sync/windows/semaphore.hpp

0001 //////////////////////////////////////////////////////////////////////////////
0002 //
0003 // (C) Copyright Ion Gaztanaga 2005-2012. Distributed under the Boost
0004 // Software License, Version 1.0. (See accompanying file
0005 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0006 //
0007 // See http://www.boost.org/libs/interprocess for documentation.
0008 //
0009 //////////////////////////////////////////////////////////////////////////////
0010
0011 #ifndef BOOST_INTERPROCESS_DETAIL_WINDOWS_SEMAPHORE_HPP
0012 #define BOOST_INTERPROCESS_DETAIL_WINDOWS_SEMAPHORE_HPP
0013
0014 #ifndef BOOST_CONFIG_HPP
0015 #  include <boost/config.hpp>
0016 #endif
0017 0018 ">#
0019 #if defined(BOOST_HAS_PRAGMA_ONCE)
0020 #  pragma once
0021 #endif
0022
0023 #include <boost/interprocess/detail/config_begin.hpp>
0024 #include <boost/interprocess/detail/workaround.hpp>
0025 #include <boost/interprocess/detail/win32_api.hpp>
0026 #include <boost/interprocess/detail/windows_intermodule_singleton.hpp>
0027 #include <boost/interprocess/sync/windows/sync_utils.hpp>
0028 #include <boost/interprocess/sync/windows/winapi_semaphore_wrapper.hpp>
0029 #include <boost/interprocess/exceptions.hpp>
0030 #include <boost/assert.hpp>
0031
0032
0033 namespace boost {
0034 namespace interprocess {
0035 namespace ipcdetail {
0036
0037 class winapi_semaphore
0038 {
0039    winapi_semaphore(const winapi_semaphore &);
0040    winapi_semaphore &operator=(const winapi_semaphore &);
0041    public:
0042
0043    winapi_semaphore(unsigned int initialCount);
0044    ~winapi_semaphore();
0045
0046    void post(unsigned int release_count = 1);
0047    void wait();
0048    bool try_wait();
0049    template<class TimePoint> bool timed_wait(const TimePoint &abs_time);
0050
0051    private:
0052    const sync_id id_;
0053    const unsigned initial_count_;
0054 };
0055
0056 inline winapi_semaphore::winapi_semaphore(unsigned int initialCount)
0057    : id_(), initial_count_(initialCount)
0058 {
0059    sync_handles &handles =
0060       windows_intermodule_singleton<sync_handles>::get();
0061    //Force smeaphore creation with the initial count
0062    bool open_or_created;
0063    handles.obtain_semaphore(this->id_, this, initialCount, &open_or_created);
0064    //The semaphore must be created, never opened
0065    BOOST_ASSERT(open_or_created);
0066    BOOST_ASSERT(open_or_created && winapi::get_last_error() != winapi::error_already_exists);
0067    (void)open_or_created;
0068 }
0069
0070 inline winapi_semaphore::~winapi_semaphore()
0071 {
0072    sync_handles &handles =
0073       windows_intermodule_singleton<sync_handles>::get();
0074    handles.destroy_handle(this->id_, this);
0075 }
0076
0077 inline void winapi_semaphore::wait()
0078 {
0079    sync_handles &handles =
0080       windows_intermodule_singleton<sync_handles>::get();
0081    //This can throw
0082    winapi_semaphore_functions sem(handles.obtain_semaphore(this->id_, this, initial_count_));
0083    sem.wait();
0084 }
0085
0086 inline bool winapi_semaphore::try_wait()
0087 {
0088    sync_handles &handles =
0089       windows_intermodule_singleton<sync_handles>::get();
0090    //This can throw
0091    winapi_semaphore_functions sem(handles.obtain_semaphore(this->id_, this, initial_count_));
0092    return sem.try_wait();
0093 }
0094
0095 template<class TimePoint>
0096 inline bool winapi_semaphore::timed_wait(const TimePoint &abs_time)
0097 {
0098    sync_handles &handles =
0099       windows_intermodule_singleton<sync_handles>::get();
0100    //This can throw
0101    winapi_semaphore_functions sem(handles.obtain_semaphore(this->id_, this, initial_count_));
0102    return sem.timed_wait(abs_time);
0103 }
0104
0105 inline void winapi_semaphore::post(unsigned release_count)
0106 {
0107    sync_handles &handles =
0108       windows_intermodule_singleton<sync_handles>::get();
0109    winapi_semaphore_functions sem(handles.obtain_semaphore(this->id_, this, initial_count_));
0110    sem.post(static_cast<long>(release_count));
0111 }
0112
0113
0114 }  //namespace ipcdetail {
0115 }  //namespace interprocess {
0116 }  //namespace boost {
0117
0118 #include <boost/interprocess/detail/config_end.hpp>
0119
0120 #endif   //BOOST_INTERPROCESS_DETAIL_WINDOWS_SEMAPHORE_HPP