def test_signals(self):
with threading_helper.wait_threads_exit():
# 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:
try:
signal.alarm(1)
signal.pause()
finally:
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 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()
with threading_helper.wait_threads_exit():
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_nt_and_posix_stack_size(self):
try:
thread.stack_size(4096)
except ValueError:
verbose_print("caught expected ValueError setting "
"stack_size(4096)")
except thread.error:
self.skipTest("platform does not support changing thread stack "
"size")
fail_msg = "stack_size(%d) failed - should succeed"
for tss in (262144, 0x100000, 0):
thread.stack_size(tss)
self.assertEqual(thread.stack_size(), tss, fail_msg % tss)
verbose_print("successfully set stack_size(%d)" % tss)
for tss in (262144, 0x100000):
verbose_print("trying stack_size = (%d)" % tss)
self.next_ident = 0
self.created = 0
with threading_helper.wait_threads_exit():
for i in range(NUMTASKS):
self.newtask()
verbose_print("waiting for all tasks to complete")
self.done_mutex.acquire()
verbose_print("all tasks done")
thread.stack_size(0)
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()
with threading_helper.wait_threads_exit():
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.monotonic()
self.assertRaises(KeyboardInterrupt, rlock.acquire, timeout=5)
dt = time.monotonic() - t1
# See rationale above in test_lock_acquire_interruption
self.assertLess(dt, 3.0)
finally:
signal.alarm(0)
signal.signal(signal.SIGALRM, oldalrm)
def test_forkinthread(self):
pid = None
def fork_thread(read_fd, write_fd):
nonlocal pid
# fork in a thread
pid = os.fork()
if pid:
# parent process
return
# child process
try:
os.close(read_fd)
os.write(write_fd, b"OK")
finally:
os._exit(0)
with threading_helper.wait_threads_exit():
thread.start_new_thread(fork_thread, (self.read_fd, self.write_fd))
self.assertEqual(os.read(self.read_fd, 2), b"OK")
os.close(self.write_fd)
self.assertIsNotNone(pid)
support.wait_process(pid, exitcode=0)
def __init__(self, f, n, wait_before_exit=False):
"""
Construct a bunch of `n` threads running the same function `f`.
If `wait_before_exit` is True, the threads won't terminate until
do_finish() is called.
"""
self.f = f
self.n = n
self.started = []
self.finished = []
self._can_exit = not wait_before_exit
self.wait_thread = threading_helper.wait_threads_exit()
self.wait_thread.__enter__()
def task():
tid = threading.get_ident()
self.started.append(tid)
try:
f()
finally:
self.finished.append(tid)
while not self._can_exit:
_wait()
try:
for i in range(n):
start_new_thread(task, ())
except:
self._can_exit = True
raise
def test__count(self):
# Test the _count() function.
orig = thread._count()
mut = thread.allocate_lock()
mut.acquire()
started = []
def task():
started.append(None)
mut.acquire()
mut.release()
with threading_helper.wait_threads_exit():
thread.start_new_thread(task, ())
while not started:
time.sleep(POLL_SLEEP)
self.assertEqual(thread._count(), orig + 1)
# Allow the task to finish.
mut.release()
# The only reliable way to be sure that the thread ended from the
# interpreter's point of view is to wait for the function object to be
# destroyed.
done = []
wr = weakref.ref(task, lambda _: done.append(None))
del task
while not done:
time.sleep(POLL_SLEEP)
self.assertEqual(thread._count(), orig)
def test__count(self):
# Test the _count() function.
orig = thread._count()
mut = thread.allocate_lock()
mut.acquire()
started = []
def task():
started.append(None)
mut.acquire()
mut.release()
with threading_helper.wait_threads_exit():
thread.start_new_thread(task, ())
for _ in support.sleeping_retry(support.LONG_TIMEOUT):
if started:
break
self.assertEqual(thread._count(), orig + 1)
# Allow the task to finish.
mut.release()
# The only reliable way to be sure that the thread ended from the
# interpreter's point of view is to wait for the function object to
# be destroyed.
done = []
wr = weakref.ref(task, lambda _: done.append(None))
del task
for _ in support.sleeping_retry(support.LONG_TIMEOUT):
if done:
break
support.gc_collect() # For PyPy or other GCs.
self.assertEqual(thread._count(), orig)
def test_forkinthread(self):
status = "not set"
def thread1():
nonlocal status
# fork in a thread
pid = os.fork()
if pid == 0:
# child
try:
os.close(self.read_fd)
os.write(self.write_fd, b"OK")
finally:
os._exit(0)
else:
# parent
os.close(self.write_fd)
pid, status = os.waitpid(pid, 0)
with threading_helper.wait_threads_exit():
thread.start_new_thread(thread1, ())
self.assertEqual(os.read(self.read_fd, 2), b"OK",
"Unable to fork() in thread")
self.assertEqual(status, 0)
def test_starting_threads(self):
with threading_helper.wait_threads_exit():
# Basic test for thread creation.
for i in range(NUMTASKS):
self.newtask()
verbose_print("waiting for tasks to complete...")
self.done_mutex.acquire()
verbose_print("all tasks done")
def test_barrier(self):
with threading_helper.wait_threads_exit():
self.bar = Barrier(NUMTASKS)
self.running = NUMTASKS
for i in range(NUMTASKS):
thread.start_new_thread(self.task2, (i, ))
verbose_print("waiting for tasks to end")
self.done_mutex.acquire()
verbose_print("tasks done")
def test_ident_of_no_threading_threads(self):
# The ident still must work for the main thread and dummy threads.
self.assertIsNotNone(threading.currentThread().ident)
def f():
ident.append(threading.currentThread().ident)
done.set()
done = threading.Event()
ident = []
with threading_helper.wait_threads_exit():
tid = _thread.start_new_thread(f, ())
done.wait()
self.assertEqual(ident[0], tid)
# Kill the "immortal" _DummyThread
del threading._active[ident[0]]
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.monotonic()
lock.acquire(timeout=0.5)
self.end = time.monotonic()
def send_signals():
for _ in range(40):
time.sleep(0.02)
os.kill(process_pid, signal.SIGUSR1)
done.release()
with threading_helper.wait_threads_exit():
# 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_unraisable_exception(self):
def task():
started.release()
raise ValueError("task failed")
started = thread.allocate_lock()
with support.catch_unraisable_exception() as cm:
with threading_helper.wait_threads_exit():
started.acquire()
thread.start_new_thread(task, ())
started.acquire()
self.assertEqual(str(cm.unraisable.exc_value), "task failed")
self.assertIs(cm.unraisable.object, task)
self.assertEqual(cm.unraisable.err_msg,
"Exception ignored in thread started by")
self.assertIsNotNone(cm.unraisable.exc_traceback)
def test_foreign_thread(self):
# Check that a "foreign" thread can use the threading module.
def f(mutex):
# Calling current_thread() forces an entry for the foreign
# thread to get made in the threading._active map.
threading.current_thread()
mutex.release()
mutex = threading.Lock()
mutex.acquire()
with threading_helper.wait_threads_exit():
tid = _thread.start_new_thread(f, (mutex,))
# Wait for the thread to finish.
mutex.acquire()
self.assertIn(tid, threading._active)
self.assertIsInstance(threading._active[tid], threading._DummyThread)
#Issue 29376
self.assertTrue(threading._active[tid].is_alive())
self.assertRegex(repr(threading._active[tid]), '_DummyThread')
del threading._active[tid]
def test_reacquire(self):
# Lock needs to be released before re-acquiring.
lock = self.locktype()
phase = []
def f():
lock.acquire()
phase.append(None)
lock.acquire()
phase.append(None)
with threading_helper.wait_threads_exit():
start_new_thread(f, ())
while len(phase) == 0:
_wait()
_wait()
self.assertEqual(len(phase), 1)
lock.release()
while len(phase) == 1:
_wait()
self.assertEqual(len(phase), 2)
