JWNL hangs during multithreaded processing

  • Andra Willits

    Andra Willits - 2009-03-18

    I am running JWNL 1.3 in an application that uses GATE for linguistic analysis.  The application uses a queue to line up strings to be processed.  Each string is popped off the queue and pulls an instance of ANNIE (Gate plugin that contains linguistic processing tools) out of a Pool.  The JWNL itself is initialized once during server start up and then the Dictionary instance is used several times throughout the application.

    The problem that I am having is at the line:
    IndexWord iw = dictionary.lookupIndexWord(
                                    POS.NOUN, word);

    It works fine through processing of each string when there is only a single thread running but as soon as I increase to 2 threads, this line will hang on random strings.  It doesn't appear to be a problem with the data as in some runs, it is able to process a particular word fine and in others, it doesn't.

    Could anyone tell me if there are issues with running JWNL in a multithreaded application?  I did try initializing the JWNL in each thread separately but this produced the same results.

    I can provide additional information if that would help as well.

    Thank you in advance.

    • Brett Walenz

      Brett Walenz - 2009-03-31

      Yes, I believe this will cause problems, as JWNL was never original designed to be operated in enterprise environments.  I don't think initializing JWNL in it's own thread would have any effect, as Dictionary is a singleton object.

      It's on the list of 'things to do' for a future release, but requires some architecture changes.

    • Vanessa Lopez

      Vanessa Lopez - 2009-07-01

      I do have the same problem too.
      I have tried to use locks while calling WordNet but it fails half of the times ..

      Looking forward for the future release

  • Aliaksandr Autayeu

    In my fork at http://extjwnl.sourceforge.net/ you can use the dictionary in a normal way, instance per thread, as opposed to the only one singletone instance. This might help resolving threading problems.


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