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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/***************************************************************************
* semaphore.cc
*
* Sat Oct 8 17:44:13 CEST 2005
* Copyright 2005 Bent Bisballe Nyeng
* deva@aasimon.org
****************************************************************************/
/*
* This file is part of DrumGizmo.
*
* DrumGizmo is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* DrumGizmo is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with DrumGizmo; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*/
#include "semaphore.h"
#include <hugin.hpp>
#include <limits>
#include <assert.h>
#include <string.h>
#include <chrono>
#include <thread>
#include "platform.h"
#if DG_PLATFORM != DG_PLATFORM_WINDOWS
// Make sure we don't include /this/ file's header...
#include <../include/semaphore.h>
#include <errno.h>
#include <stdio.h>
#include <sys/time.h>
#endif
#if DG_PLATFORM == DG_PLATFORM_OSX
//#include <Multiprocessing.h>
#include <CoreServices/CoreServices.h>
#endif
struct semaphore_private_t {
#if DG_PLATFORM == DG_PLATFORM_WINDOWS
HANDLE semaphore;
#elif DG_PLATFORM == DG_PLATFORM_OSX
MPSemaphoreID semaphore;
#else
sem_t semaphore;
#endif
};
Semaphore::Semaphore(std::size_t initial_count)
{
prv = new struct semaphore_private_t();
#if DG_PLATFORM == DG_PLATFORM_WINDOWS
prv->semaphore = CreateSemaphore(nullptr, // default security attributes
initial_count,
std::numeric_limits<LONG>::max(),
nullptr); // unnamed semaphore
#elif DG_PLATFORM == DG_PLATFORM_OSX
MPCreateSemaphore(std::numeric_limits<std::uint32_t>::max(),
initial_count,
&prv->semaphore);
#else
const int pshared = 0;
memset(&prv->semaphore, 0, sizeof(sem_t));
sem_init(&prv->semaphore, pshared, initial_count);
#endif
}
Semaphore::~Semaphore()
{
#if DG_PLATFORM == DG_PLATFORM_WINDOWS
CloseHandle(prv->semaphore);
#elif DG_PLATFORM == DG_PLATFORM_OSX
MPDeleteSemaphore(prv->semaphore);
#else
sem_destroy(&prv->semaphore);
#endif
delete prv;
}
void Semaphore::post()
{
#if DG_PLATFORM == DG_PLATFORM_WINDOWS
ReleaseSemaphore(prv->semaphore, 1, nullptr);
#elif DG_PLATFORM == DG_PLATFORM_OSX
MPSignalSemaphore(prv->semaphore);
#else
sem_post(&prv->semaphore);
#endif
}
bool Semaphore::wait(const std::chrono::milliseconds& timeout)
{
#if DG_PLATFORM == DG_PLATFORM_WINDOWS
DWORD ret = WaitForSingleObject(prv->semaphore, timeout.count());
if(ret == WAIT_TIMEOUT)
{
return false;
}
assert(ret == WAIT_OBJECT_0);
#elif DG_PLATFORM == DG_PLATFORM_OSX
auto ret = MPWaitOnSemaphore(prv->semaphore,
kDurationMillisecond * timeout.count());
if(ret == kMPTimeoutErr)
{
return false;
}
#else
struct timespec ts;
clock_gettime(CLOCK_REALTIME, &ts);
// Add timeout
time_t seconds = (time_t)(timeout.count() / 1000);
ts.tv_sec += seconds;
ts.tv_nsec += (long)((timeout.count() % 1000) * 1000000);
// Make sure we don't overflow the nanoseconds.
constexpr long nsec = 1000000000LL;
if(ts.tv_nsec >= nsec)
{
ts.tv_nsec -= nsec;
ts.tv_sec += 1;
}
again:
int ret = sem_timedwait(&prv->semaphore, &ts);
if(ret < 0)
{
if(errno == EINTR)
{
// The timed wait were interrupted prematurely so we need to wait some
// more. To prevent an infinite loop-like behaviour we make a short sleep.
std::this_thread::sleep_for(std::chrono::milliseconds(1));
goto again;
}
if(errno == ETIMEDOUT)
{
return false;
}
perror("sem_timedwait()");
assert(false);
}
#endif
return true;
}
void Semaphore::wait()
{
#if DG_PLATFORM == DG_PLATFORM_WINDOWS
WaitForSingleObject(prv->semaphore, INFINITE);
#elif DG_PLATFORM == DG_PLATFORM_OSX
MPWaitOnSemaphore(prv->semaphore, kDurationForever);
#else
again:
int ret = sem_wait(&prv->semaphore);
if(ret < 0)
{
if(errno == EINTR)
{
// The wait were interrupted prematurely so we need to wait again
// To prevent an infinite loop-like behaviour we make a short sleep.
std::this_thread::sleep_for(std::chrono::milliseconds(1));
goto again;
}
perror("sem_wait()");
assert(false);
}
#endif
}
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