diff options
| -rw-r--r-- | eclass/multiprocessing.eclass | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/eclass/multiprocessing.eclass b/eclass/multiprocessing.eclass index 5a5fe9acb56a..3c5dfff2d11c 100644 --- a/eclass/multiprocessing.eclass +++ b/eclass/multiprocessing.eclass @@ -53,6 +53,38 @@ bashpid() { sh -c 'echo ${PPID}' } +# @FUNCTION: get_nproc +# @USAGE: [${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}] # @DESCRIPTION: |