Distributed MultiThreaded Checkpointing Files

DMTCP now supports InfiniBand UD (in addition to the more common InfiniBand RC). This is becoming necessary, now that many MPI implementations are typically configured to use both InfiniBand RC and InfiniBand UD.

Other major bug fixes include:

• A regression in the multi-arch installation has been fixed. It should again be possible to configure DMTCP to support a mixture of 32- and 64-bit applications as documented in the doc/multi-arch.txt and in the DMTCP FAQ.
• A race condition was fixed that could cause a failure to restart after many checkpoint-restart cycles (i.e., a restart from a checkpoint of a restart from a checkpoint, etc.). This race condition potentially happened primarily for programs that were continually creating and destroying many threads or continually using mmap to create and destroy many BSD-style shared memory regions among different processes.
• The dmtcp_set_coord_ckpt_dir("dirname") utility in dmtcp.h (for DMTCP plugins) now also supports relative pathnames for "dirname".
• The dmtcp.h file now uses the macro DMTCP_VOID instead of the macro VOID. This avoids name clashes with user include files that also define a macro VOID.
• The modify-env plugin has raised the maximum size of "dmtcp_env.txt" to over 12,000 bytes (and warns if a still larger size is used).
• Some additional utilities in dmtcp.h for DMTCP plugins, that were labelled "FOR EXPERTS ONLY" are now directly supported without modification of the DMTCP source code.
• An improved error message is provided when a target application launched with dmtcp_launch --no-coordinator tries to use fork. (Fork creates a second process, and a DMTCP coordinator is needed when there is more than one process.)