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Diffstat (limited to 'src/corelib/thread/qmutex.h')
| -rw-r--r-- | src/corelib/thread/qmutex.h | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/src/corelib/thread/qmutex.h b/src/corelib/thread/qmutex.h new file mode 100644 index 0000000000..5f75195b4e --- /dev/null +++ b/src/corelib/thread/qmutex.h @@ -0,0 +1,248 @@ +/**************************************************************************** +** +** 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. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the Technology Preview License Agreement accompanying +** this package. +** +** GNU Lesser General Public License Usage +** Alternatively, 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. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** +** +** +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#ifndef QMUTEX_H +#define QMUTEX_H + +#include <QtCore/qglobal.h> +#include <QtCore/qatomic.h> +#include <new> + +QT_BEGIN_HEADER + +QT_BEGIN_NAMESPACE + +QT_MODULE(Core) + +#ifndef QT_NO_THREAD + +class QAtomicInt; +class QMutexData; + +class Q_CORE_EXPORT QMutex +{ + friend class QWaitCondition; + friend class QWaitConditionPrivate; + +public: + enum RecursionMode { NonRecursive, Recursive }; + + explicit QMutex(RecursionMode mode = NonRecursive); + ~QMutex(); + + void lock(); //### Qt5: make inline; + inline void lockInline(); + bool tryLock(); //### Qt5: make inline; + bool tryLock(int timeout); + inline bool tryLockInline(); + void unlock(); //### Qt5: make inline; + inline void unlockInline(); + +#if defined(QT3_SUPPORT) + inline QT3_SUPPORT bool locked() + { + if (!tryLock()) + return true; + unlock(); + return false; + } + inline QT3_SUPPORT_CONSTRUCTOR QMutex(bool recursive) + { + new (this) QMutex(recursive ? Recursive : NonRecursive); + } +#endif + +private: + void lockInternal(); + void unlockInternal(); + Q_DISABLE_COPY(QMutex) + + QMutexData *d; +}; + +class Q_CORE_EXPORT QMutexLocker +{ +public: + inline explicit QMutexLocker(QMutex *m) + { + Q_ASSERT_X((reinterpret_cast<quintptr>(m) & quintptr(1u)) == quintptr(0), + "QMutexLocker", "QMutex pointer is misaligned"); + if (m) { + m->lockInline(); + val = reinterpret_cast<quintptr>(m) | quintptr(1u); + } else { + val = 0; + } + } + inline ~QMutexLocker() { unlock(); } + + inline void unlock() + { + if ((val & quintptr(1u)) == quintptr(1u)) { + val &= ~quintptr(1u); + mutex()->unlockInline(); + } + } + + inline void relock() + { + if (val) { + if ((val & quintptr(1u)) == quintptr(0u)) { + mutex()->lockInline(); + val |= quintptr(1u); + } + } + } + +#if defined(Q_CC_MSVC) +#pragma warning( push ) +#pragma warning( disable : 4312 ) // ignoring the warning from /Wp64 +#endif + + inline QMutex *mutex() const + { + return reinterpret_cast<QMutex *>(val & ~quintptr(1u)); + } + +#if defined(Q_CC_MSVC) +#pragma warning( pop ) +#endif + +private: + Q_DISABLE_COPY(QMutexLocker) + + quintptr val; +}; + +class QMutexData +{ + public: + QAtomicInt contenders; + const uint recursive : 1; + uint reserved : 31; + protected: + QMutexData(QMutex::RecursionMode mode); + ~QMutexData(); +}; + +#ifdef QT_NO_DEBUG +inline void QMutex::unlockInline() +{ + if (d->recursive) { + unlock(); + } else if (!d->contenders.testAndSetRelease(1, 0)) { + unlockInternal(); + } +} + +inline bool QMutex::tryLockInline() +{ + if (d->recursive) { + return tryLock(); + } else { + return d->contenders.testAndSetAcquire(0, 1); + } +} + +inline void QMutex::lockInline() +{ + if (d->recursive) { + lock(); + } else if(!tryLockInline()) { + lockInternal(); + } +} +#else // QT_NO_DEBUG +//in debug we do not use inline calls in order to allow debugging tools +// to hook the mutex locking functions. +inline void QMutex::unlockInline() { unlock(); } +inline bool QMutex::tryLockInline() { return tryLock(); } +inline void QMutex::lockInline() { lock(); } +#endif // QT_NO_DEBUG + + +#else // QT_NO_THREAD + + +class Q_CORE_EXPORT QMutex +{ +public: + enum RecursionMode { NonRecursive, Recursive }; + + inline explicit QMutex(RecursionMode mode = NonRecursive) { Q_UNUSED(mode); } + inline ~QMutex() {} + + static inline void lock() {} + static inline void lockInline() {} + static inline bool tryLock(int timeout = 0) { Q_UNUSED(timeout); return true; } + static inline bool tryLockInline() { return true; } + static inline void unlock() {} + static inline void unlockInline() {} + +#if defined(QT3_SUPPORT) + static inline QT3_SUPPORT bool locked() { return false; } +#endif + +private: + Q_DISABLE_COPY(QMutex) +}; + +class Q_CORE_EXPORT QMutexLocker +{ +public: + inline explicit QMutexLocker(QMutex *) {} + inline ~QMutexLocker() {} + + static inline void unlock() {} + static void relock() {} + static inline QMutex *mutex() { return 0; } + +private: + Q_DISABLE_COPY(QMutexLocker) +}; + +#endif // QT_NO_THREAD + +QT_END_NAMESPACE + +QT_END_HEADER + +#endif // QMUTEX_H |