Charm++ parallel programming system

[Phil Miller <mille121 AT illinois.edu>]

We have recently finalized the release of stable version 6.6.0 of Charm++. It is tagged in our git repository as 'v6.6.0'. It can also be downloaded as a tarball from <http://charm.cs.illinois.edu/distrib/charm-6.6.0.tar.gz>.

As reported in the release notes, the major changes since the 6.5 series are as follows:

- Machine target files for Cray XC systems ('gni-crayxc') have been added

- Interoperability with MPI code using native communication interfaces on Blue
  Gene Q (PAMI) and Cray XE/XK/XC (uGNI) systems, in addition to the universal
  MPI communication interface

- Support for partitioned jobs on all machine types, including TCP/IP and IB
  Verbs networks using 'netlrts' and 'verbs' machine layers

- A substantially improved version of our asynchronous library, CkIO, for
  parallel output of large files

- Narrowing the circumstances in which the runtime system will send
  overhead-inducing ReductionStarting messages

- A new fully distributed load balancing strategy, DistributedLB, that produces
  high quality results with very low latency

- An API for applications to feed custom per-object data to specialized load
  balancing strategies (e.g. physical simulation coordinates)

- SMP builds on LRTS-based machine layers (pamilrts, gni, mpi, netlrts, verbs)
  support tracing messages through communication threads

- Thread affinity mapping with +pemap now supports Intel's Hyperthreading more
  conveniently

- After restarting from a checkpoint, thread affinity will use new
  +pemap/+commap arguments

- Queue order randomization options were added to assist in debugging race
  conditions in application and runtime code

- The full runtime code and associated libraries can now compile under the C11
  and C++11/14 standards.

- Numerous bug fixes, performance enhancements, and smaller improvements in the
  provided runtime facilities

- Deprecations
  * The long-unsupported FEM library has been deprecated in favor of ParFUM
  * The CmiBool typedefs have been deleted, as C++ bool has long been universal
  * Future versions of the runtime system and libraries will require some degree
    of support for C++11 features from compilers

A fuller listing of features added and bugs fixed can be seen in our issue tracker at
<https://charm.cs.illinois.edu/redmine/projects/charm/issues?f[]=fixed_version_id&group_by=tracker&op[fixed_version_id]=%3D&set_filter=1&sort=id&utf8=%E2%9C%93&v[fixed_version_id][]=4>

Or by examining the version control logs relative to the previous release tag, 'v6.5.1'.