Skip to content

Commit 9abee72

Browse files
authored
bpo-31479: Always reset the signal alarm in tests (#3588)
* bpo-31479: Always reset the signal alarm in tests Use "try: ... finally: signal.signal(0)" pattern to make sure that tests don't "leak" a pending fatal signal alarm. * Move two more alarm() calls into the try block Fix also typo: replace signal.signal(0) with signal.alarm(0) * Move another signal.alarm() into the try block
1 parent a92941f commit 9abee72

File tree

6 files changed

+56
-40
lines changed

6 files changed

+56
-40
lines changed

Lib/test/signalinterproctester.py

Lines changed: 7 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -74,10 +74,13 @@ def test_interprocess_signal(self):
7474
# Nothing should happen: SIGUSR2 is ignored
7575
child.wait()
7676

77-
signal.alarm(1)
78-
self.wait_signal(None, 'SIGALRM', KeyboardInterrupt)
79-
self.assertEqual(self.got_signals, {'SIGHUP': 1, 'SIGUSR1': 1,
80-
'SIGALRM': 0})
77+
try:
78+
signal.alarm(1)
79+
self.wait_signal(None, 'SIGALRM', KeyboardInterrupt)
80+
self.assertEqual(self.got_signals, {'SIGHUP': 1, 'SIGUSR1': 1,
81+
'SIGALRM': 0})
82+
finally:
83+
signal.alarm(0)
8184

8285

8386
if __name__ == "__main__":

Lib/test/test_io.py

Lines changed: 3 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -3940,6 +3940,7 @@ def on_alarm(*args):
39403940
if isinstance(exc, RuntimeError):
39413941
self.assertTrue(str(exc).startswith("reentrant call"), str(exc))
39423942
finally:
3943+
signal.alarm(0)
39433944
wio.close()
39443945
os.close(r)
39453946

@@ -3968,6 +3969,7 @@ def alarm_handler(sig, frame):
39683969
# - third raw read() returns b"bar"
39693970
self.assertEqual(decode(rio.read(6)), "foobar")
39703971
finally:
3972+
signal.alarm(0)
39713973
rio.close()
39723974
os.close(w)
39733975
os.close(r)
@@ -4035,6 +4037,7 @@ def alarm2(sig, frame):
40354037
self.assertIsNone(error)
40364038
self.assertEqual(N, sum(len(x) for x in read_results))
40374039
finally:
4040+
signal.alarm(0)
40384041
write_finished = True
40394042
os.close(w)
40404043
os.close(r)

Lib/test/test_pty.py

Lines changed: 3 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -51,14 +51,11 @@ class PtyTest(unittest.TestCase):
5151
def setUp(self):
5252
# isatty() and close() can hang on some platforms. Set an alarm
5353
# before running the test to make sure we don't hang forever.
54-
self.old_alarm = signal.signal(signal.SIGALRM, self.handle_sig)
54+
old_alarm = signal.signal(signal.SIGALRM, self.handle_sig)
55+
self.addCleanup(signal.signal, signal.SIGALRM, old_alarm)
56+
self.addCleanup(signal.alarm, 0)
5557
signal.alarm(10)
5658

57-
def tearDown(self):
58-
# remove alarm, restore old alarm handler
59-
signal.alarm(0)
60-
signal.signal(signal.SIGALRM, self.old_alarm)
61-
6259
def handle_sig(self, sig, frame):
6360
self.fail("isatty hung")
6461

Lib/test/test_selectors.py

Lines changed: 22 additions & 18 deletions
Original file line numberDiff line numberDiff line change
@@ -399,17 +399,19 @@ def handler(*args):
399399

400400
orig_alrm_handler = signal.signal(signal.SIGALRM, handler)
401401
self.addCleanup(signal.signal, signal.SIGALRM, orig_alrm_handler)
402-
self.addCleanup(signal.alarm, 0)
403402

404-
signal.alarm(1)
403+
try:
404+
signal.alarm(1)
405405

406-
s.register(rd, selectors.EVENT_READ)
407-
t = time()
408-
# select() is interrupted by a signal which raises an exception
409-
with self.assertRaises(InterruptSelect):
410-
s.select(30)
411-
# select() was interrupted before the timeout of 30 seconds
412-
self.assertLess(time() - t, 5.0)
406+
s.register(rd, selectors.EVENT_READ)
407+
t = time()
408+
# select() is interrupted by a signal which raises an exception
409+
with self.assertRaises(InterruptSelect):
410+
s.select(30)
411+
# select() was interrupted before the timeout of 30 seconds
412+
self.assertLess(time() - t, 5.0)
413+
finally:
414+
signal.alarm(0)
413415

414416
@unittest.skipUnless(hasattr(signal, "alarm"),
415417
"signal.alarm() required for this test")
@@ -421,17 +423,19 @@ def test_select_interrupt_noraise(self):
421423

422424
orig_alrm_handler = signal.signal(signal.SIGALRM, lambda *args: None)
423425
self.addCleanup(signal.signal, signal.SIGALRM, orig_alrm_handler)
424-
self.addCleanup(signal.alarm, 0)
425426

426-
signal.alarm(1)
427+
try:
428+
signal.alarm(1)
427429

428-
s.register(rd, selectors.EVENT_READ)
429-
t = time()
430-
# select() is interrupted by a signal, but the signal handler doesn't
431-
# raise an exception, so select() should by retries with a recomputed
432-
# timeout
433-
self.assertFalse(s.select(1.5))
434-
self.assertGreaterEqual(time() - t, 1.0)
430+
s.register(rd, selectors.EVENT_READ)
431+
t = time()
432+
# select() is interrupted by a signal, but the signal handler doesn't
433+
# raise an exception, so select() should by retries with a recomputed
434+
# timeout
435+
self.assertFalse(s.select(1.5))
436+
self.assertGreaterEqual(time() - t, 1.0)
437+
finally:
438+
signal.alarm(0)
435439

436440

437441
class ScalableSelectorMixIn:

Lib/test/test_socket.py

Lines changed: 14 additions & 9 deletions
Original file line numberDiff line numberDiff line change
@@ -3854,7 +3854,6 @@ def setUp(self):
38543854
orig_alrm_handler = signal.signal(signal.SIGALRM,
38553855
lambda signum, frame: 1 / 0)
38563856
self.addCleanup(signal.signal, signal.SIGALRM, orig_alrm_handler)
3857-
self.addCleanup(self.setAlarm, 0)
38583857

38593858
# Timeout for socket operations
38603859
timeout = 4.0
@@ -3891,9 +3890,12 @@ def setUp(self):
38913890
def checkInterruptedRecv(self, func, *args, **kwargs):
38923891
# Check that func(*args, **kwargs) raises
38933892
# errno of EINTR when interrupted by a signal.
3894-
self.setAlarm(self.alarm_time)
3895-
with self.assertRaises(ZeroDivisionError) as cm:
3896-
func(*args, **kwargs)
3893+
try:
3894+
self.setAlarm(self.alarm_time)
3895+
with self.assertRaises(ZeroDivisionError) as cm:
3896+
func(*args, **kwargs)
3897+
finally:
3898+
self.setAlarm(0)
38973899

38983900
def testInterruptedRecvTimeout(self):
38993901
self.checkInterruptedRecv(self.serv.recv, 1024)
@@ -3948,10 +3950,13 @@ def checkInterruptedSend(self, func, *args, **kwargs):
39483950
# Check that func(*args, **kwargs), run in a loop, raises
39493951
# OSError with an errno of EINTR when interrupted by a
39503952
# signal.
3951-
with self.assertRaises(ZeroDivisionError) as cm:
3952-
while True:
3953-
self.setAlarm(self.alarm_time)
3954-
func(*args, **kwargs)
3953+
try:
3954+
with self.assertRaises(ZeroDivisionError) as cm:
3955+
while True:
3956+
self.setAlarm(self.alarm_time)
3957+
func(*args, **kwargs)
3958+
finally:
3959+
self.setAlarm(0)
39553960

39563961
# Issue #12958: The following tests have problems on OS X prior to 10.7
39573962
@support.requires_mac_ver(10, 7)
@@ -4675,8 +4680,8 @@ def alarm_handler(signal, frame):
46754680
raise Alarm
46764681
old_alarm = signal.signal(signal.SIGALRM, alarm_handler)
46774682
try:
4678-
signal.alarm(2) # POSIX allows alarm to be up to 1 second early
46794683
try:
4684+
signal.alarm(2) # POSIX allows alarm to be up to 1 second early
46804685
foo = self.serv.accept()
46814686
except socket.timeout:
46824687
self.fail("caught timeout instead of Alarm")

Lib/test/test_threadsignals.py

Lines changed: 7 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -56,9 +56,11 @@ def test_signals(self):
5656
# wait for it return.
5757
if signal_blackboard[signal.SIGUSR1]['tripped'] == 0 \
5858
or signal_blackboard[signal.SIGUSR2]['tripped'] == 0:
59-
signal.alarm(1)
60-
signal.pause()
61-
signal.alarm(0)
59+
try:
60+
signal.alarm(1)
61+
signal.pause()
62+
finally:
63+
signal.alarm(0)
6264

6365
self.assertEqual( signal_blackboard[signal.SIGUSR1]['tripped'], 1)
6466
self.assertEqual( signal_blackboard[signal.SIGUSR1]['tripped_by'],
@@ -98,6 +100,7 @@ def test_lock_acquire_interruption(self):
98100
# after timeout return of lock.acquire() (which can fool assertRaises).
99101
self.assertLess(dt, 3.0)
100102
finally:
103+
signal.alarm(0)
101104
signal.signal(signal.SIGALRM, oldalrm)
102105

103106
@unittest.skipIf(USING_PTHREAD_COND,
@@ -131,6 +134,7 @@ def other_thread():
131134
# See rationale above in test_lock_acquire_interruption
132135
self.assertLess(dt, 3.0)
133136
finally:
137+
signal.alarm(0)
134138
signal.signal(signal.SIGALRM, oldalrm)
135139

136140
def acquire_retries_on_intr(self, lock):

0 commit comments

Comments
 (0)