Digging into the root causes of [1] it appears that there are a number of threading / timing issues with the current AsyncContextImpl. Running the provided test case with ab -n 50 -c 20 triggers the error every couple of runs. The error appears to occur when the thread where complete() is called finishes before the thread where startAsync() is called.
There were a number of places / ways this could happen: - the checks if current state are not thread safe - the state changes are atomic but the actions that are part of that state were not atomic - the spec requirement the complete() and dispatch() must wait until the thread where startAsync() is called completes are not met - socket level processing is handled by the executor so there is no guarantee of processing order I had a couple of false starts trying to fix this but my current attempt [2] is showing some promise. The test case from [1] runs without error with ab -n 5000 -c 400 with or without -k. At the moment [2] is in a very rough and ready state and only handles startAsync() and complete() for the BIO HTTP connector. I wanted to give folks early sight of this patch so I could incorporate any early feedback. I plan to expand the patch to cover dispatch(), timeouts, the other connectors, passing our test cases and passing the TCK before committing. I'm not sure how long that will take. I hope to get this done this week. Mark [1] https://issues.apache.org/bugzilla/show_bug.cgi?id=49884 [2] http://people.apache.org/~markt/patches/2010-09-12-async-refactoring.patch --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@tomcat.apache.org For additional commands, e-mail: dev-h...@tomcat.apache.org
