def read_sigmask():
return signal.pthread_sigmask(signal.SIG_BLOCK, [])
+ if sys.platform == "darwin":
+ import faulthandler
+ # The fault handler timeout thread masks all signals. If the main
+ # thread masks also SIGUSR1, all threads mask this signal. In this
+ # case, on Mac OS X, if we send SIGUSR1 to the process, the signal
+ # is pending in the main or the faulthandler timeout thread.
+ # Unblock SIGUSR1 in the main thread calls the signal handler only
+ # if the signal is pending for the main thread.
+ #
+ # Stop the faulthandler timeout thread to workaround this problem.
+ # Another solution would be to send the signal directly to the main
+ # thread using pthread_kill(), but Python doesn't expose this
+ # function.
+ faulthandler.cancel_dump_tracebacks_later()
+
old_handler = signal.signal(signum, handler)
self.addCleanup(signal.signal, signum, old_handler)