You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and dots ('.'), can be up to 35 characters long. Letters must be lowercase.
119 lines
4.4 KiB
119 lines
4.4 KiB
////////////////////////////////////////////////////////////////////////////// |
|
// |
|
// (C) Copyright Ion Gaztanaga 2005-2009. 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_SEMAPHORE_HPP |
|
#define BOOST_INTERPROCESS_SEMAPHORE_HPP |
|
|
|
/// @cond |
|
|
|
#if (defined _MSC_VER) && (_MSC_VER >= 1200) |
|
# pragma once |
|
#endif |
|
|
|
#include <boost/interprocess/detail/config_begin.hpp> |
|
#include <boost/interprocess/detail/workaround.hpp> |
|
#include <boost/interprocess/creation_tags.hpp> |
|
#include <boost/interprocess/exceptions.hpp> |
|
#include <boost/interprocess/detail/posix_time_types_wrk.hpp> |
|
|
|
#if !defined(BOOST_INTERPROCESS_FORCE_GENERIC_EMULATION) && \ |
|
(defined(BOOST_INTERPROCESS_POSIX_PROCESS_SHARED) && defined(BOOST_INTERPROCESS_POSIX_NAMED_SEMAPHORES)) |
|
#include <fcntl.h> //O_CREAT, O_*... |
|
#include <unistd.h> //close |
|
#include <string> //std::string |
|
#include <semaphore.h> //sem_* family, SEM_VALUE_MAX |
|
#include <sys/stat.h> //mode_t, S_IRWXG, S_IRWXO, S_IRWXU, |
|
#include <boost/interprocess/sync/posix/semaphore_wrapper.hpp> |
|
#define BOOST_INTERPROCESS_USE_POSIX |
|
#else |
|
#include <boost/interprocess/detail/atomic.hpp> |
|
#include <boost/cstdint.hpp> |
|
#include <boost/interprocess/detail/os_thread_functions.hpp> |
|
#define BOOST_INTERPROCESS_USE_GENERIC_EMULATION |
|
#endif |
|
|
|
/// @endcond |
|
|
|
//!\file |
|
//!Describes a interprocess_semaphore class for inter-process synchronization |
|
|
|
namespace boost { |
|
|
|
namespace interprocess { |
|
|
|
//!Wraps a interprocess_semaphore that can be placed in shared memory and can be |
|
//!shared between processes. Allows timed lock tries |
|
class interprocess_semaphore |
|
{ |
|
/// @cond |
|
//Non-copyable |
|
interprocess_semaphore(const interprocess_semaphore &); |
|
interprocess_semaphore &operator=(const interprocess_semaphore &); |
|
/// @endcond |
|
public: |
|
//!Creates a interprocess_semaphore with the given initial count. |
|
//!interprocess_exception if there is an error.*/ |
|
interprocess_semaphore(unsigned int initialCount); |
|
|
|
//!Destroys the interprocess_semaphore. |
|
//!Does not throw |
|
~interprocess_semaphore(); |
|
|
|
//!Increments the interprocess_semaphore count. If there are processes/threads blocked waiting |
|
//!for the interprocess_semaphore, then one of these processes will return successfully from |
|
//!its wait function. If there is an error an interprocess_exception exception is thrown. |
|
void post(); |
|
|
|
//!Decrements the interprocess_semaphore. If the interprocess_semaphore value is not greater than zero, |
|
//!then the calling process/thread blocks until it can decrement the counter. |
|
//!If there is an error an interprocess_exception exception is thrown. |
|
void wait(); |
|
|
|
//!Decrements the interprocess_semaphore if the interprocess_semaphore's value is greater than zero |
|
//!and returns true. If the value is not greater than zero returns false. |
|
//!If there is an error an interprocess_exception exception is thrown. |
|
bool try_wait(); |
|
|
|
//!Decrements the interprocess_semaphore if the interprocess_semaphore's value is greater |
|
//!than zero and returns true. Otherwise, waits for the interprocess_semaphore |
|
//!to the posted or the timeout expires. If the timeout expires, the |
|
//!function returns false. If the interprocess_semaphore is posted the function |
|
//!returns true. If there is an error throws sem_exception |
|
bool timed_wait(const boost::posix_time::ptime &abs_time); |
|
|
|
//!Returns the interprocess_semaphore count |
|
// int get_count() const; |
|
/// @cond |
|
private: |
|
#if defined(BOOST_INTERPROCESS_USE_GENERIC_EMULATION) |
|
volatile boost::uint32_t m_count; |
|
#else |
|
ipcdetail::semaphore_wrapper m_sem; |
|
#endif //#if defined(BOOST_INTERPROCESS_USE_GENERIC_EMULATION) |
|
/// @endcond |
|
}; |
|
|
|
} //namespace interprocess { |
|
|
|
} //namespace boost { |
|
|
|
#ifdef BOOST_INTERPROCESS_USE_GENERIC_EMULATION |
|
# undef BOOST_INTERPROCESS_USE_GENERIC_EMULATION |
|
# include <boost/interprocess/sync/emulation/interprocess_semaphore.hpp> |
|
#endif |
|
|
|
#ifdef BOOST_INTERPROCESS_USE_POSIX |
|
# undef BOOST_INTERPROCESS_USE_POSIX |
|
# include <boost/interprocess/sync/posix/interprocess_semaphore.hpp> |
|
#endif |
|
|
|
#include <boost/interprocess/detail/config_end.hpp> |
|
|
|
#endif //BOOST_INTERPROCESS_SEMAPHORE_HPP
|
|
|