On 10/22/12 14:12, Till Oliver Knoll wrote: > So the net effect is that the "worker thread" does "one loop too much" > - but /eventually/ it will see that m_continue has been set to 'false' > and will terminate. And that is exactly what we want and hence "good > enough" (no need for protecting the member m_continue with a mutex!).
Hi Till, you don't need a mutex, but you need a guarantee that the compiler will recognize that you use that variable for inter-thread synchronization. Volatile does not do that. Qt's QAtomicInt or C++11's std::atomic_bool or std::atomic_flag will work fine. A good read of what volatile actually is for and how it differs from these atomic variables is available from the links I posted in my other reply to this thread. A great source for information are also various articles speaking about the "memory model" -- if you're interested and have some time to spare, I'd suggest reading them. It was definitely fun for me. With kind regards Jan -- Trojita, a fast e-mail client -- http://trojita.flaska.net/
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