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1319 lines (1064 loc) · 44.9 KB
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import test.support
# Skip tests if _multiprocessing wasn't built.
test.support.import_module('_multiprocessing')
# Skip tests if sem_open implementation is broken.
test.support.import_module('multiprocessing.synchronize')
from test.support.script_helper import assert_python_ok
import contextlib
import itertools
import logging
from logging.handlers import QueueHandler
import os
import queue
import sys
import threading
import time
import unittest
import weakref
from pickle import PicklingError
from concurrent import futures
from concurrent.futures._base import (
PENDING, RUNNING, CANCELLED, CANCELLED_AND_NOTIFIED, FINISHED, Future,
BrokenExecutor)
from concurrent.futures.process import BrokenProcessPool
from multiprocessing import get_context
import multiprocessing.process
import multiprocessing.util
def create_future(state=PENDING, exception=None, result=None):
f = Future()
f._state = state
f._exception = exception
f._result = result
return f
PENDING_FUTURE = create_future(state=PENDING)
RUNNING_FUTURE = create_future(state=RUNNING)
CANCELLED_FUTURE = create_future(state=CANCELLED)
CANCELLED_AND_NOTIFIED_FUTURE = create_future(state=CANCELLED_AND_NOTIFIED)
EXCEPTION_FUTURE = create_future(state=FINISHED, exception=OSError())
SUCCESSFUL_FUTURE = create_future(state=FINISHED, result=42)
INITIALIZER_STATUS = 'uninitialized'
def mul(x, y):
return x * y
def capture(*args, **kwargs):
return args, kwargs
def sleep_and_raise(t):
time.sleep(t)
raise Exception('this is an exception')
def sleep_and_print(t, msg):
time.sleep(t)
print(msg)
sys.stdout.flush()
def init(x):
global INITIALIZER_STATUS
INITIALIZER_STATUS = x
def get_init_status():
return INITIALIZER_STATUS
def init_fail(log_queue=None):
if log_queue is not None:
logger = logging.getLogger('concurrent.futures')
logger.addHandler(QueueHandler(log_queue))
logger.setLevel('CRITICAL')
logger.propagate = False
time.sleep(0.1) # let some futures be scheduled
raise ValueError('error in initializer')
class MyObject(object):
def my_method(self):
pass
class EventfulGCObj():
def __init__(self, ctx):
mgr = get_context(ctx).Manager()
self.event = mgr.Event()
def __del__(self):
self.event.set()
def make_dummy_object(_):
return MyObject()
class BaseTestCase(unittest.TestCase):
def setUp(self):
self._thread_key = test.support.threading_setup()
def tearDown(self):
test.support.reap_children()
test.support.threading_cleanup(*self._thread_key)
class ExecutorMixin:
worker_count = 5
executor_kwargs = {}
def setUp(self):
super().setUp()
self.t1 = time.monotonic()
if hasattr(self, "ctx"):
self.executor = self.executor_type(
max_workers=self.worker_count,
mp_context=self.get_context(),
**self.executor_kwargs)
else:
self.executor = self.executor_type(
max_workers=self.worker_count,
**self.executor_kwargs)
self._prime_executor()
def tearDown(self):
self.executor.shutdown(wait=True)
self.executor = None
dt = time.monotonic() - self.t1
if test.support.verbose:
print("%.2fs" % dt, end=' ')
self.assertLess(dt, 300, "synchronization issue: test lasted too long")
super().tearDown()
def get_context(self):
return get_context(self.ctx)
def _prime_executor(self):
# Make sure that the executor is ready to do work before running the
# tests. This should reduce the probability of timeouts in the tests.
futures = [self.executor.submit(time.sleep, 0.1)
for _ in range(self.worker_count)]
for f in futures:
f.result()
class ThreadPoolMixin(ExecutorMixin):
executor_type = futures.ThreadPoolExecutor
class ProcessPoolForkMixin(ExecutorMixin):
executor_type = futures.ProcessPoolExecutor
ctx = "fork"
def get_context(self):
if sys.platform == "win32":
self.skipTest("require unix system")
return super().get_context()
class ProcessPoolSpawnMixin(ExecutorMixin):
executor_type = futures.ProcessPoolExecutor
ctx = "spawn"
class ProcessPoolForkserverMixin(ExecutorMixin):
executor_type = futures.ProcessPoolExecutor
ctx = "forkserver"
def get_context(self):
if sys.platform == "win32":
self.skipTest("require unix system")
return super().get_context()
def create_executor_tests(mixin, bases=(BaseTestCase,),
executor_mixins=(ThreadPoolMixin,
ProcessPoolForkMixin,
ProcessPoolForkserverMixin,
ProcessPoolSpawnMixin)):
def strip_mixin(name):
if name.endswith(('Mixin', 'Tests')):
return name[:-5]
elif name.endswith('Test'):
return name[:-4]
else:
return name
for exe in executor_mixins:
name = ("%s%sTest"
% (strip_mixin(exe.__name__), strip_mixin(mixin.__name__)))
cls = type(name, (mixin,) + (exe,) + bases, {})
globals()[name] = cls
class InitializerMixin(ExecutorMixin):
worker_count = 2
def setUp(self):
global INITIALIZER_STATUS
INITIALIZER_STATUS = 'uninitialized'
self.executor_kwargs = dict(initializer=init,
initargs=('initialized',))
super().setUp()
def test_initializer(self):
futures = [self.executor.submit(get_init_status)
for _ in range(self.worker_count)]
for f in futures:
self.assertEqual(f.result(), 'initialized')
class FailingInitializerMixin(ExecutorMixin):
worker_count = 2
def setUp(self):
if hasattr(self, "ctx"):
# Pass a queue to redirect the child's logging output
self.mp_context = self.get_context()
self.log_queue = self.mp_context.Queue()
self.executor_kwargs = dict(initializer=init_fail,
initargs=(self.log_queue,))
else:
# In a thread pool, the child shares our logging setup
# (see _assert_logged())
self.mp_context = None
self.log_queue = None
self.executor_kwargs = dict(initializer=init_fail)
super().setUp()
def test_initializer(self):
with self._assert_logged('ValueError: error in initializer'):
try:
future = self.executor.submit(get_init_status)
except BrokenExecutor:
# Perhaps the executor is already broken
pass
else:
with self.assertRaises(BrokenExecutor):
future.result()
# At some point, the executor should break
t1 = time.monotonic()
while not self.executor._broken:
if time.monotonic() - t1 > 5:
self.fail("executor not broken after 5 s.")
time.sleep(0.01)
# ... and from this point submit() is guaranteed to fail
with self.assertRaises(BrokenExecutor):
self.executor.submit(get_init_status)
def _prime_executor(self):
pass
@contextlib.contextmanager
def _assert_logged(self, msg):
if self.log_queue is not None:
yield
output = []
try:
while True:
output.append(self.log_queue.get_nowait().getMessage())
except queue.Empty:
pass
else:
with self.assertLogs('concurrent.futures', 'CRITICAL') as cm:
yield
output = cm.output
self.assertTrue(any(msg in line for line in output),
output)
create_executor_tests(InitializerMixin)
create_executor_tests(FailingInitializerMixin)
class ExecutorShutdownTest:
def test_run_after_shutdown(self):
self.executor.shutdown()
self.assertRaises(RuntimeError,
self.executor.submit,
pow, 2, 5)
def test_interpreter_shutdown(self):
# Test the atexit hook for shutdown of worker threads and processes
rc, out, err = assert_python_ok('-c', """if 1:
from concurrent.futures import {executor_type}
from time import sleep
from test.test_concurrent_futures import sleep_and_print
if __name__ == "__main__":
context = '{context}'
if context == "":
t = {executor_type}(5)
else:
from multiprocessing import get_context
context = get_context(context)
t = {executor_type}(5, mp_context=context)
t.submit(sleep_and_print, 1.0, "apple")
""".format(executor_type=self.executor_type.__name__,
context=getattr(self, "ctx", "")))
# Errors in atexit hooks don't change the process exit code, check
# stderr manually.
self.assertFalse(err)
self.assertEqual(out.strip(), b"apple")
def test_submit_after_interpreter_shutdown(self):
# Test the atexit hook for shutdown of worker threads and processes
rc, out, err = assert_python_ok('-c', """if 1:
import atexit
@atexit.register
def run_last():
try:
t.submit(id, None)
except RuntimeError:
print("runtime-error")
raise
from concurrent.futures import {executor_type}
if __name__ == "__main__":
context = '{context}'
if not context:
t = {executor_type}(5)
else:
from multiprocessing import get_context
context = get_context(context)
t = {executor_type}(5, mp_context=context)
t.submit(id, 42).result()
""".format(executor_type=self.executor_type.__name__,
context=getattr(self, "ctx", "")))
# Errors in atexit hooks don't change the process exit code, check
# stderr manually.
self.assertIn("RuntimeError: cannot schedule new futures", err.decode())
self.assertEqual(out.strip(), b"runtime-error")
def test_hang_issue12364(self):
fs = [self.executor.submit(time.sleep, 0.1) for _ in range(50)]
self.executor.shutdown()
for f in fs:
f.result()
class ThreadPoolShutdownTest(ThreadPoolMixin, ExecutorShutdownTest, BaseTestCase):
def _prime_executor(self):
pass
def test_threads_terminate(self):
def acquire_lock(lock):
lock.acquire()
sem = threading.Semaphore(0)
for i in range(3):
self.executor.submit(acquire_lock, sem)
self.assertEqual(len(self.executor._threads), 3)
for i in range(3):
sem.release()
self.executor.shutdown()
for t in self.executor._threads:
t.join()
def test_context_manager_shutdown(self):
with futures.ThreadPoolExecutor(max_workers=5) as e:
executor = e
self.assertEqual(list(e.map(abs, range(-5, 5))),
[5, 4, 3, 2, 1, 0, 1, 2, 3, 4])
for t in executor._threads:
t.join()
def test_del_shutdown(self):
executor = futures.ThreadPoolExecutor(max_workers=5)
executor.map(abs, range(-5, 5))
threads = executor._threads
del executor
for t in threads:
t.join()
def test_thread_names_assigned(self):
executor = futures.ThreadPoolExecutor(
max_workers=5, thread_name_prefix='SpecialPool')
executor.map(abs, range(-5, 5))
threads = executor._threads
del executor
for t in threads:
self.assertRegex(t.name, r'^SpecialPool_[0-4]$')
t.join()
def test_thread_names_default(self):
executor = futures.ThreadPoolExecutor(max_workers=5)
executor.map(abs, range(-5, 5))
threads = executor._threads
del executor
for t in threads:
# Ensure that our default name is reasonably sane and unique when
# no thread_name_prefix was supplied.
self.assertRegex(t.name, r'ThreadPoolExecutor-\d+_[0-4]$')
t.join()
class ProcessPoolShutdownTest(ExecutorShutdownTest):
def _prime_executor(self):
pass
def test_processes_terminate(self):
self.executor.submit(mul, 21, 2)
self.executor.submit(mul, 6, 7)
self.executor.submit(mul, 3, 14)
self.assertEqual(len(self.executor._processes), 5)
processes = self.executor._processes
self.executor.shutdown()
for p in processes.values():
p.join()
def test_context_manager_shutdown(self):
with futures.ProcessPoolExecutor(max_workers=5) as e:
processes = e._processes
self.assertEqual(list(e.map(abs, range(-5, 5))),
[5, 4, 3, 2, 1, 0, 1, 2, 3, 4])
for p in processes.values():
p.join()
def test_del_shutdown(self):
executor = futures.ProcessPoolExecutor(max_workers=5)
list(executor.map(abs, range(-5, 5)))
queue_management_thread = executor._queue_management_thread
processes = executor._processes
call_queue = executor._call_queue
queue_management_thread = executor._queue_management_thread
del executor
# Make sure that all the executor resources were properly cleaned by
# the shutdown process
queue_management_thread.join()
for p in processes.values():
p.join()
call_queue.join_thread()
create_executor_tests(ProcessPoolShutdownTest,
executor_mixins=(ProcessPoolForkMixin,
ProcessPoolForkserverMixin,
ProcessPoolSpawnMixin))
class WaitTests:
def test_first_completed(self):
future1 = self.executor.submit(mul, 21, 2)
future2 = self.executor.submit(time.sleep, 1.5)
done, not_done = futures.wait(
[CANCELLED_FUTURE, future1, future2],
return_when=futures.FIRST_COMPLETED)
self.assertEqual(set([future1]), done)
self.assertEqual(set([CANCELLED_FUTURE, future2]), not_done)
def test_first_completed_some_already_completed(self):
future1 = self.executor.submit(time.sleep, 1.5)
finished, pending = futures.wait(
[CANCELLED_AND_NOTIFIED_FUTURE, SUCCESSFUL_FUTURE, future1],
return_when=futures.FIRST_COMPLETED)
self.assertEqual(
set([CANCELLED_AND_NOTIFIED_FUTURE, SUCCESSFUL_FUTURE]),
finished)
self.assertEqual(set([future1]), pending)
def test_first_exception(self):
future1 = self.executor.submit(mul, 2, 21)
future2 = self.executor.submit(sleep_and_raise, 1.5)
future3 = self.executor.submit(time.sleep, 3)
finished, pending = futures.wait(
[future1, future2, future3],
return_when=futures.FIRST_EXCEPTION)
self.assertEqual(set([future1, future2]), finished)
self.assertEqual(set([future3]), pending)
def test_first_exception_some_already_complete(self):
future1 = self.executor.submit(divmod, 21, 0)
future2 = self.executor.submit(time.sleep, 1.5)
finished, pending = futures.wait(
[SUCCESSFUL_FUTURE,
CANCELLED_FUTURE,
CANCELLED_AND_NOTIFIED_FUTURE,
future1, future2],
return_when=futures.FIRST_EXCEPTION)
self.assertEqual(set([SUCCESSFUL_FUTURE,
CANCELLED_AND_NOTIFIED_FUTURE,
future1]), finished)
self.assertEqual(set([CANCELLED_FUTURE, future2]), pending)
def test_first_exception_one_already_failed(self):
future1 = self.executor.submit(time.sleep, 2)
finished, pending = futures.wait(
[EXCEPTION_FUTURE, future1],
return_when=futures.FIRST_EXCEPTION)
self.assertEqual(set([EXCEPTION_FUTURE]), finished)
self.assertEqual(set([future1]), pending)
def test_all_completed(self):
future1 = self.executor.submit(divmod, 2, 0)
future2 = self.executor.submit(mul, 2, 21)
finished, pending = futures.wait(
[SUCCESSFUL_FUTURE,
CANCELLED_AND_NOTIFIED_FUTURE,
EXCEPTION_FUTURE,
future1,
future2],
return_when=futures.ALL_COMPLETED)
self.assertEqual(set([SUCCESSFUL_FUTURE,
CANCELLED_AND_NOTIFIED_FUTURE,
EXCEPTION_FUTURE,
future1,
future2]), finished)
self.assertEqual(set(), pending)
def test_timeout(self):
future1 = self.executor.submit(mul, 6, 7)
future2 = self.executor.submit(time.sleep, 6)
finished, pending = futures.wait(
[CANCELLED_AND_NOTIFIED_FUTURE,
EXCEPTION_FUTURE,
SUCCESSFUL_FUTURE,
future1, future2],
timeout=5,
return_when=futures.ALL_COMPLETED)
self.assertEqual(set([CANCELLED_AND_NOTIFIED_FUTURE,
EXCEPTION_FUTURE,
SUCCESSFUL_FUTURE,
future1]), finished)
self.assertEqual(set([future2]), pending)
class ThreadPoolWaitTests(ThreadPoolMixin, WaitTests, BaseTestCase):
def test_pending_calls_race(self):
# Issue #14406: multi-threaded race condition when waiting on all
# futures.
event = threading.Event()
def future_func():
event.wait()
oldswitchinterval = sys.getswitchinterval()
sys.setswitchinterval(1e-6)
try:
fs = {self.executor.submit(future_func) for i in range(100)}
event.set()
futures.wait(fs, return_when=futures.ALL_COMPLETED)
finally:
sys.setswitchinterval(oldswitchinterval)
create_executor_tests(WaitTests,
executor_mixins=(ProcessPoolForkMixin,
ProcessPoolForkserverMixin,
ProcessPoolSpawnMixin))
class AsCompletedTests:
# TODO(brian@sweetapp.com): Should have a test with a non-zero timeout.
def test_no_timeout(self):
future1 = self.executor.submit(mul, 2, 21)
future2 = self.executor.submit(mul, 7, 6)
completed = set(futures.as_completed(
[CANCELLED_AND_NOTIFIED_FUTURE,
EXCEPTION_FUTURE,
SUCCESSFUL_FUTURE,
future1, future2]))
self.assertEqual(set(
[CANCELLED_AND_NOTIFIED_FUTURE,
EXCEPTION_FUTURE,
SUCCESSFUL_FUTURE,
future1, future2]),
completed)
def test_zero_timeout(self):
future1 = self.executor.submit(time.sleep, 2)
completed_futures = set()
try:
for future in futures.as_completed(
[CANCELLED_AND_NOTIFIED_FUTURE,
EXCEPTION_FUTURE,
SUCCESSFUL_FUTURE,
future1],
timeout=0):
completed_futures.add(future)
except futures.TimeoutError:
pass
self.assertEqual(set([CANCELLED_AND_NOTIFIED_FUTURE,
EXCEPTION_FUTURE,
SUCCESSFUL_FUTURE]),
completed_futures)
def test_duplicate_futures(self):
# Issue 20367. Duplicate futures should not raise exceptions or give
# duplicate responses.
# Issue #31641: accept arbitrary iterables.
future1 = self.executor.submit(time.sleep, 2)
completed = [
f for f in futures.as_completed(itertools.repeat(future1, 3))
]
self.assertEqual(len(completed), 1)
def test_free_reference_yielded_future(self):
# Issue #14406: Generator should not keep references
# to finished futures.
futures_list = [Future() for _ in range(8)]
futures_list.append(create_future(state=CANCELLED_AND_NOTIFIED))
futures_list.append(create_future(state=FINISHED, result=42))
with self.assertRaises(futures.TimeoutError):
for future in futures.as_completed(futures_list, timeout=0):
futures_list.remove(future)
wr = weakref.ref(future)
del future
self.assertIsNone(wr())
futures_list[0].set_result("test")
for future in futures.as_completed(futures_list):
futures_list.remove(future)
wr = weakref.ref(future)
del future
self.assertIsNone(wr())
if futures_list:
futures_list[0].set_result("test")
def test_correct_timeout_exception_msg(self):
futures_list = [CANCELLED_AND_NOTIFIED_FUTURE, PENDING_FUTURE,
RUNNING_FUTURE, SUCCESSFUL_FUTURE]
with self.assertRaises(futures.TimeoutError) as cm:
list(futures.as_completed(futures_list, timeout=0))
self.assertEqual(str(cm.exception), '2 (of 4) futures unfinished')
create_executor_tests(AsCompletedTests)
class ExecutorTest:
# Executor.shutdown() and context manager usage is tested by
# ExecutorShutdownTest.
def test_submit(self):
future = self.executor.submit(pow, 2, 8)
self.assertEqual(256, future.result())
def test_submit_keyword(self):
future = self.executor.submit(mul, 2, y=8)
self.assertEqual(16, future.result())
future = self.executor.submit(capture, 1, self=2, fn=3)
self.assertEqual(future.result(), ((1,), {'self': 2, 'fn': 3}))
with self.assertRaises(TypeError):
self.executor.submit(fn=capture, arg=1)
with self.assertRaises(TypeError):
self.executor.submit(arg=1)
def test_map(self):
self.assertEqual(
list(self.executor.map(pow, range(10), range(10))),
list(map(pow, range(10), range(10))))
self.assertEqual(
list(self.executor.map(pow, range(10), range(10), chunksize=3)),
list(map(pow, range(10), range(10))))
def test_map_exception(self):
i = self.executor.map(divmod, [1, 1, 1, 1], [2, 3, 0, 5])
self.assertEqual(i.__next__(), (0, 1))
self.assertEqual(i.__next__(), (0, 1))
self.assertRaises(ZeroDivisionError, i.__next__)
def test_map_timeout(self):
results = []
try:
for i in self.executor.map(time.sleep,
[0, 0, 6],
timeout=5):
results.append(i)
except futures.TimeoutError:
pass
else:
self.fail('expected TimeoutError')
self.assertEqual([None, None], results)
def test_shutdown_race_issue12456(self):
# Issue #12456: race condition at shutdown where trying to post a
# sentinel in the call queue blocks (the queue is full while processes
# have exited).
self.executor.map(str, [2] * (self.worker_count + 1))
self.executor.shutdown()
@test.support.cpython_only
def test_no_stale_references(self):
# Issue #16284: check that the executors don't unnecessarily hang onto
# references.
my_object = MyObject()
my_object_collected = threading.Event()
my_object_callback = weakref.ref(
my_object, lambda obj: my_object_collected.set())
# Deliberately discarding the future.
self.executor.submit(my_object.my_method)
del my_object
collected = my_object_collected.wait(timeout=5.0)
self.assertTrue(collected,
"Stale reference not collected within timeout.")
def test_max_workers_negative(self):
for number in (0, -1):
with self.assertRaisesRegex(ValueError,
"max_workers must be greater "
"than 0"):
self.executor_type(max_workers=number)
def test_free_reference(self):
# Issue #14406: Result iterator should not keep an internal
# reference to result objects.
for obj in self.executor.map(make_dummy_object, range(10)):
wr = weakref.ref(obj)
del obj
self.assertIsNone(wr())
class ThreadPoolExecutorTest(ThreadPoolMixin, ExecutorTest, BaseTestCase):
def test_map_submits_without_iteration(self):
"""Tests verifying issue 11777."""
finished = []
def record_finished(n):
finished.append(n)
self.executor.map(record_finished, range(10))
self.executor.shutdown(wait=True)
self.assertCountEqual(finished, range(10))
def test_default_workers(self):
executor = self.executor_type()
expected = min(32, (os.cpu_count() or 1) + 4)
self.assertEqual(executor._max_workers, expected)
def test_saturation(self):
executor = self.executor_type(4)
def acquire_lock(lock):
lock.acquire()
sem = threading.Semaphore(0)
for i in range(15 * executor._max_workers):
executor.submit(acquire_lock, sem)
self.assertEqual(len(executor._threads), executor._max_workers)
for i in range(15 * executor._max_workers):
sem.release()
executor.shutdown(wait=True)
def test_idle_thread_reuse(self):
executor = self.executor_type()
executor.submit(mul, 21, 2).result()
executor.submit(mul, 6, 7).result()
executor.submit(mul, 3, 14).result()
self.assertEqual(len(executor._threads), 1)
executor.shutdown(wait=True)
class ProcessPoolExecutorTest(ExecutorTest):
@unittest.skipUnless(sys.platform=='win32', 'Windows-only process limit')
def test_max_workers_too_large(self):
with self.assertRaisesRegex(ValueError,
"max_workers must be <= 61"):
futures.ProcessPoolExecutor(max_workers=62)
def test_killed_child(self):
# When a child process is abruptly terminated, the whole pool gets
# "broken".
futures = [self.executor.submit(time.sleep, 3)]
# Get one of the processes, and terminate (kill) it
p = next(iter(self.executor._processes.values()))
p.terminate()
for fut in futures:
self.assertRaises(BrokenProcessPool, fut.result)
# Submitting other jobs fails as well.
self.assertRaises(BrokenProcessPool, self.executor.submit, pow, 2, 8)
def test_map_chunksize(self):
def bad_map():
list(self.executor.map(pow, range(40), range(40), chunksize=-1))
ref = list(map(pow, range(40), range(40)))
self.assertEqual(
list(self.executor.map(pow, range(40), range(40), chunksize=6)),
ref)
self.assertEqual(
list(self.executor.map(pow, range(40), range(40), chunksize=50)),
ref)
self.assertEqual(
list(self.executor.map(pow, range(40), range(40), chunksize=40)),
ref)
self.assertRaises(ValueError, bad_map)
@classmethod
def _test_traceback(cls):
raise RuntimeError(123) # some comment
def test_traceback(self):
# We want ensure that the traceback from the child process is
# contained in the traceback raised in the main process.
future = self.executor.submit(self._test_traceback)
with self.assertRaises(Exception) as cm:
future.result()
exc = cm.exception
self.assertIs(type(exc), RuntimeError)
self.assertEqual(exc.args, (123,))
cause = exc.__cause__
self.assertIs(type(cause), futures.process._RemoteTraceback)
self.assertIn('raise RuntimeError(123) # some comment', cause.tb)
with test.support.captured_stderr() as f1:
try:
raise exc
except RuntimeError:
sys.excepthook(*sys.exc_info())
self.assertIn('raise RuntimeError(123) # some comment',
f1.getvalue())
def test_ressources_gced_in_workers(self):
# Ensure that argument for a job are correctly gc-ed after the job
# is finished
obj = EventfulGCObj(self.ctx)
future = self.executor.submit(id, obj)
future.result()
self.assertTrue(obj.event.wait(timeout=1))
create_executor_tests(ProcessPoolExecutorTest,
executor_mixins=(ProcessPoolForkMixin,
ProcessPoolForkserverMixin,
ProcessPoolSpawnMixin))
def hide_process_stderr():
import io
sys.stderr = io.StringIO()
def _crash(delay=None):
"""Induces a segfault."""
if delay:
time.sleep(delay)
import faulthandler
faulthandler.disable()
faulthandler._sigsegv()
def _exit():
"""Induces a sys exit with exitcode 1."""
sys.exit(1)
def _raise_error(Err):
"""Function that raises an Exception in process."""
hide_process_stderr()
raise Err()
def _return_instance(cls):
"""Function that returns a instance of cls."""
hide_process_stderr()
return cls()
class CrashAtPickle(object):
"""Bad object that triggers a segfault at pickling time."""
def __reduce__(self):
_crash()
class CrashAtUnpickle(object):
"""Bad object that triggers a segfault at unpickling time."""
def __reduce__(self):
return _crash, ()
class ExitAtPickle(object):
"""Bad object that triggers a process exit at pickling time."""
def __reduce__(self):
_exit()
class ExitAtUnpickle(object):
"""Bad object that triggers a process exit at unpickling time."""
def __reduce__(self):
return _exit, ()
class ErrorAtPickle(object):
"""Bad object that triggers an error at pickling time."""
def __reduce__(self):
from pickle import PicklingError
raise PicklingError("Error in pickle")
class ErrorAtUnpickle(object):
"""Bad object that triggers an error at unpickling time."""
def __reduce__(self):
from pickle import UnpicklingError
return _raise_error, (UnpicklingError, )
class ExecutorDeadlockTest:
TIMEOUT = 15
@classmethod
def _sleep_id(cls, x, delay):
time.sleep(delay)
return x
def _fail_on_deadlock(self, executor):
# If we did not recover before TIMEOUT seconds, consider that the
# executor is in a deadlock state and forcefully clean all its
# composants.
import faulthandler
from tempfile import TemporaryFile
with TemporaryFile(mode="w+") as f:
faulthandler.dump_traceback(file=f)
f.seek(0)
tb = f.read()
for p in executor._processes.values():
p.terminate()
# This should be safe to call executor.shutdown here as all possible
# deadlocks should have been broken.
executor.shutdown(wait=True)
print(f"\nTraceback:\n {tb}", file=sys.__stderr__)
self.fail(f"Executor deadlock:\n\n{tb}")
def test_crash(self):
# extensive testing for deadlock caused by crashes in a pool.
self.executor.shutdown(wait=True)
crash_cases = [
# Check problem occurring while pickling a task in
# the task_handler thread
(id, (ErrorAtPickle(),), PicklingError, "error at task pickle"),
# Check problem occurring while unpickling a task on workers
(id, (ExitAtUnpickle(),), BrokenProcessPool,
"exit at task unpickle"),
(id, (ErrorAtUnpickle(),), BrokenProcessPool,
"error at task unpickle"),
(id, (CrashAtUnpickle(),), BrokenProcessPool,
"crash at task unpickle"),
# Check problem occurring during func execution on workers
(_crash, (), BrokenProcessPool,
"crash during func execution on worker"),
(_exit, (), SystemExit,
"exit during func execution on worker"),
(_raise_error, (RuntimeError, ), RuntimeError,
"error during func execution on worker"),
# Check problem occurring while pickling a task result
# on workers
(_return_instance, (CrashAtPickle,), BrokenProcessPool,
"crash during result pickle on worker"),
(_return_instance, (ExitAtPickle,), SystemExit,
"exit during result pickle on worker"),
(_return_instance, (ErrorAtPickle,), PicklingError,
"error during result pickle on worker"),
# Check problem occurring while unpickling a task in
# the result_handler thread
(_return_instance, (ErrorAtUnpickle,), BrokenProcessPool,
"error during result unpickle in result_handler"),
(_return_instance, (ExitAtUnpickle,), BrokenProcessPool,
"exit during result unpickle in result_handler")
]
for func, args, error, name in crash_cases:
with self.subTest(name):
# The captured_stderr reduces the noise in the test report
with test.support.captured_stderr():
executor = self.executor_type(
max_workers=2, mp_context=get_context(self.ctx))
res = executor.submit(func, *args)