G1 may incorrectly try to reclaim humongous non-Array objects containing references

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    • Type: Bug
    • Resolution: Duplicate
    • Priority: P3
    • 9
    • Affects Version/s: 8u40, 9
    • Component/s: hotspot
    • gc

      In JDK-8027959 G1 introduced early reclaim for humongous objects that have no references.

      The check whether a humongous object has no references is performed whether the object is not an object array.
      This automatically exclude those.

      However it is possible that regular non-array objects are humongous: while there is a limit on the number of members of a particular class, subclasses may be larger. That means that regular objects can be humongous.

      Which is a problem because regular objects may contain references that might be missed if they are reclaimed during a concurrent marking cycle.

            Assignee:
            Kim Barrett
            Reporter:
            Thomas Schatzl
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              Created:
              Updated:
              Resolved: