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

    41 

    42 #ifndef QREADWRITELOCK_H

    43 #define QREADWRITELOCK_H

    44 

    45 #include <QtCore/qglobal.h>

    46 #include <limits.h> // ### Qt 5: remove

    47 

    48 QT_BEGIN_HEADER

    49 

    50 QT_BEGIN_NAMESPACE

    51 

    52 QT_MODULE(Core)

    53 

    54 #ifndef QT_NO_THREAD

    55 

    56 struct QReadWriteLockPrivate;

    57 

    58 class Q_CORE_EXPORT QReadWriteLock

    59 {

    60 public:

    61     enum RecursionMode { NonRecursive, Recursive };

    62 

    63     QReadWriteLock(); // ### Qt 5: merge with below

    64     QReadWriteLock(RecursionMode recursionMode);

    65     ~QReadWriteLock();

    66 

    67     void lockForRead();

    68     bool tryLockForRead();

    69     bool tryLockForRead(int timeout);

    70 

    71     void lockForWrite();

    72     bool tryLockForWrite();

    73     bool tryLockForWrite(int timeout);

    74 

    75     void unlock();

    76 

    77 private:

    78     Q_DISABLE_COPY(QReadWriteLock)

    79     QReadWriteLockPrivate *d;

    80 

    81     friend class QWaitCondition;

    82 };

    83 

    84 #if defined(Q_CC_MSVC)

    85 #pragma warning( push )

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

    87 #endif

    88 

    89 class Q_CORE_EXPORT QReadLocker

    90 {

    91 public:

    92     inline QReadLocker(QReadWriteLock *readWriteLock);

    93 

    94     inline ~QReadLocker()

    95     { unlock(); }

    96 

    97     inline void unlock()

    98     {

    99         if (q_lock) {

   100             if ((q_val & quintptr(1u)) == quintptr(1u)) {

   101                 q_val &= ~quintptr(1u);

   102                 q_lock->unlock();

   103             }

   104         }

   105     }

   106 

   107     inline void relock()

   108     {

   109         if (q_lock) {

   110             if ((q_val & quintptr(1u)) == quintptr(0u)) {

   111                 q_lock->lockForRead();

   112                 q_val |= quintptr(1u);

   113             }

   114         }

   115     }

   116 

   117     inline QReadWriteLock *readWriteLock() const

   118     { return reinterpret_cast<QReadWriteLock *>(q_val & ~quintptr(1u)); }

   119 

   120 private:

   121     Q_DISABLE_COPY(QReadLocker)

   122     union {

   123         QReadWriteLock *q_lock;

   124         quintptr q_val;

   125     };

   126 };

   127 

   128 inline QReadLocker::QReadLocker(QReadWriteLock *areadWriteLock)

   129     : q_lock(areadWriteLock)

   130 {

   131     Q_ASSERT_X((q_val & quintptr(1u)) == quintptr(0),

   132                "QReadLocker", "QReadWriteLock pointer is misaligned");

   133     relock();

   134 }

   135 

   136 class Q_CORE_EXPORT QWriteLocker

   137 {

   138 public:

   139     inline QWriteLocker(QReadWriteLock *readWriteLock);

   140 

   141     inline ~QWriteLocker()

   142     { unlock(); }

   143 

   144     inline void unlock()

   145     {

   146         if (q_lock) {

   147             if ((q_val & quintptr(1u)) == quintptr(1u)) {

   148                 q_val &= ~quintptr(1u);

   149                 q_lock->unlock();

   150             }

   151         }

   152     }

   153 

   154     inline void relock()

   155     {

   156         if (q_lock) {

   157             if ((q_val & quintptr(1u)) == quintptr(0u)) {

   158                 q_lock->lockForWrite();

   159                 q_val |= quintptr(1u);

   160             }

   161         }

   162     }

   163 

   164     inline QReadWriteLock *readWriteLock() const

   165     { return reinterpret_cast<QReadWriteLock *>(q_val & ~quintptr(1u)); }

   166 

   167 

   168 private:

   169     Q_DISABLE_COPY(QWriteLocker)

   170     union{

   171         QReadWriteLock *q_lock;

   172         quintptr q_val;

   173     };

   174 };

   175 

   176 inline QWriteLocker::QWriteLocker(QReadWriteLock *areadWriteLock)

   177     : q_lock(areadWriteLock)

   178 {

   179     Q_ASSERT_X((q_val & quintptr(1u)) == quintptr(0),

   180                "QWriteLocker", "QReadWriteLock pointer is misaligned");

   181     relock();

   182 }

   183 

   184 #if defined(Q_CC_MSVC)

   185 #pragma warning( pop )

   186 #endif

   187 

   188 #else // QT_NO_THREAD

   189 

   190 class Q_CORE_EXPORT QReadWriteLock

   191 {

   192 public:

   193     enum RecursionMode { NonRecursive, Recursive };

   194     inline explicit QReadWriteLock(RecursionMode = NonRecursive) { }

   195     inline ~QReadWriteLock() { }

   196 

   197     static inline void lockForRead() { }

   198     static inline bool tryLockForRead() { return true; }

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

   200 

   201     static inline void lockForWrite() { }

   202     static inline bool tryLockForWrite() { return true; }

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

   204 

   205     static inline void unlock() { }

   206 

   207 private:

   208     Q_DISABLE_COPY(QReadWriteLock)

   209 };

   210 

   211 class Q_CORE_EXPORT QReadLocker

   212 {

   213 public:

   214     inline QReadLocker(QReadWriteLock *) { }

   215     inline ~QReadLocker() { }

   216 

   217     static inline void unlock() { }

   218     static inline void relock() { }

   219     static inline QReadWriteLock *readWriteLock() { return 0; }

   220 

   221 private:

   222     Q_DISABLE_COPY(QReadLocker)

   223 };

   224 

   225 class Q_CORE_EXPORT QWriteLocker

   226 {

   227 public:

   228     inline explicit QWriteLocker(QReadWriteLock *) { }

   229     inline ~QWriteLocker() { }

   230 

   231     static inline void unlock() { }

   232     static inline void relock() { }

   233     static inline QReadWriteLock *readWriteLock() { return 0; }

   234 

   235 private:

   236     Q_DISABLE_COPY(QWriteLocker)

   237 };

   238 

   239 #endif // QT_NO_THREAD

   240 

   241 QT_END_NAMESPACE

   242 

   243 QT_END_HEADER

   244 

   245 #endif // QREADWRITELOCK_H