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  1. JDK
  2. JDK-6652736

well known classes in system dictionary are inefficiently processed

    Details

    • Type: Bug
    • Status: Closed
    • Priority: P3
    • Resolution: Fixed
    • Affects Version/s: 7
    • Fix Version/s: hs10
    • Component/s: hotspot
    • Labels:
      None
    • Subcomponent:
    • Resolved In Build:
      b02
    • CPU:
      generic
    • OS:
      generic

      Backports

        Description

        The SystemDictionary class has about 60 C static variables which hold well-known classes. They should be consolidated into a single static block of C array-type, indexed by an enum, as in vmSymbols. This will simplify maintenance and scaling and allow certain optimizations.

        At JVM bootstrap, approximately 25% of all symbol lookups resolve to these symbols. It is probably worthwhile making a fast path for these (using vmSymbols::find_sid).

        The object code which operates on these classes as a group (for GC and initialization) will be much more compact if they are made into an array indexed by an enum. Several object files are smaller by 1-10Kb, including systemDictionary.o, vmStructs.o, javaClasses.o, and jvm.o, and the DLL is about 40Kb smaller.

        The number of well-known classes will increase as new low-level features are added to support other languages. Adding them should be as simple as adding new vmSymbols.

        Benefits:
         - fewer symbols in the binary
         - code simplification
         - a fast path through the class lookup routine
         - easier expansion in the future

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                • Assignee:
                  jrose John Rose
                  Reporter:
                  jrose John Rose
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