id summary reporter owner description type status priority milestone component resolution keywords cc branch branch_author launchpad_bug 3207 new t.web2.client.http.HTTPClientChannelRequest.connectionLost loops and errbacks incorrectly camrdale camrdale "The twisted.web2.client.http.HTTPClientChannelRequest.connectionLost function introduced in this revision is broken: {{{ Revision 21366, 11.2 kB (checked in by therve, 6 months ago) Merge web2-client-connectionlost-2304 Author: therve Reviewer: dreid Fixes #2304 Fix the connectionLost method of web2 client request so that errors are propagated to the response deferred. Also it handles the case where the headers are sent and the error happens during the streaming (after the response deferred). }}} Firstly, the call to _error() will cause a loop as it calls the channels abortParse(), which calls setReadPersistent() to set it to False, which calls connectionLost(), etc.... This causes an errback to be called multiple times, leading to tracebacks such as: {{{ Traceback (most recent call last): File ""/usr/lib/python2.5/site-packages/twisted/application/app.py"", line 269, in runReactorWithLogging reactor.run() File ""/usr/lib/python2.5/site-packages/twisted/internet/posixbase.py"", line 223, in run self.mainLoop() File ""/usr/lib/python2.5/site-packages/twisted/internet/posixbase.py"", line 234, in mainLoop self.doIteration(t) File ""/usr/lib/python2.5/site-packages/twisted/internet/selectreactor.py"", line 140, in doSelect _logrun(selectable, _drdw, selectable, method, dict) --- --- File ""/usr/lib/python2.5/site-packages/twisted/python/log.py"", line 51, in callWithLogger return callWithContext({""system"": lp}, func, *args, **kw) File ""/usr/lib/python2.5/site-packages/twisted/python/log.py"", line 36, in callWithContext return context.call({ILogContext: newCtx}, func, *args, **kw) File ""/usr/lib/python2.5/site-packages/twisted/python/context.py"", line 59, in callWithContext return self.currentContext().callWithContext(ctx, func, *args, **kw) File ""/usr/lib/python2.5/site-packages/twisted/python/context.py"", line 37, in callWithContext return func(*args,**kw) File ""/usr/lib/python2.5/site-packages/twisted/internet/selectreactor.py"", line 156, in _doReadOrWrite self._disconnectSelectable(selectable, why, method==""doRead"") File ""/usr/lib/python2.5/site-packages/twisted/internet/posixbase.py"", line 262, in _disconnectSelectable selectable.connectionLost(failure.Failure(why)) File ""/usr/lib/python2.5/site-packages/twisted/internet/tcp.py"", line 576, in connectionLost Connection.connectionLost(self, reason) File ""/usr/lib/python2.5/site-packages/twisted/internet/tcp.py"", line 416, in connectionLost protocol.connectionLost(reason) File ""/usr/lib/python2.5/site-packages/twisted/web2/client/http.py"", line 363, in connectionLost request.connectionLost(reason) File ""/usr/lib/python2.5/site-packages/twisted/web2/client/http.py"", line 168, in connectionLost self._error(reason) File ""/usr/lib/python2.5/site-packages/twisted/web2/client/http.py"", line 155, in _error self.abortParse() File ""/usr/lib/python2.5/site-packages/twisted/web2/channel/http.py"", line 330, in abortParse self.channel.setReadPersistent(False) File ""/usr/lib/python2.5/site-packages/twisted/web2/client/http.py"", line 353, in setReadPersistent request.connectionLost(None) File ""/usr/lib/python2.5/site-packages/twisted/web2/client/http.py"", line 168, in connectionLost self._error(reason) File ""/usr/lib/python2.5/site-packages/twisted/web2/client/http.py"", line 155, in _error self.abortParse() File ""/usr/lib/python2.5/site-packages/twisted/web2/channel/http.py"", line 330, in abortParse self.channel.setReadPersistent(False) File ""/usr/lib/python2.5/site-packages/twisted/web2/client/http.py"", line 353, in setReadPersistent request.connectionLost(None) File ""/usr/lib/python2.5/site-packages/twisted/web2/client/http.py"", line 168, in connectionLost self._error(reason) File ""/usr/lib/python2.5/site-packages/twisted/web2/client/http.py"", line 159, in _error self.responseDefer.errback(err) File ""/usr/lib/python2.5/site-packages/twisted/internet/defer.py"", line 264, in errback self._startRunCallbacks(fail) File ""/usr/lib/python2.5/site-packages/twisted/internet/defer.py"", line 293, in _startRunCallbacks raise AlreadyCalledError twisted.internet.defer.AlreadyCalledError: }}} Secondly, the call to connectionLost() on line 353 in the setReadPersistent() function now needs to send a failure as argument rather than None, as this gets passed down to an errback eventually which generates this error: {{{ Traceback (most recent call last): File ""/usr/lib/python2.5/site-packages/twisted/python/log.py"", line 51, in callWithLogger return callWithContext({""system"": lp}, func, *args, **kw) File ""/usr/lib/python2.5/site-packages/twisted/python/log.py"", line 36, in callWithContext return context.call({ILogContext: newCtx}, func, *args, **kw) File ""/usr/lib/python2.5/site-packages/twisted/python/context.py"", line 59, in callWithContext return self.currentContext().callWithContext(ctx, func, *args, **kw) File ""/usr/lib/python2.5/site-packages/twisted/python/context.py"", line 37, in callWithContext return func(*args,**kw) --- --- File ""/usr/lib/python2.5/site-packages/twisted/internet/selectreactor.py"", line 146, in _doReadOrWrite why = getattr(selectable, method)() File ""/usr/lib/python2.5/site-packages/twisted/internet/tcp.py"", line 362, in doRead return self.protocol.dataReceived(data) File ""/usr/lib/python2.5/site-packages/twisted/protocols/basic.py"", line 239, in dataReceived return self.rawDataReceived(data) File ""/var/lib/python-support/python2.5/apt_p2p/HTTPDownloader.py"", line 37, in rawDataReceived HTTPClientProtocol.rawDataReceived(self, data) File ""/usr/lib/python2.5/site-packages/twisted/web2/client/http.py"", line 293, in rawDataReceived self.inRequests[0].rawDataReceived(data) File ""/usr/lib/python2.5/site-packages/twisted/web2/channel/http.py"", line 173, in rawDataReceived channel.setLineMode(extraneous) File ""/usr/lib/python2.5/site-packages/twisted/protocols/basic.py"", line 254, in setLineMode return self.dataReceived(extra) File ""/usr/lib/python2.5/site-packages/twisted/protocols/basic.py"", line 231, in dataReceived why = self.lineReceived(line) File ""/var/lib/python-support/python2.5/apt_p2p/HTTPDownloader.py"", line 32, in lineReceived HTTPClientProtocol.lineReceived(self, line) File ""/usr/lib/python2.5/site-packages/twisted/web2/client/http.py"", line 281, in lineReceived self.inRequests[0].lineReceived(line) File ""/usr/lib/python2.5/site-packages/twisted/web2/channel/http.py"", line 130, in lineReceived self.allHeadersReceived() # can set chunkedIn File ""/usr/lib/python2.5/site-packages/twisted/web2/channel/http.py"", line 193, in allHeadersReceived self.setConnectionParams(connHeaders) File ""/usr/lib/python2.5/site-packages/twisted/web2/channel/http.py"", line 324, in setConnectionParams self.channel.setReadPersistent(readPersistent) File ""/usr/lib/python2.5/site-packages/twisted/web2/client/http.py"", line 353, in setReadPersistent request.connectionLost(None) File ""/usr/lib/python2.5/site-packages/twisted/web2/client/http.py"", line 168, in connectionLost self._error(reason) File ""/usr/lib/python2.5/site-packages/twisted/web2/client/http.py"", line 155, in _error self.abortParse() File ""/usr/lib/python2.5/site-packages/twisted/web2/channel/http.py"", line 330, in abortParse self.channel.setReadPersistent(False) File ""/usr/lib/python2.5/site-packages/twisted/web2/client/http.py"", line 353, in setReadPersistent request.connectionLost(None) File ""/usr/lib/python2.5/site-packages/twisted/web2/client/http.py"", line 168, in connectionLost self._error(reason) File ""/usr/lib/python2.5/site-packages/twisted/web2/client/http.py"", line 159, in _error self.responseDefer.errback(err) File ""/usr/lib/python2.5/site-packages/twisted/internet/defer.py"", line 262, in errback fail = failure.Failure(fail) File ""/usr/lib/python2.5/site-packages/twisted/python/failure.py"", line 173, in __init__ raise NoCurrentExceptionError() twisted.python.failure.NoCurrentExceptionError: }}} " defect closed normal web2 wontfix therve exarkun dreid branches/web2-client-connectionlost-loop-3207 exarkun