X10 Files

X10 Release 2.5.1

HIGHLIGHTS OF THIS RELEASE

The primary features of the X10 2.5.1 release are enhancements to
Resilient and Elastic X10.  Key highlights include:
  + Full integration of the Hazelcast in-memory data grid with Managed
    X10.  Key features include new X10 APIs to utilize Hazelcast as an
    implementation of x10.util.resilient.ResilientMap, an
    implementation of resilient finish using Hazelcast (X10_RESILIENT_MODE=12), 
    and integration of Hazelcast grid initialization into the X10
    launcher (bin/x10 script).
  + Resilient X10 using Place 0 resilient finish
    (X10_RESILIENT_MODE=1) can now support the same levels of
    concurrency and distribution as non-resilient X10.  This was
    enabled by new features in the X10 runtime and network layer for
    message stratification and stronger progress guarantees for
    explicitly marked short messages (see x10.compiler.Immediate).
  + The development of additional Resilient and Elastic X10 sample
    applications. Resiliency support has been added to the Global
    Matrix Library (GML) and several of its sample applications.
    Resiliency and Elasticity have also been added to M3RLite (Main
    Memory Map Reduce Lite) and several new M3RLite sample
    applications are now available as well.
For additional information about Resilient and Elastic X10, please see
samples/resiliency and the x10-lang.org website.

LIMITATIONS OF THIS RELEASE

The size and index of arrays must be less than 2^31 with Managed X10.
An attempt to allocate a longer array causes IllegalArgumentException. 

The following features described in the 2.5 language manual do not
currently work and may be fixed in the subsequent releases:
  - Non-static type definitions as class or interface members
    (static type defs do work)

The constraint solver used by X10 typechecker is known to be incomplete 
for situations in which a constraint implies an infinite number of 
distinct constraints.

Additionally, the following features described in the language
manual do not currently work with Native X10.
  - Non-final generic instance methods
  - Exception stack traces on Cygwin

The generated C++ code requires g++ 4.2 or better to be compiled; 
we do almost all of our testing against g++ 4.4.
  + On Power/Linux and BG/Q, you may either use g++ 4.2 or better
    or xlC 11.1 or better. 

SUMMARY OF ISSUES RESOLVED IN THIS RELEASE

Below is a summary of JIRA issues addressed for the X10 2.5.1

** New Features and Improvements
    * [XTENLANG-3333] - X10 WebSite: Add information on current community projects under community
    * [XTENLANG-3443] - ArrayList.resize
    * [XTENLANG-3445] - RailUtils.scan
    * [XTENLANG-3456] - Create as many BDWGC marker threads as X10 worker threads
    * [XTENLANG-3457] - Reduce memory usage of X10RT sockets launcher processes
    * [XTENLANG-3461] - Map / reduce methods on local Matrix and Vector classes
    * [XTENLANG-3468] - Team reduce, allreduce for user-defined Arithmetic/Bitwise/Ordered struct types
    * [XTENLANG-3475] - GML: Wrap LAPACK eigensolver DSYEVX instead of DSYEV

** Bugs
    * [XTENLANG-3304] - On Resilient X10, at (p) { body } may block even if the body finished
    * [XTENLANG-3343] - Resilient X10 fails with "TOO MANY THREADS"
    * [XTENLANG-3344] - Resilient X10 fails with "TOO MANY THREADS" (another case)
    * [XTENLANG-3379] - On Resilient X10, at (p) async is not executed in parallel without X10_BUSY_WAITING
    * [XTENLANG-3428] - Elastic X10 and Runtime.Workers.multiplace
    * [XTENLANG-3435] - @NoInline on closure within static @Inline method results in wrong saved_this
    * [XTENLANG-3437] - Experimental Java MPI launcher causes SEGV with non-IBM Java VM
    * [XTENLANG-3438] - GC library and build system patch for K computer
    * [XTENLANG-3442] - Some structs can't be interface's members's return types
    * [XTENLANG-3462] - Incorrect implementation of instanceof and cast for nested generic types
    * [XTENLANG-3463] - Resilient X10 requires BUSY_WAITING=true
    * [XTENLANG-3466] - Template-related compile error in Native X10
    * [XTENLANG-3470] - Incorrect generated code for variable shadowing

** Tasks
    * [XTENLANG-3439] - Update sample programs (online; X10DT help) for 2.5.1

For the details of JIRA issues fixed in this release, see
http://jira.codehaus.org/secure/ReleaseNote.jspa?projectId=11812&version=20503

Please use the X10 JIRA to report bugs, after ensuring the problem is
not already reported:
http://jira.codehaus.org/secure/IssueNavigator.jspa?reset=true&&pid=11812&resolution=-1