README

*** Project Valhalla "L-World Value Types" Early Access ***

Prototype Version: LW2

This is an "early access" build, from "Project Valhalla" [1], aimed at testing a
"Value Types" implementation within the JVM, where-by value types may
interoperate with existing type descriptors. Otherwise known as "L-World Value
Types" (L-World) [2].

Intended for a number of expert users with active interest in the
Valhalla project, and is provided as a convenience to users needing to build
from source code (branch "lworld") [3].

Warning, not only is this build based on an incomplete version of "JDK 12",
there has been less than comprehensive testing carried out.

* System Limitations

- platforms: x64 Linux, x64 Mac OS X, Windows
- no support for atomic fields containing value types (work-in-progress for an
  update)
- no AOT, CDS, redefineclasses
- -Xint and C2 only, no C1, no tiered-compilation
- interpreter is not optimized, focus is on JIT optimization

* EA disclaimer

- EA release functionality might not be released in a GA binary.  Any EA
  functionality might be changed or removed
- EA builds do not imply that the feature is being considered to any scheduled
  OpenJDK release
- The list of supported platforms at GA might be different than the platforms
  supported during EA
- These binaries have not been tested to the same level to which Oracle would
  test a GA binary.  It has been produced for gathering feedback.  Use for any
  other purpose is at your own risk
- These binaries might be missing security vulnerabilities fixes available in GA
  binaries or in other OpenJDK projects
- Oracle does not provide support for these binaries

* Filing Bugs

Send email to valhalla-dev@openjdk.java.net

Current known issues [4]

[1] https://wiki.openjdk.java.net/display/valhalla/Main
[2] https://wiki.openjdk.java.net/display/valhalla/L-World+Value+Types
[3] http://hg.openjdk.java.net/valhalla/valhalla/
[4] https://bugs.openjdk.java.net/issues/?filter=35615