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  1. JDK
  2. JDK-8231086

Shenandoah: Stronger invariant for object-arraycopy

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    • gc
    • b15
    • generic
    • 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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          blocks

          Enhancement - null JDK-8222766 Shenandoah: streamline post-LRB CAS barrier (x86)

          • P4 - Minor loss of function, or other problem where easy workaround is present.
          • Resolved
          is blocked by

          Enhancement - null JDK-8231085 C2/GC: Better GC-interface for expanding clone

          • P4 - Minor loss of function, or other problem where easy workaround is present.
          • Resolved
          relates to

          Bug - A problem which impairs or prevents the functions of the product. JDK-8232778 Shenandoah: SBSA::arraycopy_prologue checks wrong register

          • P2 - Crashes, loss of data, severe memory leak.
          • Resolved

          Enhancement - null JDK-8231447 Shenandoah: Compilation-time regression after JDK-8231086

          • P4 - Minor loss of function, or other problem where easy workaround is present.
          • Resolved

          Enhancement - null JDK-8241065 Shenandoah: remove leftover code after JDK-8231086

          • P4 - Minor loss of function, or other problem where easy workaround is present.
          • Resolved

          Enhancement - null JDK-8260106 Shenandoah: refactor reference updating closures and related code

          • P4 - Minor loss of function, or other problem where easy workaround is present.
          • Resolved

          Bug - A problem which impairs or prevents the functions of the product. JDK-8231410 Shenandoah: clone barrier should use base pointer

          • P3 - Major loss of function.
          • Resolved

          Bug - A problem which impairs or prevents the functions of the product. JDK-8231499 Shenandoah: compiler/arraycopy/TestDefaultMethodArrayCloneDeoptC2 fails

          • P3 - Major loss of function.
          • Resolved

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              rkennke Roman Kennke
              rkennke Roman Kennke
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              Dates

                Created:
                Updated:
                Resolved: