/******************************************************************************** Copyright (C) 1992-2006 Trolltech ASA. All rights reserved.**** This file is part of the QtCore module of the Qt Toolkit.**** This file may be used under the terms of the GNU General Public** License version 2.0 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 GNU** General Public Licensing requirements will be met:** http://www.trolltech.com/products/qt/opensource.html**** If you are unsure which license is appropriate for your use, please** review the following information:** http://www.trolltech.com/products/qt/licensing.html or contact the** sales department at sales@trolltech.com.**** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.******************************************************************************/#ifndef QREADWRITELOCK_H#define QREADWRITELOCK_H#include <QtCore/qglobal.h>#include <limits.h>QT_BEGIN_HEADERQT_MODULE(Core)#ifndef QT_NO_THREADstruct QReadWriteLockPrivate;class Q_CORE_EXPORT QReadWriteLock{public:    QReadWriteLock();    ~QReadWriteLock();    void lockForRead();    bool tryLockForRead();    void lockForWrite();    bool tryLockForWrite();    void unlock();private:    Q_DISABLE_COPY(QReadWriteLock)    QReadWriteLockPrivate *d;};class Q_CORE_EXPORT QReadLocker{public:    inline QReadLocker(QReadWriteLock *readWriteLock);    inline ~QReadLocker()    { unlock(); }    inline void unlock()    {        if (q_lock) {            if ((q_val & quintptr(1u)) == quintptr(1u)) {                q_val &= ~quintptr(1u);                q_lock->unlock();            }        }    }    inline void relock()    {        if (q_lock) {            if ((q_val & quintptr(1u)) == quintptr(0u)) {                q_lock->lockForRead();                q_val |= quintptr(1u);            }        }    }    inline QReadWriteLock *readWriteLock() const    { return reinterpret_cast<QReadWriteLock *>(q_val & ~quintptr(1u)); }private:    Q_DISABLE_COPY(QReadLocker)    union {        QReadWriteLock *q_lock;        quintptr q_val;    };};inline QReadLocker::QReadLocker(QReadWriteLock *areadWriteLock)    : q_lock(areadWriteLock){ relock(); }class Q_CORE_EXPORT QWriteLocker{public:    inline QWriteLocker(QReadWriteLock *readWriteLock);    inline ~QWriteLocker()    { unlock(); }    inline void unlock()    {        if (q_lock) {            if ((q_val & quintptr(1u)) == quintptr(1u)) {                q_val &= ~quintptr(1u);                q_lock->unlock();            }        }    }    inline void relock()    {        if (q_lock) {            if ((q_val & quintptr(1u)) == quintptr(0u)) {                q_lock->lockForWrite();                q_val |= quintptr(1u);            }        }    }    inline QReadWriteLock *readWriteLock() const    { return reinterpret_cast<QReadWriteLock *>(q_val & ~quintptr(1u)); }private:    Q_DISABLE_COPY(QWriteLocker)    union{        QReadWriteLock *q_lock;        quintptr q_val;    };};inline QWriteLocker::QWriteLocker(QReadWriteLock *areadWriteLock)    : q_lock(areadWriteLock){ relock(); }#else // QT_NO_THREADclass Q_CORE_EXPORT QReadWriteLock{public:    inline explicit QReadWriteLock() { }    inline ~QReadWriteLock() { }    static inline void lockForRead() { }    static inline bool tryLockForRead() { return true; }    static inline void lockForWrite() { }    static inline bool tryLockForWrite() { 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_THREADQT_END_HEADER#endif // QREADWRITELOCK_H