QWaitCondition issue

moravas

Hi Folks,

I have an unit test code, which should test the thread safety behavioral of a test class. The testcode is the following:
@
public: threadWorker() {
}

public: virtual void run();

public: static const int logCountPerThread;
public: static const int threadCount;
public: static QWaitCondition waitCondition;
public: static cacheType logs;

private: QMutex _sync;
private: QMutex _end;

private: cacheType _cache;
};
@

The definition of the static variables:
@
cacheType threadWorker::logs;
const int threadWorker::threadCount = 100;
QWaitCondition threadWorker::waitCondition;
const int threadWorker::logCountPerThread = 10000;
@

and the worker method itself:
@
void threadWorker::run() {
_sync.lock();
qDebug() << "thread started, and _sync locked";
waitCondition.wait(&_sync);

qDebug() << "woke up";
for(int count = 0; count < logCountPerThread; count++) {
    _cache.insert(core::logging::log(core::logging::logSeverity::info, QString()).id, 0);
}

QMutexLocker lock(&_end);
qDebug() << "_end locked";
for(cacheType::iterator it = _cache.begin(); it != _cache.end(); ++it) {
    logs.insert(it.key(), 0);
}

_cache.clear();
_sync.unlock();

}
@
I deploy the threads from the following method:
@
void logTest::concurentInsatnce() {
QVector<threadWorker*> pool;
for(int count = 0; count < threadWorker::threadCount; count++) {
pool.push_back(new threadWorker());
pool.last()->start();
}

threadWorker::waitCondition.wakeAll();
qDebug() << "wake all sent";

for(threadWorker* thread: pool) {
    qDebug() << "start for waiting thread";
    thread->wait();
    qDebug() << "thread exited";
}

QVERIFY2(threadWorker::logs.size() == threadWorker::logCountPerThread * threadWorker::threadCount,   "unequal object count");

}
@
(OFF: I'm sorry for the lot's of debug outputs)

I observed two main error cases:

I start only one thread by adjusting the value of threadWorker::threadCount. In this case, it seems, that the execution is terminated at the "waitCondition.wait(&_sync);", however the debugger output tell, that the wakeAll() signal sent.
another error case is the current state, what you can see: I start 100 threads. In this case, I see, that few threads are finising its work, and exit normaly, but another threads "don't see" the wakeAll.

Can anybody help me?

Regards,
Norbert