/**************************************************************************** | |
** | |
** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). | |
** All rights reserved. | |
** Contact: Nokia Corporation (qt-info@nokia.com) | |
** | |
** This file is part of the QtCore module of the Qt Toolkit. | |
** | |
** $QT_BEGIN_LICENSE:LGPL$ | |
** GNU Lesser General Public License Usage | |
** This file may be used under the terms of the GNU Lesser General Public | |
** License version 2.1 as published by the Free Software Foundation and | |
** appearing in the file LICENSE.LGPL included in the packaging of this | |
** file. Please review the following information to ensure the GNU Lesser | |
** General Public License version 2.1 requirements will be met: | |
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. | |
** | |
** In addition, as a special exception, Nokia gives you certain additional | |
** rights. These rights are described in the Nokia Qt LGPL Exception | |
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. | |
** | |
** GNU General Public License Usage | |
** Alternatively, this file may be used under the terms of the GNU General | |
** Public License version 3.0 as published by the Free Software Foundation | |
** and appearing in the file LICENSE.GPL included in the packaging of this | |
** file. Please review the following information to ensure the GNU General | |
** Public License version 3.0 requirements will be met: | |
** http://www.gnu.org/copyleft/gpl.html. | |
** | |
** Other Usage | |
** Alternatively, this file may be used in accordance with the terms and | |
** conditions contained in a signed written agreement between you and Nokia. | |
** | |
** | |
** | |
** | |
** | |
** $QT_END_LICENSE$ | |
** | |
****************************************************************************/ | |
#include "qplatformdefs.h" | |
#include "qwaitcondition.h" | |
#include "qmutex.h" | |
#include "qreadwritelock.h" | |
#include "qatomic.h" | |
#include "qstring.h" | |
#include "qmutex_p.h" | |
#include "qreadwritelock_p.h" | |
#include <errno.h> | |
#ifndef QT_NO_THREAD | |
QT_BEGIN_NAMESPACE | |
static void report_error(int code, const char *where, const char *what) | |
{ | |
if (code != 0) | |
qWarning("%s: %s failure: %s", where, what, qPrintable(qt_error_string(code))); | |
} | |
class QWaitConditionPrivate { | |
public: | |
pthread_mutex_t mutex; | |
pthread_cond_t cond; | |
int waiters; | |
int wakeups; | |
bool wait(unsigned long time) | |
{ | |
int code; | |
forever { | |
if (time != ULONG_MAX) { | |
struct timeval tv; | |
gettimeofday(&tv, 0); | |
timespec ti; | |
ti.tv_nsec = (tv.tv_usec + (time % 1000) * 1000) * 1000; | |
ti.tv_sec = tv.tv_sec + (time / 1000) + (ti.tv_nsec / 1000000000); | |
ti.tv_nsec %= 1000000000; | |
code = pthread_cond_timedwait(&cond, &mutex, &ti); | |
} else { | |
code = pthread_cond_wait(&cond, &mutex); | |
} | |
if (code == 0 && wakeups == 0) { | |
// many vendors warn of spurios wakeups from | |
// pthread_cond_wait(), especially after signal delivery, | |
// even though POSIX doesn't allow for it... sigh | |
continue; | |
} | |
break; | |
} | |
Q_ASSERT_X(waiters > 0, "QWaitCondition::wait", "internal error (waiters)"); | |
--waiters; | |
if (code == 0) { | |
Q_ASSERT_X(wakeups > 0, "QWaitCondition::wait", "internal error (wakeups)"); | |
--wakeups; | |
} | |
report_error(pthread_mutex_unlock(&mutex), "QWaitCondition::wait()", "mutex unlock"); | |
if (code && code != ETIMEDOUT) | |
report_error(code, "QWaitCondition::wait()", "cv wait"); | |
return (code == 0); | |
} | |
}; | |
QWaitCondition::QWaitCondition() | |
{ | |
d = new QWaitConditionPrivate; | |
report_error(pthread_mutex_init(&d->mutex, NULL), "QWaitCondition", "mutex init"); | |
report_error(pthread_cond_init(&d->cond, NULL), "QWaitCondition", "cv init"); | |
d->waiters = d->wakeups = 0; | |
} | |
QWaitCondition::~QWaitCondition() | |
{ | |
report_error(pthread_cond_destroy(&d->cond), "QWaitCondition", "cv destroy"); | |
report_error(pthread_mutex_destroy(&d->mutex), "QWaitCondition", "mutex destroy"); | |
delete d; | |
} | |
void QWaitCondition::wakeOne() | |
{ | |
report_error(pthread_mutex_lock(&d->mutex), "QWaitCondition::wakeOne()", "mutex lock"); | |
d->wakeups = qMin(d->wakeups + 1, d->waiters); | |
report_error(pthread_cond_signal(&d->cond), "QWaitCondition::wakeOne()", "cv signal"); | |
report_error(pthread_mutex_unlock(&d->mutex), "QWaitCondition::wakeOne()", "mutex unlock"); | |
} | |
void QWaitCondition::wakeAll() | |
{ | |
report_error(pthread_mutex_lock(&d->mutex), "QWaitCondition::wakeAll()", "mutex lock"); | |
d->wakeups = d->waiters; | |
report_error(pthread_cond_broadcast(&d->cond), "QWaitCondition::wakeAll()", "cv broadcast"); | |
report_error(pthread_mutex_unlock(&d->mutex), "QWaitCondition::wakeAll()", "mutex unlock"); | |
} | |
bool QWaitCondition::wait(QMutex *mutex, unsigned long time) | |
{ | |
if (! mutex) | |
return false; | |
if (mutex->d->recursive) { | |
qWarning("QWaitCondition: cannot wait on recursive mutexes"); | |
return false; | |
} | |
report_error(pthread_mutex_lock(&d->mutex), "QWaitCondition::wait()", "mutex lock"); | |
++d->waiters; | |
mutex->unlock(); | |
bool returnValue = d->wait(time); | |
mutex->lock(); | |
return returnValue; | |
} | |
bool QWaitCondition::wait(QReadWriteLock *readWriteLock, unsigned long time) | |
{ | |
if (!readWriteLock || readWriteLock->d->accessCount == 0) | |
return false; | |
if (readWriteLock->d->accessCount < -1) { | |
qWarning("QWaitCondition: cannot wait on QReadWriteLocks with recursive lockForWrite()"); | |
return false; | |
} | |
report_error(pthread_mutex_lock(&d->mutex), "QWaitCondition::wait()", "mutex lock"); | |
++d->waiters; | |
int previousAccessCount = readWriteLock->d->accessCount; | |
readWriteLock->unlock(); | |
bool returnValue = d->wait(time); | |
if (previousAccessCount < 0) | |
readWriteLock->lockForWrite(); | |
else | |
readWriteLock->lockForRead(); | |
return returnValue; | |
} | |
QT_END_NAMESPACE | |
#endif // QT_NO_THREAD |