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-rw-r--r-- | NEWS | 33 |
1 files changed, 3 insertions, 30 deletions
@@ -283,37 +283,10 @@ to the distribution" above. Futures are like promises, but begun immediately in a new thread. See the "Futures" section in the reference manual. -** New syntax: parallel FORM ... +** New threading functions: parallel, letpar, par-map, and friends -Compute the results of FORM ... in parallel (in a separate thread for -each form) and return them as multiple values. - -** New syntax: letpar ((VAR EXP) ...) BODYFORM ... - -Like 'let' but evaluates the binding expressions EXP ... in parallel. - -** New functions: par-map, par-for-each PROC ARGLIST ... - -Like 'map' and 'for-each' but evaluate the procedure PROC in a -separate thread for each (set of) argument(s). All applications are -guaranteed to be completed before the procedure returns. - -** New functions: n-par-map, n-par-for-each N PROC ARGLIST ... - -Like 'par-map' and 'par-for-each' but evaluate the procedure PROC in N -threads. This is useful when PROC uses large amounts of resources -and/or the argument list(s) is/are long so that one thread per (set -of) argument(s) would consume too much system resources. On a -dual-CPU system, N = 4 would often be a good choice. - -** New function: n-for-each-par-map N S-PROC P-PROC ARGLIST ... - -Using N parallel processes, apply S-PROC in serial order to each -result of applying P-PROC to each set of arguments in the argument -lists ARGLIST ... - -Like a composition of 'for-each' and 'n-par-map', but allows S-PROC to -start processing while the results of P-PROC are being produced. +These are convenient ways to run calculations in parallel in new +threads. See "Parallel forms" in the manual for details. ** Fair mutexes and condition variables |