diff options
Diffstat (limited to 'Source/OpenEXR/IlmThread/IlmThreadSemaphorePosixCompat.cpp')
-rw-r--r-- | Source/OpenEXR/IlmThread/IlmThreadSemaphorePosixCompat.cpp | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/Source/OpenEXR/IlmThread/IlmThreadSemaphorePosixCompat.cpp b/Source/OpenEXR/IlmThread/IlmThreadSemaphorePosixCompat.cpp new file mode 100644 index 0000000..33f2a5b --- /dev/null +++ b/Source/OpenEXR/IlmThread/IlmThreadSemaphorePosixCompat.cpp @@ -0,0 +1,155 @@ +/////////////////////////////////////////////////////////////////////////// +// +// 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 |