Use deferred.addTimeout instead of time_bound_deferred

This doesn't feel like a wheel we need to reinvent.

synapse/http/matrixfederationclient.py

@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 # Copyright 2014-2016 OpenMarket Ltd
+# Copyright 2018 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.
@@ -12,17 +13,19 @@
 # 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.
-import synapse.util.retryutils
 from twisted.internet import defer, reactor, protocol
 from twisted.internet.error import DNSLookupError
 from twisted.web.client import readBody, HTTPConnectionPool, Agent
 from twisted.web.http_headers import Headers
 from twisted.web._newclient import ResponseDone
 
+from synapse.http import cancelled_to_request_timed_out_error
 from synapse.http.endpoint import matrix_federation_endpoint
+import synapse.metrics
 from synapse.util.async import sleep
 from synapse.util import logcontext
-import synapse.metrics
+from synapse.util.logcontext import make_deferred_yieldable
+import synapse.util.retryutils
 
 from canonicaljson import encode_canonical_json
 
@@ -184,21 +187,19 @@ class MatrixFederationHttpClient(object):
                         producer = body_callback(method, http_url_bytes, headers_dict)
 
                     try:
-                        def send_request():
-                            request_deferred = self.agent.request(
-                                method,
-                                url_bytes,
-                                Headers(headers_dict),
-                                producer
-                            )
-
-                            return self.clock.time_bound_deferred(
-                                request_deferred,
-                                time_out=timeout / 1000. if timeout else 60,
-                            )
-
-                        with logcontext.PreserveLoggingContext():
-                            response = yield send_request()
+                        request_deferred = self.agent.request(
+                            method,
+                            url_bytes,
+                            Headers(headers_dict),
+                            producer
+                        )
+                        request_deferred.addTimeout(
+                            timeout / 1000. if timeout else 60,
+                            reactor, cancelled_to_request_timed_out_error,
+                        )
+                        response = yield make_deferred_yieldable(
+                            request_deferred,
+                        )
 
                         log_result = "%d %s" % (response.code, response.phrase,)
                         break