Can anyone help resolve this? On Tue, Dec 01, 2009 at 01:34:11PM +0100, Daniel Mack wrote: > while debugging more details about the Mac OS X port of pulseaudio, I > constently stumble over more and more things that demand attention. > > One thing is that poll() is entirely broken on Mac OS X and causes the > CPU to suck 100% load because the timeout parameter is ignored. I fixed > that already by enabling the legacy 'poll via select' workaround that > has been in the PA tree for a long time (and originally for Windows). > Will post patches soon. > > But even with that workaround enabled, the PA daemon often fails to > start with a command line as simple as > > $ ./pulseaudio -vvn -L module-null-sink -C > > The above should bring me to an interactive prompt, but it doesn't, at > least not always. When debugging that, I always find a thread hung in > read(), caused by the pa_fdsem code. This execution path waits for some > user of a pa_fdsem to call pa_fdsem_post(). > > I suspect this implementation to be racy, but I might have not > understood the sematic of this data type. Is a pa_fdsem supposed to be > accessed by more than one reader/writer? I wrote a little test which > shows that the latter does not work reliably: > > https://gist.github.com/1e8ba0dc00c94a05c090 > > I would expect thread #0 to eat one of the two references it posted, so > there is one free for thread #1. However, this test only ever succeeds > if thread #1's wait() happens to be called right between the two posts > in thread #0. IOW, it mostly fails and hangs. > > Can anyone explain whether this is a bug or if I'm digging at the wrong > place? While the plain logic behind all this is fairly simple, I'm just > not aware of how things are supposed to work in PA. > > Thanks, > Daniel > > _______________________________________________ > pulseaudio-discuss mailing list > pulseaudio-discuss at mail.0pointer.de > https://tango.0pointer.de/mailman/listinfo/pulseaudio-discuss
