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****************************************************************************/

#ifndef QMUTEX_H

#define QMUTEX_H

#include <QtCore/qglobal.h>

#include <new>

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

QT_MODULE(Core)

#ifndef QT_NO_THREAD

class QMutexPrivate;

class Q_CORE_EXPORT QMutex

{

    friend class QWaitCondition;

    friend class QWaitConditionPrivate;

public:

    enum RecursionMode { NonRecursive, Recursive };

    explicit QMutex(RecursionMode mode = NonRecursive);

    ~QMutex();

    void lock();

    bool tryLock();

    bool tryLock(int timeout);

    void unlock();

#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:

    Q_DISABLE_COPY(QMutex)

    QMutexPrivate *d;

};

class Q_CORE_EXPORT QMutexLocker

{

public:

    inline explicit QMutexLocker(QMutex *m)

        : val(reinterpret_cast<quintptr>(m))

    {

        Q_ASSERT_X((val & quintptr(1u)) == quintptr(0),

                   "QMutexLocker", "QMutex pointer is misaligned");

        relock();

    }

    inline ~QMutexLocker() { unlock(); }

    inline void unlock()

    {

        if (val) {

            if ((val & quintptr(1u)) == quintptr(1u)) {

                val &= ~quintptr(1u);

                mutex()->unlock();

            }

        }

    }

    inline void relock()

    {

        if (val) {

            if ((val & quintptr(1u)) == quintptr(0u)) {

                mutex()->lock();

                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;

};

#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 bool tryLock() { return true; }

    static inline bool tryLock(int timeout) { Q_UNUSED(timeout); return true; }

    static void unlock() {}

#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