="_top"><code class="computeroutput"><span class="identifier">MPI_Keyval_free</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node119.html#Node119" target="_top"><code class="computeroutput"><span class="identifier">MPI_Attr_put</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node119.html#Node119" target="_top"><code class="computeroutput"><span class="identifier">MPI_Attr_get</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node119.html#Node119" target="_top"><code class="computeroutput"><span class="identifier">MPI_Attr_delete</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +</tbody> +</table></div> +</div> +<br class="table-break"><p> + Boost.MPI will provide complete support for creating communicators with different + topologies and later querying those topologies. Support for graph topologies + is provided via an interface to the <a href="http://www.boost.org/libs/graph/doc/index.html" target="_top">Boost + Graph Library (BGL)</a>, where a communicator can be created which matches + the structure of any BGL graph, and the graph topology of a communicator + can be viewed as a BGL graph for use in existing, generic graph algorithms. + </p> +<div class="table"> +<a name="mpi.tutorial.c_mapping.t11"></a><p class="title"><b>Table 17.12. Process topologies</b></p> +<div class="table-contents"><table class="table" summary="Process topologies"> +<colgroup> +<col> +<col> +</colgroup> +<thead><tr> +<th> + <p> + C Function/Constant + </p> + </th> +<th> + <p> + Boost.MPI Equivalent + </p> + </th> +</tr></thead> +<tbody> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_GRAPH</span></code> + </p> + </td> +<td> + <p> + unnecessary; use <code class="computeroutput">communicator::has_graph_topology</code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_CART</span></code> + </p> + </td> +<td> + <p> + unnecessary; use <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html#id768201-bb">communicator::has_cartesian_topology</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node133.html#Node133" target="_top"><code class="computeroutput"><span class="identifier">MPI_Cart_create</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node134.html#Node134" target="_top"><code class="computeroutput"><span class="identifier">MPI_Dims_create</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node135.html#Node135" target="_top"><code class="computeroutput"><span class="identifier">MPI_Graph_create</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput">communicator::with_graph_topology</code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node136.html#Node136" target="_top"><code class="computeroutput"><span class="identifier">MPI_Topo_test</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput">communicator::has_graph_topology</code>, + <code class="computeroutput"><a class="link" href="../boost/mpi/communicator.html#id768201-bb">communicator::has_cartesian_topology</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node136.html#Node136" target="_top"><code class="computeroutput"><span class="identifier">MPI_Graphdims_get</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="reference.html#boost.mpi.num_vertices">num_vertices</a></code>, + <code class="computeroutput"><a class="link" href="reference.html#boost.mpi.num_edges">num_edges</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node136.html#Node136" target="_top"><code class="computeroutput"><span class="identifier">MPI_Graph_get</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="reference.html#boost.mpi.vertices">vertices</a></code>, + <code class="computeroutput"><a class="link" href="reference.html#boost.mpi.edges">edges</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node136.html#Node136" target="_top"><code class="computeroutput"><span class="identifier">MPI_Cartdim_get</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node136.html#Node136" target="_top"><code class="computeroutput"><span class="identifier">MPI_Cart_get</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node136.html#Node136" target="_top"><code class="computeroutput"><span class="identifier">MPI_Cart_rank</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node136.html#Node136" target="_top"><code class="computeroutput"><span class="identifier">MPI_Cart_coords</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node136.html#Node136" target="_top"><code class="computeroutput"><span class="identifier">MPI_Graph_neighbors_count</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="reference.html#boost.mpi.out_degree">out_degree</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node136.html#Node136" target="_top"><code class="computeroutput"><span class="identifier">MPI_Graph_neighbors</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="reference.html#boost.mpi.out_edges">out_edges</a></code>, + <code class="computeroutput"><a class="link" href="reference.html#boost.mpi.adjacent_vertices">adjacent_vertices</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node137.html#Node137" target="_top"><code class="computeroutput"><span class="identifier">MPI_Cart_shift</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node138.html#Node138" target="_top"><code class="computeroutput"><span class="identifier">MPI_Cart_sub</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node139.html#Node139" target="_top"><code class="computeroutput"><span class="identifier">MPI_Cart_map</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node139.html#Node139" target="_top"><code class="computeroutput"><span class="identifier">MPI_Graph_map</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +</tbody> +</table></div> +</div> +<br class="table-break"><p> + Boost.MPI supports environmental inquires through the <code class="computeroutput"><a class="link" href="../boost/mpi/environment.html" title="Class environment">environment</a></code> class. + </p> +<div class="table"> +<a name="mpi.tutorial.c_mapping.t12"></a><p class="title"><b>Table 17.13. Environmental inquiries</b></p> +<div class="table-contents"><table class="table" summary="Environmental inquiries"> +<colgroup> +<col> +<col> +</colgroup> +<thead><tr> +<th> + <p> + C Function/Constant + </p> + </th> +<th> + <p> + Boost.MPI Equivalent + </p> + </th> +</tr></thead> +<tbody> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_TAG_UB</span></code> + </p> + </td> +<td> + <p> + unnecessary; use <code class="computeroutput"><a class="link" href="../boost/mpi/environment.html#id770803-bb">environment::max_tag</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_HOST</span></code> + </p> + </td> +<td> + <p> + unnecessary; use <code class="computeroutput"><a class="link" href="../boost/mpi/environment.html#id769921-bb">environment::host_rank</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_IO</span></code> + </p> + </td> +<td> + <p> + unnecessary; use <code class="computeroutput"><a class="link" href="../boost/mpi/environment.html#id769957-bb">environment::io_rank</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node143.html#Node147" target="_top"><code class="computeroutput"><span class="identifier">MPI_Get_processor_name</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/environment.html#id770002-bb">environment::processor_name</a></code> + </p> + </td> +</tr> +</tbody> +</table></div> +</div> +<br class="table-break"><p> + Boost.MPI translates MPI errors into exceptions, reported via the <code class="computeroutput"><a class="link" href="../boost/mpi/exception.html" title="Class exception">exception</a></code> + class. + </p> +<div class="table"> +<a name="mpi.tutorial.c_mapping.t13"></a><p class="title"><b>Table 17.14. Error handling</b></p> +<div class="table-contents"><table class="table" summary="Error handling"> +<colgroup> +<col> +<col> +</colgroup> +<thead><tr> +<th> + <p> + C Function/Constant + </p> + </th> +<th> + <p> + Boost.MPI Equivalent + </p> + </th> +</tr></thead> +<tbody> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_ERRORS_ARE_FATAL</span></code> + </p> + </td> +<td> + <p> + unused; errors are translated into Boost.MPI exceptions + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_ERRORS_RETURN</span></code> + </p> + </td> +<td> + <p> + unused; errors are translated into Boost.MPI exceptions + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node148.html#Node148" target="_top"><code class="computeroutput"><span class="identifier">MPI_errhandler_create</span></code></a> + </p> + </td> +<td> + <p> + unused; errors are translated into Boost.MPI exceptions + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node148.html#Node148" target="_top"><code class="computeroutput"><span class="identifier">MPI_errhandler_set</span></code></a> + </p> + </td> +<td> + <p> + unused; errors are translated into Boost.MPI exceptions + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node148.html#Node148" target="_top"><code class="computeroutput"><span class="identifier">MPI_errhandler_get</span></code></a> + </p> + </td> +<td> + <p> + unused; errors are translated into Boost.MPI exceptions + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node148.html#Node148" target="_top"><code class="computeroutput"><span class="identifier">MPI_errhandler_free</span></code></a> + </p> + </td> +<td> + <p> + unused; errors are translated into Boost.MPI exceptions + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node148.html#Node148" target="_top"><code class="computeroutput"><span class="identifier">MPI_Error_string</span></code></a> + </p> + </td> +<td> + <p> + used internally by Boost.MPI + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node149.html#Node149" target="_top"><code class="computeroutput"><span class="identifier">MPI_Error_class</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/exception.html#id770097-bb">exception::error_class</a></code> + </p> + </td> +</tr> +</tbody> +</table></div> +</div> +<br class="table-break"><p> + The MPI timing facilities are exposed via the Boost.MPI <code class="computeroutput"><a class="link" href="../boost/mpi/timer.html" title="Class timer">timer</a></code> class, which provides + an interface compatible with the <a href="http://www.boost.org/libs/timer/index.html" target="_top">Boost + Timer library</a>. + </p> +<div class="table"> +<a name="mpi.tutorial.c_mapping.t14"></a><p class="title"><b>Table 17.15. Timing facilities</b></p> +<div class="table-contents"><table class="table" summary="Timing facilities"> +<colgroup> +<col> +<col> +</colgroup> +<thead><tr> +<th> + <p> + C Function/Constant + </p> + </th> +<th> + <p> + Boost.MPI Equivalent + </p> + </th> +</tr></thead> +<tbody> +<tr> +<td> + <p> + <code class="computeroutput"><span class="identifier">MPI_WTIME_IS_GLOBAL</span></code> + </p> + </td> +<td> + <p> + unnecessary; use <code class="computeroutput"><a class="link" href="../boost/mpi/timer.html#id775983-bb">timer::time_is_global</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node150.html#Node150" target="_top"><code class="computeroutput"><span class="identifier">MPI_Wtime</span></code></a> + </p> + </td> +<td> + <p> + use <code class="computeroutput"><a class="link" href="../boost/mpi/timer.html#id775924-bb">timer::elapsed</a></code> to determine + the time elapsed from some specific starting point + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node150.html#Node150" target="_top"><code class="computeroutput"><span class="identifier">MPI_Wtick</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/timer.html#id775950-bb">timer::elapsed_min</a></code> + </p> + </td> +</tr> +</tbody> +</table></div> +</div> +<br class="table-break"><p> + MPI startup and shutdown are managed by the construction and descruction + of the Boost.MPI <code class="computeroutput"><a class="link" href="../boost/mpi/environment.html" title="Class environment">environment</a></code> + class. + </p> +<div class="table"> +<a name="mpi.tutorial.c_mapping.t15"></a><p class="title"><b>Table 17.16. Startup/shutdown facilities</b></p> +<div class="table-contents"><table class="table" summary="Startup/shutdown facilities"> +<colgroup> +<col> +<col> +</colgroup> +<thead><tr> +<th> + <p> + C Function + </p> + </th> +<th> + <p> + Boost.MPI Equivalent + </p> + </th> +</tr></thead> +<tbody> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node151.html#Node151" target="_top"><code class="computeroutput"><span class="identifier">MPI_Init</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/environment.html" title="Class environment">environment</a></code> + constructor + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node151.html#Node151" target="_top"><code class="computeroutput"><span class="identifier">MPI_Finalize</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/environment.html" title="Class environment">environment</a></code> + destructor + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node151.html#Node151" target="_top"><code class="computeroutput"><span class="identifier">MPI_Initialized</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/environment.html#id770748-bb">environment::initialized</a></code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node151.html#Node151" target="_top"><code class="computeroutput"><span class="identifier">MPI_Abort</span></code></a> + </p> + </td> +<td> + <p> + <code class="computeroutput"><a class="link" href="../boost/mpi/environment.html#id770709-bb">environment::abort</a></code> + </p> + </td> +</tr> +</tbody> +</table></div> +</div> +<br class="table-break"><p> + Boost.MPI does not provide any support for the profiling facilities in MPI + 1.1. + </p> +<div class="table"> +<a name="mpi.tutorial.c_mapping.t16"></a><p class="title"><b>Table 17.17. Profiling interface</b></p> +<div class="table-contents"><table class="table" summary="Profiling interface"> +<colgroup> +<col> +<col> +</colgroup> +<thead><tr> +<th> + <p> + C Function + </p> + </th> +<th> + <p> + Boost.MPI Equivalent + </p> + </th> +</tr></thead> +<tbody> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node153.html#Node153" target="_top"><code class="computeroutput"><span class="identifier">PMPI_</span><span class="special">*</span></code> + routines</a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +<tr> +<td> + <p> + <a href="http://www.mpi-forum.org/docs/mpi-11-html/node156.html#Node156" target="_top"><code class="computeroutput"><span class="identifier">MPI_Pcontrol</span></code></a> + </p> + </td> +<td> + <p> + unsupported + </p> + </td> +</tr> +</tbody> +</table></div> +</div> +<br class="table-break"> +</div> +</div> +<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> +<td align="left"></td> +<td align="right"><div class="copyright-footer">Copyright © 2005-2007 Douglas Gregor, + Matthias Troyer, Trustees of Indiana University<p> + Distributed under the Boost Software License, Version 1.0. (See accompanying + file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top"> + http://www.boost.org/LICENSE_1_0.txt </a>) + </p> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="getting_started.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../mpi.html"><img src="../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="reference.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> |