diff --git a/synapse/util/__init__.py b/synapse/util/__init__.py index 680ea928c..c237d003b 100644 --- a/synapse/util/__init__.py +++ b/synapse/util/__init__.py @@ -13,6 +13,7 @@ # See the License for the specific language governing permissions and # limitations under the License. +import functools import logging from itertools import islice @@ -66,7 +67,7 @@ class Clock(object): f(function): The function to call repeatedly. msec(float): How long to wait between calls in milliseconds. """ - call = task.LoopingCall(f) + call = task.LoopingCall(_log_exception_wrapper(f)) call.clock = self._reactor call.start(msec / 1000.0, now=False) return call @@ -109,3 +110,19 @@ def batch_iter(iterable, size): sourceiter = iter(iterable) # call islice until it returns an empty tuple return iter(lambda: tuple(islice(sourceiter, size)), ()) + + +def _log_exception_wrapper(f): + """Used to wrap looping calls to log loudly if they get killed + """ + + @functools.wraps(f) + def wrap(*args, **kwargs): + try: + logger.info("Running looping call") + return f(*args, **kwargs) + except: # noqa: E722, as we reraise the exception this is fine. + logger.exception("Looping called died") + raise + + return wrap