boost/interprocess/sync/windows/semaphore.hpp
//////////////////////////////////////////////////////////////////////////////
//
// (C) Copyright Ion Gaztanaga 2005-2011. 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_DETAIL_WINDOWS_SEMAPHORE_HPP
#define BOOST_INTERPROCESS_DETAIL_WINDOWS_SEMAPHORE_HPP
#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/detail/posix_time_types_wrk.hpp>
#include <boost/interprocess/detail/win32_api.hpp>
#include <boost/interprocess/detail/intermodule_singleton.hpp>
#include <boost/interprocess/sync/windows/sync_utils.hpp>
#include <boost/interprocess/exceptions.hpp>
namespace boost {
namespace interprocess {
namespace ipcdetail {
class windows_semaphore
{
windows_semaphore(const windows_semaphore &);
windows_semaphore &operator=(const windows_semaphore &);
public:
windows_semaphore(unsigned int initialCount);
~windows_semaphore();
void post(long release_count = 1);
void wait();
bool try_wait();
bool timed_wait(const boost::posix_time::ptime &abs_time);
private:
const sync_id id_;
};
inline windows_semaphore::windows_semaphore(unsigned int initialCount)
: id_()
{
sync_handles &handles =
intermodule_singleton<sync_handles>::get();
//Force smeaphore creation with the initial count
bool open_or_created;
handles.obtain_semaphore(this->id_, initialCount, &open_or_created);
//The semaphore must be created, never opened
assert(open_or_created);
assert(open_or_created && winapi::get_last_error() != winapi::error_already_exists);
(void)open_or_created;
}
inline windows_semaphore::~windows_semaphore()
{
sync_handles &handles =
intermodule_singleton<sync_handles>::get();
handles.destroy_handle(this->id_);
}
inline void windows_semaphore::wait(void)
{
sync_handles &handles =
intermodule_singleton<sync_handles>::get();
//This can throw
void *hnd = handles.obtain_semaphore(this->id_, 0);
unsigned long ret = winapi::wait_for_single_object(hnd, winapi::infinite_time);
if(ret == winapi::wait_failed){
error_info err(winapi::get_last_error());
throw interprocess_exception(err);
}
}
inline bool windows_semaphore::try_wait(void)
{
sync_handles &handles =
intermodule_singleton<sync_handles>::get();
//This can throw
void *hnd = handles.obtain_semaphore(this->id_, 0);
unsigned long ret = winapi::wait_for_single_object(hnd, 0);
if(ret == winapi::wait_failed){
error_info err(winapi::get_last_error());
throw interprocess_exception(err);
}
return ret != winapi::wait_timeout;
}
inline bool windows_semaphore::timed_wait(const boost::posix_time::ptime &abs_time)
{
if(abs_time == boost::posix_time::pos_infin){
this->wait();
return true;
}
boost::posix_time::ptime now
= boost::posix_time::microsec_clock::universal_time();
unsigned long ms = (unsigned long)(abs_time-now).total_milliseconds();
sync_handles &handles =
intermodule_singleton<sync_handles>::get();
//This can throw
void *hnd = handles.obtain_semaphore(this->id_, 0);
unsigned long ret = winapi::wait_for_single_object(hnd, ms);
if(ret == winapi::wait_failed){
error_info err(winapi::get_last_error());
throw interprocess_exception(err);
}
return ret != winapi::wait_timeout;
}
inline void windows_semaphore::post(long release_count)
{
sync_handles &handles =
intermodule_singleton<sync_handles>::get();
//This can throw
void *hnd = handles.obtain_semaphore(this->id_, 0);
long prev_count;
int ret = winapi::release_semaphore(hnd, release_count, &prev_count);
(void)ret;
assert(ret);
}
} //namespace ipcdetail {
} //namespace interprocess {
} //namespace boost {
#include <boost/interprocess/detail/config_end.hpp>
#endif //BOOST_INTERPROCESS_DETAIL_WINDOWS_SEMAPHORE_HPP