diff options
Diffstat (limited to 'synapse/util')
| -rw-r--r-- | synapse/util/async_helpers.py | 88 | ||||
| -rw-r--r-- | synapse/util/retryutils.py | 2 |
2 files changed, 26 insertions, 64 deletions
diff --git a/synapse/util/async_helpers.py b/synapse/util/async_helpers.py index 40c2946129..ec7b2c9672 100644 --- a/synapse/util/async_helpers.py +++ b/synapse/util/async_helpers.py @@ -374,29 +374,25 @@ class ReadWriteLock(object): defer.returnValue(_ctx_manager()) -class DeferredTimeoutError(Exception): - """ - This error is raised by default when a L{Deferred} times out. - """ - +def _cancelled_to_timed_out_error(value, timeout): + if isinstance(value, failure.Failure): + value.trap(CancelledError) + raise defer.TimeoutError(timeout, "Deferred") + return value -def add_timeout_to_deferred(deferred, timeout, reactor, on_timeout_cancel=None): - """ - Add a timeout to a deferred by scheduling it to be cancelled after - timeout seconds. - This is essentially a backport of deferred.addTimeout, which was introduced - in twisted 16.5. +def timeout_deferred(deferred, timeout, reactor, on_timeout_cancel=None): + """The in built twisted `Deferred.addTimeout` fails to time out deferreds + that have a canceller that throws exceptions. This method creates a new + deferred that wraps and times out the given deferred, correctly handling + the case where the given deferred's canceller throws. - If the deferred gets timed out, it errbacks with a DeferredTimeoutError, - unless a cancelable function was passed to its initialization or unless - a different on_timeout_cancel callable is provided. + NOTE: Unlike `Deferred.addTimeout`, this function returns a new deferred Args: - deferred (defer.Deferred): deferred to be timed out - timeout (Number): seconds to time out after - reactor (twisted.internet.reactor): the Twisted reactor to use - + deferred (Deferred) + timeout (float): Timeout in seconds + reactor (twisted.internet.reactor): The twisted reactor to use on_timeout_cancel (callable): A callable which is called immediately after the deferred times out, and not if this deferred is otherwise cancelled before the timeout. @@ -406,48 +402,10 @@ def add_timeout_to_deferred(deferred, timeout, reactor, on_timeout_cancel=None): the timeout. The default callable (if none is provided) will translate a - CancelledError Failure into a DeferredTimeoutError. - """ - timed_out = [False] - - def time_it_out(): - timed_out[0] = True - deferred.cancel() - - delayed_call = reactor.callLater(timeout, time_it_out) - - def convert_cancelled(value): - if timed_out[0]: - to_call = on_timeout_cancel or _cancelled_to_timed_out_error - return to_call(value, timeout) - return value - - deferred.addBoth(convert_cancelled) + CancelledError Failure into a defer.TimeoutError. - def cancel_timeout(result): - # stop the pending call to cancel the deferred if it's been fired - if delayed_call.active(): - delayed_call.cancel() - return result - - deferred.addBoth(cancel_timeout) - - -def _cancelled_to_timed_out_error(value, timeout): - if isinstance(value, failure.Failure): - value.trap(CancelledError) - raise DeferredTimeoutError(timeout, "Deferred") - return value - - -def timeout_no_seriously(deferred, timeout, reactor): - """The in build twisted deferred addTimeout (and the method above) - completely fail to time things out under some unknown circumstances. - - Lets try a different way of timing things out and maybe that will make - things work?! - - TODO: Kill this with fire. + Returns: + Deferred """ new_d = defer.Deferred() @@ -457,16 +415,20 @@ def timeout_no_seriously(deferred, timeout, reactor): def time_it_out(): timed_out[0] = True - if not new_d.called: - new_d.errback(DeferredTimeoutError(timeout, "Deferred")) + try: + deferred.cancel() + except: # noqa: E722, if we throw any exception it'll break time outs + logger.exception("Canceller failed during timeout") - deferred.cancel() + if not new_d.called: + new_d.errback(defer.TimeoutError(timeout, "Deferred")) delayed_call = reactor.callLater(timeout, time_it_out) def convert_cancelled(value): if timed_out[0]: - return _cancelled_to_timed_out_error(value, timeout) + to_call = on_timeout_cancel or _cancelled_to_timed_out_error + return to_call(value, timeout) return value deferred.addBoth(convert_cancelled) diff --git a/synapse/util/retryutils.py b/synapse/util/retryutils.py index 8a3a06fd74..26cce7d197 100644 --- a/synapse/util/retryutils.py +++ b/synapse/util/retryutils.py @@ -188,7 +188,7 @@ class RetryDestinationLimiter(object): else: self.retry_interval = self.min_retry_interval - logger.debug( + logger.info( "Connection to %s was unsuccessful (%s(%s)); backoff now %i", self.destination, exc_type, exc_val, self.retry_interval ) |