HPX V0.8.0 (Mar 23, 2012)

We have had roughly 1000 commits since the last release and we have closed approximately 70 tickets (bugs, feature requests, etc.).

General changes

• Improved PBS support, allowing for arbitrary naming schemes of node-hostnames.

• Finished verification of the reference counting framework.

• Implemented decrement merging logic to optimize the distributed reference counting system.

• Restructured the LCO framework. Renamed hpx::lcos::eager_future<> and hpx::lcos::lazy_future<> into hpx::lcos::packaged_task and hpx::lcos::deferred_packaged_task. Split hpx::lcos::promise into hpx::lcos::packaged_task and hpx::lcos::future. Added ‘local’ futures (in namespace hpx::lcos::local).

• Improved the general performance of local and remote action invocations. This (under certain circumstances) drastically reduces the number of copies created for each of the parameters and return values.

• Reworked the performance counter framework. Performance counters are now created only when needed, which reduces the overall resource requirements. The new framework allows for much more flexible creation and management of performance counters. The new sine example application demonstrates some of the capabilities of the new infrastructure.

• Added a buildbot-based continuous build system which gives instant, automated feedback on each commit to SVN.

• Added more automated tests to verify proper functioning of HPX.

• Started to create documentation for HPX and its API.

• Added documentation toolchain to the build system.

• Added dataflow LCO.

• Changed default HPX command line options to have hpx: prefix. For instance, the former option --threads is now --hpx:threads. This has been done to make ambiguities with possible application specific command line options as unlikely as possible. See the section HPX Command Line Options for a full list of available options.

• Added the possibility to define command line aliases. The former short (one-letter) command line options have been predefined as aliases for backwards compatibility. See the section HPX Command Line Options for a detailed description of command line option aliasing.

• Network connections are now cached based on the connected host. The number of simultaneous connections to a particular host is now limited. Parcels are buffered and bundled if all connections are in use.

• Added more refined thread affinity control. This is based on the external library Portable Hardware Locality (HWLOC).

• Improved support for Windows builds with CMake.

• Added support for components to register their own command line options.

• Added the possibility to register custom startup/shutdown functions for any component. These functions are guaranteed to be executed by an HPX thread.

• Added two new experimental thread schedulers: hierarchy_scheduler and periodic_priority_scheduler. These can be activated by using the command line options --hpx:queuing=hierarchy or --hpx:queuing=periodic.

Example applications

• Graph500 performance benchmark (thanks to Matthew Anderson for contributing this application).

• GTC (Gyrokinetic Toroidal Code): a skeleton for particle in cell type codes.

• Random Memory Access: an example demonstrating random memory accesses in a large array

• ShenEOS example, demonstrating partitioning of large read-only data structures and exposing an interpolation API.

• Sine performance counter demo.

• Accumulator examples demonstrating how to write and use HPX components.

• Quickstart examples (like hello_world, fibonacci, quicksort, factorial, etc.) demonstrating simple HPX concepts which introduce some of the concepts in HPX.

• Load balancing and work stealing demos.

API changes

• Moved all local LCOs into a separate namespace hpx::lcos::local (for instance, hpx::lcos::local_mutex is now hpx::lcos::local::mutex).

• Replaced hpx::actions::function with hpx::util::function. Cleaned up related code.

• Removed hpx::traits::handle_gid and moved handling of global reference counts into the corresponding serialization code.

• Changed terminology: prefix is now called locality_id, renamed the corresponding API functions (such as hpx::get_prefix, which is now called hpx::get_locality_id).

• Adding hpx::find_remote_localities, and hpx::get_num_localities.

• Changed performance counter naming scheme to make it more bash friendly. The new performance counter naming scheme is now

  /object{parentname#parentindex/instance#index}/counter#parameters
  

• Added hpx::get_worker_thread_num replacing hpx::threadmanager_base::get_thread_num.

• Renamed hpx::get_num_os_threads to hpx::get_os_threads_count.

• Added hpx::threads::get_thread_count.

• Restructured the Futures sub-system, renaming types in accordance with the terminology used by the C++11 ISO standard.

Bug fixes (closed tickets)

Here is a list of the important tickets we closed for this release:

• Issue #31 - Specialize handle_gid<> for examples and tests

• Issue #72 - Fix AGAS reference counting

• Issue #104 - heartbeat throws an exception when decrefing the performance counter it’s watching

• Issue #111 - throttle causes an exception on the target application

• Issue #142 - One failed component loading causes an unrelated component to fail

• Issue #165 - Remote exception propagation bug in AGAS reference counting test

• Issue #186 - Test credit exhaustion/splitting (e.g. prepare_gid and symbol NS)

• Issue #188 - Implement remaining AGAS reference counting test cases

• Issue #258 - No type checking of GIDs in stubs classes

• Issue #271 - Seg fault/shared pointer assertion in distributed code

• Issue #281 - CMake options need descriptive text

• Issue #283 - AGAS caching broken (gva_cache needs to be rewritten with ICL)

• Issue #285 - HPX_INSTALL root directory not the same as CMAKE_INSTALL_PREFIX

• Issue #286 - New segfault in dataflow applications

• Issue #289 - Exceptions should only be logged if not handled

• Issue #290 - c++11 tests failure

• Issue #293 - Build target for component libraries

• Issue #296 - Compilation error with Boost V1.49rc1

• Issue #298 - Illegal instructions on termination

• Issue #299 - gravity aborts with multiple threads

• Issue #301 - Build error with Boost trunk

• Issue #303 - Logging assertion failure in distributed runs

• Issue #304 - Exception ‘what’ strings are lost when exceptions from decode_parcel are reported

• Issue #306 - Performance counter user interface issues

• Issue #307 - Logging exception in distributed runs

• Issue #308 - Logging deadlocks in distributed

• Issue #309 - Reference counting test failures and exceptions

• Issue #311 - Merge AGAS remote_interface with the runtime_support object

• Issue #314 - Object tracking for id_types

• Issue #315 - Remove handle_gid and handle credit splitting in id_type serialization

• Issue #320 - applier::get_locality_id() should return an error value (or throw an exception)

• Issue #321 - Optimization for id_types which are never split should be restored

• Issue #322 - Command line processing ignored with Boost 1.47.0

• Issue #323 - Credit exhaustion causes object to stay alive

• Issue #324 - Duplicate exception messages

• Issue #326 - Integrate Quickbook with CMake

• Issue #329 - –help and –version should still work

• Issue #330 - Create pkg-config files

• Issue #337 - Improve usability of performance counter timestamps

• Issue #338 - Non-std exceptions deriving from std::exceptions in tfunc may be sliced

• Issue #339 - Decrease the number of send_pending_parcels threads

• Issue #343 - Dynamically setting the stack size doesn’t work

• Issue #351 - ‘make install’ does not update documents

• Issue #353 - Disable FIXMEs in the docs by default; add a doc developer CMake option to enable FIXMEs

• Issue #355 - ‘make’ doesn’t do anything after correct configuration

• Issue #356 - Don’t use hpx::util::static_ in topology code

• Issue #359 - Infinite recursion in hpx::tuple serialization

• Issue #361 - Add compile time option to disable logging completely

• Issue #364 - Installation seriously broken in r7443