X10 Release 2.5.0
HIGHLIGHTS OF THIS RELEASE
X10 Release 2.5.0 includes a redesign of several X10 standard library
APIs to better support Resilient and Elastic X10. In particular, we
have rethought various aspects of Place-related functionality to more
naturally support execution over a dynamically varying set of
Places. For all the details, please see the X10Doc for x10.lang.Place,
x10.lang.PlaceGroup, and x10.lang.PlaceTopology.
Some of the key changes are:
+ The removal of static constants such as PlaceGroup.WORLD,
and Place.MAX_PLACES. They are replaced by Place.places()
and Place.numPlaces() which return values that represent
the current view on the dynamically changeable set of Places
available to the computation.
+ The removal of iteration functionality (next/prev) from Place.
This functionality is now provided only through PlaceGroup.
+ The addition of PlaceTopology to provide a more flexible set of
APIs describing the topological relationships of Places.
X10 2.5.0 also includes a set of enabling runtime system changes to
better support the embedding of X10 and the XRX runtime into larger
programs written in other programming languages. These changes are
surfaced to the programmer via a new set of APIs on x10.lang.Runtime
that support initializing the XRX runtime, submitting jobs for
execution by the XRX runtime, job cancellation, and runtime shutdown.
A backwards incompatible change to the x10.util.Map interface removes
the usage of x10.util.Box on the return value of the put and get
methods of Map by requiring that Values stored in Map satisfy the
haszero constraint (XTENLANG-573). This may require adjustment in
application code that uses implementation of x10.util.Map.
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 2.5.0
** New Features and Improvements
* [XTENLANG-573] - x10.util.HashMap & Boxing
* [XTENLANG-1955] - Calling external MPI Library(PWSMP) on multiple nodes has performance issue
* [XTENLANG-2493] - static val members with constant values should be const in generated C++
* [XTENLANG-2866] - Modernize x10.util.Map (and others) to provide operators as shorthands
* [XTENLANG-3181] - Ensure graceful failure of X10 runtime in presence of failures
* [XTENLANG-3302] - Faster put, remove for MapSet
* [XTENLANG-3394] - Upgrade to bdwgc 7.4.x
* [XTENLANG-3399] - Rail.uncountedCopy for Managed X10
* [XTENLANG-3401] - X10 implementation of Team reduce, allreduce
* [XTENLANG-3411] - Native X10: codegen for string literals
* [XTENLANG-3414] - GML arbitrary place group distribution
* [XTENLANG-3416] - Need Watcher.await with timeout
* [XTENLANG-3423] - Change MultipleExceptions.exceptions to Rail[CheckedThrowable]
* [XTENLANG-3429] - Change default value of X10_NTHREADS from 1 to availableProcessors
* [XTENLANG-3430] - X10 implementation of Team scatter
** Bugs
* [XTENLANG-3051] - Cannot pass "INIT_THREADS" flag to Java runtime
* [XTENLANG-3312] - Rail.asyncCopy sometime fails on large input
* [XTENLANG-3313] - x10c should detect recursive jar creation
* [XTENLANG-3371] - Race condition in Runtime.Workers.multiplace
* [XTENLANG-3372] - Intermittent stack overflow in polyglot
* [XTENLANG-3390] - Allow X10 values to be serialized via Java serialization
* [XTENLANG-3392] - Initial activity does not drop its clocks upon terminating.
* [XTENLANG-3395] - Spurious wake-up in x10.util.concurrent.SPMDBarrier causes deadlock
* [XTENLANG-3396] - Fail to compile a static method in Native X10
* [XTENLANG-3398] - Evaluation of Team.WORLD hangs on multi places with JavaSockets
* [XTENLANG-3400] - PlaceLocalHandles: remove dependency on Place 0 for id assignment
* [XTENLANG-3408] - Performance of JavaSockets transport
* [XTENLANG-3413] - Native X10: closures in generic methods that do not capture type params should go in .cc not .h
* [XTENLANG-3417] - Support generation of a jar file which includes no X10/Java source files
* [XTENLANG-3418] - Reader#{mark(Int),available():Int} should use Long rather than Int
* [XTENLANG-3421] - C++ post compilation error (missing inclusion of x10/lang/Float.h)
* [XTENLANG-3425] - Inconsistencies between Managed and Native implementations of zero-size Rail.asyncCopy, Rail.uncountedCopy
* [XTENLANG-3426] - Update online help contents for X10DT 2.5
* [XTENLANG-3431] - Killing second place results in program termination
* [XTENLANG-3432] - Fix to experimental Java MPI launcher
** Tasks
* [XTENLANG-3201] - Need official release of GML
For the details of JIRA issues fixed in this release, see
http://jira.codehaus.org/secure/ReleaseNote.jspa?projectId=11812&version=19141
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
