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     2 **

     3 ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).

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    16 ** GNU Lesser General Public License Usage

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    18 ** General Public License version 2.1 as published by the Free Software

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    38 ** $QT_END_LICENSE$

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    40 ****************************************************************************/

    41 

    42 #ifndef QMUTEX_H

    43 #define QMUTEX_H

    44 

    45 #include <QtCore/qglobal.h>

    46 #include <new>

    47 

    48 QT_BEGIN_HEADER

    49 

    50 QT_BEGIN_NAMESPACE

    51 

    52 QT_MODULE(Core)

    53 

    54 #ifndef QT_NO_THREAD

    55 

    56 class QMutexPrivate;

    57 

    58 class Q_CORE_EXPORT QMutex

    59 {

    60     friend class QWaitCondition;

    61     friend class QWaitConditionPrivate;

    62 

    63 public:

    64     enum RecursionMode { NonRecursive, Recursive };

    65 

    66     explicit QMutex(RecursionMode mode = NonRecursive);

    67     ~QMutex();

    68 

    69     void lock();

    70     bool tryLock();

    71     bool tryLock(int timeout);

    72     void unlock();

    73 

    74 #if defined(QT3_SUPPORT)

    75     inline QT3_SUPPORT bool locked()

    76     {

    77         if (!tryLock())

    78             return true;

    79         unlock();

    80         return false;

    81     }

    82     inline QT3_SUPPORT_CONSTRUCTOR QMutex(bool recursive)

    83     {

    84         new (this) QMutex(recursive ? Recursive : NonRecursive);

    85     }

    86 #endif

    87 

    88 private:

    89     Q_DISABLE_COPY(QMutex)

    90 

    91     QMutexPrivate *d;

    92 };

    93 

    94 class Q_CORE_EXPORT QMutexLocker

    95 {

    96 public:

    97     inline explicit QMutexLocker(QMutex *m)

    98         : mtx(m)

    99     {

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

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

   102         relock();

   103     }

   104     inline ~QMutexLocker() { unlock(); }

   105 

   106     inline void unlock()

   107     {

   108         if (mtx) {

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

   110                 val &= ~quintptr(1u);

   111                 mtx->unlock();

   112             }

   113         }

   114     }

   115 

   116     inline void relock()

   117     {

   118         if (mtx) {

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

   120                 mtx->lock();

   121                 val |= quintptr(1u);

   122             }

   123         }

   124     }

   125 

   126 #if defined(Q_CC_MSVC)

   127 #pragma warning( push )

   128 #pragma warning( disable : 4312 ) // ignoring the warning from /Wp64

   129 #endif

   130 

   131     inline QMutex *mutex() const

   132     {

   133         return reinterpret_cast<QMutex *>(val & ~quintptr(1u));

   134     }

   135 

   136 #if defined(Q_CC_MSVC)

   137 #pragma warning( pop )

   138 #endif

   139 

   140 private:

   141     Q_DISABLE_COPY(QMutexLocker)

   142 

   143     union {

   144         QMutex *mtx;

   145         quintptr val;

   146     };

   147 };

   148 

   149 #else // QT_NO_THREAD

   150 

   151 

   152 class Q_CORE_EXPORT QMutex

   153 {

   154 public:

   155     enum RecursionMode { NonRecursive, Recursive };

   156 

   157     inline explicit QMutex(RecursionMode mode = NonRecursive) { Q_UNUSED(mode); }

   158     inline ~QMutex() {}

   159 

   160     static inline void lock() {}

   161     static inline bool tryLock() { return true; }

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

   163     static void unlock() {}

   164 

   165 #if defined(QT3_SUPPORT)

   166     static inline QT3_SUPPORT bool locked() { return false; }

   167 #endif

   168 

   169 private:

   170     Q_DISABLE_COPY(QMutex)

   171 };

   172 

   173 class Q_CORE_EXPORT QMutexLocker

   174 {

   175 public:

   176     inline explicit QMutexLocker(QMutex *) {}

   177     inline ~QMutexLocker() {}

   178 

   179     static inline void unlock() {}

   180     static void relock() {}

   181     static inline QMutex *mutex() { return 0; }

   182 

   183 private:

   184     Q_DISABLE_COPY(QMutexLocker)

   185 };

   186 

   187 #endif // QT_NO_THREAD

   188 

   189 QT_END_NAMESPACE

   190 

   191 QT_END_HEADER

   192 

   193 #endif // QMUTEX_H