cpython/Lib/test/test_asyncio/test_futures.py

549 lines
18 KiB
Python

"""Tests for futures.py."""
import concurrent.futures
import re
import sys
import threading
import unittest
from unittest import mock
import asyncio
from asyncio import test_utils
try:
from test import support
except ImportError:
from asyncio import test_support as support
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):
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 FutureTests(test_utils.TestCase):
def setUp(self):
self.loop = self.new_test_loop()
self.addCleanup(self.loop.close)
def test_initial_state(self):
f = asyncio.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 = asyncio.Future()
self.assertIs(f._loop, self.loop)
def test_constructor_positional(self):
# Make sure Future doesn't accept a positional argument
self.assertRaises(TypeError, asyncio.Future, 42)
def test_cancel(self):
f = asyncio.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 = asyncio.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 = asyncio.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 = asyncio.Future(loop=self.loop)
f.set_exception(RuntimeError)
self.assertIsInstance(f.exception(), RuntimeError)
def test_yield_from_twice(self):
f = asyncio.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 = asyncio.Future(loop=self.loop)
frame = f_pending_debug._source_traceback[-1]
self.assertEqual(repr(f_pending_debug),
'<Future pending created at %s:%s>'
% (frame[0], frame[1]))
f_pending_debug.cancel()
self.loop.set_debug(False)
f_pending = asyncio.Future(loop=self.loop)
self.assertEqual(repr(f_pending), '<Future pending>')
f_pending.cancel()
f_cancelled = asyncio.Future(loop=self.loop)
f_cancelled.cancel()
self.assertEqual(repr(f_cancelled), '<Future cancelled>')
f_result = asyncio.Future(loop=self.loop)
f_result.set_result(4)
self.assertEqual(repr(f_result), '<Future finished result=4>')
self.assertEqual(f_result.result(), 4)
exc = RuntimeError()
f_exception = asyncio.Future(loop=self.loop)
f_exception.set_exception(exc)
self.assertEqual(repr(f_exception),
'<Future 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 = asyncio.Future(loop=self.loop)
f_one_callbacks.add_done_callback(_fakefunc)
fake_repr = func_repr(_fakefunc)
self.assertRegex(repr(f_one_callbacks),
r'<Future pending cb=\[%s\]>' % fake_repr)
f_one_callbacks.cancel()
self.assertEqual(repr(f_one_callbacks),
'<Future cancelled>')
f_two_callbacks = asyncio.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'<Future pending cb=\[%s, %s\]>'
% (first_repr, last_repr))
f_many_callbacks = asyncio.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'<Future pending cb=\[%s\]>' % cb_regex)
f_many_callbacks.cancel()
self.assertEqual(repr(f_many_callbacks),
'<Future cancelled>')
def test_copy_state(self):
from asyncio.futures import _copy_future_state
f = asyncio.Future(loop=self.loop)
f.set_result(10)
newf = asyncio.Future(loop=self.loop)
_copy_future_state(f, newf)
self.assertTrue(newf.done())
self.assertEqual(newf.result(), 10)
f_exception = asyncio.Future(loop=self.loop)
f_exception.set_exception(RuntimeError())
newf_exception = asyncio.Future(loop=self.loop)
_copy_future_state(f_exception, newf_exception)
self.assertTrue(newf_exception.done())
self.assertRaises(RuntimeError, newf_exception.result)
f_cancelled = asyncio.Future(loop=self.loop)
f_cancelled.cancel()
newf_cancelled = asyncio.Future(loop=self.loop)
_copy_future_state(f_cancelled, newf_cancelled)
self.assertTrue(newf_cancelled.cancelled())
def test_iter(self):
fut = asyncio.Future(loop=self.loop)
def coro():
yield from fut
def test():
arg1, arg2 = coro()
self.assertRaises(AssertionError, test)
fut.cancel()
@mock.patch('asyncio.base_events.logger')
def test_tb_logger_abandoned(self, m_log):
fut = asyncio.Future(loop=self.loop)
del fut
self.assertFalse(m_log.error.called)
@mock.patch('asyncio.base_events.logger')
def test_tb_logger_result_unretrieved(self, m_log):
fut = asyncio.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 = asyncio.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 = asyncio.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 = asyncio.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 = asyncio.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.assertIsInstance(f2, asyncio.Future)
self.assertEqual(res, 'oi')
self.assertNotEqual(ident, threading.get_ident())
def test_wrap_future_future(self):
f1 = asyncio.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)
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 = asyncio.Future(loop=self.loop)
lineno = sys._getframe().f_lineno - 1
self.assertIsInstance(future._source_traceback, list)
self.assertEqual(future._source_traceback[-1][: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 = asyncio.Future(loop=self.loop)
if debug:
source_traceback = future._source_traceback
future.set_exception(exc)
future = None
test_utils.run_briefly(self.loop)
support.gc_collect()
if sys.version_info >= (3, 4):
if debug:
frame = source_traceback[-1]
regex = (r'^Future exception was never retrieved\n'
r'future: <Future finished exception=MemoryError\(\) '
r'created at {filename}:{lineno}>\n'
r'source_traceback: Object '
r'created at \(most recent call last\):\n'
r' File'
r'.*\n'
r' File "{filename}", line {lineno}, '
r'in check_future_exception_never_retrieved\n'
r' future = asyncio\.Future\(loop=self\.loop\)$'
).format(filename=re.escape(frame[0]),
lineno=frame[1])
else:
regex = (r'^Future exception was never retrieved\n'
r'future: '
r'<Future finished exception=MemoryError\(\)>$'
)
exc_info = (type(exc), exc, exc.__traceback__)
m_log.error.assert_called_once_with(mock.ANY, exc_info=exc_info)
else:
if debug:
frame = source_traceback[-1]
regex = (r'^Future/Task exception was never retrieved\n'
r'Future/Task created at \(most recent call last\):\n'
r' File'
r'.*\n'
r' File "{filename}", line {lineno}, '
r'in check_future_exception_never_retrieved\n'
r' future = asyncio\.Future\(loop=self\.loop\)\n'
r'Traceback \(most recent call last\):\n'
r'.*\n'
r'MemoryError$'
).format(filename=re.escape(frame[0]),
lineno=frame[1])
else:
regex = (r'^Future/Task exception was never retrieved\n'
r'Traceback \(most recent call last\):\n'
r'.*\n'
r'MemoryError$'
)
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):
from asyncio import futures
fut = asyncio.Future(loop=self.loop)
fut.cancel()
futures._set_result_unless_cancelled(fut, 2)
self.assertTrue(fut.cancelled())
class FutureDoneCallbackTests(test_utils.TestCase):
def setUp(self):
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):
return asyncio.Future(loop=self.loop)
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')
if __name__ == '__main__':
unittest.main()