Mercurial > hg > CbC > CbC_gcc

comparison gcc/lock-and-run.sh @ 145:1830386684a0

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
gcc-9.2.0
author anatofuz
date Thu, 13 Feb 2020 11:34:05 +0900
parents 04ced10e8804
children
comparison
equal deleted inserted replaced
131:84e7813d76e9 145:1830386684a0
1 #! /bin/sh 1 #! /bin/sh
2 # Shell-based mutex using mkdir. 2 # Shell-based mutex using mkdir. This script is used in make to prefer
3 # serialized execution to avoid consuming too much RAM. If reusing it,
4 # bear in mind that the lock-breaking logic is not race-free, so disable
5 # it in err() if concurrent execution could cause more serious problems.
3 6
7 self=`basename $0`
4 lockdir="$1" prog="$2"; shift 2 || exit 1 8 lockdir="$1" prog="$2"; shift 2 || exit 1
5 9
6 # Remember when we started trying to acquire the lock. 10 # Remember when we started trying to acquire the lock.
7 count=0 11 count=0
8 touch lock-stamp.$$
9 12
10 trap 'rm -r "$lockdir" lock-stamp.$$' 0 13 err () {
14 if test -f $lockdir/lock-$1.$$; then
15 rm -rf $lockdir
16 echo "$self: *** (PID $$) removed stale $lockdir" >&2
17
18 # Possible variant for uses where races are more problematic:
19 #echo "$self: *** (PID $$) giving up, maybe rm -r $lockdir" >&2
20 #exit 42
21 else
22 touch $lockdir/lock-$1.$$
23 fi
24 }
11 25
12 until mkdir "$lockdir" 2>/dev/null; do 26 until mkdir "$lockdir" 2>/dev/null; do
13 # Say something periodically so the user knows what's up. 27 # Say something periodically so the user knows what's up.
14 if [ `expr $count % 30` = 0 ]; then 28 if [ `expr $count % 30` = 0 ]; then
15 # Reset if the lock has been renewed. 29 # Check for valid lock.
16 if [ -n "`find \"$lockdir\" -newer lock-stamp.$$`" ]; then 30 if pid=`cat $lockdir/pid 2>/dev/null` && kill -0 $pid 2>/dev/null; then
17 touch lock-stamp.$$ 31 echo "$self: (PID $$) waiting $count sec to acquire $lockdir from PID $pid" >&2
18 count=1 32 elif test -z "$pid"; then
19 # Steal the lock after 5 minutes. 33 echo "$self: (PID $$) cannot read $lockdir/pid" >&2
20 elif [ $count = 300 ]; then 34 err nopid
21 echo removing stale $lockdir >&2
22 rm -r "$lockdir"
23 else 35 else
24 echo waiting to acquire $lockdir >&2 36 echo "$self: (PID $$) cannot signal $lockdir owner PID $pid" >&2
37 err dead
25 fi 38 fi
26 fi 39 fi
27 sleep 1 40 sleep 1
28 count=`expr $count + 1` 41 count=`expr $count + 1`
29 done 42 done
30 43
44 trap 'rm -rf "$lockdir"' 0
45 echo $$ > $lockdir/pidT && mv $lockdir/pidT $lockdir/pid
46 echo "$self: (PID $$) acquired $lockdir after $count seconds" >&2
47
31 echo $prog "$@" 48 echo $prog "$@"
32 $prog "$@" 49 $prog "$@"
33 50
34 # The trap runs on exit. 51 # The trap runs on exit.