On 16/07/18 08:24, Gerlando Falauto wrote: > On Monday, July 16, 2018 at 8:13:46 AM UTC+2, Thomas Jollans wrote: >> On 16/07/18 07:39, Gerlando Falauto wrote: >>> On Monday, July 16, 2018 at 6:56:19 AM UTC+2, dieter wrote: >>>>> ... >>>>> Why is the main thread taking up so much CPU? >>>>> I believe at this point listener.stop() should only be waiting for the >>>>> helper thread to terminate, which I reckon would be implemented by >>>>> waiting on a semaphore or something (i.e. iowait i.e. 0% CPU). >>>> >>>> Maybe, you look at the source code of "listener.stop"? >>> >>> I did, forgot to mention that. Culprit is self._thread.join(). >>> Which is where it waits for the internal thread to terminate, >>> which I would've expected to wait on a lock or semaphore (pthread_join()?) >>> So there's something I'm totally missing here, which has more to do >>> with queues and threads in general than it has with logging. >>> Any ideas? >>> >> >> I have no idea what's really going on there, but a quick look through >> the source reveals that the actual waiting in Thread.join() is done by >> sem_wait(). >> >> via >> https://github.com/python/cpython/blob/13ff24582c99dfb439b1af7295b401415e7eb05b/Python/thread_pthread.h#L304 >> via >> https://github.com/python/cpython/blob/master/Modules/_threadmodule.c#L45 > > Hmm... do you think it's possible it's really getting interrupted the whole > time, effectively turning the lock into a sort of spinlock? > Any idea how to confirm that without recompiling the whole code? >
Profiling, maybe? Or you might be able to find out if it's being interrupted by listening for signals yourself (though I'm not sure which one(s))? -- https://mail.python.org/mailman/listinfo/python-list
