On Dimarts 09 Agost 2011 14:57:06 David Faure wrote: > > I just tried a test calling that function with 0 as timeout (so it always > > timeouts) and sometimes it waits until 1 second so it is quite clear it > > is waiting for the thread. > > Yes, Thiago explained to me the notion of cancellation points, and proved > me wrong. And since anyway terminate is a bad idea, this needs to be > redesigned. > > Thomas: I can't see how locking a mutex can work in a single-threaded case > (there are no threads in your code; you seem to rely on the fact that Qt > uses a thread internally in QHostInfo? That seems dangerous...). > > Thiago and I came up with a design like this: > * a single thread that makes async lookups. It's never blocked, it can > always almost immediately read new requests from a queue and start them. > * each request is encapsulated in a class that has the QString > but also a QSemaphore. > * the main thread can block using a timeout > (QSemaphore::tryAcquire(timeout)) * the request class is stored using a > shared pointer, so that it's only deleted when neither the main thread nor > the worker thread need it anymore [otherwise the deletion is a problem, in > the timeout case vs the normal case]
Works for me, do you need help implementing it [workwise not knowledgewise ;)]? Albert
