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// Copyright (C) 1999-2005 Open Source Telecom Corporation.
// Copyright (C) 2006-2010 David Sugar, Tycho Softworks.
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
//
// As a special exception, you may use this file as part of a free software
// library without restriction. Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License. This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.
//
// This exception applies only to the code released under the name GNU
// Common C++. If you copy code from other releases into a copy of GNU
// Common C++, as the General Public License permits, the exception does
// not apply to the code that you add in this way. To avoid misleading
// anyone as to the status of such modified files, you must delete
// this exception notice from them.
//
// If you write modifications of your own for GNU Common C++, it is your choice
// whether to permit this exception to apply to your modifications.
// If you do not wish that, delete this exception notice.
//
#include <cc++/config.h>
#include <cc++/export.h>
#include <cc++/exception.h>
#include <cc++/thread.h>
#include "private.h"
#include <cstdio>
#include <cstdlib>
#ifdef CCXX_NAMESPACES
namespace ost {
#endif
#ifndef WIN32
extern "C" {
#include <sys/types.h>
}
#include <cerrno>
Semaphore::Semaphore(unsigned resource)
{
pthread_mutexattr_t attr;
pthread_mutexattr_init(&attr);
pthread_mutex_init(&_mutex, &attr);
pthread_mutexattr_destroy(&attr);
if(pthread_cond_init(&_cond, NULL) && Thread::getException() == Thread::throwObject)
THROW(this);
_count = resource;
_waiters = 0;
}
Semaphore::~Semaphore()
{
// Unlock is needed to unlock the mutex in the case of a cancel during Semaphore::wait()
// see PTHREAD_COND_TIMEDWAIT(3P)
pthread_mutex_unlock(&_mutex);
pthread_cond_destroy(&_cond);
pthread_mutex_destroy(&_mutex);
}
void Semaphore::force_unlock_after_cancellation()
{
pthread_mutex_unlock(&_mutex);
}
bool Semaphore::wait(timeout_t timeout)
{
struct timespec ts;
bool flag = true;
int rc;
pthread_mutex_lock(&_mutex);
++_waiters;
if(_count)
goto exiting;
if(!timeout) {
while(_count == 0)
pthread_cond_wait(&_cond, &_mutex);
goto exiting;
}
getTimeout(&ts, timeout);
rc = pthread_cond_timedwait(&_cond, &_mutex, &ts);
if(rc == ETIMEDOUT || _count == 0)
flag = false;
exiting:
--_waiters;
if(_count)
--_count;
pthread_mutex_unlock(&_mutex);
return flag;
}
void Semaphore::post(void)
{
pthread_mutex_lock(&_mutex);
if(_waiters > 0)
pthread_cond_signal(&_cond);
++_count;
pthread_mutex_unlock(&_mutex);
}
#if 0 // stripped since only in posix
int Semaphore::getValue(void)
{
int value;
pthread_mutex_lock(&_mutex);
value = _count;
pthread_mutex_unlock(&_mutex);
return value;
}
#endif
#else
Semaphore::Semaphore(unsigned resource)
{
semObject = ::CreateSemaphore((LPSECURITY_ATTRIBUTES)NULL, (LONG)resource, MAX_SEM_VALUE, (LPCTSTR)NULL);
}
Semaphore::~Semaphore()
{
::CloseHandle(semObject);
}
bool Semaphore::wait(timeout_t timeout)
{
if(!timeout)
timeout = INFINITE;
return Thread::waitThread(semObject, timeout) == WAIT_OBJECT_0;
}
void Semaphore::post(void)
{
::ReleaseSemaphore(semObject, 1, (LPLONG)NULL);
}
#endif //WIN32
#ifdef CCXX_NAMESPACES
}
#endif
/** EMACS **
* Local variables:
* mode: c++
* c-basic-offset: 4
* End:
*/
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