mirror of
https://git.anonymousland.org/anonymousland/synapse.git
synced 2024-12-29 19:36:13 -05:00
72 lines
2.8 KiB
Python
72 lines
2.8 KiB
Python
# -*- coding: utf-8 -*-
|
|
# Copyright 2015, 2016 OpenMarket 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, reactor
|
|
from functools import wraps
|
|
from synapse.util.logcontext import LoggingContext, PreserveLoggingContext
|
|
|
|
|
|
def debug_deferreds():
|
|
"""Cause all deferreds to wait for a reactor tick before running their
|
|
callbacks. This increases the chance of getting a stack trace out of
|
|
a defer.inlineCallback since the code waiting on the deferred will get
|
|
a chance to add an errback before the deferred runs."""
|
|
|
|
# Helper method for retrieving and restoring the current logging context
|
|
# around a callback.
|
|
def with_logging_context(fn):
|
|
context = LoggingContext.current_context()
|
|
|
|
def restore_context_callback(x):
|
|
with PreserveLoggingContext(context):
|
|
return fn(x)
|
|
|
|
return restore_context_callback
|
|
|
|
# We are going to modify the __init__ method of defer.Deferred so we
|
|
# need to get a copy of the old method so we can still call it.
|
|
old__init__ = defer.Deferred.__init__
|
|
|
|
# We need to create a deferred to bounce the callbacks through the reactor
|
|
# but we don't want to add a callback when we create that deferred so we
|
|
# we create a new type of deferred that uses the old __init__ method.
|
|
# This is safe as long as the old __init__ method doesn't invoke an
|
|
# __init__ using super.
|
|
class Bouncer(defer.Deferred):
|
|
__init__ = old__init__
|
|
|
|
# We'll add this as a callback to all Deferreds. Twisted will wait until
|
|
# the bouncer deferred resolves before calling the callbacks of the
|
|
# original deferred.
|
|
def bounce_callback(x):
|
|
bouncer = Bouncer()
|
|
reactor.callLater(0, with_logging_context(bouncer.callback), x)
|
|
return bouncer
|
|
|
|
# We'll add this as an errback to all Deferreds. Twisted will wait until
|
|
# the bouncer deferred resolves before calling the errbacks of the
|
|
# original deferred.
|
|
def bounce_errback(x):
|
|
bouncer = Bouncer()
|
|
reactor.callLater(0, with_logging_context(bouncer.errback), x)
|
|
return bouncer
|
|
|
|
@wraps(old__init__)
|
|
def new__init__(self, *args, **kargs):
|
|
old__init__(self, *args, **kargs)
|
|
self.addCallbacks(bounce_callback, bounce_errback)
|
|
|
|
defer.Deferred.__init__ = new__init__
|