MULTIPROCESSING.ECLASS

Section: eclass-manpages (5)
Updated: Nov 2024
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NAME

multiprocessing.eclass - multiprocessing helper functions

DESCRIPTION

The multiprocessing eclass contains a suite of utility functions that could be helpful to controlling parallel multiple job execution. The most common use is processing MAKEOPTS in order to obtain job count.

SUPPORTED EAPIS

7 8

EXAMPLE

src_compile() {
  # custom build system that does not support most of MAKEOPTS
  ./mybs -j$(makeopts_jobs)
}

FUNCTIONS

get_nproc [${fallback:-1}]: Attempt to figure out the number of processing units available. If the value can not be determined, prints the provided fallback instead. If no fallback is provided, defaults to 1.
get_makeopts_jobs [default-jobs]: Return the number of jobs extracted from the make options (MAKEOPTS, GNUMAKEFLAGS, MAKEFLAGS). If the make options do not specify a number, then either the provided default is returned, or 1.
makeopts_jobs [${MAKEOPTS}] [${inf:-$(( $(get_nproc) + 1 ))}]: Searches the arguments (or sensible defaults) and extracts the jobs number specified therein. Useful for running non-make tools in parallel too. i.e. if the user has MAKEOPTS=-j9, this will echo "9" -- we can't return the number as bash normalizes it to [0, 255]. If the flags haven't specified a -j flag, then "1" is shown as that is the default `make` uses. If the flags specify -j without a number, ${inf} is returned (defaults to nproc).
get_makeopts_loadavg [default-loadavg]: Return the value for the load-average extracted from the make options (MAKEOPTS, GNUMAKEFLAGS, MAKEFLAGS). If the make options do not specify a value, then either the optional provided default is returned, or 999.
makeopts_loadavg [${MAKEOPTS}] [${inf:-999}]: Searches the arguments (or sensible defaults) and extracts the value set for load-average. For make and ninja based builds this will mean new jobs are not only limited by the jobs-value, but also by the current load - which might get excessive due to I/O and not just due to CPU load. Be aware that the returned number might be a floating-point number. Test whether your software supports that. If no limit is specified or --load-average is used without a number, ${inf} (defaults to 999) is returned.

AUTHORS

Brian Harring <[email protected]>
Mike Frysinger <[email protected]>

MAINTAINERS

[email protected]

REPORTING BUGS

Please report bugs via https://bugs.gentoo.org/

FILES

multiprocessing.eclass

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Time: 03:27:01 GMT, November 25, 2024