MatrixSynapse/tests/util/test_async_utils.py

104 lines
3.7 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2019 New Vector Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from twisted.internet import defer
from twisted.internet.defer import CancelledError, Deferred
from twisted.internet.task import Clock
from synapse.util import logcontext
from synapse.util.async_helpers import timeout_deferred
from synapse.util.logcontext import LoggingContext
from tests.unittest import TestCase
class TimeoutDeferredTest(TestCase):
def setUp(self):
self.clock = Clock()
def test_times_out(self):
"""Basic test case that checks that the original deferred is cancelled and that
the timing-out deferred is errbacked
"""
cancelled = [False]
def canceller(_d):
cancelled[0] = True
non_completing_d = Deferred(canceller)
timing_out_d = timeout_deferred(non_completing_d, 1.0, self.clock)
self.assertNoResult(timing_out_d)
self.assertFalse(cancelled[0], "deferred was cancelled prematurely")
self.clock.pump((1.0,))
self.assertTrue(cancelled[0], "deferred was not cancelled by timeout")
self.failureResultOf(timing_out_d, defer.TimeoutError)
def test_times_out_when_canceller_throws(self):
"""Test that we have successfully worked around
https://twistedmatrix.com/trac/ticket/9534"""
def canceller(_d):
raise Exception("can't cancel this deferred")
non_completing_d = Deferred(canceller)
timing_out_d = timeout_deferred(non_completing_d, 1.0, self.clock)
self.assertNoResult(timing_out_d)
self.clock.pump((1.0,))
self.failureResultOf(timing_out_d, defer.TimeoutError)
def test_logcontext_is_preserved_on_cancellation(self):
blocking_was_cancelled = [False]
@defer.inlineCallbacks
def blocking():
non_completing_d = Deferred()
with logcontext.PreserveLoggingContext():
try:
yield non_completing_d
except CancelledError:
blocking_was_cancelled[0] = True
raise
with logcontext.LoggingContext("one") as context_one:
# the errbacks should be run in the test logcontext
def errback(res, deferred_name):
self.assertIs(
LoggingContext.current_context(),
context_one,
"errback %s run in unexpected logcontext %s"
% (deferred_name, LoggingContext.current_context()),
)
return res
original_deferred = blocking()
original_deferred.addErrback(errback, "orig")
timing_out_d = timeout_deferred(original_deferred, 1.0, self.clock)
self.assertNoResult(timing_out_d)
self.assertIs(LoggingContext.current_context(), LoggingContext.sentinel)
timing_out_d.addErrback(errback, "timingout")
self.clock.pump((1.0,))
self.assertTrue(
blocking_was_cancelled[0], "non-completing deferred was not cancelled"
)
self.failureResultOf(timing_out_d, defer.TimeoutError)
self.assertIs(LoggingContext.current_context(), context_one)