From 58c9f206929560044fccae84c36fdd89724ccfc0 Mon Sep 17 00:00:00 2001 From: Mark Haines Date: Fri, 12 Feb 2016 13:46:59 +0000 Subject: Catch the exceptions thrown by twisted when you write to a closed connection --- synapse/http/server.py | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) (limited to 'synapse/http/server.py') diff --git a/synapse/http/server.py b/synapse/http/server.py index a90e2e1125..b17b190ee5 100644 --- a/synapse/http/server.py +++ b/synapse/http/server.py @@ -367,10 +367,29 @@ def respond_with_json_bytes(request, code, json_bytes, send_cors=False, "Origin, X-Requested-With, Content-Type, Accept") request.write(json_bytes) - request.finish() + finish_request(request) return NOT_DONE_YET +def finish_request(request): + """ Finish writing the response to the request. + + Twisted throws a RuntimeException if the connection closed before the + response was written but doesn't provide a convenient or reliable way to + determine if the connection was closed. So we catch and log the RuntimeException + + You might think that ``request.notifyFinish`` could be used to tell if the + request was finished. However the deferred it returns won't fire if the + connection was already closed, meaning we'd have to have called the method + right at the start of the request. By the time we want to write the response + it will already be too late. + """ + try: + request.finish() + except RuntimeError as e: + logger.info("Connection disconnected before response was written: %r", e) + + def _request_user_agent_is_curl(request): user_agents = request.requestHeaders.getRawHeaders( "User-Agent", default=[] -- cgit 1.4.1