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  1. JDK
  2. JDK-8231086

Shenandoah: Stronger invariant for object-arraycopy

    Details

    • Type: Enhancement
    • Status: Resolved
    • Priority: P4
    • Resolution: Fixed
    • Affects Version/s: 8-shenandoah, 11-shenandoah, 14
    • Fix Version/s: 14
    • Component/s: hotspot
    • Subcomponent:
      gc
    • Resolved In Build:
      b15
    • CPU:
      generic
    • OS:
      generic

      Description

      Currently, arraycopy operations can cause temporary from-space-references in the destination array. Those would be subsequently updated by an arraycopy-post-barrier, but it's awkward because this temporary from-space references need to be dealt with, e.g. in the CAS-obj barrier, and a few other places.
      We can update the src array before copying, and therefore ensure to never see a from-space-reference in the dst array, ever. This opens up a couple of opportunities for simplification and optimization.

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              • Assignee:
                rkennke Roman Kennke
                Reporter:
                rkennke Roman Kennke
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                • Created:
                  Updated:
                  Resolved: