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Diffstat (limited to 'src/corelib/thread/qreadwritelock.h')
| -rw-r--r-- | src/corelib/thread/qreadwritelock.h | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/src/corelib/thread/qreadwritelock.h b/src/corelib/thread/qreadwritelock.h new file mode 100644 index 0000000000..e4fd18e0e3 --- /dev/null +++ b/src/corelib/thread/qreadwritelock.h @@ -0,0 +1,239 @@ +/**************************************************************************** +** +** 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 QREADWRITELOCK_H +#define QREADWRITELOCK_H + +#include <QtCore/qglobal.h> +#include <limits.h> // ### Qt 5: remove + +QT_BEGIN_HEADER + +QT_BEGIN_NAMESPACE + +QT_MODULE(Core) + +#ifndef QT_NO_THREAD + +struct QReadWriteLockPrivate; + +class Q_CORE_EXPORT QReadWriteLock +{ +public: + enum RecursionMode { NonRecursive, Recursive }; + + QReadWriteLock(); // ### Qt 5: merge with below + QReadWriteLock(RecursionMode recursionMode); + ~QReadWriteLock(); + + void lockForRead(); + bool tryLockForRead(); + bool tryLockForRead(int timeout); + + void lockForWrite(); + bool tryLockForWrite(); + bool tryLockForWrite(int timeout); + + void unlock(); + +private: + Q_DISABLE_COPY(QReadWriteLock) + QReadWriteLockPrivate *d; + + friend class QWaitCondition; +}; + +#if defined(Q_CC_MSVC) +#pragma warning( push ) +#pragma warning( disable : 4312 ) // ignoring the warning from /Wp64 +#endif + +class Q_CORE_EXPORT QReadLocker +{ +public: + inline QReadLocker(QReadWriteLock *readWriteLock); + + inline ~QReadLocker() + { unlock(); } + + inline void unlock() + { + if (q_val) { + if ((q_val & quintptr(1u)) == quintptr(1u)) { + q_val &= ~quintptr(1u); + readWriteLock()->unlock(); + } + } + } + + inline void relock() + { + if (q_val) { + if ((q_val & quintptr(1u)) == quintptr(0u)) { + readWriteLock()->lockForRead(); + q_val |= quintptr(1u); + } + } + } + + inline QReadWriteLock *readWriteLock() const + { return reinterpret_cast<QReadWriteLock *>(q_val & ~quintptr(1u)); } + +private: + Q_DISABLE_COPY(QReadLocker) + quintptr q_val; +}; + +inline QReadLocker::QReadLocker(QReadWriteLock *areadWriteLock) + : q_val(reinterpret_cast<quintptr>(areadWriteLock)) +{ + Q_ASSERT_X((q_val & quintptr(1u)) == quintptr(0), + "QReadLocker", "QReadWriteLock pointer is misaligned"); + relock(); +} + +class Q_CORE_EXPORT QWriteLocker +{ +public: + inline QWriteLocker(QReadWriteLock *readWriteLock); + + inline ~QWriteLocker() + { unlock(); } + + inline void unlock() + { + if (q_val) { + if ((q_val & quintptr(1u)) == quintptr(1u)) { + q_val &= ~quintptr(1u); + readWriteLock()->unlock(); + } + } + } + + inline void relock() + { + if (q_val) { + if ((q_val & quintptr(1u)) == quintptr(0u)) { + readWriteLock()->lockForWrite(); + q_val |= quintptr(1u); + } + } + } + + inline QReadWriteLock *readWriteLock() const + { return reinterpret_cast<QReadWriteLock *>(q_val & ~quintptr(1u)); } + + +private: + Q_DISABLE_COPY(QWriteLocker) + quintptr q_val; +}; + +inline QWriteLocker::QWriteLocker(QReadWriteLock *areadWriteLock) + : q_val(reinterpret_cast<quintptr>(areadWriteLock)) +{ + Q_ASSERT_X((q_val & quintptr(1u)) == quintptr(0), + "QWriteLocker", "QReadWriteLock pointer is misaligned"); + relock(); +} + +#if defined(Q_CC_MSVC) +#pragma warning( pop ) +#endif + +#else // QT_NO_THREAD + +class Q_CORE_EXPORT QReadWriteLock +{ +public: + enum RecursionMode { NonRecursive, Recursive }; + inline explicit QReadWriteLock(RecursionMode = NonRecursive) { } + inline ~QReadWriteLock() { } + + static inline void lockForRead() { } + static inline bool tryLockForRead() { return true; } + static inline bool tryLockForRead(int timeout) { Q_UNUSED(timeout); return true; } + + static inline void lockForWrite() { } + static inline bool tryLockForWrite() { return true; } + static inline bool tryLockForWrite(int timeout) { Q_UNUSED(timeout); return true; } + + static inline void unlock() { } + +private: + Q_DISABLE_COPY(QReadWriteLock) +}; + +class Q_CORE_EXPORT QReadLocker +{ +public: + inline QReadLocker(QReadWriteLock *) { } + inline ~QReadLocker() { } + + static inline void unlock() { } + static inline void relock() { } + static inline QReadWriteLock *readWriteLock() { return 0; } + +private: + Q_DISABLE_COPY(QReadLocker) +}; + +class Q_CORE_EXPORT QWriteLocker +{ +public: + inline explicit QWriteLocker(QReadWriteLock *) { } + inline ~QWriteLocker() { } + + static inline void unlock() { } + static inline void relock() { } + static inline QReadWriteLock *readWriteLock() { return 0; } + +private: + Q_DISABLE_COPY(QWriteLocker) +}; + +#endif // QT_NO_THREAD + +QT_END_NAMESPACE + +QT_END_HEADER + +#endif // QREADWRITELOCK_H |