X10 Files

X10 Release 2.5.2

HIGHLIGHTS OF THIS RELEASE

Although there were no X10 language changes in X10 2.5.2, this release
does contain user-visible changes to the structure of the X10 class
library.  
   (1)  The implementation of the X10 Runtime was moved from the
        x10.lang package to a new x10.xrx package.  Unlike x10.lang,
	this package is not auto-imported into all programs. Programs
	that make calls to x10.xrx.Runtime (or other impacted classes)
	will need to be updated to import the used XRX classes. 
   (2)  We continue to improve Resilient/Elastic X10 and have made a
        number of API improvements to classes in the
	x10.util.resilient package.
   (3)  We have added built-in support for ghost regions to the
        x10.regionarray.DistArray class.  Some mostly internal changes
	to the DistArray API were made to enable this new
	functionality (XTENLANG-3488,3489).

This release also contains significant enhancements to the x10rt_mpi
implementation, including exploitation of MPI-3 non-blocking
collections by X10 Team operations to enable unrestricted mixing of
APGAS asynchronous messaging with Team collective operations.

This release is also the first time we are bundling the Lulesh proxy
application with the X10 benchmarks. We continue to improve our Lulesh
code, but believe it has now reached a level of stability and
performance that make it generally usable as a X10 benchmark.

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 2.5.2

Release Notes - X10 - Version X10 2.5.2

** New Features and Improvements
    * [XTENLANG-1373] - Support for ghost cells in distributed arrays
    * [XTENLANG-3447] - Splittable PNRG
    * [XTENLANG-3479] - Add FileReader.offset()
    * [XTENLANG-3480] - GML: add rank-one update (DGER)
    * [XTENLANG-3484] - Move XRX runtime to x10.xrx package (out of x10.lang)
    * [XTENLANG-3488] - Replace Dist.offset with Region.indexOf
    * [XTENLANG-3490] - x10rt_mpi should default to MPI_THREAD_MULTIPLE

** Bugs
    * [XTENLANG-3354] - asyncCopy deadlocks on BG/Q
    * [XTENLANG-3355] - alltoall segfaults on BG/Q
    * [XTENLANG-3485] - On MacOs the jblas library must have extension .jnilib and not .so
    * [XTENLANG-3486] - GML: transpose DenseMatrix.T(DenseMatrix) should store to invocation target
    * [XTENLANG-3489] - Replace x10.regionarray.PeriodicDist with x10.regionarray.PeriodicBoundaryConditions
    * [XTENLANG-3492] - Team creation fails over SparsePlaceGroup

For the details of JIRA issues fixed in this release, see
http://jira.codehaus.org/secure/ReleaseNote.jspa?projectId=11812&version=20767

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