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authorV3n3RiX <venerix@redcorelinux.org>2018-01-05 20:45:13 +0000
committerV3n3RiX <venerix@redcorelinux.org>2018-01-05 20:45:13 +0000
commit8fcdcec5fbdd0e3a77391e4f354218014f59f358 (patch)
treeb6aaf9c103052f2ab4a948377142f4a4233caa60 /eclass/multiprocessing.eclass
parent423d21dcfee183cc4b04d29c1621615e8c30f834 (diff)
gentoo resync : 05.01.2018
Diffstat (limited to 'eclass/multiprocessing.eclass')
-rw-r--r--eclass/multiprocessing.eclass230
1 files changed, 10 insertions, 220 deletions
diff --git a/eclass/multiprocessing.eclass b/eclass/multiprocessing.eclass
index b6e92976f73e..3e8b2f9d2540 100644
--- a/eclass/multiprocessing.eclass
+++ b/eclass/multiprocessing.eclass
@@ -1,4 +1,4 @@
-# Copyright 1999-2014 Gentoo Foundation
+# Copyright 1999-2017 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# @ECLASS: multiprocessing.eclass
@@ -7,51 +7,25 @@
# @AUTHOR:
# Brian Harring <ferringb@gentoo.org>
# Mike Frysinger <vapier@gentoo.org>
-# @BLURB: parallelization with bash (wtf?)
+# @BLURB: multiprocessing helper functions
# @DESCRIPTION:
-# The multiprocessing eclass contains a suite of functions that allow ebuilds
-# to quickly run things in parallel using shell code.
+# 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.
#
-# It has two modes: pre-fork and post-fork. If you don't want to dive into any
-# more nuts & bolts, just use the pre-fork mode. For main threads that mostly
-# spawn children and then wait for them to finish, use the pre-fork mode. For
-# main threads that do a bit of processing themselves, use the post-fork mode.
-# You may mix & match them for longer computation loops.
# @EXAMPLE:
#
# @CODE
-# # First initialize things:
-# multijob_init
-#
-# # Then hash a bunch of files in parallel:
-# for n in {0..20} ; do
-# multijob_child_init md5sum data.${n} > data.${n}
-# done
-#
-# # Then wait for all the children to finish:
-# multijob_finish
+# src_compile() {
+# # custom build system that does not support most of MAKEOPTS
+# ./mybs -j$(makeopts_jobs)
+# }
# @CODE
if [[ -z ${_MULTIPROCESSING_ECLASS} ]]; then
_MULTIPROCESSING_ECLASS=1
-# @FUNCTION: bashpid
-# @DESCRIPTION:
-# Return the process id of the current sub shell. This is to support bash
-# versions older than 4.0 that lack $BASHPID support natively. Simply do:
-# echo ${BASHPID:-$(bashpid)}
-#
-# Note: Using this func in any other way than the one above is not supported.
-bashpid() {
- # Running bashpid plainly will return incorrect results. This func must
- # be run in a subshell of the current subshell to get the right pid.
- # i.e. This will show the wrong value:
- # bashpid
- # But this will show the right value:
- # (bashpid)
- sh -c 'echo ${PPID}'
-}
-
# @FUNCTION: get_nproc
# @USAGE: [${fallback:-1}]
# @DESCRIPTION:
@@ -126,188 +100,4 @@ makeopts_loadavg() {
echo ${lavg:-${2:-999}}
}
-# @FUNCTION: multijob_init
-# @USAGE: [${MAKEOPTS}]
-# @DESCRIPTION:
-# Setup the environment for executing code in parallel.
-# You must call this before any other multijob function.
-multijob_init() {
- # When something goes wrong, try to wait for all the children so we
- # don't leave any zombies around.
- has wait ${EBUILD_DEATH_HOOKS} || EBUILD_DEATH_HOOKS+=" wait "
-
- # Setup a pipe for children to write their pids to when they finish.
- # We have to allocate two fd's because POSIX has undefined behavior
- # when using one single fd for both read and write. #487056
- # However, opening an fd for read or write only will block until the
- # opposite end is opened as well. Thus we open the first fd for both
- # read and write to not block ourselve, but use it for reading only.
- # The second fd really is opened for write only, as Cygwin supports
- # just one single read fd per FIFO. #583962
- local pipe="${T}/multijob.pipe"
- mkfifo -m 600 "${pipe}"
- redirect_alloc_fd mj_read_fd "${pipe}"
- redirect_alloc_fd mj_write_fd "${pipe}" '>'
- rm -f "${pipe}"
-
- # See how many children we can fork based on the user's settings.
- mj_max_jobs=$(makeopts_jobs "$@")
- mj_num_jobs=0
-}
-
-# @FUNCTION: multijob_child_init
-# @USAGE: [--pre|--post] [command to run in background]
-# @DESCRIPTION:
-# This function has two forms. You can use it to execute a simple command
-# in the background (and it takes care of everything else), or you must
-# call this first thing in your forked child process.
-#
-# The --pre/--post options allow you to select the child generation mode.
-#
-# @CODE
-# # 1st form: pass the command line as arguments:
-# multijob_child_init ls /dev
-# # Or if you want to use pre/post fork modes:
-# multijob_child_init --pre ls /dev
-# multijob_child_init --post ls /dev
-#
-# # 2nd form: execute multiple stuff in the background (post fork):
-# (
-# multijob_child_init
-# out=`ls`
-# if echo "${out}" | grep foo ; then
-# echo "YEAH"
-# fi
-# ) &
-# multijob_post_fork
-#
-# # 2nd form: execute multiple stuff in the background (pre fork):
-# multijob_pre_fork
-# (
-# multijob_child_init
-# out=`ls`
-# if echo "${out}" | grep foo ; then
-# echo "YEAH"
-# fi
-# ) &
-# @CODE
-multijob_child_init() {
- local mode="pre"
- case $1 in
- --pre) mode="pre" ; shift ;;
- --post) mode="post"; shift ;;
- esac
-
- if [[ $# -eq 0 ]] ; then
- trap 'echo ${BASHPID:-$(bashpid)} $? >&'${mj_write_fd} EXIT
- trap 'exit 1' INT TERM
- else
- local ret
- [[ ${mode} == "pre" ]] && { multijob_pre_fork; ret=$?; }
- ( multijob_child_init ; "$@" ) &
- [[ ${mode} == "post" ]] && { multijob_post_fork; ret=$?; }
- return ${ret}
- fi
-}
-
-# @FUNCTION: _multijob_fork
-# @INTERNAL
-# @DESCRIPTION:
-# Do the actual book keeping.
-_multijob_fork() {
- [[ $# -eq 1 ]] || die "incorrect number of arguments"
-
- local ret=0
- [[ $1 == "post" ]] && : $(( ++mj_num_jobs ))
- if [[ ${mj_num_jobs} -ge ${mj_max_jobs} ]] ; then
- multijob_finish_one
- ret=$?
- fi
- [[ $1 == "pre" ]] && : $(( ++mj_num_jobs ))
- return ${ret}
-}
-
-# @FUNCTION: multijob_pre_fork
-# @DESCRIPTION:
-# You must call this in the parent process before forking a child process.
-# If the parallel limit has been hit, it will wait for one child to finish
-# and return its exit status.
-multijob_pre_fork() { _multijob_fork pre "$@" ; }
-
-# @FUNCTION: multijob_post_fork
-# @DESCRIPTION:
-# You must call this in the parent process after forking a child process.
-# If the parallel limit has been hit, it will wait for one child to finish
-# and return its exit status.
-multijob_post_fork() { _multijob_fork post "$@" ; }
-
-# @FUNCTION: multijob_finish_one
-# @DESCRIPTION:
-# Wait for a single process to exit and return its exit code.
-multijob_finish_one() {
- [[ $# -eq 0 ]] || die "${FUNCNAME} takes no arguments"
-
- local pid ret
- read -r -u ${mj_read_fd} pid ret || die
- : $(( --mj_num_jobs ))
- return ${ret}
-}
-
-# @FUNCTION: multijob_finish
-# @DESCRIPTION:
-# Wait for all pending processes to exit and return the bitwise or
-# of all their exit codes.
-multijob_finish() {
- local ret=0
- while [[ ${mj_num_jobs} -gt 0 ]] ; do
- multijob_finish_one
- : $(( ret |= $? ))
- done
- # Let bash clean up its internal child tracking state.
- wait
-
- # Do this after reaping all the children.
- [[ $# -eq 0 ]] || die "${FUNCNAME} takes no arguments"
-
- # No need to hook anymore.
- EBUILD_DEATH_HOOKS=${EBUILD_DEATH_HOOKS/ wait / }
-
- return ${ret}
-}
-
-# @FUNCTION: redirect_alloc_fd
-# @USAGE: <var> <file> [redirection]
-# @DESCRIPTION:
-# Find a free fd and redirect the specified file via it. Store the new
-# fd in the specified variable. Useful for the cases where we don't care
-# about the exact fd #.
-redirect_alloc_fd() {
- local var=$1 file=$2 redir=${3:-"<>"}
-
- # Make sure /dev/fd is sane on Linux hosts. #479656
- if [[ ! -L /dev/fd && ${CBUILD} == *linux* ]] ; then
- eerror "You're missing a /dev/fd symlink to /proc/self/fd."
- eerror "Please fix the symlink and check your boot scripts (udev/etc...)."
- die "/dev/fd is broken"
- fi
-
- if [[ $(( (BASH_VERSINFO[0] << 8) + BASH_VERSINFO[1] )) -ge $(( (4 << 8) + 1 )) ]] ; then
- # Newer bash provides this functionality.
- eval "exec {${var}}${redir}'${file}'"
- else
- # Need to provide the functionality ourselves.
- local fd=10
- while :; do
- # Make sure the fd isn't open. It could be a char device,
- # or a symlink (possibly broken) to something else.
- if [[ ! -e /dev/fd/${fd} ]] && [[ ! -L /dev/fd/${fd} ]] ; then
- eval "exec ${fd}${redir}'${file}'" && break
- fi
- [[ ${fd} -gt 1024 ]] && die 'could not locate a free temp fd !?'
- : $(( ++fd ))
- done
- : $(( ${var} = fd ))
- fi
-}
-
fi