cpython/Lib/test/test_asyncio/test_futures.py

827 lines
25 KiB
Python

"""Tests for futures.py."""
import concurrent.futures
import gc
import re
import sys
import threading
import unittest
from unittest import mock
import asyncio
from asyncio import futures
from test.test_asyncio import utils as test_utils
from test import support
def tearDownModule():
asyncio.set_event_loop_policy(None)
def _fakefunc(f):
return f
def first_cb():
pass
def last_cb():
pass
class DuckFuture:
# Class that does not inherit from Future but aims to be duck-type
# compatible with it.
_asyncio_future_blocking = False
__cancelled = False
__result = None
__exception = None
def cancel(self):
if self.done():
return False
self.__cancelled = True
return True
def cancelled(self):
return self.__cancelled
def done(self):
return (self.__cancelled
or self.__result is not None
or self.__exception is not None)
def result(self):
assert not self.cancelled()
if self.__exception is not None:
raise self.__exception
return self.__result
def exception(self):
assert not self.cancelled()
return self.__exception
def set_result(self, result):
assert not self.done()
assert result is not None
self.__result = result
def set_exception(self, exception):
assert not self.done()
assert exception is not None
self.__exception = exception
def __iter__(self):
if not self.done():
self._asyncio_future_blocking = True
yield self
assert self.done()
return self.result()
class DuckTests(test_utils.TestCase):
def setUp(self):
super().setUp()
self.loop = self.new_test_loop()
self.addCleanup(self.loop.close)
def test_wrap_future(self):
f = DuckFuture()
g = asyncio.wrap_future(f)
assert g is f
def test_ensure_future(self):
f = DuckFuture()
g = asyncio.ensure_future(f)
assert g is f
class BaseFutureTests:
def _new_future(self, *args, **kwargs):
return self.cls(*args, **kwargs)
def setUp(self):
super().setUp()
self.loop = self.new_test_loop()
self.addCleanup(self.loop.close)
def test_isfuture(self):
class MyFuture:
_asyncio_future_blocking = None
def __init__(self):
self._asyncio_future_blocking = False
self.assertFalse(asyncio.isfuture(MyFuture))
self.assertTrue(asyncio.isfuture(MyFuture()))
self.assertFalse(asyncio.isfuture(1))
# As `isinstance(Mock(), Future)` returns `False`
self.assertFalse(asyncio.isfuture(mock.Mock()))
f = self._new_future(loop=self.loop)
self.assertTrue(asyncio.isfuture(f))
self.assertFalse(asyncio.isfuture(type(f)))
# As `isinstance(Mock(Future), Future)` returns `True`
self.assertTrue(asyncio.isfuture(mock.Mock(type(f))))
f.cancel()
def test_initial_state(self):
f = self._new_future(loop=self.loop)
self.assertFalse(f.cancelled())
self.assertFalse(f.done())
f.cancel()
self.assertTrue(f.cancelled())
def test_init_constructor_default_loop(self):
asyncio.set_event_loop(self.loop)
f = self._new_future()
self.assertIs(f._loop, self.loop)
self.assertIs(f.get_loop(), self.loop)
def test_constructor_positional(self):
# Make sure Future doesn't accept a positional argument
self.assertRaises(TypeError, self._new_future, 42)
def test_uninitialized(self):
# Test that C Future doesn't crash when Future.__init__()
# call was skipped.
fut = self.cls.__new__(self.cls, loop=self.loop)
self.assertRaises(asyncio.InvalidStateError, fut.result)
fut = self.cls.__new__(self.cls, loop=self.loop)
self.assertRaises(asyncio.InvalidStateError, fut.exception)
fut = self.cls.__new__(self.cls, loop=self.loop)
with self.assertRaises((RuntimeError, AttributeError)):
fut.set_result(None)
fut = self.cls.__new__(self.cls, loop=self.loop)
with self.assertRaises((RuntimeError, AttributeError)):
fut.set_exception(Exception)
fut = self.cls.__new__(self.cls, loop=self.loop)
with self.assertRaises((RuntimeError, AttributeError)):
fut.cancel()
fut = self.cls.__new__(self.cls, loop=self.loop)
with self.assertRaises((RuntimeError, AttributeError)):
fut.add_done_callback(lambda f: None)
fut = self.cls.__new__(self.cls, loop=self.loop)
with self.assertRaises((RuntimeError, AttributeError)):
fut.remove_done_callback(lambda f: None)
fut = self.cls.__new__(self.cls, loop=self.loop)
try:
repr(fut)
except (RuntimeError, AttributeError):
pass
fut = self.cls.__new__(self.cls, loop=self.loop)
try:
fut.__await__()
except RuntimeError:
pass
fut = self.cls.__new__(self.cls, loop=self.loop)
try:
iter(fut)
except RuntimeError:
pass
fut = self.cls.__new__(self.cls, loop=self.loop)
self.assertFalse(fut.cancelled())
self.assertFalse(fut.done())
def test_cancel(self):
f = self._new_future(loop=self.loop)
self.assertTrue(f.cancel())
self.assertTrue(f.cancelled())
self.assertTrue(f.done())
self.assertRaises(asyncio.CancelledError, f.result)
self.assertRaises(asyncio.CancelledError, f.exception)
self.assertRaises(asyncio.InvalidStateError, f.set_result, None)
self.assertRaises(asyncio.InvalidStateError, f.set_exception, None)
self.assertFalse(f.cancel())
def test_result(self):
f = self._new_future(loop=self.loop)
self.assertRaises(asyncio.InvalidStateError, f.result)
f.set_result(42)
self.assertFalse(f.cancelled())
self.assertTrue(f.done())
self.assertEqual(f.result(), 42)
self.assertEqual(f.exception(), None)
self.assertRaises(asyncio.InvalidStateError, f.set_result, None)
self.assertRaises(asyncio.InvalidStateError, f.set_exception, None)
self.assertFalse(f.cancel())
def test_exception(self):
exc = RuntimeError()
f = self._new_future(loop=self.loop)
self.assertRaises(asyncio.InvalidStateError, f.exception)
# StopIteration cannot be raised into a Future - CPython issue26221
self.assertRaisesRegex(TypeError, "StopIteration .* cannot be raised",
f.set_exception, StopIteration)
f.set_exception(exc)
self.assertFalse(f.cancelled())
self.assertTrue(f.done())
self.assertRaises(RuntimeError, f.result)
self.assertEqual(f.exception(), exc)
self.assertRaises(asyncio.InvalidStateError, f.set_result, None)
self.assertRaises(asyncio.InvalidStateError, f.set_exception, None)
self.assertFalse(f.cancel())
def test_exception_class(self):
f = self._new_future(loop=self.loop)
f.set_exception(RuntimeError)
self.assertIsInstance(f.exception(), RuntimeError)
def test_yield_from_twice(self):
f = self._new_future(loop=self.loop)
def fixture():
yield 'A'
x = yield from f
yield 'B', x
y = yield from f
yield 'C', y
g = fixture()
self.assertEqual(next(g), 'A') # yield 'A'.
self.assertEqual(next(g), f) # First yield from f.
f.set_result(42)
self.assertEqual(next(g), ('B', 42)) # yield 'B', x.
# The second "yield from f" does not yield f.
self.assertEqual(next(g), ('C', 42)) # yield 'C', y.
def test_future_repr(self):
self.loop.set_debug(True)
f_pending_debug = self._new_future(loop=self.loop)
frame = f_pending_debug._source_traceback[-1]
self.assertEqual(
repr(f_pending_debug),
f'<{self.cls.__name__} pending created at {frame[0]}:{frame[1]}>')
f_pending_debug.cancel()
self.loop.set_debug(False)
f_pending = self._new_future(loop=self.loop)
self.assertEqual(repr(f_pending), f'<{self.cls.__name__} pending>')
f_pending.cancel()
f_cancelled = self._new_future(loop=self.loop)
f_cancelled.cancel()
self.assertEqual(repr(f_cancelled), f'<{self.cls.__name__} cancelled>')
f_result = self._new_future(loop=self.loop)
f_result.set_result(4)
self.assertEqual(
repr(f_result), f'<{self.cls.__name__} finished result=4>')
self.assertEqual(f_result.result(), 4)
exc = RuntimeError()
f_exception = self._new_future(loop=self.loop)
f_exception.set_exception(exc)
self.assertEqual(
repr(f_exception),
f'<{self.cls.__name__} finished exception=RuntimeError()>')
self.assertIs(f_exception.exception(), exc)
def func_repr(func):
filename, lineno = test_utils.get_function_source(func)
text = '%s() at %s:%s' % (func.__qualname__, filename, lineno)
return re.escape(text)
f_one_callbacks = self._new_future(loop=self.loop)
f_one_callbacks.add_done_callback(_fakefunc)
fake_repr = func_repr(_fakefunc)
self.assertRegex(
repr(f_one_callbacks),
r'<' + self.cls.__name__ + r' pending cb=\[%s\]>' % fake_repr)
f_one_callbacks.cancel()
self.assertEqual(repr(f_one_callbacks),
f'<{self.cls.__name__} cancelled>')
f_two_callbacks = self._new_future(loop=self.loop)
f_two_callbacks.add_done_callback(first_cb)
f_two_callbacks.add_done_callback(last_cb)
first_repr = func_repr(first_cb)
last_repr = func_repr(last_cb)
self.assertRegex(repr(f_two_callbacks),
r'<' + self.cls.__name__ + r' pending cb=\[%s, %s\]>'
% (first_repr, last_repr))
f_many_callbacks = self._new_future(loop=self.loop)
f_many_callbacks.add_done_callback(first_cb)
for i in range(8):
f_many_callbacks.add_done_callback(_fakefunc)
f_many_callbacks.add_done_callback(last_cb)
cb_regex = r'%s, <8 more>, %s' % (first_repr, last_repr)
self.assertRegex(
repr(f_many_callbacks),
r'<' + self.cls.__name__ + r' pending cb=\[%s\]>' % cb_regex)
f_many_callbacks.cancel()
self.assertEqual(repr(f_many_callbacks),
f'<{self.cls.__name__} cancelled>')
def test_copy_state(self):
from asyncio.futures import _copy_future_state
f = self._new_future(loop=self.loop)
f.set_result(10)
newf = self._new_future(loop=self.loop)
_copy_future_state(f, newf)
self.assertTrue(newf.done())
self.assertEqual(newf.result(), 10)
f_exception = self._new_future(loop=self.loop)
f_exception.set_exception(RuntimeError())
newf_exception = self._new_future(loop=self.loop)
_copy_future_state(f_exception, newf_exception)
self.assertTrue(newf_exception.done())
self.assertRaises(RuntimeError, newf_exception.result)
f_cancelled = self._new_future(loop=self.loop)
f_cancelled.cancel()
newf_cancelled = self._new_future(loop=self.loop)
_copy_future_state(f_cancelled, newf_cancelled)
self.assertTrue(newf_cancelled.cancelled())
def test_iter(self):
fut = self._new_future(loop=self.loop)
def coro():
yield from fut
def test():
arg1, arg2 = coro()
with self.assertRaisesRegex(RuntimeError, "await wasn't used"):
test()
fut.cancel()
def test_log_traceback(self):
fut = self._new_future(loop=self.loop)
with self.assertRaisesRegex(ValueError, 'can only be set to False'):
fut._log_traceback = True
@mock.patch('asyncio.base_events.logger')
def test_tb_logger_abandoned(self, m_log):
fut = self._new_future(loop=self.loop)
del fut
self.assertFalse(m_log.error.called)
@mock.patch('asyncio.base_events.logger')
def test_tb_logger_not_called_after_cancel(self, m_log):
fut = self._new_future(loop=self.loop)
fut.set_exception(Exception())
fut.cancel()
del fut
self.assertFalse(m_log.error.called)
@mock.patch('asyncio.base_events.logger')
def test_tb_logger_result_unretrieved(self, m_log):
fut = self._new_future(loop=self.loop)
fut.set_result(42)
del fut
self.assertFalse(m_log.error.called)
@mock.patch('asyncio.base_events.logger')
def test_tb_logger_result_retrieved(self, m_log):
fut = self._new_future(loop=self.loop)
fut.set_result(42)
fut.result()
del fut
self.assertFalse(m_log.error.called)
@mock.patch('asyncio.base_events.logger')
def test_tb_logger_exception_unretrieved(self, m_log):
fut = self._new_future(loop=self.loop)
fut.set_exception(RuntimeError('boom'))
del fut
test_utils.run_briefly(self.loop)
support.gc_collect()
self.assertTrue(m_log.error.called)
@mock.patch('asyncio.base_events.logger')
def test_tb_logger_exception_retrieved(self, m_log):
fut = self._new_future(loop=self.loop)
fut.set_exception(RuntimeError('boom'))
fut.exception()
del fut
self.assertFalse(m_log.error.called)
@mock.patch('asyncio.base_events.logger')
def test_tb_logger_exception_result_retrieved(self, m_log):
fut = self._new_future(loop=self.loop)
fut.set_exception(RuntimeError('boom'))
self.assertRaises(RuntimeError, fut.result)
del fut
self.assertFalse(m_log.error.called)
def test_wrap_future(self):
def run(arg):
return (arg, threading.get_ident())
ex = concurrent.futures.ThreadPoolExecutor(1)
f1 = ex.submit(run, 'oi')
f2 = asyncio.wrap_future(f1, loop=self.loop)
res, ident = self.loop.run_until_complete(f2)
self.assertTrue(asyncio.isfuture(f2))
self.assertEqual(res, 'oi')
self.assertNotEqual(ident, threading.get_ident())
ex.shutdown(wait=True)
def test_wrap_future_future(self):
f1 = self._new_future(loop=self.loop)
f2 = asyncio.wrap_future(f1)
self.assertIs(f1, f2)
def test_wrap_future_use_global_loop(self):
with mock.patch('asyncio.futures.events') as events:
events.get_event_loop = lambda: self.loop
def run(arg):
return (arg, threading.get_ident())
ex = concurrent.futures.ThreadPoolExecutor(1)
f1 = ex.submit(run, 'oi')
f2 = asyncio.wrap_future(f1)
self.assertIs(self.loop, f2._loop)
ex.shutdown(wait=True)
def test_wrap_future_cancel(self):
f1 = concurrent.futures.Future()
f2 = asyncio.wrap_future(f1, loop=self.loop)
f2.cancel()
test_utils.run_briefly(self.loop)
self.assertTrue(f1.cancelled())
self.assertTrue(f2.cancelled())
def test_wrap_future_cancel2(self):
f1 = concurrent.futures.Future()
f2 = asyncio.wrap_future(f1, loop=self.loop)
f1.set_result(42)
f2.cancel()
test_utils.run_briefly(self.loop)
self.assertFalse(f1.cancelled())
self.assertEqual(f1.result(), 42)
self.assertTrue(f2.cancelled())
def test_future_source_traceback(self):
self.loop.set_debug(True)
future = self._new_future(loop=self.loop)
lineno = sys._getframe().f_lineno - 1
self.assertIsInstance(future._source_traceback, list)
self.assertEqual(future._source_traceback[-2][:3],
(__file__,
lineno,
'test_future_source_traceback'))
@mock.patch('asyncio.base_events.logger')
def check_future_exception_never_retrieved(self, debug, m_log):
self.loop.set_debug(debug)
def memory_error():
try:
raise MemoryError()
except BaseException as exc:
return exc
exc = memory_error()
future = self._new_future(loop=self.loop)
future.set_exception(exc)
future = None
test_utils.run_briefly(self.loop)
support.gc_collect()
if sys.version_info >= (3, 4):
regex = f'^{self.cls.__name__} exception was never retrieved\n'
exc_info = (type(exc), exc, exc.__traceback__)
m_log.error.assert_called_once_with(mock.ANY, exc_info=exc_info)
else:
regex = r'^Future/Task exception was never retrieved\n'
m_log.error.assert_called_once_with(mock.ANY, exc_info=False)
message = m_log.error.call_args[0][0]
self.assertRegex(message, re.compile(regex, re.DOTALL))
def test_future_exception_never_retrieved(self):
self.check_future_exception_never_retrieved(False)
def test_future_exception_never_retrieved_debug(self):
self.check_future_exception_never_retrieved(True)
def test_set_result_unless_cancelled(self):
fut = self._new_future(loop=self.loop)
fut.cancel()
futures._set_result_unless_cancelled(fut, 2)
self.assertTrue(fut.cancelled())
def test_future_stop_iteration_args(self):
fut = self._new_future(loop=self.loop)
fut.set_result((1, 2))
fi = fut.__iter__()
result = None
try:
fi.send(None)
except StopIteration as ex:
result = ex.args[0]
else:
self.fail('StopIteration was expected')
self.assertEqual(result, (1, 2))
def test_future_iter_throw(self):
fut = self._new_future(loop=self.loop)
fi = iter(fut)
self.assertRaises(TypeError, fi.throw,
Exception, Exception("elephant"), 32)
self.assertRaises(TypeError, fi.throw,
Exception("elephant"), Exception("elephant"))
self.assertRaises(TypeError, fi.throw, list)
def test_future_del_collect(self):
class Evil:
def __del__(self):
gc.collect()
for i in range(100):
fut = self._new_future(loop=self.loop)
fut.set_result(Evil())
@unittest.skipUnless(hasattr(futures, '_CFuture'),
'requires the C _asyncio module')
class CFutureTests(BaseFutureTests, test_utils.TestCase):
try:
cls = futures._CFuture
except AttributeError:
cls = None
def test_future_del_segfault(self):
fut = self._new_future(loop=self.loop)
with self.assertRaises(AttributeError):
del fut._asyncio_future_blocking
with self.assertRaises(AttributeError):
del fut._log_traceback
@unittest.skipUnless(hasattr(futures, '_CFuture'),
'requires the C _asyncio module')
class CSubFutureTests(BaseFutureTests, test_utils.TestCase):
try:
class CSubFuture(futures._CFuture):
pass
cls = CSubFuture
except AttributeError:
cls = None
class PyFutureTests(BaseFutureTests, test_utils.TestCase):
cls = futures._PyFuture
class BaseFutureDoneCallbackTests():
def setUp(self):
super().setUp()
self.loop = self.new_test_loop()
def run_briefly(self):
test_utils.run_briefly(self.loop)
def _make_callback(self, bag, thing):
# Create a callback function that appends thing to bag.
def bag_appender(future):
bag.append(thing)
return bag_appender
def _new_future(self):
raise NotImplementedError
def test_callbacks_remove_first_callback(self):
bag = []
f = self._new_future()
cb1 = self._make_callback(bag, 42)
cb2 = self._make_callback(bag, 17)
cb3 = self._make_callback(bag, 100)
f.add_done_callback(cb1)
f.add_done_callback(cb2)
f.add_done_callback(cb3)
f.remove_done_callback(cb1)
f.remove_done_callback(cb1)
self.assertEqual(bag, [])
f.set_result('foo')
self.run_briefly()
self.assertEqual(bag, [17, 100])
self.assertEqual(f.result(), 'foo')
def test_callbacks_remove_first_and_second_callback(self):
bag = []
f = self._new_future()
cb1 = self._make_callback(bag, 42)
cb2 = self._make_callback(bag, 17)
cb3 = self._make_callback(bag, 100)
f.add_done_callback(cb1)
f.add_done_callback(cb2)
f.add_done_callback(cb3)
f.remove_done_callback(cb1)
f.remove_done_callback(cb2)
f.remove_done_callback(cb1)
self.assertEqual(bag, [])
f.set_result('foo')
self.run_briefly()
self.assertEqual(bag, [100])
self.assertEqual(f.result(), 'foo')
def test_callbacks_remove_third_callback(self):
bag = []
f = self._new_future()
cb1 = self._make_callback(bag, 42)
cb2 = self._make_callback(bag, 17)
cb3 = self._make_callback(bag, 100)
f.add_done_callback(cb1)
f.add_done_callback(cb2)
f.add_done_callback(cb3)
f.remove_done_callback(cb3)
f.remove_done_callback(cb3)
self.assertEqual(bag, [])
f.set_result('foo')
self.run_briefly()
self.assertEqual(bag, [42, 17])
self.assertEqual(f.result(), 'foo')
def test_callbacks_invoked_on_set_result(self):
bag = []
f = self._new_future()
f.add_done_callback(self._make_callback(bag, 42))
f.add_done_callback(self._make_callback(bag, 17))
self.assertEqual(bag, [])
f.set_result('foo')
self.run_briefly()
self.assertEqual(bag, [42, 17])
self.assertEqual(f.result(), 'foo')
def test_callbacks_invoked_on_set_exception(self):
bag = []
f = self._new_future()
f.add_done_callback(self._make_callback(bag, 100))
self.assertEqual(bag, [])
exc = RuntimeError()
f.set_exception(exc)
self.run_briefly()
self.assertEqual(bag, [100])
self.assertEqual(f.exception(), exc)
def test_remove_done_callback(self):
bag = []
f = self._new_future()
cb1 = self._make_callback(bag, 1)
cb2 = self._make_callback(bag, 2)
cb3 = self._make_callback(bag, 3)
# Add one cb1 and one cb2.
f.add_done_callback(cb1)
f.add_done_callback(cb2)
# One instance of cb2 removed. Now there's only one cb1.
self.assertEqual(f.remove_done_callback(cb2), 1)
# Never had any cb3 in there.
self.assertEqual(f.remove_done_callback(cb3), 0)
# After this there will be 6 instances of cb1 and one of cb2.
f.add_done_callback(cb2)
for i in range(5):
f.add_done_callback(cb1)
# Remove all instances of cb1. One cb2 remains.
self.assertEqual(f.remove_done_callback(cb1), 6)
self.assertEqual(bag, [])
f.set_result('foo')
self.run_briefly()
self.assertEqual(bag, [2])
self.assertEqual(f.result(), 'foo')
def test_remove_done_callbacks_list_mutation(self):
# see http://bugs.python.org/issue28963 for details
fut = self._new_future()
fut.add_done_callback(str)
for _ in range(63):
fut.add_done_callback(id)
class evil:
def __eq__(self, other):
fut.remove_done_callback(id)
return False
fut.remove_done_callback(evil())
def test_schedule_callbacks_list_mutation_1(self):
# see http://bugs.python.org/issue28963 for details
def mut(f):
f.remove_done_callback(str)
fut = self._new_future()
fut.add_done_callback(mut)
fut.add_done_callback(str)
fut.add_done_callback(str)
fut.set_result(1)
test_utils.run_briefly(self.loop)
def test_schedule_callbacks_list_mutation_2(self):
# see http://bugs.python.org/issue30828 for details
fut = self._new_future()
fut.add_done_callback(str)
for _ in range(63):
fut.add_done_callback(id)
max_extra_cbs = 100
extra_cbs = 0
class evil:
def __eq__(self, other):
nonlocal extra_cbs
extra_cbs += 1
if extra_cbs < max_extra_cbs:
fut.add_done_callback(id)
return False
fut.remove_done_callback(evil())
@unittest.skipUnless(hasattr(futures, '_CFuture'),
'requires the C _asyncio module')
class CFutureDoneCallbackTests(BaseFutureDoneCallbackTests,
test_utils.TestCase):
def _new_future(self):
return futures._CFuture(loop=self.loop)
@unittest.skipUnless(hasattr(futures, '_CFuture'),
'requires the C _asyncio module')
class CSubFutureDoneCallbackTests(BaseFutureDoneCallbackTests,
test_utils.TestCase):
def _new_future(self):
class CSubFuture(futures._CFuture):
pass
return CSubFuture(loop=self.loop)
class PyFutureDoneCallbackTests(BaseFutureDoneCallbackTests,
test_utils.TestCase):
def _new_future(self):
return futures._PyFuture(loop=self.loop)
if __name__ == '__main__':
unittest.main()