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 #if defined(BOOST_HAS_PRAGMA_ONCE)
0019 #  pragma once
0020 #endif
0021
0022 #include <boost/interprocess/detail/config_begin.hpp>
0023 #include <boost/interprocess/detail/workaround.hpp>
0024 #include <boost/interprocess/detail/win32_api.hpp>
0025 #include <boost/interprocess/detail/windows_intermodule_singleton.hpp>
0026 #include <boost/interprocess/sync/windows/sync_utils.hpp>
0027 #include <boost/interprocess/sync/windows/winapi_semaphore_wrapper.hpp>
0028 #include <boost/interprocess/exceptions.hpp>
0029 #include <boost/assert.hpp>
0030
0031
0032 namespace boost {
0033 namespace interprocess {
0034 namespace ipcdetail {
0035
0036 class winapi_semaphore
0037 {
0038    winapi_semaphore(const winapi_semaphore &);
0039    winapi_semaphore &operator=(const winapi_semaphore &);
0040    public:
0041
0042    winapi_semaphore(unsigned int initialCount);
0043    ~winapi_semaphore();
0044
0045    void post(unsigned int release_count = 1);
0046    void wait();
0047    bool try_wait();
0048    template<class TimePoint> bool timed_wait(const TimePoint &abs_time);
0049
0050    private:
0051    const sync_id id_;
0052    const unsigned initial_count_;
0053 };
0054
0055 inline winapi_semaphore::winapi_semaphore(unsigned int initialCount)
0056    : id_(), initial_count_(initialCount)
0057 {
0058    sync_handles &handles =
0059       windows_intermodule_singleton<sync_handles>::get();
0060    //Force smeaphore creation with the initial count
0061    bool open_or_created;
0062    handles.obtain_semaphore(this->id_, this, initialCount, &open_or_created);
0063    //The semaphore must be created, never opened
0064    BOOST_ASSERT(open_or_created);
0065    BOOST_ASSERT(open_or_created && winapi::get_last_error() != winapi::error_already_exists);
0066    (void)open_or_created;
0067 }
0068
0069 inline winapi_semaphore::~winapi_semaphore()
0070 {
0071    sync_handles &handles =
0072       windows_intermodule_singleton<sync_handles>::get();
0073    handles.destroy_handle(this->id_, this);
0074 }
0075
0076 inline void winapi_semaphore::wait()
0077 {
0078    sync_handles &handles =
0079       windows_intermodule_singleton<sync_handles>::get();
0080    //This can throw
0081    winapi_semaphore_functions sem(handles.obtain_semaphore(this->id_, this, initial_count_));
0082    sem.wait();
0083 }
0084
0085 inline bool winapi_semaphore::try_wait()
0086 {
0087    sync_handles &handles =
0088       windows_intermodule_singleton<sync_handles>::get();
0089    //This can throw
0090    winapi_semaphore_functions sem(handles.obtain_semaphore(this->id_, this, initial_count_));
0091    return sem.try_wait();
0092 }
0093
0094 template<class TimePoint>
0095 inline bool winapi_semaphore::timed_wait(const TimePoint &abs_time)
0096 {
0097    sync_handles &handles =
0098       windows_intermodule_singleton<sync_handles>::get();
0099    //This can throw
0100    winapi_semaphore_functions sem(handles.obtain_semaphore(this->id_, this, initial_count_));
0101    return sem.timed_wait(abs_time);
0102 }
0103
0104 inline void winapi_semaphore::post(unsigned release_count)
0105 {
0106    sync_handles &handles =
0107       windows_intermodule_singleton<sync_handles>::get();
0108    winapi_semaphore_functions sem(handles.obtain_semaphore(this->id_, this, initial_count_));
0109    sem.post(static_cast<long>(release_count));
0110 }
0111
0112
0113 }  //namespace ipcdetail {
0114 }  //namespace interprocess {
0115 }  //namespace boost {
0116
0117 #include <boost/interprocess/detail/config_end.hpp>
0118
0119 #endif   //BOOST_INTERPROCESS_DETAIL_WINDOWS_SEMAPHORE_HPP