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# qmutex.h

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    00001 /****************************************************************************
    00002 **
    00003 ** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
    00004 ** All rights reserved.
    00005 ** Contact: Nokia Corporation (qt-info@nokia.com)
    00006 **
    00007 ** This file is part of the QtCore module of the Qt Toolkit.
    00008 **
    00009 ** $QT_BEGIN_LICENSE:LGPL$
    00010 ** Commercial Usage
    00011 ** Licensees holding valid Qt Commercial licenses may use this file in
    00012 ** accordance with the Qt Commercial License Agreement provided with the
    00013 ** Software or, alternatively, in accordance with the terms contained in
    00014 ** a written agreement between you and Nokia.
    00015 **
    00016 ** GNU Lesser General Public License Usage
    00017 ** Alternatively, this file may be used under the terms of the GNU Lesser
    00018 ** General Public License version 2.1 as published by the Free Software
    00019 ** Foundation and appearing in the file LICENSE.LGPL included in the
    00020 ** packaging of this file.  Please review the following information to
    00021 ** ensure the GNU Lesser General Public License version 2.1 requirements
    00022 ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
    00023 **
    00024 ** In addition, as a special exception, Nokia gives you certain additional
    00025 ** rights.  These rights are described in the Nokia Qt LGPL Exception
    00026 ** version 1.1, included in the file LGPL_EXCEPTION.txt in this module.
    00027 **
    00028 ** GNU General Public License Usage
    00029 ** Alternatively, this file may be used under the terms of the GNU
    00030 ** General Public License version 3.0 as published by the Free Software
    00031 ** Foundation and appearing in the file LICENSE.GPL included in the
    00032 ** packaging of this file.  Please review the following information to
    00033 ** ensure the GNU General Public License version 3.0 requirements will be
    00034 ** met: http://www.gnu.org/copyleft/gpl.html.
    00035 **
    00036 ** If you have questions regarding the use of this file, please contact
    00037 ** Nokia at qt-info@nokia.com.
    00038 ** $QT_END_LICENSE$
    00039 **
    00040 ****************************************************************************/
    00041
    00042 #ifndef QMUTEX_H
    00043 #define QMUTEX_H
    00044
    00045 #include <QtCore/qglobal.h>
    00046 #include <new>
    00047
    00048 QT_BEGIN_HEADER
    00049
    00050 QT_BEGIN_NAMESPACE
    00051
    00052 QT_MODULE(Core)
    00053
    00054 #ifndef QT_NO_THREAD
    00055
    00056 class QMutexPrivate;
    00057
    00058 class Q_CORE_EXPORT QMutex
    00059 {
    00060     friend class QWaitCondition;
    00061     friend class QWaitConditionPrivate;
    00062
    00063 public:
    00064     enum RecursionMode { NonRecursive, Recursive };
    00065
    00066     explicit QMutex(RecursionMode mode = NonRecursive);
    00067     ~QMutex();
    00068
    00069     void lock();
    00070     bool tryLock();
    00071     bool tryLock(int timeout);
    00072     void unlock();
    00073
    00074 #if defined(QT3_SUPPORT)
    00075     inline QT3_SUPPORT bool locked()
    00076     {
    00077         if (!tryLock())
    00078             return true;
    00079         unlock();
    00080         return false;
    00081     }
    00082     inline QT3_SUPPORT_CONSTRUCTOR QMutex(bool recursive)
    00083     {
    00084         new (this) QMutex(recursive ? Recursive : NonRecursive);
    00085     }
    00086 #endif
    00087
    00088 private:
    00089     Q_DISABLE_COPY(QMutex)
    00090
    00091     QMutexPrivate *d;
    00092 };
    00093
    00094 class Q_CORE_EXPORT QMutexLocker
    00095 {
    00096 public:
    00097     inline explicit QMutexLocker(QMutex *m)
    00098     {
    00099         Q_ASSERT_X((reinterpret_cast<quintptr>(m) & quintptr(1u)) == quintptr(0),
    00100                    "QMutexLocker", "QMutex pointer is misaligned");
    00101         if (m) {
    00102             m->lock();
    00103             val = reinterpret_cast<quintptr>(m) | quintptr(1u);
    00104         } else {
    00105             val = 0;
    00106         }
    00107     }
    00108     inline ~QMutexLocker() { unlock(); }
    00109
    00110     inline void unlock()
    00111     {
    00112         if ((val & quintptr(1u)) == quintptr(1u)) {
    00113             val &= ~quintptr(1u);
    00114             mutex()->unlock();
    00115         }
    00116     }
    00117
    00118     inline void relock()
    00119     {
    00120         if (val) {
    00121             if ((val & quintptr(1u)) == quintptr(0u)) {
    00122                 mutex()->lock();
    00123                 val |= quintptr(1u);
    00124             }
    00125         }
    00126     }
    00127
    00128 #if defined(Q_CC_MSVC)
    00129 #pragma warning( push )
    00130 #pragma warning( disable : 4312 ) // ignoring the warning from /Wp64
    00131 #endif
    00132
    00133     inline QMutex *mutex() const
    00134     {
    00135         return reinterpret_cast<QMutex *>(val & ~quintptr(1u));
    00136     }
    00137
    00138 #if defined(Q_CC_MSVC)
    00139 #pragma warning( pop )
    00140 #endif
    00141
    00142 private:
    00143     Q_DISABLE_COPY(QMutexLocker)
    00144
    00145     quintptr val;
    00146 };
    00147
    00148 #else // QT_NO_THREAD
    00149
    00150
    00151 class Q_CORE_EXPORT QMutex
    00152 {
    00153 public:
    00154     enum RecursionMode { NonRecursive, Recursive };
    00155
    00156     inline explicit QMutex(RecursionMode mode = NonRecursive) { Q_UNUSED(mode); }
    00157     inline ~QMutex() {}
    00158
    00159     static inline void lock() {}
    00160     static inline bool tryLock() { return true; }
    00161     static inline bool tryLock(int timeout) { Q_UNUSED(timeout); return true; }
    00162     static void unlock() {}
    00163
    00164 #if defined(QT3_SUPPORT)
    00165     static inline QT3_SUPPORT bool locked() { return false; }
    00166 #endif
    00167
    00168 private:
    00169     Q_DISABLE_COPY(QMutex)
    00170 };
    00171
    00172 class Q_CORE_EXPORT QMutexLocker
    00173 {
    00174 public:
    00175     inline explicit QMutexLocker(QMutex *) {}
    00176     inline ~QMutexLocker() {}
    00177
    00178     static inline void unlock() {}
    00179     static void relock() {}
    00180     static inline QMutex *mutex() { return 0; }
    00181
    00182 private:
    00183     Q_DISABLE_COPY(QMutexLocker)
    00184 };
    00185
    00186 #endif // QT_NO_THREAD
    00187
    00188 QT_END_NAMESPACE
    00189
    00190 QT_END_HEADER
    00191
    00192 #endif // QMUTEX_H