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  1. JDK
  2. JDK-8171855

Move package name transformations during module bootstrap into native code

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    Details

    • Type: Bug
    • Status: Resolved
    • Priority: P3
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 9
    • Component/s: core-libs

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        Description

        During module setup, we do a number of transformations from package name strings to the VM internal form, e.g., "java.lang" -> "java/lang".

        Proof-of-concept patch:
        http://cr.openjdk.java.net/~redestad/scratch/module_package_names/

        By moving this transformation into the VM we improve a number of startup metrics: fewer early JIT compilations triggered, first GC postponed, and a small improvement in wall clock time (as measured on 1 CPU, 8 cores, no active hyperthreads):

        $ time for i in {1..100} ; do $BASELINE/bin/java Hello > /dev/null ; done

        real 0m12.856s
        user 0m18.360s
        sys 0m2.888s

        $ time for i in {1..100} ; do $PATCHED/bin/java Hello > /dev/null ; done

        real 0m12.687s
        user 0m16.784s
        sys 0m2.560s

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                Assignee:
                redestad Claes Redestad
                Reporter:
                redestad Claes Redestad
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