1 Reply Latest reply on Jul 10, 2008 6:07 AM by Adrian Brock

    JBCL-7 - ClassLoader validation

    Adrian Brock Master

      I've committed some work that does the majority of this work,
      but it is still incomplete and almost certainly requires a bit more refactoring

      This introduces the notion of a ClassLoadingSpace
      which is really just a Set of related ClassLoading modules.

      The ClassLoadingSpace has a two phase api:

      join() - for when a module joins a classloading space
      split() - for when a module leaves a classloading space
      resolve() - work out when classloading spaces need to join
      unresolve() - nothing currently ;-)

      The basic strategy is that as each module is added to the ClassLoading
      a ClassLoaderSpace of just that module is constructed.

      Then during the resolution, it figures out that it and an imported Module
      need to be in the same ClassLoadingSpace so it does a join on the
      their respective ClassLoadingSpaces.

      Consistency checks are done during the join()

      The work still to do at this point is:

      * Tests (and handling) for circularity/self-depdendency in imports
      * Handling of split packages (i.e. two modules have the same
      package at the same version - but probably different classes, e.g. language packs)
      * Validation of optional imports (e.g. uses constraints) currently, I'm ignoring these
      * Better error reporting, i.e. more info on why a conflict occurs (why the
      modules are related) rather than just that a conflict has occurred

      Also, currently the initial resolve() is done at ClassLoading.addModule().
      But since that is an inCallback throwing an error from there
      doesn't lead to a failed deployment, just a warning. So this needs
      to be revisited (it should just be done lazily when the MC calls back on
      the RequirementDependencyItem).