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Diffstat (limited to 'boost/interprocess/xsi_shared_memory.hpp')
-rw-r--r-- | boost/interprocess/xsi_shared_memory.hpp | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/boost/interprocess/xsi_shared_memory.hpp b/boost/interprocess/xsi_shared_memory.hpp new file mode 100644 index 0000000000..3d09c77399 --- /dev/null +++ b/boost/interprocess/xsi_shared_memory.hpp @@ -0,0 +1,201 @@ +////////////////////////////////////////////////////////////////////////////// +// +// (C) Copyright Ion Gaztanaga 2009. Distributed under the Boost +// Software License, Version 1.0. (See accompanying file +// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) +// +// See http://www.boost.org/libs/interprocess for documentation. +// +////////////////////////////////////////////////////////////////////////////// + +#ifndef BOOST_INTERPROCESS_XSI_SHARED_MEMORY_HPP +#define BOOST_INTERPROCESS_XSI_SHARED_MEMORY_HPP + +#include <boost/interprocess/detail/config_begin.hpp> +#include <boost/interprocess/detail/workaround.hpp> +#include <boost/detail/workaround.hpp> + +#if !defined(BOOST_INTERPROCESS_XSI_SHARED_MEMORY_OBJECTS) +#error "This header can't be used in operating systems without XSI (System V) shared memory support" +#endif + +#include <boost/interprocess/creation_tags.hpp> +#include <boost/interprocess/exceptions.hpp> +#include <boost/interprocess/detail/utilities.hpp> +#include <boost/move/move.hpp> +#include <boost/interprocess/detail/os_file_functions.hpp> +#include <boost/interprocess/interprocess_fwd.hpp> +#include <boost/interprocess/exceptions.hpp> +#include <boost/interprocess/xsi_key.hpp> +#include <boost/interprocess/permissions.hpp> +#include <sys/shm.h> +#include <cstddef> +#include <boost/cstdint.hpp> + +//!\file +//!Describes a class representing a native xsi shared memory. + +namespace boost { +namespace interprocess { + +//!A class that wraps XSI (System V) shared memory. +//!Unlike shared_memory_object, xsi_shared_memory needs a valid +//!xsi_key to identify a shared memory object. +//! +//!Warning: XSI shared memory and interprocess portable +//!shared memory (boost::interprocess::shared_memory_object) +//!can't communicate between them. +class xsi_shared_memory +{ + /// @cond + //Non-copyable and non-assignable + BOOST_MOVABLE_BUT_NOT_COPYABLE(xsi_shared_memory) + /// @endcond + + public: + //!Default constructor. + //!Represents an empty xsi_shared_memory. + xsi_shared_memory(); + + //!Initializes *this with a shmid previously obtained (possibly from another process) + //!This lower-level initializer allows shared memory mapping without having a key. + xsi_shared_memory(open_only_t, int shmid) + : m_shmid (shmid) + {} + + //!Creates a new XSI shared memory from 'key', with size "size" and permissions "perm". + //!If the shared memory previously exists, throws an error. + xsi_shared_memory(create_only_t, const xsi_key &key, std::size_t size, const permissions& perm = permissions()) + { this->priv_open_or_create(ipcdetail::DoCreate, key, perm, size); } + + //!Opens an existing shared memory with identifier 'key' or creates a new XSI shared memory from + //!identifier 'key', with size "size" and permissions "perm". + xsi_shared_memory(open_or_create_t, const xsi_key &key, std::size_t size, const permissions& perm = permissions()) + { this->priv_open_or_create(ipcdetail::DoOpenOrCreate, key, perm, size); } + + //!Tries to open a XSI shared memory with identifier 'key' + //!If the shared memory does not previously exist, it throws an error. + xsi_shared_memory(open_only_t, const xsi_key &key) + { this->priv_open_or_create(ipcdetail::DoOpen, key, permissions(), 0); } + + //!Moves the ownership of "moved"'s shared memory object to *this. + //!After the call, "moved" does not represent any shared memory object. + //!Does not throw + xsi_shared_memory(BOOST_RV_REF(xsi_shared_memory) moved) + : m_shmid(-1) + { this->swap(moved); } + + //!Moves the ownership of "moved"'s shared memory to *this. + //!After the call, "moved" does not represent any shared memory. + //!Does not throw + xsi_shared_memory &operator=(BOOST_RV_REF(xsi_shared_memory) moved) + { + xsi_shared_memory tmp(boost::move(moved)); + this->swap(tmp); + return *this; + } + + //!Swaps two xsi_shared_memorys. Does not throw + void swap(xsi_shared_memory &other); + + //!Destroys *this. The shared memory won't be destroyed, just + //!this connection to it. Use remove() to destroy the shared memory. + ~xsi_shared_memory(); + + //!Returns the shared memory ID that + //!identifies the shared memory + int get_shmid() const; + + //!Returns the mapping handle. + //!Never throws + mapping_handle_t get_mapping_handle() const; + + //!Erases the XSI shared memory object identified by shmid + //!from the system. + //!Returns false on error. Never throws + static bool remove(int shmid); + + /// @cond + private: + + //!Closes a previously opened file mapping. Never throws. + bool priv_open_or_create( ipcdetail::create_enum_t type + , const xsi_key &key + , const permissions& perm + , std::size_t size); + int m_shmid; + /// @endcond +}; + +/// @cond + +inline xsi_shared_memory::xsi_shared_memory() + : m_shmid(-1) +{} + +inline xsi_shared_memory::~xsi_shared_memory() +{} + +inline int xsi_shared_memory::get_shmid() const +{ return m_shmid; } + +inline void xsi_shared_memory::swap(xsi_shared_memory &other) +{ + std::swap(m_shmid, other.m_shmid); +} + +inline mapping_handle_t xsi_shared_memory::get_mapping_handle() const +{ mapping_handle_t mhnd = { m_shmid, true}; return mhnd; } + +inline bool xsi_shared_memory::priv_open_or_create + (ipcdetail::create_enum_t type, const xsi_key &key, const permissions& permissions, std::size_t size) +{ + int perm = permissions.get_permissions(); + perm &= 0x01FF; + int shmflg = perm; + + switch(type){ + case ipcdetail::DoOpen: + shmflg |= 0; + break; + case ipcdetail::DoCreate: + shmflg |= IPC_CREAT | IPC_EXCL; + break; + case ipcdetail::DoOpenOrCreate: + shmflg |= IPC_CREAT; + break; + default: + { + error_info err = other_error; + throw interprocess_exception(err); + } + } + + int ret = ::shmget(key.get_key(), size, shmflg); + int shmid = ret; + if((type == ipcdetail::DoOpen) && (-1 != ret)){ + //Now get the size + ::shmid_ds xsi_ds; + ret = ::shmctl(ret, IPC_STAT, &xsi_ds); + size = xsi_ds.shm_segsz; + } + if(-1 == ret){ + error_info err = system_error_code(); + throw interprocess_exception(err); + } + + m_shmid = shmid; + return true; +} + +inline bool xsi_shared_memory::remove(int shmid) +{ return -1 != ::shmctl(shmid, IPC_RMID, 0); } + +///@endcond + +} //namespace interprocess { +} //namespace boost { + +#include <boost/interprocess/detail/config_end.hpp> + +#endif //BOOST_INTERPROCESS_XSI_SHARED_MEMORY_HPP |