Hello.
For the MUA i maintain i yet implemented parallel tests, and now
wanted to add a reaper process which automatically kills tests
which need longer than X seconds. That turns out to be more
complicated than i thought, it works just fine in mksh, but does
not work at all in dash (which can also not access variables from
within traps it seems), and in bash it works 100% reliably only
when started in-code, but not if placed in a jobreaper_start().
This is on CRUX Linux 3.5 (GNU C based), self-compiled (standard
/etc/pkgmk.conf flags -O2 -march=x86-64 -pipe), bash 5.0.7.
Imagine
echo shell is $SHELL/$0
(
int= hot=
echo 'Starting job reaper'
trap 'int=1 hot=1' HUP
trap 'int=1 hot=' INT
trap 'echo "Stopping job reaper"; exit 0' TERM
trap '' EXIT
while [ 1 ]; do
int=
sleep ${JOBWAIT} &
wait
if [ -z "${int}" ] && [ -n "${hot}" ]; then
i=0 l=
while [ ${i} -lt ${MAXJOBS} ]; do
i=`add ${i} 1`
if [ -f t.${i}.pid ] && read p < t.${i}.pid; then
kill -KILL ${p}
${rm} -f t.${i}.result
l="${l} ${i}"
fi
done
[ -n "${l}" ] &&
printf '%s!! Reaped job(s)%s after %s seconds%s\n' \
"${COLOR_ERR_ON}" "${l}" ${JOBWAIT} "${COLOR_ERR_OFF}"
fi
done
) </dev/null & #>/dev/null 2>&1 &
JOBREAPER=$!
This works a hundred percent reliable if placed alongside the
normal code, but if i place it in a function jobreaper_start(),
then i would say my success rate is about 60 percent:
Spawing up to 4 tests in parallel
shell is /bin/bash//home/steffen/src/nail.git/mx-test.sh
Starting job reaper
... [1=vpospar] [2=atxplode] .. wait(1)
/home/steffen/src/nail.git/mx-test.sh: line 401: 2487 Killed
( if ${mkdir} t.${JOBS}.d; then
cd t.${JOBS}.d; eval t_${1} ${JOBS} ${1};
fi; ${rm} -f ../t.${JOBS}.pid ) > t.${JOBS}.io 2>&1 < /dev/null
[vpospar]
1:ok ifs:ok
!! Reaped job(s) 2 after 3 seconds
..
versus
Spawing up to 4 tests in parallel
shell is /bin/bash//home/steffen/src/nail.git/mx-test.sh
... [1=vpospar] [2=atxplode] .. wait(1)
/home/steffen/src/nail.git/mx-test.sh: line 405: kill: (2560) - No such
process
[vpospar]
1:ok ifs:ok
[atxplode]
1:ok
/home/steffen/src/nail.git/mx-test.sh: line 364: kill: (2560) - No such
process
...
The code is driven via
else
if have_feat debug; then
if have_feat devel; then
DUMPERR=y
ARGS="${ARGS} -Smemdebug"
fi
elif have_feat devel; then
LOOPS_MAX=${LOOPS_BIG}
fi
color_init
if [ -z "${RUN_TEST}" ] || [ ${#} -eq 0 ]; then
jobs_max
printf 'Spawing up to %s tests in parallel\n' ${MAXJOBS}
jobreaper_start
(Inject above code here plain and all ok it seems.)
t_all
else
...
fi
jobreaper_stop
Injecting code plain is a bit painful because i need it twice.
I hope i am not missing something, i most likely do, since i would
have thought that the builtin kill would recognize that i am
actually killing something that came in via $! (though it never
started up it seems).
Interesting to me is that dash shows exactly the same errors (but
always, in practice).
--steffen
|
|Der Kragenbaer, The moon bear,
|der holt sich munter he cheerfully and one by one
|einen nach dem anderen runter wa.ks himself off
|(By Robert Gernhardt)
