////////////////////////////////////////////////////////////////////////////// | |
// | |
// (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/interprocess/detail/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_INTERPROCESS_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(detail::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(detail::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(detail::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_INTERPROCESS_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_INTERPROCESS_RV_REF(xsi_shared_memory) moved) | |
{ | |
xsi_shared_memory tmp(boost::interprocess::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( detail::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 | |
(detail::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 detail::DoOpen: | |
shmflg |= 0; | |
break; | |
case detail::DoCreate: | |
shmflg |= IPC_CREAT | IPC_EXCL; | |
break; | |
case detail::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 == detail::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 |