Uploaded image for project: 'Commons JEXL'
  1. Commons JEXL
  2. JEXL-61

Usage of strong references on Method/Constructor & WeakHashMap usage

    XMLWordPrintableJSON

Details

    • Improvement
    • Status: Closed
    • Major
    • Resolution: Fixed
    • 2.0, 2.0.1
    • 2.0
    • None

    Description

      In MethodMap and IntrospectorBase in 2.0, we are using strong references on Method(s) and Constructor(s).
      However, the ClassMap is using a WeakHashMap keyed on class and IntrospectorBase use SoftRefence on classes to allow the GC to remove them if the need arise.
      I might misunderstand the whole thing but it seems "odd" since the GC can probaby not remove a class for which a strong reference on method or constructor exists; the getDeclaringClass seems to prevent this from being possible. The fix would be to use SoftReference on those List<Method> and Constructor used in the code.
      The second - nitpicking - oddity is that a WeakHashMap is not the best fit for the kind of cache Jexl is using; a "SoftHashMap" should be a better choice; but the previous fix could prevent the inherent WeakHashMap problem too since holding those methods/ctors through SoftReference should still make "hard enough" references to the classes held by the keys for them to be removed.
      In any case, the code is this way since its origin and no-one has complained (yet) about this (obscure feature to me) which documented intent is to "detect class loader changes"., thus the low priority. My (wild)guess is that anyone having really encountered this issue probably increased permSpace size for other reasons.

      Attachments

        Activity

          People

            henrib Henri Biestro
            henrib Henri Biestro
            Votes:
            0 Vote for this issue
            Watchers:
            0 Start watching this issue

            Dates

              Created:
              Updated:
              Resolved: