Make the http server handle coroutine-making REST servlets (#5475)

tests/unittest.py

@@ -17,6 +17,7 @@ import gc
 import hashlib
 import hmac
 import logging
+import time
 
 from mock import Mock
 
@@ -24,7 +25,8 @@ from canonicaljson import json
 
 import twisted
 import twisted.logger
-from twisted.internet.defer import Deferred
+from twisted.internet.defer import Deferred, succeed
+from twisted.python.threadpool import ThreadPool
 from twisted.trial import unittest
 
 from synapse.api.constants import EventTypes
@@ -164,6 +166,7 @@ class HomeserverTestCase(TestCase):
 
     servlets = []
     hijack_auth = True
+    needs_threadpool = False
 
     def setUp(self):
         """
@@ -192,15 +195,19 @@ class HomeserverTestCase(TestCase):
             if self.hijack_auth:
 
                 def get_user_by_access_token(token=None, allow_guest=False):
-                    return {
-                        "user": UserID.from_string(self.helper.auth_user_id),
-                        "token_id": 1,
-                        "is_guest": False,
-                    }
+                    return succeed(
+                        {
+                            "user": UserID.from_string(self.helper.auth_user_id),
+                            "token_id": 1,
+                            "is_guest": False,
+                        }
+                    )
 
                 def get_user_by_req(request, allow_guest=False, rights="access"):
-                    return create_requester(
-                        UserID.from_string(self.helper.auth_user_id), 1, False, None
+                    return succeed(
+                        create_requester(
+                            UserID.from_string(self.helper.auth_user_id), 1, False, None
+                        )
                     )
 
                 self.hs.get_auth().get_user_by_req = get_user_by_req
@@ -209,9 +216,26 @@ class HomeserverTestCase(TestCase):
                     return_value="1234"
                 )
 
+        if self.needs_threadpool:
+            self.reactor.threadpool = ThreadPool()
+            self.addCleanup(self.reactor.threadpool.stop)
+            self.reactor.threadpool.start()
+
         if hasattr(self, "prepare"):
             self.prepare(self.reactor, self.clock, self.hs)
 
+    def wait_on_thread(self, deferred, timeout=10):
+        """
+        Wait until a Deferred is done, where it's waiting on a real thread.
+        """
+        start_time = time.time()
+
+        while not deferred.called:
+            if start_time + timeout < time.time():
+                raise ValueError("Timed out waiting for threadpool")
+            self.reactor.advance(0.01)
+            time.sleep(0.01)
+
     def make_homeserver(self, reactor, clock):
         """
         Make and return a homeserver.