NEWS.md

In bettermc: Enhanced Fork-Based Parallelization

bettermc 1.2.1

New Features

• add support for overloading parallel::mclapply() with bettermc::mclapply() via the bettermcExt-package on GitHub; this enables the use of bettermc::mclapply() by third-party packages originally using mclapply() from the parallel-package, e.g. doMC or rstan
• when applying over a character vector, that vector is now - by default - used to name the (otherwise unnamed) result (argument mc.use.names)
• tracebacks from etry() (and hence also from mclapply()) now contain an overview of the local variables and their values (essentially the output of ls.str() applied to all the frames on the call stack)
• new argument mc.system.time to mclapply(): if TRUE measure and return the CPU (and other) times used by the invocations of FUN
• the formal arguments mc.allow.fatal and mc.allow.error to mclapply() gain a new valid value: NA, which is the same as TRUE, but suppresses the warnings which would normally signal that there was a (fatal) error

Bug Fixes

• fix test failure if suggested progress-package is not available
• avoid progress bar job blocking main process

Misc

• make the format of this very file NEWS.md compatible with news()
• avoid a superfluous clang -Wuninitialized as requested by CRAN
• avoid a CRAN warning regarding "unlikely file names for src files"

bettermc 1.1.2

Misc

• work around an issue in base R w.r.t. source references and lazy loading as discussed in https://stat.ethz.ch/pipermail/r-devel/2021-April/080599.html
• prepare for upcoming changes to Rinternals.h
• do no longer assign to ATTRIB() and OBJECT()
• do no longer depend on SEXPREC_ALIGN

bettermc 1.1.1

New Features

Windows Support

This package can now also be installed on Windows, where it offers a reduced set of features. Most notably, bettermc::mclapply() (just like parallel::mclapply()) falls back on serial execution, since forking is not available on Windows. Still, this allows code employing bettermc::mclapply(), which was originally developed for Linux or macOS, to be run on Windows.

Seeding

• restore the state of the random number generator (RNG) at the end of mclapply() to what it was before; this makes the RNG state of the parent process immune to changes to arguments such as mc.cores or mc.force.fork
• new argument mc.retry.fixed.seed to mclapply(): TRUE invokes FUN() for a particular element of X with the same fixed seed on every retry; default is FALSE

Misc

• the environment variable "BMC_RETRY" now indicates the current retry ("0" means first try, a value of "1" first retry, etc.)
• new argument mc.retry.silent to mclapply(): TRUE suppresses the messages indicating failures during intermediate retires; default is FALSE

Bug Fixes

• on retires, output, messages etc. might have been prefixed with the wrong index w.r.t. X
• on the first call of mclapply() in a session, the environment variable MC_CORES was not respected
• fix wrong length of affinity.list if mc.force.fork == TRUE && length(X) == 1
• fix tiny memory leaks reported by Valgrind in allocate_from_shm()
• fix invalid write reported by Valgrind in allocate_from_shm()
• mark memory returned by custom allocator in allocate_from_shm() for Valgrind as defined (cf. https://stat.ethz.ch/pipermail/r-devel/2021-March/080572.html)
• fix test failure on macOS with a page size of more than 4 KiB

bettermc 1.0.1

• initial CRAN release

bettermc documentation built on April 14, 2023, 12:31 a.m.