bin/helper-functions.sh

   1 #!/bin/bash
   2 # Copyright 1999-2012 Gentoo Foundation
   3 # Distributed under the terms of the GNU General Public License v2
   4
   5 # For routines we want to use in ebuild-helpers/ but don't want to
   6 # expose to the general ebuild environment.
   7
   8 source "${PORTAGE_BIN_PATH:-/usr/lib/portage/bin}"/isolated-functions.sh
   9
  10 #
  11 # API functions for doing parallel processing
  12 #
  13 __numjobs() {
  14         # Copied from eutils.eclass:makeopts_jobs()
  15         local jobs=$(echo " ${MAKEOPTS} " | \
  16                 sed -r -n 's:.*[[:space:]](-j|--jobs[=[:space:]])[[:space:]]*([0-9]+).*:\2:p')
  17         echo ${jobs:-1}
  18 }
  19
  20 __multijob_init() {
  21         # Setup a pipe for children to write their pids to when they finish.
  22         mj_control_pipe=$(mktemp -t multijob.XXXXXX)
  23         rm "${mj_control_pipe}"
  24         mkfifo "${mj_control_pipe}"
  25         __redirect_alloc_fd mj_control_fd "${mj_control_pipe}"
  26         rm -f "${mj_control_pipe}"
  27
  28         # See how many children we can fork based on the user's settings.
  29         mj_max_jobs=$(__numjobs)
  30         mj_num_jobs=0
  31 }
  32
  33 __multijob_child_init() {
  34         trap 'echo ${BASHPID} $? >&'${mj_control_fd} EXIT
  35         trap 'exit 1' INT TERM
  36 }
  37
  38 __multijob_finish_one() {
  39         local pid ret
  40         read -r -u ${mj_control_fd} pid ret
  41         : $(( --mj_num_jobs ))
  42         return ${ret}
  43 }
  44
  45 __multijob_finish() {
  46         local ret=0
  47         while [[ ${mj_num_jobs} -gt 0 ]] ; do
  48                 __multijob_finish_one
  49                 : $(( ret |= $? ))
  50         done
  51         # Let bash clean up its internal child tracking state.
  52         wait
  53         return ${ret}
  54 }
  55
  56 __multijob_post_fork() {
  57         : $(( ++mj_num_jobs ))
  58         if [[ ${mj_num_jobs} -ge ${mj_max_jobs} ]] ; then
  59                 __multijob_finish_one
  60         fi
  61         return $?
  62 }
  63
  64 # @FUNCTION: __redirect_alloc_fd
  65 # @USAGE: <var> <file> [redirection]
  66 # @DESCRIPTION:
  67 # Find a free fd and redirect the specified file via it.  Store the new
  68 # fd in the specified variable.  Useful for the cases where we don't care
  69 # about the exact fd #.
  70 __redirect_alloc_fd() {
  71         local var=$1 file=$2 redir=${3:-"<>"}
  72
  73         if [[ $(( (BASH_VERSINFO[0] << 8) + BASH_VERSINFO[1] )) -ge $(( (4 << 8) + 1 )) ]] ; then
  74                         # Newer bash provides this functionality.
  75                         eval "exec {${var}}${redir}'${file}'"
  76         else
  77                         # Need to provide the functionality ourselves.
  78                         local fd=10
  79                         local fddir=/dev/fd
  80                         # Prefer /proc/self/fd if available (/dev/fd
  81                         # doesn't work on solaris, see bug #474536).
  82                         [[ -d /proc/self/fd ]] && fddir=/proc/self/fd
  83                         while :; do
  84                                         # Make sure the fd isn't open.  It could be a char device,
  85                                         # or a symlink (possibly broken) to something else.
  86                                         if [[ ! -e ${fddir}/${fd} ]] && [[ ! -L ${fddir}/${fd} ]] ; then
  87                                                         eval "exec ${fd}${redir}'${file}'" && break
  88                                         fi
  89                                         [[ ${fd} -gt 1024 ]] && die "__redirect_alloc_fd failed"
  90                                         : $(( ++fd ))
  91                         done
  92                         : $(( ${var} = fd ))
  93         fi
  94 }