path: root/src/ToolBox/SOS/Strike/sosdocsunix.txt

-------------------------------------------------------------------------------
NOTE: THIS FILE CONTAINS SOS DOCUMENTATION. THE FORMAT OF THE FILE IS:

<optional comments>
COMMAND: <cmd name, all lower case>
<descriptive text of the command>
\\ <these are two backslashes, immediately followed by a newline>

<repeat the sequence above>

The first command is "contents" which is the general help screen. The rest 
correspond to SOS command names. This file is embedded as a resource in the SOS 
binary. Be sure to list any new commands here.
-------------------------------------------------------------------------------



COMMAND: contents.
SOS is a debugger extension DLL designed to aid in the debugging of managed
programs. Functions are listed by category, then roughly in order of
importance. Shortcut names for popular functions are listed in parenthesis.
Type "soshelp <functionname>" for detailed info on that function. 

Object Inspection                  Examining code and stacks
-----------------------------      -----------------------------
DumpObj (dumpobj)                  Threads (clrthreads)
DumpArray                          ThreadState
DumpStackObjects (dso)             IP2MD (ip2md)
DumpHeap (dumpheap)                u (clru)
DumpVC                             DumpStack (dumpstack)
GCRoot (gcroot)                    EEStack (eestack)
PrintException (pe)                ClrStack (clrstack) 
                                   GCInfo
                                   EHInfo
                                   bpmd (bpmd)

Examining CLR data structures      Diagnostic Utilities
-----------------------------      -----------------------------
DumpDomain                         VerifyHeap
EEHeap (eeheap)                    FindAppDomain          
Name2EE (name2ee)                  DumpLog (dumplog)
DumpMT (dumpmt)
DumpClass (dumpclass)
DumpMD (dumpmd)                    
Token2EE                           
DumpModule (dumpmodule)
DumpAssembly
DumpRuntimeTypes
DumpIL (dumpil)
DumpSig
DumpSigElem

Examining the GC history           Other
-----------------------------      -----------------------------
HistInit (histinit)                FAQ
HistRoot (histroot)                CreateDump (createdump)
HistObj  (histobj)                 Help (soshelp)
HistObjFind (histobjfind)
HistClear (histclear)
\\

COMMAND: faq.
>> Where can I get the right version of SOS for my build?

If you are running a xplat version of coreclr, the sos module (exact name
is platform dependent) is installed in the same directory as the main coreclr
module. There is also an lldb sos plugin command that allows the path where
the sos, dac and dbi modules are loaded:

    "setsospath /home/user/coreclr/bin/Product/Linux.x64.Debug""

If you are using a dump file created on another machine, it is a little bit
more complex. You need to make sure the dac module that came with that install
is in the directory set with the above command.

>> I have a chicken and egg problem. I want to use SOS commands, but the CLR
   isn't loaded yet. What can I do?

TBD

>> I got the following error message. Now what?

	
	(lldb) sos DumpStackObjects
	The coreclr module is not loaded yet in the target process
	(lldb) 

This means that the clr is not loaded yet, or has been unloaded. You need to 
wait until your managed program is running in order to use these commands. If 
you have just started the program a good way to do this is to type 

    breakpoint set coreclr`EEStartup

in the debugger, and let it run. After the function EEStartup is finished, 
there will be a minimal managed environment for executing SOS commands.

\\

COMMAND: dumpobj.
DumpObj [-nofields] <object address>

This command allows you to examine the fields of an object, as well as learn 
important properties of the object such as the EEClass, the MethodTable, and 
the size.

You might find an object pointer by running DumpStackObjects and choosing
from the resultant list. Here is a simple object:

	(lldb) dumpobj a79d40
	Name: Customer
	MethodTable: 009038ec
	EEClass: 03ee1b84
	Size: 20(0x14) bytes
	 (/home/user/pub/unittest)
	Fields:
	      MT    Field   Offset                 Type  VT     Attr    Value Name
	009038ec  4000008        4             Customer   0 instance 00a79ce4 name
	009038ec  4000009        8                 Bank   0 instance 00a79d2c bank

Note that fields of type Customer and Bank are themselves objects, and you can 
run DumpObj on them too. You could look at the field directly in memory using
the offset given. "dd a79d40+8 l1" would allow you to look at the bank field 
directly. Be careful about using this to set memory breakpoints, since objects
can move around in the garbage collected heap.

What else can you do with an object? You might run GCRoot, to determine what 
roots are keeping it alive. Or you can find all objects of that type with 
"dumpheap -type Customer".

The column VT contains the value 1 if the field is a valuetype structure, and
0 if the field contains a pointer to another object. For valuetypes, you can 
take the MethodTable pointer in the MT column, and the Value and pass them to 
the command DumpVC.

The arguments in detail:
-nofields:     do not print fields of the object, useful for objects like String
\\

COMMAND: dumparray.
DumpArray 
	[-start <startIndex>]
	[-length <length>]
	[-details]
	[-nofields]
	<array object address>

This command allows you to examine elements of an array object.
The arguments in detail:
 -start <startIndex>: optional, only supported for single dimension array. 
                      Specify from which index the command shows the elements.
 -length <length>:    optional, only supported for single dimension array. 
                      Specify how many elements to show.
 -details:            optional. Ask the command to print out details
                      of the element using DumpObj and DumpVC format.
 -nofields:           optional, only takes effect when -details is used. Do
                      not print fields of the elements. Useful for arrays of
                      objects like String

 Example output:

	(lldb) sos DumpArray -start 2 -length 3 -details 00ad28d0 
	Name: Value[]
	MethodTable: 03e41044
	EEClass: 03e40fc0
	Size: 132(0x84) bytes
	Array: Rank 1, Number of elements 10, Type VALUETYPE
	Element Type: Value
	[2] 00ad28f0
	    Name: Value
	    MethodTable 03e40f4c
	    EEClass: 03ef1698
	    Size: 20(0x14) bytes
	     (/home/user/bugs/225271/arraytest)
	    Fields:
	          MT    Field   Offset                 Type       Attr    Value Name
	    5b9a628c  4000001        0         System.Int32   instance        2 x
	    5b9a628c  4000002        4         System.Int32   instance        4 y
	    5b9a628c  4000003        8         System.Int32   instance        6 z
	[3] 00ad28fc
	    Name: Value
	    MethodTable 03e40f4c
	    EEClass: 03ef1698
	    Size: 20(0x14) bytes
	     (/home/user/bugs/225271/arraytest)
	    Fields:
	          MT    Field   Offset                 Type       Attr    Value Name
	    5b9a628c  4000001        0         System.Int32   instance        3 x
	    5b9a628c  4000002        4         System.Int32   instance        6 y
	    5b9a628c  4000003        8         System.Int32   instance        9 z
	[4] 00ad2908
	    Name: Value
	    MethodTable 03e40f4c
	    EEClass: 03ef1698
	    Size: 20(0x14) bytes
	     (/home/user/bugs/225271/arraytest.exe)
	    Fields:
	          MT    Field   Offset                 Type       Attr    Value Name
	    5b9a628c  4000001        0         System.Int32   instance        4 x
	    5b9a628c  4000002        4         System.Int32   instance        8 y
	    5b9a628c  4000003        8         System.Int32   instance       12 z


\\

COMMAND: dumpstackobjects.
DumpStackObjects [-verify] [top stack [bottom stack]]

This command will display any managed objects it finds within the bounds of 
the current stack. Combined with the stack tracing commands like K and 
CLRStack, it is a good aid to determining the values of locals and 
parameters.

If you use the -verify option, each non-static CLASS field of an object
candidate is validated. This helps to eliminate false positives. It is not
on by default because very often in a debugging scenario, you are 
interested in objects with invalid fields.

The abbreviation dso can be used for brevity.
\\

COMMAND: dumpheap.
DumpHeap [-stat] 
         [-strings] 
         [-short]
         [-min <size>] 
         [-max <size>] 
         [-live]
         [-dead]
         [-thinlock] 
         [-startAtLowerBound]
         [-mt <MethodTable address>] 
         [-type <partial type name>] 
         [start [end]]

DumpHeap is a powerful command that traverses the garbage collected heap, 
collection statistics about objects. With it's various options, it can look for
particular types, restrict to a range, or look for ThinLocks (see SyncBlk 
documentation). Finally, it will provide a warning if it detects excessive 
fragmentation in the GC heap. 

When called without options, the output is first a list of objects in the heap,
followed by a report listing all the types found, their size and number:

	(lldb) dumpheap
	 Address       MT     Size
	00a71000 0015cde8       12 Free
	00a7100c 0015cde8       12 Free
	00a71018 0015cde8       12 Free
	00a71024 5ba58328       68
	00a71068 5ba58380       68
	00a710ac 5ba58430       68
	00a710f0 5ba5dba4       68
	...
	total 619 objects
	Statistics:
	      MT    Count TotalSize Class Name
	5ba7607c        1        12 System.Security.Permissions.HostProtectionResource
	5ba75d54        1        12 System.Security.Permissions.SecurityPermissionFlag
	5ba61f18        1        12 System.Collections.CaseInsensitiveComparer
	...
	0015cde8        6     10260      Free
	5ba57bf8      318     18136 System.String
	...

"Free" objects are simply regions of space the garbage collector can use later.
If 30% or more of the heap contains "Free" objects, the process may suffer from
heap fragmentation. This is usually caused by pinning objects for a long time 
combined with a high rate of allocation. Here is example output where DumpHeap
provides a warning about fragmentation:

	<After the Statistics section>
	Fragmented blocks larger than 1MB:
	    Addr     Size Followed by
	00a780c0    1.5MB    00bec800 System.Byte[]
	00da4e38    1.2MB    00ed2c00 System.Byte[]
	00f16df0    1.2MB    01044338 System.Byte[]

The arguments in detail:

-stat     Restrict the output to the statistical type summary
-strings  Restrict the output to a statistical string value summary
-short    Limits output to just the address of each object. This allows you
          to easily pipe output from the command to another debugger 
          command for automation.
-min      Ignore objects less than the size given in bytes
-max      Ignore objects larger than the size given in bytes
-live     Only print live objects
-dead     Only print dead objects (objects which will be collected in the
          next full GC)
-thinlock Report on any ThinLocks (an efficient locking scheme, see SyncBlk 
          documentation for more info)
-startAtLowerBound 
          Force heap walk to begin at lower bound of a supplied address range.
          (During plan phase, the heap is often not walkable because objects 
          are being moved. In this case, DumpHeap may report spurious errors, 
          in particular bad objects. It may be possible to traverse more of 
          the heap after the reported bad object. Even if you specify an 
          address range, DumpHeap will start its walk from the beginning of 
          the heap by default. If it finds a bad object before the specified 
          range, it will stop before displaying the part of the heap in which 
          you are interested. This switch will force DumpHeap to begin its 
          walk at the specified lower bound. You must supply the address of a 
          good object as the lower bound for this to work. Display memory at 
          the address of the bad object to manually find the next method 
          table (use DumpMT to verify). If the GC is currently in a call to 
          memcopy, You may also be able to find the next object's address by 
          adding the size to the start address given as parameters.) 
-mt       List only those objects with the MethodTable given
-type     List only those objects whose type name is a substring match of the 
          string provided. 
start     Begin listing from this address
end       Stop listing at this address

A special note about -type: Often, you'd like to find not only Strings, but
System.Object arrays that are constrained to contain Strings. ("new 
String[100]" actually creates a System.Object array, but it can only hold
System.String object pointers). You can use -type in a special way to find
these arrays. Just pass "-type System.String[]" and those Object arrays will
be returned. More generally, "-type <Substring of interesting type>[]".

The start/end parameters can be obtained from the output of eeheap -gc. For 
example, if you only want to list objects in the large heap segment:

	(lldb) eeheap -gc
	Number of GC Heaps: 1
	generation 0 starts at 0x00c32754
	generation 1 starts at 0x00c32748
	generation 2 starts at 0x00a71000
	 segment    begin allocated     size
	00a70000 00a71000  010443a8 005d33a8(6108072)
	Large object heap starts at 0x01a71000
	 segment    begin allocated     size
	01a70000 01a71000  01a75000 0x00004000(16384)
	Total Size  0x5d73a8(6124456)
	------------------------------
	GC Heap Size  0x5d73a8(6124456)

	(lldb) dumpheap 1a71000 1a75000
	 Address       MT     Size
	01a71000 5ba88bd8     2064
	01a71810 0019fe48     2032 Free
	01a72000 5ba88bd8     4096
	01a73000 0019fe48     4096 Free
	01a74000 5ba88bd8     4096
	total 5 objects
	Statistics:
	      MT    Count TotalSize Class Name
	0019fe48        2      6128      Free
	5ba88bd8        3     10256 System.Object[]
	Total 5 objects

Finally, if GC heap corruption is present, you may see an error like this:

	(lldb) dumpheap -stat
	object 00a73d24: does not have valid MT
	curr_object : 00a73d24
	Last good object: 00a73d14
	----------------

That indicates a serious problem. See the help for VerifyHeap for more 
information on diagnosing the cause.
\\

COMMAND: dumpvc.
DumpVC <MethodTable address> <Address>

DumpVC allows you to examine the fields of a value class. In C#, this is a 
struct, and lives on the stack or within an Object on the GC heap. You need
to know the MethodTable address to tell SOS how to interpret the fields, as
a value class is not a first-class object with it's own MethodTable as the
first field. For example:

	(lldb) sos DumpObj a79d98
	Name: Mainy
	MethodTable: 009032d8
	EEClass: 03ee1424
	Size: 28(0x1c) bytes
	 (/home/user/pub/unittest)
	Fields:
	      MT    Field   Offset                 Type       Attr    Value Name
	0090320c  4000010        4            VALUETYPE   instance 00a79d9c m_valuetype
	009032d8  400000f        4                CLASS     static 00a79d54 m_sExcep

m_valuetype is a value type. The value in the MT column (0090320c) is the 
MethodTable for it, and the Value column provides the start address:

	(lldb) sos DumpVC 0090320c 00a79d9c
	Name: Funny
	MethodTable 0090320c
	EEClass: 03ee14b8
	Size: 28(0x1c) bytes
	 (/home/user/pub/unittest)
	Fields:
	      MT    Field   Offset                 Type       Attr    Value Name
	0090320c  4000001        0                CLASS   instance 00a743d8 signature
	0090320c  4000002        8         System.Int32   instance     2345 m1
	0090320c  4000003       10       System.Boolean   instance        1 b1
	0090320c  4000004        c         System.Int32   instance     1234 m2
	0090320c  4000005        4                CLASS   instance 00a79d98 backpointer

DumpVC is quite a specialized function. Some managed programs make heavy use 
of value classes, while others do not.
\\

COMMAND: gcroot.
GCRoot [-nostacks] <Object address>

GCRoot looks for references (or roots) to an object. These can exist in four
places:

   1. On the stack
   2. Within a GC Handle
   3. In an object ready for finalization
   4. As a member of an object found in 1, 2 or 3 above.

First, all stacks will be searched for roots, then handle tables, and finally
the freachable queue of the finalizer. Some caution about the stack roots: 
GCRoot doesn't attempt to determine if a stack root it encountered is valid 
or is old (discarded) data. You would have to use CLRStack and U to 
disassemble the frame that the local or argument value belongs to in order to 
determine if it is still in use.

Because people often want to restrict the search to gc handles and freachable
objects, there is a -nostacks option.
\\

COMMAND: pe.
COMMAND: printexception.
PrintException [-nested] [-lines] [-ccw] [<Exception object address>] [<CCW pointer>]

This will format fields of any object derived from System.Exception. One of the
more useful aspects is that it will format the _stackTrace field, which is a 
binary array. If _stackTraceString field is not filled in, that can be helpful 
for debugging. You can of course use DumpObj on the same exception object to 
explore more fields.

If called with no parameters, PrintException will look for the last outstanding 
exception on the current thread and print it. This will be the same exception
that shows up in a run of clrthreads.

PrintException will notify you if there are any nested exceptions on the 
current managed thread. (A nested exception occurs when you throw another
exception within a catch handler already being called for another exception).
If there are nested exceptions, you can re-run PrintException with the 
"-nested" option to get full details on the nested exception objects. The
clrthreads command will also tell you which threads have nested exceptions.

PrintException can display source information if available, by specifying the 
-lines command line argument.

PrintException prints the exception object corresponding to a given CCW pointer, 
which can be specified using the -ccw option. 

The abbreviation 'pe' can be used for brevity.
\\

COMMAND: threadstate.
ThreadState value

The clrthreads command outputs, among other things, the state of the thread.
This is a bit field which corresponds to various states the thread is in.
To check the state of the thread, simply pass that bit field from the
output of clrthreads into ThreadState.

Example:
    (lldb) clrthreads
    ThreadCount:      2
    UnstartedThread:  0
    BackgroundThread: 1
    PendingThread:    0
    DeadThread:       0
    Hosted Runtime:   no
                                          PreEmptive   GC Alloc           Lock
           ID OSID ThreadOBJ    State     GC       Context       Domain   Count APT Exception
       0    1  250 0019b068      a020 Disabled 02349668:02349fe8 0015def0     0 MTA
       2    2  944 001a6020      b220 Enabled  00000000:00000000 0015def0     0 MTA (Finalizer)
    0:003> sos ThreadState b220
        Legal to Join
        Background
        CLR Owns
        CoInitialized
        In Multi Threaded Apartment

Possible thread states:
    Thread Abort Requested
    GC Suspend Pending
    User Suspend Pending
    Debug Suspend Pending
    GC On Transitions
    Legal to Join
    Yield Requested
    Hijacked by the GC
    Blocking GC for Stack Overflow
    Background
    Unstarted
    Dead
    CLR Owns
    CoInitialized
    In Single Threaded Apartment
    In Multi Threaded Apartment
    Reported Dead
    Fully initialized
    Task Reset
    Sync Suspended
    Debug Will Sync
    Stack Crawl Needed
    Suspend Unstarted
    Aborted
    Thread Pool Worker Thread
    Interruptible
    Interrupted
    Completion Port Thread
    Abort Initiated
    Finalized
    Failed to Start
    Detached
\\
COMMAND: threads.
COMMAND: clrthreads.
Threads [-live] [-special] 

Threads (clrthreads) lists all the mananaged threads in the process. 

-live:     optional. Only print threads associated with a live thread.
-special:  optional. With this switch, the command will display all the special
           threads created by CLR. Those threads might not be managed threads 
           so they might not be shown in the first part of the command's 
           output. Example of special threads include: GC threads (in 
           concurrent GC and server GC), Debugger helper threads, Finalizer 
           threads, AppDomain Unload threads, and Threadpool timer threads.

Each thread has many attributes, many of which can be ignored. The important 
ones are discussed below:

There are three ID columns: 

1) The debugger shorthand ID (When the runtime is hosted this column might 
   display the special string "<<<<" when this internal thread object is not 
   associated with any physical thread - this may happen when the host reuses
   the runtime internal thread object)
2) The CLR Thread ID
3) The OS thread ID.  

If PreEmptiveGC is enabled for a thread, then a garbage collection 
can occur while that thread is running. For example, if you break in while
a managed thread is making a PInvoke call to a Win32 function, that thread 
will be in PreEmptive GC mode. 

The Domain column indicates what AppDomain the thread is currently executing
in. You can pass this value to DumpDomain to find out more. 

The APT column gives the COM apartment mode. 

Exception will list the last thrown exception (if any) for the thread. More
details can be obtained by passing the pointer value to PrintException. If
you get the notation "(nested exceptions)", you can get details on those
exceptions by switching to the thread in question, and running 
"PrintException -nested".
\\

COMMAND: clrstack.
CLRStack [-a] [-l] [-p] [-n] [-f]
CLRStack [-a] [-l] [-p] [-i] [variable name] [frame]

CLRStack attempts to provide a true stack trace for managed code only. It is
handy for clean, simple traces when debugging straightforward managed 
programs. The -p parameter will show arguments to the managed function. The 
-l parameter can be used to show information on local variables in a frame.
SOS can't retrieve local names at this time, so the output for locals is in
the format <local address> = <value>. The -a (all) parameter is a short-cut
for -l and -p combined. 

The -f option (full mode) displays the native frames intermixing them with
the managed frames and the assembly name and function offset for the managed
frames.

If the debugger has the option SYMOPT_LOAD_LINES specified (either by the
.lines or .symopt commands), SOS will look up the symbols for every managed 
frame and if successful will display the corresponding source file name and 
line number. The -n (No line numbers) parameter can be specified to disable 
this behavior.

When you see methods with the name "[Frame:...", that indicates a transition 
between managed and unmanaged code. You could run IP2MD on the return 
addresses in the call stack to get more information on each managed method.

On x64 platforms, Transition Frames are not displayed at this time. To avoid
heavy optimization of parameters and locals one can request the JIT compiler
to not optimize functions in the managed app by creating a file myapp.ini 
(if your program is myapp.exe) in the same directory. Put the following lines
in myapp.ini and re-run:

[.NET Framework Debugging Control]
GenerateTrackingInfo=1
AllowOptimize=0

The -i option is a new EXPERIMENTAL addition to CLRStack and will use the ICorDebug
interfaces to display the managed stack and variables. With this option you can also 
view and expand arrays and fields for managed variables. If a stack frame number is 
specified in the command line, CLRStack will show you the parameters and/or locals 
only for that frame (provided you specify -l or -p or -a of course). If a variable 
name and a stack frame number are specified in the command line, CLRStack will show 
you the parameters and/or locals for that frame, and will also show you the fields 
for that variable name you specified. Here are some examples: 
   clrstack -i -a           : This will show you all parameters and locals for all frames
   clrstack -i -a 3         : This will show you all parameters and locals, for frame 3
   clrstack -i var1 0       : This will show you the fields of 'var1' for frame 0
   clrstack -i var1.abc 2   : This will show you the fields of 'var1', and expand
                              'var1.abc' to show you the fields of the 'abc' field,
                              for frame 2.
   clrstack -i var1.[basetype] 0   : This will show you the fields of 'var1', and
                                     expand the base type of 'var1' to show you its
                                     fields.
   clrstack -i var1.[6] 0   : If 'var1' is an array, this will show you the element
                              at index 6 in the array, along with its fields
The -i options uses DML output for a better debugging experience, so typically you
should only need to execute "clrstack -i", and from there, click on the DML 
hyperlinks to inspect the different managed stack frames and managed variables.                             
\\

COMMAND: createdump.
createdump [options] [dumpFileName]
-n - create minidump.
-h - create minidump with heap (default).
-t - create triage minidump.
-d - enable diagnostic messages.

Creates a platform (ELF core on Linux, etc.) minidump. The pid can be placed in the dump 
file name with %d. The default is '/tmp/coredump.%d'.
\\

COMMAND: ip2md.
IP2MD <Code address>

Given an address in managed JITTED code, IP2MD attempts to find the MethodDesc
associated with it. For example, this output from K:

	(lldb) bt 
        ...
        frame #9: 0x00007fffffffbf60 0x00007ffff61c6d89 libcoreclr.so`MethodDesc::DoPrestub(this=0x00007ffff041f870, pDispatchingMT=0x0000000000000000) + 3001 at prestub.cpp:1490
        frame #10: 0x00007fffffffc140 0x00007ffff61c5f17 libcoreclr.so`::PreStubWorker(pTransitionBlock=0x00007fffffffc9a8, pMD=0x00007ffff041f870) + 1399 at prestub.cpp:1037
        frame #11: 0x00007fffffffc920 0x00007ffff5f5238c libcoreclr.so`ThePreStub + 92 at theprestubamd64.S:800
        frame #12: 0x00007fffffffca10 0x00007ffff04981cc
        frame #13: 0x00007fffffffca30 0x00007ffff049773c
        frame #14: 0x00007fffffffca80 0x00007ffff04975ad
        ...
        frame #22: 0x00007fffffffcc90 0x00007ffff5f51a0f libcoreclr.so`CallDescrWorkerInternal + 124 at calldescrworkeramd64.S:863
        frame #23: 0x00007fffffffccb0 0x00007ffff5d6d6dc libcoreclr.so`CallDescrWorkerWithHandler(pCallDescrData=0x00007fffffffce80, fCriticalCall=0) + 476 at callhelpers.cpp:88
        frame #24: 0x00007fffffffcd00 0x00007ffff5d6eb38 libcoreclr.so`MethodDescCallSite::CallTargetWorker(this=0x00007fffffffd0c8, pArguments=0x00007fffffffd048) + 2504 at callhelpers.cpp:633

	(lldb) ip2md 0x00007ffff049773c
        MethodDesc:   00007ffff7f71920
        Method Name:  Microsoft.Win32.SafeHandles.SafeFileHandle.Open(System.Func`1<Int32>)
        Class:        00007ffff0494bf8
        MethodTable:  00007ffff7f71a58
        mdToken:      0000000006000008
        Module:       00007ffff7f6b938
        IsJitted:     yes
        CodeAddr:     00007ffff04976c0
        Transparency: Critical

We have taken a return address into Mainy.Main, and discovered information 
about that method. You could run U, DumpMT, DumpClass, DumpMD, or 
DumpModule on the fields listed to learn more.

The "Source line" output will only be present if the debugger can find the 
symbols for the managed module containing the given <code address>, and if the 
debugger is configured to load line number information.
\\

COMMAND: clru.
COMMAND: u.
U [-gcinfo] [-ehinfo] [-n] [-o] <MethodDesc address> | <Code address>

Presents an annotated disassembly of a managed method when given a MethodDesc
pointer for the method, or a code address within the method body. Unlike the
debugger "U" function, the entire method from start to finish is printed,
with annotations that convert metadata tokens to names.

	<example output>
	...
	03ef015d b901000000       mov     ecx,0x1
	03ef0162 ff156477a25b     call   dword ptr [mscorlib_dll+0x3c7764 (5ba27764)] (System.Console.InitializeStdOutError(Boolean), mdToken: 06000713)
	03ef0168 a17c20a701       mov     eax,[01a7207c] (Object: SyncTextWriter)
	03ef016d 89442414         mov     [esp+0x14],eax

If you pass the -gcinfo flag, you'll get inline display of the GCInfo for
the method. You can also obtain this information with the GCInfo command.

If you pass the -ehinfo flag, you'll get inline display of exception info
for the method. (Beginning and end of try/finally/catch handlers, etc.).
You can also obtain this information with the EHInfo command.

If you pass the -o flag, the byte offset of each instruction from the
beginning of the method will be printed in addition to the absolute address of
the instruction.

If the debugger has the option SYMOPT_LOAD_LINES specified (either by the
.lines or .symopt commands), and if symbols are available for the managed
module containing the method being examined, the output of the command will
include the source file name and line number corresponding to the 
disassembly. The -n (No line numbers) flag can be specified to disable this
behavior.

	<example output>
	...
	c:\Code\prj.mini\exc.cs @ 38:
	001b00b0 8b0d3020ab03    mov     ecx,dword ptr ds:[3AB2030h] ("Break in debugger. When done type <Enter> to continue: ")
	001b00b6 e8d5355951      call    mscorlib_ni+0x8b3690 (51743690) (System.Console.Write(System.String), mdToken: 0600091b)
	001b00bb 90              nop

	c:\Code\prj.mini\exc.cs @ 39:
	001b00bc e863cdc651      call    mscorlib_ni+0xf8ce24 (51e1ce24) (System.Console.ReadLine(), mdToken: 060008f6)
	>>> 001b00c1 90              nop
	...
\\

COMMAND: dumpstack.
DumpStack [-EE] [-n] [top stack [bottom stack]]

[x86 and x64 documentation]

This command provides a verbose stack trace obtained by "scraping." Therefore
the output is very noisy and potentially confusing. The command is good for
viewing the complete call stack when "kb" gets confused. For best results,
make sure you have valid symbols.

-EE will only show managed functions.

If the debugger has the option SYMOPT_LOAD_LINES specified (either by the
.lines or .symopt commands), SOS will look up the symbols for every managed 
frame and if successful will display the corresponding source file name and 
line number. The -n (No line numbers) parameter can be specified to disable 
this behavior.

You can also pass a stack range to limit the output.
\\

COMMAND: eestack.
EEStack [-short] [-EE]

This command runs DumpStack on all threads in the process. The -EE option is 
passed directly to DumpStack. The -short option tries to narrow down the 
output to "interesting" threads only, which is defined by

1) The thread has taken a lock.
2) The thread has been "hijacked" in order to allow a garbage collection.
3) The thread is currently in managed code.

See the documentation for DumpStack for more info.
\\

COMMAND: ehinfo.
EHInfo (<MethodDesc address> | <Code address>)

EHInfo shows the exception handling blocks in a jitted method. For each 
handler, it shows the type, including code addresses and offsets for the clause
block and the handler block. For a TYPED handler, this would be the "try" and
"catch" blocks respectively.

Sample output:

	(lldb) sos EHInfo 33bbd3a
	MethodDesc: 03310f68
	Method Name: MainClass.Main()
	Class: 03571358
	MethodTable: 0331121c
	mdToken: 0600000b
	Module: 001e2fd8
	IsJitted: yes
	CodeAddr: 033bbca0
	Transparency: Critical

	EHHandler 0: TYPED catch(System.IO.FileNotFoundException) 
	Clause: [033bbd2b, 033bbd3c] [8b, 9c]
	Handler: [033bbd3c, 033bbd50] [9c, b0]

	EHHandler 1: FINALLY
	Clause: [033bbd83, 033bbda3] [e3, 103]
	Handler: [033bbda3, 033bbdc5] [103, 125]

	EHHandler 2: TYPED catch(System.Exception)
	Clause: [033bbd7a, 033bbdc5] [da, 125]
	Handler: [033bbdc5, 033bbdd6] [125, 136]

\\

COMMAND: gcinfo.
GCInfo (<MethodDesc address> | <Code address>)

GCInfo is especially useful for CLR Devs who are trying to determine if there 
is a bug in the JIT Compiler. It parses the GCEncoding for a method, which is a
compressed stream of data indicating when registers or stack locations contain 
managed objects. It is important to keep track of this information, because if 
a garbage collection occurs, the collector needs to know where roots are so it 
can update them with new object pointer values.

Here is sample output where you can see the change in register state. Normally 
you would print this output out and read it alongside a disassembly of the 
method. For example, the notation "reg EDI becoming live" at offset 0x11 of the
method might correspond to a "mov edi,ecx" statement.

	(lldb) sos GCInfo 5b68dbb8   (5b68dbb8 is the start of a JITTED method)
	entry point 5b68dbb8
	preJIT generated code
	GC info 5b9f2f09
	Method info block:
	    method      size   = 0036
	    prolog      size   =  19
	    epilog      size   =   8
	    epilog     count   =   1
	    epilog      end    = yes
	    saved reg.  mask   = 000B
	    ebp frame          = yes
	    fully interruptible=yes
	    double align       = no
	    security check     = no
	    exception handlers = no
	    local alloc        = no
	    edit & continue    = no
	    varargs            = no
	    argument   count   =   4
	    stack frame size   =   1
	    untracked count    =   5
	    var ptr tab count  =   0
	    epilog        at   002E
	36 D4 8C C7 AA |
	93 F3 40 05    |

	Pointer table:
	14             |             [EBP+14H] an untracked  local
	10             |             [EBP+10H] an untracked  local
	0C             |             [EBP+0CH] an untracked  local
	08             |             [EBP+08H] an untracked  local
	44             |             [EBP-04H] an untracked  local
	F1 79          | 0011        reg EDI becoming live
	72             | 0013        reg ESI becoming live
	83             | 0016        push ptr  0
	8B             | 0019        push ptr  1
	93             | 001C        push ptr  2
	9B             | 001F        push ptr  3
	56             | 0025        reg EDX becoming live
	4A             | 0027        reg ECX becoming live
	0E             | 002D        reg ECX becoming dead
	10             | 002D        reg EDX becoming dead
	E0             | 002D        pop  4 ptrs
	F0 31          | 0036        reg ESI becoming dead
	38             | 0036        reg EDI becoming dead
	FF             |

This function is important for CLR Devs, but very difficult for anyone else to 
make sense of it. You would usually come to use it if you suspect a gc heap 
corruption bug caused by invalid GCEncoding for a particular method.
\\

COMMAND: bpmd.
bpmd [-nofuturemodule] <module name> <method name> [<il offset>]
bpmd <source file name>:<line number>
bpmd -md <MethodDesc>
bpmd -list
bpmd -clear <pending breakpoint number>
bpmd -clearall

bpmd provides managed breakpoint support. If it can resolve the method name
to a loaded, jitted or ngen'd function it will create a breakpoint with "bp".
If not then either the module that contains the method hasn't been loaded yet
or the module is loaded, but the function is not jitted yet. In these cases,
bpmd asks the Windows Debugger to receive CLR Notifications, and waits to
receive news of module loads and JITs, at which time it will try to resolve 
the function to a breakpoint. -nofuturemodule can be used to suppress 
creating a breakpoint against a module that has not yet been loaded.

Management of the list of pending breakpoints can be done via bpmd -list,
bpmd -clear, and bpmd -clearall commands. bpmd -list generates a list of 
all of the pending breakpoints. If the pending breakpoint has a non-zero 
module id, then that pending breakpoint is specific to function in that 
particular loaded module. If the pending breakpoint has a zero module id, then
the breakpoint applies to modules that have not yet been loaded. Use 
bpmd -clear or bpmd -clearall to remove pending breakpoints from the list.

This brings up a good question: "I want to set a breakpoint on the main
method of my application. How can I do this?"

  1) Stop after coreclr is loaded - TBD

  2) Add the breakpoint with command such as:
       bpmd myapp.exe MyApp.Main
  3) g
  4) You will stop at the start of MyApp.Main. If you type "bl" you will 
     see the breakpoint listed.

To correctly specify explicitly implemented methods make sure to retrieve the
method name from the metadata, or from the output of the "dumpmt -md" command. 
For example:

	public interface I1
	{
	    void M1();
	}
	public class ExplicitItfImpl : I1
	{
	    ...
	    void I1.M1()		// this method's name is 'I1.M1'
	    { ... }
	}

	bpmd myapp.exe ExplicitItfImpl.I1.M1


bpmd works equally well with generic types. Adding a breakpoint on a generic 
type sets breakpoints on all already JIT-ted generic methods and sets a pending 
breakpoint for any instantiation that will be JIT-ted in the future.

Example for generics:
	Given the following two classes:

	class G3<T1, T2, T3> 
	{
		...
		public void F(T1 p1, T2 p2, T3 p3)
		{ ... }
	}

	public class G1<T> {
		// static method
		static public void G<W>(W w)
		{ ... }
	}

	One would issue the following commands to set breapoints on G3.F() and 
	G1.G():

	bpmd myapp.exe G3`3.F
	bpmd myapp.exe G1`1.G

And for explicitly implemented methods on generic interfaces:
	public interface IT1<T>
	{
	    void M1(T t);
	}

	public class ExplicitItfImpl<U> : IT1<U>
	{
	    ...
	    void IT1<U>.M1(U u)	// this method's name is 'IT1<U>.M1'
	    { ... }
	}

	bpmd bpmd.exe ExplicitItfImpl`1.IT1<U>.M1

Additional examples:
	If IT1 and ExplicitItfImpl are types declared inside another class, 
	Outer, the bpmd command would become:

	bpmd bpmd.exe Outer+ExplicitItfImpl`1.Outer.IT1<U>.M1

	(note that the fully qualified type name for ExplicitItfImpl became
	Outer+ExplicitItfImpl, using the '+' separator, while the method name
	is Outer.IT1<U>.M1, using a '.' as the separator)

	Furthermore, if the Outer class resides in a namespace, NS, the bpmd 
	command to use becomes:

	bpmd bpmd.exe NS.Outer+ExplicitItfImpl`1.NS.Outer.IT1<U>.M1

bpmd does not accept offsets nor parameters in the method name. You can add
an IL offset as an optional parameter seperate from the name. If there are overloaded
methods, bpmd will set a breakpoint for all of them.

In the case of hosted environments such as SQL, the module name may be 
complex, like 'price, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null'.
For this case, just be sure to surround the module name with single quotes,
like:

bpmd 'price, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null' Price.M2

\\

COMMAND: dumpdomain.
DumpDomain [<Domain address>]

When called with no parameters, DumpDomain will list all the AppDomains in the
process. It enumerates each Assembly loaded into those AppDomains as well. 
In addition to your application domain, and any domains it might create, there
are two special domains: the Shared Domain and the System Domain.

Any Assembly pointer in the output can be passed to DumpAssembly. Any Module 
pointer in the output can be passed to DumpModule. Any AppDomain pointer can 
be passed to DumpDomain to limit output only to that AppDomain. Other 
functions provide an AppDomain pointer as well, such as clrthreads where it lists
the current AppDomain for each thread.
\\

COMMAND: eeheap.
EEHeap [-gc] [-loader]

EEHeap enumerates process memory consumed by internal CLR data structures. You
can limit the output by passing "-gc" or "-loader". All information will be 
displayed otherwise.

The information for the Garbage Collector lists the ranges of each Segment in 
the managed heap. This can be useful if you believe you have an object pointer.
If the pointer falls within a segment range given by "eeheap -gc", then you do
have an object pointer, and can attempt to run "dumpobj" on it.

Here is output for a simple program:

	(lldb) eeheap -gc
	Number of GC Heaps: 1
	generation 0 starts at 0x00a71018
	generation 1 starts at 0x00a7100c
	generation 2 starts at 0x00a71000
	 segment    begin allocated     size
	00a70000 00a71000  00a7e01c 0000d01c(53276)
	Large object heap starts at 0x01a71000
	 segment    begin allocated     size
	01a70000 01a71000  01a76000 0x00005000(20480)
	Total Size   0x1201c(73756)
	------------------------------
	GC Heap Size   0x1201c(73756)

So the total size of the GC Heap is only 72K. On a large web server, with 
multiple processors, you can expect to see a GC Heap of 400MB or more. The 
Garbage Collector attempts to collect and reclaim memory only when required to
by memory pressure for better performance. You can also see the notion of 
"generations," wherein the youngest objects live in generation 0, and 
long-lived objects eventually get "promoted" to generation 2.

The loader output lists various private heaps associated with AppDomains. It 
also lists heaps associated with the JIT compiler, and heaps associated with 
Modules. For example:

	(lldb) eeheap -loader
	Loader Heap:
	--------------------------------------
	System Domain: 5e0662a0
	LowFrequencyHeap:008f0000(00002000:00001000) Size: 0x00001000 bytes.
	HighFrequencyHeap:008f2000(00008000:00001000) Size: 0x00001000 bytes.
	StubHeap:008fa000(00002000:00001000) Size: 0x00001000 bytes.
	Total size: 0x3000(12288)bytes
	--------------------------------------
	Shared Domain: 5e066970
	LowFrequencyHeap:00920000(00002000:00001000) 03e30000(00010000:00003000) Size: 0x00004000 bytes.
	Wasted: 0x00001000 bytes.
	HighFrequencyHeap:00922000(00008000:00001000) Size: 0x00001000 bytes.
	StubHeap:0092a000(00002000:00001000) Size: 0x00001000 bytes.
	Total size: 0x6000(24576)bytes
	--------------------------------------
	Domain 1: 14f000
	LowFrequencyHeap:00900000(00002000:00001000) 03ee0000(00010000:00003000) Size: 0x00004000 bytes.
	Wasted: 0x00001000 bytes.
	HighFrequencyHeap:00902000(00008000:00003000) Size: 0x00003000 bytes.
	StubHeap:0090a000(00002000:00001000) Size: 0x00001000 bytes.
	Total size: 0x8000(32768)bytes
	--------------------------------------
	Jit code heap:
	Normal JIT:03ef0000(00010000:00002000) Size: 0x00002000 bytes.
	Total size: 0x2000(8192)bytes
	--------------------------------------
	Module Thunk heaps:
	Module 5ba22410: Size: 0x00000000 bytes.
	Module 001c1320: Size: 0x00000000 bytes.
	Module 001c03f0: Size: 0x00000000 bytes.
	Module 001caa38: Size: 0x00000000 bytes.
	Total size: 0x0(0)bytes
	--------------------------------------
	Module Lookup Table heaps:
	Module 5ba22410:Size: 0x00000000 bytes.
	Module 001c1320:Size: 0x00000000 bytes.
	Module 001c03f0:Size: 0x00000000 bytes.
	Module 001caa38:03ec0000(00010000:00002000) Size: 0x00002000 bytes.
	Total size: 0x2000(8192)bytes
	--------------------------------------
	Total LoaderHeap size: 0x15000(86016)bytes
	=======================================

By using eeheap to keep track of the growth of these private heaps, we are 
able to rule out or include them as a source of a memory leak.
\\

COMMAND: name2ee.
Name2EE <module name> <type or method name>
Name2EE <module name>!<type or method name>

This function allows you to turn a class name into a MethodTable and EEClass. 
It turns a method name into a MethodDesc. Here is an example for a method:

	(lldb) name2ee unittest.exe MainClass.Main
	Module: 001caa38
	Token: 0x0600000d
	MethodDesc: 00902f40
	Name: MainClass.Main()
	JITTED Code Address: 03ef00b8

and for a class:

	(lldb) name2ee unittest!MainClass
	Module: 001caa38
	Token: 0x02000005
	MethodTable: 009032d8
	EEClass: 03ee1424
	Name: MainClass

The module you are "browsing" with Name2EE needs to be loaded in the process. 
To get a type name exactly right, first browse the module with ILDASM. You
can also pass * as the <module name> to search all loaded managed modules.
<module name> can also be the debugger's name for a module, such as
mscorlib or image00400000.

The <module>!<type> syntax is also supported. You can use an asterisk on the 
left of the !, but the type on the right side needs to be fully qualified.

If you are looking for a way to display a static field of a class (and you
don't have an instance of the class, so dumpobj won't help you), note that
once you have the EEClass, you can run DumpClass, which will display the
value of all static fields.

There is yet one more way to specify a module name. In the case of modules
loaded from an assembly store (such as a SQL db) rather than disk, the
module name will look like this:

price, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null

For this kind of module, simply use price as the module name:

	0:044> name2ee price Price
	Module: 10f028b0 (price, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null)
	Token: 0x02000002
	MethodTable: 11a47ae0
	EEClass: 11a538c8
	Name: Price

Where are we getting these module names from? Run DumpDomain to see a list of
all loaded modules in all domains. And remember that you can browse all the
types in a module with DumpModule -mt <module pointer>.
\\

COMMAND: dumpmt.
DumpMT [-MD] <MethodTable address>

Examine a MethodTable. Each managed object has a MethodTable pointer at the 
start. If you pass the "-MD" flag, you'll also see a list of all the methods 
defined on the object. 
\\

COMMAND: dumpclass.
DumpClass <EEClass address>

The EEClass is a data structure associated with an object type. DumpClass 
will show attributes, as well as list the fields of the type. The output is 
similar to DumpObj. Although static field values will be displayed, 
non-static values won't because you need an instance of an object for that.

You can get an EEClass to look at from DumpMT, DumpObj, Name2EE, and 
Token2EE among others.
\\

COMMAND: dumpmd.
DumpMD <MethodDesc address>

This command lists information about a MethodDesc. You can use ip2md to turn 
a code address in a managed function into a MethodDesc:

	(lldb) dumpmd 902f40
	Method Name: Mainy.Main()
	Class: 03ee1424
	MethodTable: 009032d8
	mdToken: 0600000d
	Module: 001caa78
	IsJitted: yes
	CodeAddr: 03ef00b8

If IsJitted is "yes," you can run U on the CodeAddr pointer to see a 
disassembly of the JITTED code.  You can call also DumpClass, DumpMT, 
DumpModule on the Class, MethodTable and Module fields above.
\\

COMMAND: token2ee.
Token2EE <module name> <token>

This function allows you to turn a metadata token into a MethodTable or 
MethodDesc. Here is an example showing class tokens being resolved:

	(lldb) sos Token2EE unittest.exe 02000003
	Module: 001caa38
	Token: 0x02000003
	MethodTable: 0090375c
	EEClass: 03ee1ae0
	Name: Bank
	(lldb) sos Token2EE image00400000 02000004
	Module: 001caa38
	Token: 0x02000004
	MethodTable: 009038ec
	EEClass: 03ee1b84
	Name: Customer

The module you are "browsing" with Token2EE needs to be loaded in the process. 
This function doesn't see much use, especially since a tool like ILDASM can 
show the mapping between metadata tokens and types/methods in a friendlier way. 
But it could be handy sometimes.

You can pass "*" for <module name> to find what that token maps to in every
loaded managed module. <module name> can also be the debugger's name for a 
module, such as mscorlib or image00400000.
\\

COMMAND: dumpmodule.
DumpModule [-mt] <Module address>

You can get a Module address from DumpDomain, DumpAssembly and other 
functions. Here is sample output:

	(lldb) sos DumpModule 1caa50
	Name: /home/user/pub/unittest
	Attributes: PEFile
	Assembly: 001ca248
	LoaderHeap: 001cab3c
	TypeDefToMethodTableMap: 03ec0010
	TypeRefToMethodTableMap: 03ec0024
	MethodDefToDescMap: 03ec0064
	FieldDefToDescMap: 03ec00a4
	MemberRefToDescMap: 03ec00e8
	FileReferencesMap: 03ec0128
	AssemblyReferencesMap: 03ec012c
	MetaData start address: 00402230 (1888 bytes)

The Maps listed map metadata tokens to CLR data structures. Without going into 
too much detail, you can examine memory at those addresses to find the 
appropriate structures. For example, the TypeDefToMethodTableMap above can be 
examined:

	(lldb) dd 3ec0010
	03ec0010  00000000 00000000 0090320c 0090375c
	03ec0020  009038ec ...

This means TypeDef token 2 maps to a MethodTable with the value 0090320c. You 
can run DumpMT to verify that. The MethodDefToDescMap takes a MethodDef token 
and maps it to a MethodDesc, which can be passed to dumpmd.

There is a new option "-mt", which will display the types defined in a module,
and the types referenced by the module. For example:

	(lldb) sos DumpModule -mt 1aa580
	Name: /home/user/pub/unittest
	...<etc>...
	MetaData start address: 0040220c (1696 bytes)

	Types defined in this module

	      MT    TypeDef Name
	--------------------------------------------------------------------------
	030d115c 0x02000002 Funny
	030d1228 0x02000003 Mainy

	Types referenced in this module

	      MT    TypeRef Name
	--------------------------------------------------------------------------
	030b6420 0x01000001 System.ValueType
	030b5cb0 0x01000002 System.Object
	030fceb4 0x01000003 System.Exception
	0334e374 0x0100000c System.Console
	03167a50 0x0100000e System.Runtime.InteropServices.GCHandle
	0336a048 0x0100000f System.GC

\\

COMMAND: dumpassembly.
DumpAssembly <Assembly address>

Example output:

	(lldb) sos DumpAssembly 1ca248
	Parent Domain: 0014f000
	Name: /home/user/pub/unittest
	ClassLoader: 001ca060
	  Module Name
	001caa50 /home/user/pub/unittest

An assembly can consist of multiple modules, and those will be listed. You can
get an Assembly address from the output of DumpDomain.
\\

COMMAND: dumpruntimetypes.
DumpRuntimeTypes 

DumpRuntimeTypes finds all System.RuntimeType objects in the gc heap and 
prints the type name and MethodTable they refer too. Sample output:

	 Address   Domain       MT Type Name
	------------------------------------------------------------------------------
	  a515f4   14a740 5baf8d28 System.TypedReference
	  a51608   14a740 5bb05764 System.Globalization.BaseInfoTable
	  a51958   14a740 5bb05b24 System.Globalization.CultureInfo
	  a51a44   14a740 5bb06298 System.Globalization.GlobalizationAssembly
	  a51de0   14a740 5bb069c8 System.Globalization.TextInfo
	  a56b98   14a740 5bb12d28 System.Security.Permissions.HostProtectionResource
	  a56bbc   14a740 5baf7248 System.Int32
	  a56bd0   14a740 5baf3fdc System.String
	  a56cfc   14a740 5baf36a4 System.ValueType
	...

This command will print a "?" in the domain column if the type is loaded into multiple
AppDomains.  For example:

    (lldb) sos DumpRuntimeTypes
     Address   Domain       MT Type Name              
    ------------------------------------------------------------------------------
     28435a0        ?   3f6a8c System.TypedReference
     28435b4        ?   214d6c System.ValueType
     28435c8        ?   216314 System.Enum
     28435dc        ?   2147cc System.Object
     284365c        ?   3cd57c System.IntPtr
     2843670        ?   3feaac System.Byte
     2843684        ?   23a544c System.IEquatable`1[[System.IntPtr, mscorlib]]
     2843784        ?   3c999c System.Int32
     2843798        ?   3caa04 System.IEquatable`1[[System.Int32, mscorlib]]
\\

COMMAND: dumpsig.
DumpSig <sigaddr> <moduleaddr>

This command dumps the signature of a method or field given by <sigaddr>.  This is
useful when you are debugging parts of the runtime which returns a raw PCCOR_SIGNATURE
structure and need to know what its contents are.

Sample output for a method:
    0:000> sos DumpSig 0x000007fe`ec20879d 0x000007fe`eabd1000
    [DEFAULT] [hasThis] Void (Boolean,String,String)

The first section of the output is the calling convention.  This includes, but is not
limited to, "[DEFAULT]", "[C]", "[STDCALL]", "[THISCALL]", and so on.  The second
portion of the output is either "[hasThis]" or "[explicit]" for whether the method
is an instance method or a static method respectively.  The third portion of the 
output is the return value (in this case a "void").  Finally, the method's arguments
are printed as the final portion of the output.

Sample output for a field:
    0:000> sos DumpSig 0x000007fe`eb7fd8cd 0x000007fe`eabd1000
    [FIELD] ValueClass System.RuntimeTypeHandle 

DumpSig will also work with generics.  Here is the output for the following
function:
    public A Test(IEnumerable<B> n)

    0:000> sos DumpSig 00000000`00bc2437 000007ff00043178 
    [DEFAULT] [hasThis] __Canon (Class System.Collections.Generic.IEnumerable`1<__Canon>)
\\

COMMAND: dumpsigelem.
DumpSigElem <sigaddr> <moduleaddr>

This command dumps a single element of a signature object.  For most circumstances,
you should use DumpSig to look at individual signature objects, but if you find a 
signature that has been corrupted in some manner you can use DumpSigElem to read out 
the valid portions of it.

If we look at a valid signature object for a method we see the following:
    0:000> dumpsig 0x000007fe`ec20879d 0x000007fe`eabd1000
    [DEFAULT] [hasThis] Void (Boolean,String,String)

We can look at the individual elements of this object by adding the offsets into the 
object which correspond to the return value and parameters:
    0:000> sos DumpSigElem 0x000007fe`ec20879d+2 0x000007fe`eabd1000
    Void
    0:000> sos DumpSigElem 0x000007fe`ec20879d+3 0x000007fe`eabd1000
    Boolean
    0:000> sos DumpSigElem 0x000007fe`ec20879d+4 0x000007fe`eabd1000
    String
    0:000> sos DumpSigElem 0x000007fe`ec20879d+5 0x000007fe`eabd1000
    String

We can do something similar for fields.  Here is the full signature of a field:
    0:000> dumpsig 0x000007fe`eb7fd8cd 0x000007fe`eabd1000
    [FIELD] ValueClass System.RuntimeTypeHandle 

Using DumpSigElem we can find the type of the field by adding the offset of it (1) to 
the address of the signature:
    0:000> sos DumpSigElem 0x000007fe`eb7fd8cd+1 0x000007fe`eabd1000
    ValueClass System.RuntimeTypeHandle

DumpSigElem will also work with generics.  Let a function be defined as follows:
    public A Test(IEnumerable<B> n)

The elements of this signature can be obtained by adding offsets into the signature
when calling DumpSigElem:

    0:000> sos DumpSigElem 00000000`00bc2437+2 000007ff00043178 
    __Canon
    0:000> sos DumpSigElem 00000000`00bc2437+4 000007ff00043178 
    Class System.Collections.Generic.IEnumerable`1<__Canon>

The actual offsets that you should add are determined by the contents of the
signature itself.  By trial and error you should be able to find various elements
of the signature.
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COMMAND: dumpil.
DumpIL <Managed DynamicMethod object> | 
       <DynamicMethodDesc pointer> |
       <MethodDesc pointer> |
        /i <IL pointer>

DumpIL prints the IL code associated with a managed method. We added this
function specifically to debug DynamicMethod code which was constructed on
the fly. Happily it works for non-dynamic code as well.

You can use it in four ways: 

  1) If you have a System.Reflection.Emit.DynamicMethod object, just pass
     the pointer as the first argument. 
  2) If you have a DynamicMethodDesc pointer you can use that to print the
     IL associated with the dynamic method.
  3) If you have an ordinary MethodDesc, you can see the IL for that as well,
     just pass it as the first argument.
  4) If you have a pointer directly to the IL, specify /i followed by the
     the IL address.  This is useful for writers of profilers that instrument
     IL.
     

Note that dynamic IL is constructed a bit differently. Rather than referring
to metadata tokens, the IL points to objects in a managed object array. Here
is a simple example of the output for a dynamic method:

  0:000> sos DumpIL b741dc
  This is dynamic IL. Exception info is not reported at this time.
  If a token is unresolved, run "sos DumpObj <addr>" on the addr given
  in parenthesis. You can also look at the token table yourself, by
  running "DumpArray 00b77388".

  IL_0000: ldstr 70000002 "Inside invoked method "
  IL_0005: call 6000003 System.Console.WriteLine(System.String)
  IL_000a: ldc.i4.1
  IL_000b: newarr 2000004 "System.Int32"
  IL_0010: stloc.0
  IL_0011: ldloc.0
  IL_0012: ret
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COMMAND: verifyheap.
VerifyHeap

VerifyHeap is a diagnostic tool that checks the garbage collected heap for 
signs of corruption. It walks objects one by one in a pattern like this:

    o = firstobject;
    while(o != endobject)
    {
        o.ValidateAllFields();
        o = (Object *) o + o.Size();
    }

If an error is found, VerifyHeap will report it. I'll take a perfectly good 
object and corrupt it:

	(lldb) dumpobj a79d40
	Name: Customer
	MethodTable: 009038ec
	EEClass: 03ee1b84
	Size: 20(0x14) bytes
	 (/home/user/pub/unittest)
	Fields:
	      MT    Field   Offset                 Type       Attr    Value Name
	009038ec  4000008        4                CLASS   instance 00a79ce4 name
	009038ec  4000009        8                CLASS   instance 00a79d2c bank
	009038ec  400000a        c       System.Boolean   instance        1 valid

	(lldb) ed a79d40+4 01  (change the name field to the bogus pointer value 1)
	(lldb) sos VerifyHeap
	object 01ee60dc: bad member 00000003 at 01EE6168
	Last good object: 01EE60C4.

If this gc heap corruption exists, there is a serious bug in your own code or 
in the CLR. In user code, an error in constructing PInvoke calls can cause 
this problem, and running with Managed Debugging Assistants is advised. If that
possibility is eliminated, consider contacting Microsoft Product Support for
help.
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COMMAND: dumplog.
DumpLog [-addr <addressOfStressLog>] [<Filename>]

To aid in diagnosing hard-to-reproduce stress failures, the CLR team added an 
in-memory log capability. The idea was to avoid using locks or I/O which could 
disturb a fragile repro environment. The DumpLog function allows you to write 
that log out to a file. If no Filename is specified, the file "Stresslog.txt" 
in the current directory is created.

The optional argument addr allows one to specify a stress log other then the 
default one.

	(lldb) dumplog
	Attempting to dump Stress log to file 'StressLog.txt'
	.................
	SUCCESS: Stress log dumped

To turn on the stress log, set the following registry keys under
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework:


(DWORD) StressLog = 1
(DWORD) LogFacility = 0xffffffbf (this is a bit mask, almost all logging is on.
                                  This is also the default value if the key 
                                  isn't specified)
(DWORD) StressLogSize = 65536    (this is the default value if the key isn't
                                  specified)
(DWORD) LogLevel = 6             (this is the default value if the key isn't
                                  specified.  The higher the number the more
                                  detailed logs are generated.  The maximum 
                                  value is decimal 10)

StressLogSize is the size in bytes of the in-memory log allocated for each 
thread in the process. In the case above, each thread gets a 64K log. You 
could increase this to get more logging, but more memory will be required for 
this log in the process. For example, 20 threads with 524288 bytes per thread 
has a memory demand of 10 Megabytes. The stress log is circular so new entries 
will replace older ones on threads which have reached their buffer limit.

The log facilities are defined as follows:
    GC           0x00000001
    GCINFO       0x00000002
    STUBS        0x00000004
    JIT          0x00000008
    LOADER       0x00000010
    METADATA     0x00000020
    SYNC         0x00000040
    EEMEM        0x00000080
    GCALLOC      0x00000100
    CORDB        0x00000200
    CLASSLOADER  0x00000400
    CORPROF      0x00000800
    REMOTING     0x00001000
    DBGALLOC     0x00002000
    EH           0x00004000
    ENC          0x00008000
    ASSERT       0x00010000
    VERIFIER     0x00020000
    THREADPOOL   0x00040000
    GCROOTS      0x00080000
    INTEROP      0x00100000
    MARSHALER    0x00200000
    IJW          0x00400000
    ZAP          0x00800000
    STARTUP      0x01000000
    APPDOMAIN    0x02000000
    CODESHARING  0x04000000
    STORE        0x08000000
    SECURITY     0x10000000
    LOCKS        0x20000000
    BCL          0x40000000

Here is some sample output:

	3560   9.981137099 : `SYNC`               RareEnablePremptiveGC: entering. 
	Thread state = a030

	3560   9.981135033 : `GC`GCALLOC`GCROOTS` ========== ENDGC 4194 (gen = 2, 
	collect_classes = 0) ==========={

	3560   9.981125826 : `GC`                         Segment mem 00C61000 alloc 
	= 00D071F0 used 00D09254 committed 00D17000

	3560   9.981125726 : `GC`                     Generation 0 [00CED07C, 00000000
	] cur = 00000000

	3560   9.981125529 : `GC`                     Generation 1 [00CED070, 00000000
	] cur = 00000000

	3560   9.981125103 : `GC`                     Generation 2 [00C61000, 00000000
	] cur = 00000000

	3560   9.981124963 : `GC`                 GC Heap 00000000

	3560   9.980618994 : `GC`GCROOTS`         GcScanHandles (Promotion Phase = 0)

The first column is the OS thread ID for the thread appending to the log, 
the second column is the timestamp, the third is the facility category for the 
log entry, and the fourth contains the log message. The facility field is 
expressed as `facility1`facility2`facility3`.  This facilitates the creation of 
filters for displaying only specific message categories.  To make sense of this 
log, you would probably want the Shared Source CLI to find out exactly where 
the log comes from.
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COMMAND: findappdomain.
FindAppDomain <Object address>

FindAppDomain will attempt to resolve the AppDomain of an object. For example,
using an Object Pointer from the output of DumpStackObjects:

	(lldb) sos FindAppDomain 00a79d98
	AppDomain: 0014f000
	Name: unittest.exe
	ID: 1

You can find out more about the AppDomain with the DumpDomain command. Not 
every object has enough clues about it's origin to determine the AppDomain. 
Objects with Finalizers are the easiest case, as the CLR needs to be able to 
call those when an AppDomain shuts down.
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COMMAND: histinit.
HistInit

Before running any of the Hist - family commands you need to initialize the SOS 
structures from the stress log saved in the debuggee.  This is achieved by the 
HistInit command.

Sample output:

	(lldb) histinit
	Attempting to read Stress log
	STRESS LOG:
	    facilitiesToLog  = 0xffffffff
	    levelToLog       = 6
	    MaxLogSizePerThread = 0x10000 (65536)
	    MaxTotalLogSize = 0x1000000 (16777216)
	    CurrentTotalLogChunk = 9
	    ThreadsWithLogs  = 3
	    Clock frequency  = 3.392 GHz
	    Start time         15:26:31
	    Last message time  15:26:56
	    Total elapsed time 25.077 sec
	.....................................
	---------------------------- 2407 total entries -----------------------------


	SUCCESS: GCHist structures initialized

\\

COMMAND: histobjfind.
HistObjFind <obj_address>

To examine log entries related to an object whose present address is known one 
would use this command. The output of this command contains all entries that 
reference the object:

	(lldb) histobjfind 028970d4 
	 GCCount   Object                                  Message
	---------------------------------------------------------
	    2296 028970d4 Promotion for root 01e411b8 (MT = 5b6c5cd8)
	    2296 028970d4 Relocation NEWVALUE for root 00223fc4
	    2296 028970d4 Relocation NEWVALUE for root 01e411b8
	...
	    2295 028970d4 Promotion for root 01e411b8 (MT = 5b6c5cd8)
	    2295 028970d4 Relocation NEWVALUE for root 00223fc4
	    2295 028970d4 Relocation NEWVALUE for root 01e411b8
	...

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COMMAND: histroot.
HistRoot <root>

The root value obtained from !HistObjFind can be used to track the movement of 
an object through the GCs.

HistRoot provides information related to both promotions and relocations of the 
root specified as the argument.

	(lldb) histroot 01e411b8 
	 GCCount    Value       MT Promoted?                Notes
	---------------------------------------------------------
	    2296 028970d4 5b6c5cd8       yes 
	    2295 028970d4 5b6c5cd8       yes 
	    2294 028970d4 5b6c5cd8       yes 
	    2293 028970d4 5b6c5cd8       yes 
	    2292 028970d4 5b6c5cd8       yes 
	    2291 028970d4 5b6c5cd8       yes 
	    2290 028970d4 5b6c5cd8       yes 
	    2289 028970d4 5b6c5cd8       yes 
	    2288 028970d4 5b6c5cd8       yes 
	    2287 028970d4 5b6c5cd8       yes 
	    2286 028970d4 5b6c5cd8       yes 
	    2285 028970d4 5b6c5cd8       yes 
	     322 028970e8 5b6c5cd8       yes Duplicate promote/relocs
	...

\\

COMMAND: histobj.
HistObj <obj_address>

This command examines all stress log relocation records and displays the chain 
of GC relocations that may have led to the address passed in as an argument.
Conceptually the output is:

		GenN    obj_address   root1, root2, root3,
		GenN-1  prev_obj_addr root1, root2,
		GenN-2  prev_prev_oa  root1, root4, 
		...

Sample output:
	(lldb) histobj 028970d4 
	 GCCount   Object                                    Roots
	---------------------------------------------------------
	    2296 028970d4 00223fc4, 01e411b8, 
	    2295 028970d4 00223fc4, 01e411b8, 
	    2294 028970d4 00223fc4, 01e411b8, 
	    2293 028970d4 00223fc4, 01e411b8, 
	    2292 028970d4 00223fc4, 01e411b8, 
	    2291 028970d4 00223fc4, 01e411b8, 
	    2290 028970d4 00223fc4, 01e411b8, 
	    2289 028970d4 00223fc4, 01e411b8, 
	    2288 028970d4 00223fc4, 01e411b8, 
	    2287 028970d4 00223fc4, 01e411b8, 
	    2286 028970d4 00223fc4, 01e411b8, 
	    2285 028970d4 00223fc4, 01e411b8, 
	     322 028970d4 01e411b8, 
	       0 028970d4 

\\

COMMAND: histclear.
HistClear

This command releases any resources used by the Hist-family of commands. 
Generally there's no need to call this explicitly, as each HistInit will first 
cleanup the previous resources.

	(lldb) histclear
	Completed successfully.

\\