/usr/lib/python3.4/test/test_threadsignals.py is in libpython3.4-testsuite 3.4.2-1.
This file is owned by root:root, with mode 0o644.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 | """PyUnit testing that threads honor our signal semantics"""
import unittest
import signal
import os
import sys
from test.support import run_unittest, import_module
thread = import_module('_thread')
import time
if (sys.platform[:3] == 'win'):
raise unittest.SkipTest("Can't test signal on %s" % sys.platform)
process_pid = os.getpid()
signalled_all=thread.allocate_lock()
USING_PTHREAD_COND = (sys.thread_info.name == 'pthread'
and sys.thread_info.lock == 'mutex+cond')
def registerSignals(for_usr1, for_usr2, for_alrm):
usr1 = signal.signal(signal.SIGUSR1, for_usr1)
usr2 = signal.signal(signal.SIGUSR2, for_usr2)
alrm = signal.signal(signal.SIGALRM, for_alrm)
return usr1, usr2, alrm
# The signal handler. Just note that the signal occurred and
# from who.
def handle_signals(sig,frame):
signal_blackboard[sig]['tripped'] += 1
signal_blackboard[sig]['tripped_by'] = thread.get_ident()
# a function that will be spawned as a separate thread.
def send_signals():
os.kill(process_pid, signal.SIGUSR1)
os.kill(process_pid, signal.SIGUSR2)
signalled_all.release()
class ThreadSignals(unittest.TestCase):
def test_signals(self):
# Test signal handling semantics of threads.
# 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.
signalled_all.acquire()
self.spawnSignallingThread()
signalled_all.acquire()
# 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
# and might be out of order.) If we haven't seen
# the signals yet, send yet another signal and
# wait for it return.
if signal_blackboard[signal.SIGUSR1]['tripped'] == 0 \
or signal_blackboard[signal.SIGUSR2]['tripped'] == 0:
signal.alarm(1)
signal.pause()
signal.alarm(0)
self.assertEqual( signal_blackboard[signal.SIGUSR1]['tripped'], 1)
self.assertEqual( signal_blackboard[signal.SIGUSR1]['tripped_by'],
thread.get_ident())
self.assertEqual( signal_blackboard[signal.SIGUSR2]['tripped'], 1)
self.assertEqual( signal_blackboard[signal.SIGUSR2]['tripped_by'],
thread.get_ident())
signalled_all.release()
def spawnSignallingThread(self):
thread.start_new_thread(send_signals, ())
def alarm_interrupt(self, sig, frame):
raise KeyboardInterrupt
@unittest.skipIf(USING_PTHREAD_COND,
'POSIX condition variables cannot be interrupted')
# Issue #20564: sem_timedwait() cannot be interrupted on OpenBSD
@unittest.skipIf(sys.platform.startswith('openbsd'),
'lock cannot be interrupted on OpenBSD')
def test_lock_acquire_interruption(self):
# Mimic receiving a SIGINT (KeyboardInterrupt) with SIGALRM while stuck
# in a deadlock.
# XXX this test can fail when the legacy (non-semaphore) implementation
# of locks is used in thread_pthread.h, see issue #11223.
oldalrm = signal.signal(signal.SIGALRM, self.alarm_interrupt)
try:
lock = thread.allocate_lock()
lock.acquire()
signal.alarm(1)
t1 = time.time()
self.assertRaises(KeyboardInterrupt, lock.acquire, timeout=5)
dt = time.time() - t1
# Checking that KeyboardInterrupt was raised is not sufficient.
# We want to assert that lock.acquire() was interrupted because
# of the signal, not that the signal handler was called immediately
# after timeout return of lock.acquire() (which can fool assertRaises).
self.assertLess(dt, 3.0)
finally:
signal.signal(signal.SIGALRM, oldalrm)
@unittest.skipIf(USING_PTHREAD_COND,
'POSIX condition variables cannot be interrupted')
# Issue #20564: sem_timedwait() cannot be interrupted on OpenBSD
@unittest.skipIf(sys.platform.startswith('openbsd'),
'lock cannot be interrupted on OpenBSD')
def test_rlock_acquire_interruption(self):
# Mimic receiving a SIGINT (KeyboardInterrupt) with SIGALRM while stuck
# in a deadlock.
# XXX this test can fail when the legacy (non-semaphore) implementation
# of locks is used in thread_pthread.h, see issue #11223.
oldalrm = signal.signal(signal.SIGALRM, self.alarm_interrupt)
try:
rlock = thread.RLock()
# For reentrant locks, the initial acquisition must be in another
# thread.
def other_thread():
rlock.acquire()
thread.start_new_thread(other_thread, ())
# Wait until we can't acquire it without blocking...
while rlock.acquire(blocking=False):
rlock.release()
time.sleep(0.01)
signal.alarm(1)
t1 = time.time()
self.assertRaises(KeyboardInterrupt, rlock.acquire, timeout=5)
dt = time.time() - t1
# See rationale above in test_lock_acquire_interruption
self.assertLess(dt, 3.0)
finally:
signal.signal(signal.SIGALRM, oldalrm)
def acquire_retries_on_intr(self, lock):
self.sig_recvd = False
def my_handler(signal, frame):
self.sig_recvd = True
old_handler = signal.signal(signal.SIGUSR1, my_handler)
try:
def other_thread():
# Acquire the lock in a non-main thread, so this test works for
# RLocks.
lock.acquire()
# Wait until the main thread is blocked in the lock acquire, and
# then wake it up with this.
time.sleep(0.5)
os.kill(process_pid, signal.SIGUSR1)
# Let the main thread take the interrupt, handle it, and retry
# the lock acquisition. Then we'll let it run.
time.sleep(0.5)
lock.release()
thread.start_new_thread(other_thread, ())
# Wait until we can't acquire it without blocking...
while lock.acquire(blocking=False):
lock.release()
time.sleep(0.01)
result = lock.acquire() # Block while we receive a signal.
self.assertTrue(self.sig_recvd)
self.assertTrue(result)
finally:
signal.signal(signal.SIGUSR1, old_handler)
def test_lock_acquire_retries_on_intr(self):
self.acquire_retries_on_intr(thread.allocate_lock())
def test_rlock_acquire_retries_on_intr(self):
self.acquire_retries_on_intr(thread.RLock())
def test_interrupted_timed_acquire(self):
# Test to make sure we recompute lock acquisition timeouts when we
# receive a signal. Check this by repeatedly interrupting a lock
# acquire in the main thread, and make sure that the lock acquire times
# out after the right amount of time.
# NOTE: this test only behaves as expected if C signals get delivered
# to the main thread. Otherwise lock.acquire() itself doesn't get
# interrupted and the test trivially succeeds.
self.start = None
self.end = None
self.sigs_recvd = 0
done = thread.allocate_lock()
done.acquire()
lock = thread.allocate_lock()
lock.acquire()
def my_handler(signum, frame):
self.sigs_recvd += 1
old_handler = signal.signal(signal.SIGUSR1, my_handler)
try:
def timed_acquire():
self.start = time.time()
lock.acquire(timeout=0.5)
self.end = time.time()
def send_signals():
for _ in range(40):
time.sleep(0.02)
os.kill(process_pid, signal.SIGUSR1)
done.release()
# Send the signals from the non-main thread, since the main thread
# is the only one that can process signals.
thread.start_new_thread(send_signals, ())
timed_acquire()
# Wait for thread to finish
done.acquire()
# This allows for some timing and scheduling imprecision
self.assertLess(self.end - self.start, 2.0)
self.assertGreater(self.end - self.start, 0.3)
# If the signal is received several times before PyErr_CheckSignals()
# is called, the handler will get called less than 40 times. Just
# check it's been called at least once.
self.assertGreater(self.sigs_recvd, 0)
finally:
signal.signal(signal.SIGUSR1, old_handler)
def test_main():
global signal_blackboard
signal_blackboard = { signal.SIGUSR1 : {'tripped': 0, 'tripped_by': 0 },
signal.SIGUSR2 : {'tripped': 0, 'tripped_by': 0 },
signal.SIGALRM : {'tripped': 0, 'tripped_by': 0 } }
oldsigs = registerSignals(handle_signals, handle_signals, handle_signals)
try:
run_unittest(ThreadSignals)
finally:
registerSignals(*oldsigs)
if __name__ == '__main__':
test_main()
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