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Diffstat (limited to 'doc/src/snippets/code/src_corelib_thread_qmutex.cpp')
-rw-r--r-- | doc/src/snippets/code/src_corelib_thread_qmutex.cpp | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/doc/src/snippets/code/src_corelib_thread_qmutex.cpp b/doc/src/snippets/code/src_corelib_thread_qmutex.cpp new file mode 100644 index 0000000..e79bb35 --- /dev/null +++ b/doc/src/snippets/code/src_corelib_thread_qmutex.cpp @@ -0,0 +1,153 @@ +//! [0] +int number = 6; + +void method1() +{ + number *= 5; + number /= 4; +} + +void method2() +{ + number *= 3; + number /= 2; +} +//! [0] + + +//! [1] +// method1() +number *= 5; // number is now 30 +number /= 4; // number is now 7 + +// method2() +number *= 3; // number is now 21 +number /= 2; // number is now 10 +//! [1] + + +//! [2] +// Thread 1 calls method1() +number *= 5; // number is now 30 + +// Thread 2 calls method2(). +// +// Most likely Thread 1 has been put to sleep by the operating +// system to allow Thread 2 to run. +number *= 3; // number is now 90 +number /= 2; // number is now 45 + +// Thread 1 finishes executing. +number /= 4; // number is now 11, instead of 10 +//! [2] + + +//! [3] +QMutex mutex; +int number = 6; + +void method1() +{ + mutex.lock(); + number *= 5; + number /= 4; + mutex.unlock(); +} + +void method2() +{ + mutex.lock(); + number *= 3; + number /= 2; + mutex.unlock(); +} +//! [3] + + +//! [4] +int complexFunction(int flag) +{ + mutex.lock(); + + int retVal = 0; + + switch (flag) { + case 0: + case 1: + mutex.unlock(); + return moreComplexFunction(flag); + case 2: + { + int status = anotherFunction(); + if (status < 0) { + mutex.unlock(); + return -2; + } + retVal = status + flag; + } + break; + default: + if (flag > 10) { + mutex.unlock(); + return -1; + } + break; + } + + mutex.unlock(); + return retVal; +} +//! [4] + + +//! [5] +int complexFunction(int flag) +{ + QMutexLocker locker(&mutex); + + int retVal = 0; + + switch (flag) { + case 0: + case 1: + return moreComplexFunction(flag); + case 2: + { + int status = anotherFunction(); + if (status < 0) + return -2; + retVal = status + flag; + } + break; + default: + if (flag > 10) + return -1; + break; + } + + return retVal; +} +//! [5] + + +//! [6] +class SignalWaiter +{ +private: + QMutexLocker locker; + +public: + SignalWaiter(QMutex *mutex) + : locker(mutex) + { + } + + void waitForSignal() + { + ... + while (!signalled) + waitCondition.wait(locker.mutex()); + ... + } +}; +//! [6] |