/src/FreeImage/Source/OpenEXR/IlmThread/IlmThreadSemaphorePosixCompat.cpp
https://bitbucket.org/cabalistic/ogredeps/ · C++ · 155 lines · 84 code · 31 blank · 40 comment · 12 complexity · cde5c631bab05b16d71a7e85a7ac4c11 MD5 · raw file
- ///////////////////////////////////////////////////////////////////////////
- //
- // Copyright (c) 2005, Industrial Light & Magic, a division of Lucas
- // Digital Ltd. LLC
- //
- // All rights reserved.
- //
- // Redistribution and use in source and binary forms, with or without
- // modification, are permitted provided that the following conditions are
- // met:
- // * Redistributions of source code must retain the above copyright
- // notice, this list of conditions and the following disclaimer.
- // * Redistributions in binary form must reproduce the above
- // copyright notice, this list of conditions and the following disclaimer
- // in the documentation and/or other materials provided with the
- // distribution.
- // * Neither the name of Industrial Light & Magic nor the names of
- // its contributors may be used to endorse or promote products derived
- // from this software without specific prior written permission.
- //
- // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- //
- ///////////////////////////////////////////////////////////////////////////
- //-----------------------------------------------------------------------------
- //
- // class Semaphore -- implementation for for platforms that do
- // support Posix threads but do not support Posix semaphores,
- // for example, OS X
- //
- //-----------------------------------------------------------------------------
- #include "IlmBaseConfig.h"
- #if HAVE_PTHREAD && !HAVE_POSIX_SEMAPHORES
- #include "IlmThreadSemaphore.h"
- #include "Iex.h"
- #include <assert.h>
- namespace IlmThread {
- Semaphore::Semaphore (unsigned int value)
- {
- if (int error = ::pthread_mutex_init (&_semaphore.mutex, 0))
- Iex::throwErrnoExc ("Cannot initialize mutex (%T).", error);
- if (int error = ::pthread_cond_init (&_semaphore.nonZero, 0))
- Iex::throwErrnoExc ("Cannot initialize condition variable (%T).",
- error);
- _semaphore.count = value;
- _semaphore.numWaiting = 0;
- }
- Semaphore::~Semaphore ()
- {
- int error = ::pthread_cond_destroy (&_semaphore.nonZero);
- assert (error == 0);
- error = ::pthread_mutex_destroy (&_semaphore.mutex);
- assert (error == 0);
- }
- void
- Semaphore::wait ()
- {
- ::pthread_mutex_lock (&_semaphore.mutex);
- _semaphore.numWaiting++;
- while (_semaphore.count == 0)
- {
- if (int error = ::pthread_cond_wait (&_semaphore.nonZero,
- &_semaphore.mutex))
- {
- ::pthread_mutex_unlock (&_semaphore.mutex);
- Iex::throwErrnoExc ("Cannot wait on condition variable (%T).",
- error);
- }
- }
- _semaphore.numWaiting--;
- _semaphore.count--;
- ::pthread_mutex_unlock (&_semaphore.mutex);
- }
- bool
- Semaphore::tryWait ()
- {
- ::pthread_mutex_lock (&_semaphore.mutex);
-
- if (_semaphore.count == 0)
- {
- ::pthread_mutex_unlock (&_semaphore.mutex);
- return false;
- }
- else
- {
- _semaphore.count--;
- ::pthread_mutex_unlock (&_semaphore.mutex);
- return true;
- }
- }
- void
- Semaphore::post ()
- {
- ::pthread_mutex_lock (&_semaphore.mutex);
- if (_semaphore.numWaiting > 0)
- {
- if (int error = ::pthread_cond_signal (&_semaphore.nonZero))
- {
- ::pthread_mutex_unlock (&_semaphore.mutex);
- Iex::throwErrnoExc ("Cannot signal condition variable (%T).",
- error);
- }
- }
- _semaphore.count++;
- ::pthread_mutex_unlock (&_semaphore.mutex);
- }
- int
- Semaphore::value () const
- {
- ::pthread_mutex_lock (&_semaphore.mutex);
- int value = _semaphore.count;
- ::pthread_mutex_unlock (&_semaphore.mutex);
- return value;
- }
- } // namespace IlmThread
- #endif