From 32e7c9e7f20b57dd081023ac42d6931a8da9b3a3 Mon Sep 17 00:00:00 2001
From: Amber Brown <hawkowl@atleastfornow.net>
Date: Thu, 20 Jun 2019 19:32:02 +1000
Subject: Run Black. (#5482)

---
 synapse/util/caches/__init__.py            |   6 +-
 synapse/util/caches/descriptors.py         | 100 +++++++++++++++--------------
 synapse/util/caches/dictionary_cache.py    |  15 +++--
 synapse/util/caches/expiringcache.py       |  18 ++++--
 synapse/util/caches/lrucache.py            |  14 +++-
 synapse/util/caches/response_cache.py      |  22 +++----
 synapse/util/caches/stream_change_cache.py |  13 ++--
 synapse/util/caches/treecache.py           |   1 +
 synapse/util/caches/ttlcache.py            |   1 +
 9 files changed, 109 insertions(+), 81 deletions(-)

(limited to 'synapse/util/caches')

diff --git a/synapse/util/caches/__init__.py b/synapse/util/caches/__init__.py
index f37d5bec08..8271229015 100644
--- a/synapse/util/caches/__init__.py
+++ b/synapse/util/caches/__init__.py
@@ -104,8 +104,8 @@ def register_cache(cache_type, cache_name, cache):
 
 
 KNOWN_KEYS = {
-    key: key for key in
-    (
+    key: key
+    for key in (
         "auth_events",
         "content",
         "depth",
@@ -150,7 +150,7 @@ def intern_dict(dictionary):
 
 
 def _intern_known_values(key, value):
-    intern_keys = ("event_id", "room_id", "sender", "user_id", "type", "state_key",)
+    intern_keys = ("event_id", "room_id", "sender", "user_id", "type", "state_key")
 
     if key in intern_keys:
         return intern_string(value)
diff --git a/synapse/util/caches/descriptors.py b/synapse/util/caches/descriptors.py
index 187510576a..d2f25063aa 100644
--- a/synapse/util/caches/descriptors.py
+++ b/synapse/util/caches/descriptors.py
@@ -40,9 +40,7 @@ _CacheSentinel = object()
 
 
 class CacheEntry(object):
-    __slots__ = [
-        "deferred", "callbacks", "invalidated"
-    ]
+    __slots__ = ["deferred", "callbacks", "invalidated"]
 
     def __init__(self, deferred, callbacks):
         self.deferred = deferred
@@ -73,7 +71,9 @@ class Cache(object):
         self._pending_deferred_cache = cache_type()
 
         self.cache = LruCache(
-            max_size=max_entries, keylen=keylen, cache_type=cache_type,
+            max_size=max_entries,
+            keylen=keylen,
+            cache_type=cache_type,
             size_callback=(lambda d: len(d)) if iterable else None,
             evicted_callback=self._on_evicted,
         )
@@ -133,10 +133,7 @@ class Cache(object):
     def set(self, key, value, callback=None):
         callbacks = [callback] if callback else []
         self.check_thread()
-        entry = CacheEntry(
-            deferred=value,
-            callbacks=callbacks,
-        )
+        entry = CacheEntry(deferred=value, callbacks=callbacks)
 
         existing_entry = self._pending_deferred_cache.pop(key, None)
         if existing_entry:
@@ -191,9 +188,7 @@ class Cache(object):
     def invalidate_many(self, key):
         self.check_thread()
         if not isinstance(key, tuple):
-            raise TypeError(
-                "The cache key must be a tuple not %r" % (type(key),)
-            )
+            raise TypeError("The cache key must be a tuple not %r" % (type(key),))
         self.cache.del_multi(key)
 
         # if we have a pending lookup for this key, remove it from the
@@ -244,29 +239,25 @@ class _CacheDescriptorBase(object):
             raise Exception(
                 "Not enough explicit positional arguments to key off for %r: "
                 "got %i args, but wanted %i. (@cached cannot key off *args or "
-                "**kwargs)"
-                % (orig.__name__, len(all_args), num_args)
+                "**kwargs)" % (orig.__name__, len(all_args), num_args)
             )
 
         self.num_args = num_args
 
         # list of the names of the args used as the cache key
-        self.arg_names = all_args[1:num_args + 1]
+        self.arg_names = all_args[1 : num_args + 1]
 
         # self.arg_defaults is a map of arg name to its default value for each
         # argument that has a default value
         if arg_spec.defaults:
-            self.arg_defaults = dict(zip(
-                all_args[-len(arg_spec.defaults):],
-                arg_spec.defaults
-            ))
+            self.arg_defaults = dict(
+                zip(all_args[-len(arg_spec.defaults) :], arg_spec.defaults)
+            )
         else:
             self.arg_defaults = {}
 
         if "cache_context" in self.arg_names:
-            raise Exception(
-                "cache_context arg cannot be included among the cache keys"
-            )
+            raise Exception("cache_context arg cannot be included among the cache keys")
 
         self.add_cache_context = cache_context
 
@@ -304,12 +295,24 @@ class CacheDescriptor(_CacheDescriptorBase):
             ``cache_context``) to use as cache keys. Defaults to all named
             args of the function.
     """
-    def __init__(self, orig, max_entries=1000, num_args=None, tree=False,
-                 inlineCallbacks=False, cache_context=False, iterable=False):
+
+    def __init__(
+        self,
+        orig,
+        max_entries=1000,
+        num_args=None,
+        tree=False,
+        inlineCallbacks=False,
+        cache_context=False,
+        iterable=False,
+    ):
 
         super(CacheDescriptor, self).__init__(
-            orig, num_args=num_args, inlineCallbacks=inlineCallbacks,
-            cache_context=cache_context)
+            orig,
+            num_args=num_args,
+            inlineCallbacks=inlineCallbacks,
+            cache_context=cache_context,
+        )
 
         max_entries = int(max_entries * get_cache_factor_for(orig.__name__))
 
@@ -356,7 +359,9 @@ class CacheDescriptor(_CacheDescriptorBase):
                     return args[0]
                 else:
                     return self.arg_defaults[nm]
+
         else:
+
             def get_cache_key(args, kwargs):
                 return tuple(get_cache_key_gen(args, kwargs))
 
@@ -383,8 +388,7 @@ class CacheDescriptor(_CacheDescriptorBase):
 
             except KeyError:
                 ret = defer.maybeDeferred(
-                    logcontext.preserve_fn(self.function_to_call),
-                    obj, *args, **kwargs
+                    logcontext.preserve_fn(self.function_to_call), obj, *args, **kwargs
                 )
 
                 def onErr(f):
@@ -437,8 +441,9 @@ class CacheListDescriptor(_CacheDescriptorBase):
     results.
     """
 
-    def __init__(self, orig, cached_method_name, list_name, num_args=None,
-                 inlineCallbacks=False):
+    def __init__(
+        self, orig, cached_method_name, list_name, num_args=None, inlineCallbacks=False
+    ):
         """
         Args:
             orig (function)
@@ -451,7 +456,8 @@ class CacheListDescriptor(_CacheDescriptorBase):
                 be wrapped by defer.inlineCallbacks
         """
         super(CacheListDescriptor, self).__init__(
-            orig, num_args=num_args, inlineCallbacks=inlineCallbacks)
+            orig, num_args=num_args, inlineCallbacks=inlineCallbacks
+        )
 
         self.list_name = list_name
 
@@ -463,7 +469,7 @@ class CacheListDescriptor(_CacheDescriptorBase):
         if self.list_name not in self.arg_names:
             raise Exception(
                 "Couldn't see arguments %r for %r."
-                % (self.list_name, cached_method_name,)
+                % (self.list_name, cached_method_name)
             )
 
     def __get__(self, obj, objtype=None):
@@ -494,8 +500,10 @@ class CacheListDescriptor(_CacheDescriptorBase):
             # If the cache takes a single arg then that is used as the key,
             # otherwise a tuple is used.
             if num_args == 1:
+
                 def arg_to_cache_key(arg):
                     return arg
+
             else:
                 keylist = list(keyargs)
 
@@ -505,8 +513,7 @@ class CacheListDescriptor(_CacheDescriptorBase):
 
             for arg in list_args:
                 try:
-                    res = cache.get(arg_to_cache_key(arg),
-                                    callback=invalidate_callback)
+                    res = cache.get(arg_to_cache_key(arg), callback=invalidate_callback)
                     if not isinstance(res, ObservableDeferred):
                         results[arg] = res
                     elif not res.has_succeeded():
@@ -554,18 +561,15 @@ class CacheListDescriptor(_CacheDescriptorBase):
                 args_to_call = dict(arg_dict)
                 args_to_call[self.list_name] = list(missing)
 
-                cached_defers.append(defer.maybeDeferred(
-                    logcontext.preserve_fn(self.function_to_call),
-                    **args_to_call
-                ).addCallbacks(complete_all, errback))
+                cached_defers.append(
+                    defer.maybeDeferred(
+                        logcontext.preserve_fn(self.function_to_call), **args_to_call
+                    ).addCallbacks(complete_all, errback)
+                )
 
             if cached_defers:
-                d = defer.gatherResults(
-                    cached_defers,
-                    consumeErrors=True,
-                ).addCallbacks(
-                    lambda _: results,
-                    unwrapFirstError
+                d = defer.gatherResults(cached_defers, consumeErrors=True).addCallbacks(
+                    lambda _: results, unwrapFirstError
                 )
                 return logcontext.make_deferred_yieldable(d)
             else:
@@ -586,8 +590,9 @@ class _CacheContext(namedtuple("_CacheContext", ("cache", "key"))):
         self.cache.invalidate(self.key)
 
 
-def cached(max_entries=1000, num_args=None, tree=False, cache_context=False,
-           iterable=False):
+def cached(
+    max_entries=1000, num_args=None, tree=False, cache_context=False, iterable=False
+):
     return lambda orig: CacheDescriptor(
         orig,
         max_entries=max_entries,
@@ -598,8 +603,9 @@ def cached(max_entries=1000, num_args=None, tree=False, cache_context=False,
     )
 
 
-def cachedInlineCallbacks(max_entries=1000, num_args=None, tree=False,
-                          cache_context=False, iterable=False):
+def cachedInlineCallbacks(
+    max_entries=1000, num_args=None, tree=False, cache_context=False, iterable=False
+):
     return lambda orig: CacheDescriptor(
         orig,
         max_entries=max_entries,
diff --git a/synapse/util/caches/dictionary_cache.py b/synapse/util/caches/dictionary_cache.py
index 6c0b5a4094..6834e6f3ae 100644
--- a/synapse/util/caches/dictionary_cache.py
+++ b/synapse/util/caches/dictionary_cache.py
@@ -35,6 +35,7 @@ class DictionaryEntry(namedtuple("DictionaryEntry", ("full", "known_absent", "va
             there.
         value (dict): The full or partial dict value
     """
+
     def __len__(self):
         return len(self.value)
 
@@ -84,13 +85,15 @@ class DictionaryCache(object):
             self.metrics.inc_hits()
 
             if dict_keys is None:
-                return DictionaryEntry(entry.full, entry.known_absent, dict(entry.value))
+                return DictionaryEntry(
+                    entry.full, entry.known_absent, dict(entry.value)
+                )
             else:
-                return DictionaryEntry(entry.full, entry.known_absent, {
-                    k: entry.value[k]
-                    for k in dict_keys
-                    if k in entry.value
-                })
+                return DictionaryEntry(
+                    entry.full,
+                    entry.known_absent,
+                    {k: entry.value[k] for k in dict_keys if k in entry.value},
+                )
 
         self.metrics.inc_misses()
         return DictionaryEntry(False, set(), {})
diff --git a/synapse/util/caches/expiringcache.py b/synapse/util/caches/expiringcache.py
index f369780277..cddf1ed515 100644
--- a/synapse/util/caches/expiringcache.py
+++ b/synapse/util/caches/expiringcache.py
@@ -28,8 +28,15 @@ SENTINEL = object()
 
 
 class ExpiringCache(object):
-    def __init__(self, cache_name, clock, max_len=0, expiry_ms=0,
-                 reset_expiry_on_get=False, iterable=False):
+    def __init__(
+        self,
+        cache_name,
+        clock,
+        max_len=0,
+        expiry_ms=0,
+        reset_expiry_on_get=False,
+        iterable=False,
+    ):
         """
         Args:
             cache_name (str): Name of this cache, used for logging.
@@ -67,8 +74,7 @@ class ExpiringCache(object):
 
         def f():
             return run_as_background_process(
-                "prune_cache_%s" % self._cache_name,
-                self._prune_cache,
+                "prune_cache_%s" % self._cache_name, self._prune_cache
             )
 
         self._clock.looping_call(f, self._expiry_ms / 2)
@@ -153,7 +159,9 @@ class ExpiringCache(object):
 
         logger.debug(
             "[%s] _prune_cache before: %d, after len: %d",
-            self._cache_name, begin_length, len(self)
+            self._cache_name,
+            begin_length,
+            len(self),
         )
 
     def __len__(self):
diff --git a/synapse/util/caches/lrucache.py b/synapse/util/caches/lrucache.py
index b684f24e7b..1536cb64f3 100644
--- a/synapse/util/caches/lrucache.py
+++ b/synapse/util/caches/lrucache.py
@@ -49,8 +49,15 @@ class LruCache(object):
     Can also set callbacks on objects when getting/setting which are fired
     when that key gets invalidated/evicted.
     """
-    def __init__(self, max_size, keylen=1, cache_type=dict, size_callback=None,
-                 evicted_callback=None):
+
+    def __init__(
+        self,
+        max_size,
+        keylen=1,
+        cache_type=dict,
+        size_callback=None,
+        evicted_callback=None,
+    ):
         """
         Args:
             max_size (int):
@@ -93,9 +100,12 @@ class LruCache(object):
 
         cached_cache_len = [0]
         if size_callback is not None:
+
             def cache_len():
                 return cached_cache_len[0]
+
         else:
+
             def cache_len():
                 return len(cache)
 
diff --git a/synapse/util/caches/response_cache.py b/synapse/util/caches/response_cache.py
index afb03b2e1b..b1da81633c 100644
--- a/synapse/util/caches/response_cache.py
+++ b/synapse/util/caches/response_cache.py
@@ -35,12 +35,10 @@ class ResponseCache(object):
         self.pending_result_cache = {}  # Requests that haven't finished yet.
 
         self.clock = hs.get_clock()
-        self.timeout_sec = timeout_ms / 1000.
+        self.timeout_sec = timeout_ms / 1000.0
 
         self._name = name
-        self._metrics = register_cache(
-            "response_cache", name, self
-        )
+        self._metrics = register_cache("response_cache", name, self)
 
     def size(self):
         return len(self.pending_result_cache)
@@ -100,8 +98,7 @@ class ResponseCache(object):
         def remove(r):
             if self.timeout_sec:
                 self.clock.call_later(
-                    self.timeout_sec,
-                    self.pending_result_cache.pop, key, None,
+                    self.timeout_sec, self.pending_result_cache.pop, key, None
                 )
             else:
                 self.pending_result_cache.pop(key, None)
@@ -147,14 +144,15 @@ class ResponseCache(object):
         """
         result = self.get(key)
         if not result:
-            logger.info("[%s]: no cached result for [%s], calculating new one",
-                        self._name, key)
+            logger.info(
+                "[%s]: no cached result for [%s], calculating new one", self._name, key
+            )
             d = run_in_background(callback, *args, **kwargs)
             result = self.set(key, d)
         elif not isinstance(result, defer.Deferred) or result.called:
-            logger.info("[%s]: using completed cached result for [%s]",
-                        self._name, key)
+            logger.info("[%s]: using completed cached result for [%s]", self._name, key)
         else:
-            logger.info("[%s]: using incomplete cached result for [%s]",
-                        self._name, key)
+            logger.info(
+                "[%s]: using incomplete cached result for [%s]", self._name, key
+            )
         return make_deferred_yieldable(result)
diff --git a/synapse/util/caches/stream_change_cache.py b/synapse/util/caches/stream_change_cache.py
index 625aedc940..235f64049c 100644
--- a/synapse/util/caches/stream_change_cache.py
+++ b/synapse/util/caches/stream_change_cache.py
@@ -77,9 +77,8 @@ class StreamChangeCache(object):
 
         if stream_pos >= self._earliest_known_stream_pos:
             changed_entities = {
-                self._cache[k] for k in self._cache.islice(
-                    start=self._cache.bisect_right(stream_pos),
-                )
+                self._cache[k]
+                for k in self._cache.islice(start=self._cache.bisect_right(stream_pos))
             }
 
             result = changed_entities.intersection(entities)
@@ -114,8 +113,10 @@ class StreamChangeCache(object):
         assert type(stream_pos) is int
 
         if stream_pos >= self._earliest_known_stream_pos:
-            return [self._cache[k] for k in self._cache.islice(
-                start=self._cache.bisect_right(stream_pos))]
+            return [
+                self._cache[k]
+                for k in self._cache.islice(start=self._cache.bisect_right(stream_pos))
+            ]
         else:
             return None
 
@@ -136,7 +137,7 @@ class StreamChangeCache(object):
             while len(self._cache) > self._max_size:
                 k, r = self._cache.popitem(0)
                 self._earliest_known_stream_pos = max(
-                    k, self._earliest_known_stream_pos,
+                    k, self._earliest_known_stream_pos
                 )
                 self._entity_to_key.pop(r, None)
 
diff --git a/synapse/util/caches/treecache.py b/synapse/util/caches/treecache.py
index dd4c9e6067..9a72218d85 100644
--- a/synapse/util/caches/treecache.py
+++ b/synapse/util/caches/treecache.py
@@ -9,6 +9,7 @@ class TreeCache(object):
     efficiently.
     Keys must be tuples.
     """
+
     def __init__(self):
         self.size = 0
         self.root = {}
diff --git a/synapse/util/caches/ttlcache.py b/synapse/util/caches/ttlcache.py
index 5ba1862506..2af8ca43b1 100644
--- a/synapse/util/caches/ttlcache.py
+++ b/synapse/util/caches/ttlcache.py
@@ -155,6 +155,7 @@ class TTLCache(object):
 @attr.s(frozen=True, slots=True)
 class _CacheEntry(object):
     """TTLCache entry"""
+
     # expiry_time is the first attribute, so that entries are sorted by expiry.
     expiry_time = attr.ib()
     key = attr.ib()
-- 
cgit 1.5.1


From ef8c62758cb682205c538215a0c04f008f9c967a Mon Sep 17 00:00:00 2001
From: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>
Date: Tue, 25 Jun 2019 14:19:21 +0100
Subject: Prevent multiple upgrades on the same room at once (#5051)

Closes #4583

Does slightly less than #5045, which prevented a room from being upgraded multiple times, one after another. This PR still allows that, but just prevents two from happening at the same time.

Mostly just to mitigate the fact that servers are slow and it can take a moment for the room upgrade to actually complete. We don't want people sending another request to upgrade the room when really they just thought the first didn't go through.
---
 changelog.d/5051.bugfix               |   1 +
 synapse/handlers/room.py              | 140 +++++++++++++++++++++-------------
 synapse/util/caches/response_cache.py |   2 +-
 3 files changed, 91 insertions(+), 52 deletions(-)
 create mode 100644 changelog.d/5051.bugfix

(limited to 'synapse/util/caches')

diff --git a/changelog.d/5051.bugfix b/changelog.d/5051.bugfix
new file mode 100644
index 0000000000..bfa22cc759
--- /dev/null
+++ b/changelog.d/5051.bugfix
@@ -0,0 +1 @@
+Prevent >1 room upgrades happening simultaneously on the same room.
diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py
index 89d89fc27c..db3f8cb76b 100644
--- a/synapse/handlers/room.py
+++ b/synapse/handlers/room.py
@@ -32,6 +32,7 @@ from synapse.storage.state import StateFilter
 from synapse.types import RoomAlias, RoomID, RoomStreamToken, StreamToken, UserID
 from synapse.util import stringutils
 from synapse.util.async_helpers import Linearizer
+from synapse.util.caches.response_cache import ResponseCache
 from synapse.visibility import filter_events_for_client
 
 from ._base import BaseHandler
@@ -40,6 +41,8 @@ logger = logging.getLogger(__name__)
 
 id_server_scheme = "https://"
 
+FIVE_MINUTES_IN_MS = 5 * 60 * 1000
+
 
 class RoomCreationHandler(BaseHandler):
 
@@ -75,6 +78,12 @@ class RoomCreationHandler(BaseHandler):
         # linearizer to stop two upgrades happening at once
         self._upgrade_linearizer = Linearizer("room_upgrade_linearizer")
 
+        # If a user tries to update the same room multiple times in quick
+        # succession, only process the first attempt and return its result to
+        # subsequent requests
+        self._upgrade_response_cache = ResponseCache(
+            hs, "room_upgrade", timeout_ms=FIVE_MINUTES_IN_MS
+        )
         self._server_notices_mxid = hs.config.server_notices_mxid
 
         self.third_party_event_rules = hs.get_third_party_event_rules()
@@ -95,67 +104,96 @@ class RoomCreationHandler(BaseHandler):
 
         user_id = requester.user.to_string()
 
-        with (yield self._upgrade_linearizer.queue(old_room_id)):
-            # start by allocating a new room id
-            r = yield self.store.get_room(old_room_id)
-            if r is None:
-                raise NotFoundError("Unknown room id %s" % (old_room_id,))
-            new_room_id = yield self._generate_room_id(
-                creator_id=user_id, is_public=r["is_public"]
-            )
+        # Check if this room is already being upgraded by another person
+        for key in self._upgrade_response_cache.pending_result_cache:
+            if key[0] == old_room_id and key[1] != user_id:
+                # Two different people are trying to upgrade the same room.
+                # Send the second an error.
+                #
+                # Note that this of course only gets caught if both users are
+                # on the same homeserver.
+                raise SynapseError(
+                    400, "An upgrade for this room is currently in progress"
+                )
 
-            logger.info("Creating new room %s to replace %s", new_room_id, old_room_id)
+        # Upgrade the room
+        #
+        # If this user has sent multiple upgrade requests for the same room
+        # and one of them is not complete yet, cache the response and
+        # return it to all subsequent requests
+        ret = yield self._upgrade_response_cache.wrap(
+            (old_room_id, user_id),
+            self._upgrade_room,
+            requester,
+            old_room_id,
+            new_version,  # args for _upgrade_room
+        )
+        defer.returnValue(ret)
 
-            # we create and auth the tombstone event before properly creating the new
-            # room, to check our user has perms in the old room.
-            tombstone_event, tombstone_context = (
-                yield self.event_creation_handler.create_event(
-                    requester,
-                    {
-                        "type": EventTypes.Tombstone,
-                        "state_key": "",
-                        "room_id": old_room_id,
-                        "sender": user_id,
-                        "content": {
-                            "body": "This room has been replaced",
-                            "replacement_room": new_room_id,
-                        },
-                    },
-                    token_id=requester.access_token_id,
-                )
-            )
-            old_room_version = yield self.store.get_room_version(old_room_id)
-            yield self.auth.check_from_context(
-                old_room_version, tombstone_event, tombstone_context
-            )
+    @defer.inlineCallbacks
+    def _upgrade_room(self, requester, old_room_id, new_version):
+        user_id = requester.user.to_string()
+
+        # start by allocating a new room id
+        r = yield self.store.get_room(old_room_id)
+        if r is None:
+            raise NotFoundError("Unknown room id %s" % (old_room_id,))
+        new_room_id = yield self._generate_room_id(
+            creator_id=user_id, is_public=r["is_public"]
+        )
+
+        logger.info("Creating new room %s to replace %s", new_room_id, old_room_id)
 
-            yield self.clone_existing_room(
+        # we create and auth the tombstone event before properly creating the new
+        # room, to check our user has perms in the old room.
+        tombstone_event, tombstone_context = (
+            yield self.event_creation_handler.create_event(
                 requester,
-                old_room_id=old_room_id,
-                new_room_id=new_room_id,
-                new_room_version=new_version,
-                tombstone_event_id=tombstone_event.event_id,
+                {
+                    "type": EventTypes.Tombstone,
+                    "state_key": "",
+                    "room_id": old_room_id,
+                    "sender": user_id,
+                    "content": {
+                        "body": "This room has been replaced",
+                        "replacement_room": new_room_id,
+                    },
+                },
+                token_id=requester.access_token_id,
             )
+        )
+        old_room_version = yield self.store.get_room_version(old_room_id)
+        yield self.auth.check_from_context(
+            old_room_version, tombstone_event, tombstone_context
+        )
 
-            # now send the tombstone
-            yield self.event_creation_handler.send_nonmember_event(
-                requester, tombstone_event, tombstone_context
-            )
+        yield self.clone_existing_room(
+            requester,
+            old_room_id=old_room_id,
+            new_room_id=new_room_id,
+            new_room_version=new_version,
+            tombstone_event_id=tombstone_event.event_id,
+        )
 
-            old_room_state = yield tombstone_context.get_current_state_ids(self.store)
+        # now send the tombstone
+        yield self.event_creation_handler.send_nonmember_event(
+            requester, tombstone_event, tombstone_context
+        )
 
-            # update any aliases
-            yield self._move_aliases_to_new_room(
-                requester, old_room_id, new_room_id, old_room_state
-            )
+        old_room_state = yield tombstone_context.get_current_state_ids(self.store)
 
-            # and finally, shut down the PLs in the old room, and update them in the new
-            # room.
-            yield self._update_upgraded_room_pls(
-                requester, old_room_id, new_room_id, old_room_state
-            )
+        # update any aliases
+        yield self._move_aliases_to_new_room(
+            requester, old_room_id, new_room_id, old_room_state
+        )
+
+        # and finally, shut down the PLs in the old room, and update them in the new
+        # room.
+        yield self._update_upgraded_room_pls(
+            requester, old_room_id, new_room_id, old_room_state
+        )
 
-            defer.returnValue(new_room_id)
+        defer.returnValue(new_room_id)
 
     @defer.inlineCallbacks
     def _update_upgraded_room_pls(
diff --git a/synapse/util/caches/response_cache.py b/synapse/util/caches/response_cache.py
index b1da81633c..cbe54d45dd 100644
--- a/synapse/util/caches/response_cache.py
+++ b/synapse/util/caches/response_cache.py
@@ -137,7 +137,7 @@ class ResponseCache(object):
 
             *args: positional parameters to pass to the callback, if it is used
 
-            **kwargs: named paramters to pass to the callback, if it is used
+            **kwargs: named parameters to pass to the callback, if it is used
 
         Returns:
             twisted.internet.defer.Deferred: yieldable result
-- 
cgit 1.5.1