diff options
| -rw-r--r-- | changelog.d/4799.misc | 1 | ||||
| -rw-r--r-- | synapse/notifier.py | 65 |
2 files changed, 6 insertions, 60 deletions
diff --git a/changelog.d/4799.misc b/changelog.d/4799.misc new file mode 100644 index 0000000000..5ab11a5c0b --- /dev/null +++ b/changelog.d/4799.misc @@ -0,0 +1 @@ +Clean up some replication code. diff --git a/synapse/notifier.py b/synapse/notifier.py index de02b1017e..ff589660da 100644 --- a/synapse/notifier.py +++ b/synapse/notifier.py @@ -178,8 +178,6 @@ class Notifier(object): self.remove_expired_streams, self.UNUSED_STREAM_EXPIRY_MS ) - self.replication_deferred = ObservableDeferred(defer.Deferred()) - # This is not a very cheap test to perform, but it's only executed # when rendering the metrics page, which is likely once per minute at # most when scraping it. @@ -205,7 +203,9 @@ class Notifier(object): def add_replication_callback(self, cb): """Add a callback that will be called when some new data is available. - Callback is not given any arguments. + Callback is not given any arguments. It should *not* return a Deferred - if + it needs to do any asynchronous work, a background thread should be started and + wrapped with run_as_background_process. """ self.replication_callbacks.append(cb) @@ -517,60 +517,5 @@ class Notifier(object): def notify_replication(self): """Notify the any replication listeners that there's a new event""" - with PreserveLoggingContext(): - deferred = self.replication_deferred - self.replication_deferred = ObservableDeferred(defer.Deferred()) - deferred.callback(None) - - # the callbacks may well outlast the current request, so we run - # them in the sentinel logcontext. - # - # (ideally it would be up to the callbacks to know if they were - # starting off background processes and drop the logcontext - # accordingly, but that requires more changes) - for cb in self.replication_callbacks: - cb() - - @defer.inlineCallbacks - def wait_for_replication(self, callback, timeout): - """Wait for an event to happen. - - Args: - callback: Gets called whenever an event happens. If this returns a - truthy value then ``wait_for_replication`` returns, otherwise - it waits for another event. - timeout: How many milliseconds to wait for callback return a truthy - value. - - Returns: - A deferred that resolves with the value returned by the callback. - """ - listener = _NotificationListener(None) - - end_time = self.clock.time_msec() + timeout - - while True: - listener.deferred = self.replication_deferred.observe() - result = yield callback() - if result: - break - - now = self.clock.time_msec() - if end_time <= now: - break - - listener.deferred = timeout_deferred( - listener.deferred, - timeout=(end_time - now) / 1000., - reactor=self.hs.get_reactor(), - ) - - try: - with PreserveLoggingContext(): - yield listener.deferred - except defer.TimeoutError: - break - except defer.CancelledError: - break - - defer.returnValue(result) + for cb in self.replication_callbacks: + cb() |