How to use memory bits for thread synchronization

[tovax]

This post is deleted!

[tovax]

Producer:

forever {
    while (!flag) {
        sleep(1)
    }
    waitCondition.wakeOne();
}

Consumer:

forever {
    mutex.lock();
    waitCondition.wait(&mutex);
    doSomething();
    mutex.unlock();
}

Is this correct, please?
Can I wait for the condition only in the consumer thread?
Producer:

eventLoop.exec(); // "flag" will be updated automatically by third-party library.

Consumer:

forever {
    wait(!flag); // how to wait "flag" true without sleep?
    doSomething();
}

[Kent-Dorfman]

the simplest way are the std::atomic types, which are part of the c++ standard now. your question and example are heavily weighted toward the language standard and have little to do with Qt primatives.