| ////////////////////////////////////////////////////////////////////////////// |
| // |
| // (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 |