(original) (raw)

changeset: 69425:fdcbc8453304 parent: 69422:fcd20a565b95 parent: 69424:28ab8c6ad8f9 user: Victor Stinner victor.stinner@haypocalc.com date: Mon Apr 18 16:30:17 2011 +0200 files: Lib/test/test_threadsignals.py Misc/NEWS description: (Merge 3.2) Issue #11768: The signal handler of the signal module only calls Py_AddPendingCall() for the first signal to fix a deadlock on reentrant or parallel calls. PyErr_SetInterrupt() writes also into the wake up file. diff -r fcd20a565b95 -r fdcbc8453304 Lib/test/test_threadsignals.py --- a/Lib/test/test_threadsignals.py Mon Apr 18 10:11:06 2011 -0400 +++ b/Lib/test/test_threadsignals.py Mon Apr 18 16:30:17 2011 +0200 @@ -30,14 +30,9 @@ # a function that will be spawned as a separate thread. def send_signals(): - print("send_signals: enter (thread %s)" % thread.get_ident(), file=sys.stderr) - print("send_signals: raise SIGUSR1", file=sys.stderr) os.kill(process_pid, signal.SIGUSR1) - print("send_signals: raise SIGUSR2", file=sys.stderr) os.kill(process_pid, signal.SIGUSR2) - print("send_signals: release signalled_all", file=sys.stderr) signalled_all.release() - print("send_signals: exit (thread %s)" % thread.get_ident(), file=sys.stderr) class ThreadSignals(unittest.TestCase): @@ -46,12 +41,9 @@ # We spawn a thread, have the thread send two signals, and # wait for it to finish. Check that we got both signals # and that they were run by the main thread. - print("test_signals: acquire lock (thread %s)" % thread.get_ident(), file=sys.stderr) signalled_all.acquire() self.spawnSignallingThread() - print("test_signals: wait lock (thread %s)" % thread.get_ident(), file=sys.stderr) signalled_all.acquire() - print("test_signals: lock acquired", file=sys.stderr) # the signals that we asked the kernel to send # will come back, but we don't know when. # (it might even be after the thread exits diff -r fcd20a565b95 -r fdcbc8453304 Misc/NEWS --- a/Misc/NEWS Mon Apr 18 10:11:06 2011 -0400 +++ b/Misc/NEWS Mon Apr 18 16:30:17 2011 +0200 @@ -110,6 +110,10 @@ Library ------- +- Issue #11768: The signal handler of the signal module only calls + Py_AddPendingCall() for the first signal to fix a deadlock on reentrant or + parallel calls. PyErr_SetInterrupt() writes also into the wake up file. + - Issue #11492: fix several issues with header folding in the email package. - Issue #11852: Add missing imports and update tests. diff -r fcd20a565b95 -r fdcbc8453304 Modules/signalmodule.c --- a/Modules/signalmodule.c Mon Apr 18 10:11:06 2011 -0400 +++ b/Modules/signalmodule.c Mon Apr 18 16:30:17 2011 +0200 @@ -166,6 +166,20 @@ } static void +trip_signal(int sig_num) +{ + Handlers[sig_num].tripped = 1; + if (is_tripped) + return; + /* Set is_tripped after setting .tripped, as it gets + cleared in PyErr_CheckSignals() before .tripped. */ + is_tripped = 1; + Py_AddPendingCall(checksignals_witharg, NULL); + if (wakeup_fd != -1) + write(wakeup_fd, "\0", 1); +} + +static void signal_handler(int sig_num) { int save_errno = errno; @@ -182,13 +196,7 @@ if (getpid() == main_pid) #endif { - Handlers[sig_num].tripped = 1; - /* Set is_tripped after setting .tripped, as it gets - cleared in PyErr_CheckSignals() before .tripped. */ - is_tripped = 1; - Py_AddPendingCall(checksignals_witharg, NULL); - if (wakeup_fd != -1) - write(wakeup_fd, "\0", 1); + trip_signal(sig_num); } #ifndef HAVE_SIGACTION @@ -946,9 +954,7 @@ void PyErr_SetInterrupt(void) { - is_tripped = 1; - Handlers[SIGINT].tripped = 1; - Py_AddPendingCall((int (*)(void *))PyErr_CheckSignals, NULL); + trip_signal(SIGINT); } void /victor.stinner@haypocalc.com