# Copyright 1999-2022 Gentoo Authors # Distributed under the terms of the GNU General Public License v2 # @ECLASS: multiprocessing.eclass # @MAINTAINER: # base-system@gentoo.org # @AUTHOR: # Brian Harring <ferringb@gentoo.org> # Mike Frysinger <vapier@gentoo.org> # @SUPPORTED_EAPIS: 5 6 7 8 # @BLURB: 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. # # @EXAMPLE: # # @CODE # src_compile() { # # custom build system that does not support most of MAKEOPTS # ./mybs -j$(makeopts_jobs) # } # @CODE case ${EAPI:-0} in [5678]) ;; *) die "${ECLASS}: EAPI ${EAPI:-0} not supported" ;; esac if [[ -z ${_MULTIPROCESSING_ECLASS} ]]; then _MULTIPROCESSING_ECLASS=1 # @FUNCTION: get_nproc # @USAGE: [${fallback:-1}] # @DESCRIPTION: # 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_nproc() { local nproc # GNU if type -P nproc &>/dev/null; then nproc=$(nproc) fi # BSD if [[ -z ${nproc} ]] && type -P sysctl &>/dev/null; then nproc=$(sysctl -n hw.ncpu 2>/dev/null) fi # fallback to python2.6+ # note: this may fail (raise NotImplementedError) if [[ -z ${nproc} ]] && type -P python &>/dev/null; then nproc=$(python -c 'import multiprocessing; print(multiprocessing.cpu_count());' 2>/dev/null) fi if [[ -n ${nproc} ]]; then echo "${nproc}" else echo "${1:-1}" fi } # @FUNCTION: makeopts_jobs # @USAGE: [${MAKEOPTS}] [${inf:-$(( $(get_nproc) + 1 ))}] # @DESCRIPTION: # Searches the arguments (defaults to ${MAKEOPTS}) 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). makeopts_jobs() { [[ $# -eq 0 ]] && set -- "${MAKEOPTS}" # This assumes the first .* will be more greedy than the second .* # since POSIX doesn't specify a non-greedy match (i.e. ".*?"). local jobs=$(echo " $* " | sed -r -n \ -e 's:.*[[:space:]](-[a-z]*j|--jobs[=[:space:]])[[:space:]]*([0-9]+).*:\2:p' \ -e "s:.*[[:space:]](-[a-z]*j|--jobs)[[:space:]].*:${2:-$(( $(get_nproc) + 1 ))}:p") echo ${jobs:-1} } # @FUNCTION: makeopts_loadavg # @USAGE: [${MAKEOPTS}] [${inf:-999}] # @DESCRIPTION: # Searches the arguments (defaults to ${MAKEOPTS}) 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. makeopts_loadavg() { [[ $# -eq 0 ]] && set -- "${MAKEOPTS}" # This assumes the first .* will be more greedy than the second .* # since POSIX doesn't specify a non-greedy match (i.e. ".*?"). local lavg=$(echo " $* " | sed -r -n \ -e 's:.*[[:space:]](-[a-z]*l|--(load-average|max-load)[=[:space:]])[[:space:]]*([0-9]+(\.[0-9]+)?)[[:space:]].*:\3:p' \ -e "s:.*[[:space:]](-[a-z]*l|--(load-average|max-load))[[:space:]].*:${2:-999}:p") # Default to ${inf} since the default is to not use a load limit. echo ${lavg:-${2:-999}} } fi