On Wed, 2013-03-20 at 09:32 +0100, David Henningsson wrote: > On 03/20/2013 08:57 AM, Tanu Kaskinen wrote: > > On Tue, 2013-03-19 at 13:20 +0100, Thomas Martitz wrote: > >> Am 19.03.2013 10:56, schrieb Tanu Kaskinen: > >>> I'd be OK with adding pa_simple_writable/readable_size(). I believe the > >>> multi-threading aspect of adding the write/read callbacks unavoidably > >>> makes writing applications not-simple, so the simple API probably > >>> shouldn't have those callbacks. > >>> > >> > >> It's not unlikely that an application that uses blocking or polling > >> methods uses an extra thread for that, which it wouldn't do if it could > >> use the callback method. So in this case the callback would simplify the > >> application, because the multi threading aspect is not in the > >> application logic but in pulseaudio. I don't know how common this case > >> is, but I would expect it's rather common. > > > > The applications would still need to be aware of the threading. > > pa_simple_read/write() is expected to be done from the main thread, so > > the application necessarily needs to implement some communication method > > between the two threads. > > From what I can see, there is no such restriction of the simple API. It > does not have a concept of a "main thread", so as long as you don't call > into the simple API from two threads at the same time you should be just > fine, e g, it would be perfectly valid to do pa_simple_new in one > thread, and later call pa_simple_write from another thread. pa_simple_write() calls pa_threaded_mainloop_wait(), and pa_threaded_mainloop_wait() has this assertion: pa_assert(!m->thread || !pa_thread_is_running(m->thread) || !in_worker(m)); The in_worker() check will fail, if pa_simple_write() was called from the callback context. -- Tanu
