Torque3D/Engine/source/platformX86UNIX/threads/semaphore.cpp

107 lines
3.6 KiB
C++

//-----------------------------------------------------------------------------
// Copyright (c) 2012 GarageGames, LLC
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//-----------------------------------------------------------------------------
#include "platformX86UNIX/platformX86UNIX.h"
#include "platform/threads/semaphore.h"
//MGT: converted SDL to OS semaphores to remove dependency on SDL in dedicated server
#include <unistd.h>
#include <sys/types.h>
#include <errno.h>
#include <semaphore.h>
#include <time.h>
struct PlatformSemaphore
{
sem_t semaphore;
bool initialized;
PlatformSemaphore(S32 initialCount)
{
initialized = true;
if (sem_init(&semaphore, 0, initialCount) == -1) {
initialized = false;
AssertFatal(0, "PlatformSemaphore constructor - Failed to create Semaphore.");
}
}
~PlatformSemaphore()
{
sem_destroy(&semaphore);
initialized = false;
}
};
Semaphore::Semaphore(S32 initialCount)
{
mData = new PlatformSemaphore(initialCount);
}
Semaphore::~Semaphore()
{
AssertFatal(mData, "Semaphore destructor - Invalid semaphore.");
delete mData;
}
bool Semaphore::acquire(bool block, S32 timeoutMS)
{
AssertFatal(mData && mData->initialized, "Semaphore::acquire - Invalid semaphore.");
if (block)
{
//SDL was removed so I do not now if this still holds true or not with OS calls but my guess is they are used underneath SDL anyway
// Semaphore acquiring is different from the MacOS/Win realization because SDL_SemWaitTimeout() with "infinite" timeout can be too heavy on some platforms.
// (see "man SDL_SemWaitTimeout(3)" for more info)
// "man" states to avoid the use of SDL_SemWaitTimeout at all, but at current stage this looks like a valid and working solution, so keeping it this way.
// [bank / Feb-2010]
if (timeoutMS == -1)
{
if (sem_wait(&mData->semaphore) < 0)
AssertFatal(false, "Semaphore::acquire - Wait failed.");
}
else
{
//convert timeoutMS to timespec
timespec ts;
if (clock_gettime(CLOCK_REALTIME, &ts) == -1) {
AssertFatal(false, "Semaphore::acquire - clock_realtime failed.");
}
ts.tv_sec += timeoutMS / 1000;
ts.tv_nsec += (timeoutMS % 1000) * 1000;
if (sem_timedwait(&mData->semaphore, &ts) < 0)
AssertFatal(false, "Semaphore::acquire - Wait with timeout failed.");
}
return (true);
}
else
{
int res = sem_trywait(&mData->semaphore);
return (res == 0);
}
}
void Semaphore::release()
{
AssertFatal(mData, "Semaphore::releaseSemaphore - Invalid semaphore.");
sem_post(&mData->semaphore);
}
//MGT: end