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• The Minimal Value Types project is an early prototype for Value Types
  • provides initial subset of Value Type functionality
  • provides a new type which is:
    • immutable, identity-agnostic, non-nullable, non-synchronizable, final
    • does not inherit from java.lang.Object

• • Value Types contained in References, other Value Types or in Arrays are flattenable
  • Value Types can
  • Arrays of value types are flattened
  • Can contain primitives or references

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How to Try Minimal Value Types:

Early Access Binaries

http://jdk.java.net/valhalla/

Repository and Build Instructions

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hg clone http://hg.openjdk.java.net/valhalla/valhalla valhalla-mvt

cd valhalla-mvt

sh get_source.sh

hg defpath du <openjdkname> 

hg sh common/bin/hgforest.sh update -r mvtmvt // name of branch

To update repository: 

cd valhalla-mvt

sh common/bin/hgforest.sh pull

hg pull

hg sh common/bin/hgforest.sh update -r mvt  // name of branch

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http://cr.openjdk.java.net/~chegar/docs/sandbox.html // instructions for working with branch repositories (not yet updated for consolidation)

Note: Valhalla is a child of the jdk10/hs repository, to keep current with latest hotspot development.

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• platforms: x64 Linux, x64 Mac OS Xno verifier (work-in-progress for an update)
• no VarHandles (work-in-progress for an update)
• no support for atomic fields containing value types (work-in-progress for an update)
• no JNI, unsafe, jvmti, redefineclasses, reflection
• -Xint and C2 only, no C1, no tiered-compilation
• interpreter is not optimized, focus is on JIT optimization
• Need additional USE CASES for optimizations
• Working on additional test cases

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