#!/bin/bash
#  $HeadURL$ $LastChangedRevision$

#  Note this error message is sent to the terminal as it is imperative the user understands the failure.
[ $(id -u) = 0 ] || { echo "${0##*/}: this test can only pass when run as root" >/dev/tty; exit 1; }

echo "setting up environment ..."
export JS_NAME=$(tr -dc A-Za-z0-9 </dev/urandom | head -c 8)
export JS_SHELL=$ADETEST_MODROOT/share/shepherd/js-shepherd
export JS_SHEPHERD_WARNINGS_ENABLED=false     #  make js-shepherd quieter

echo "defining support functions ..."
wait_for_jobs()
{
    while [ $(jsq | sed 1,3d | egrep -c '(running|pending)') != 0 ]; do
        sleep 0.5
    done
}

echo "starting jsd ..."
MAX_MEM=524288
#  Note that we cast all kill messages to KILLED and that there will be
#  at least one of them, but how many we can't say; hence the 'sort -u'.
#  The shepherd may or may not complain about child processes it will
#  kill; so for these deduplication is not enough, we just discard any
#  such messages.
jsd --suspend -r mem:$MAX_MEM,slots:1 2>&1 | sed -r -e 's/.*[Kk]illed.*/KILLED/' -e '/child processes \([1-9][0-9, ]*\) are still running/d' | sort -u &
JSD_PID=$!
sleep 5  #  settle time

#echo "submitting a blocking job and letting it start ..."
#jss -r mem:$MAX_MEM,slots:1 "sleep 10" > /dev/null
#sleep 2
#jsq

echo "submitting jobs restricted to progressively less and less memory ..."
MEM=$MAX_MEM
while :; do
    #  We use 'od' rather than 'dd' because od can output hex without needing
    #  '... | base64', which means that it's exit code can be caught be the
    #  while loop, which in turn means that the job can detect when, not it, 
    #  but *od* gets OOM-killed. (With 'dd | bash64' the while loop keeps
    #  looping because the OOM killer only kills a *single* process, not the
    #  entire cgroup.
    #
    #  Note that we choose not to put an echo after all the 'echo -n's: this
    #  helps ensure that each job produces precisely one line of output which
    #  makes it easier to grep out acceptable lines, which, even when
    #  successful vary quite a lot in format.
    jss -r mem:$MEM,slots:1 "error() { echo \"\$JS_JOB_ID: ERROR: \$1\" >&2; exit 1; }; echo -n \"\${JS_MEM_LIMIT}KB: \"; BLOBS=(); while BLOBS[\${#BLOBS[*]}]=\"\$(od -A n -N1M -t x8 < /dev/urandom)\"; do echo -n '.'; done; error \"od got killed; exiting ...\"" > /dev/null
    [ $MEM != 1 ] || break
    ((MEM/=2))
done
#jsq 

echo "waiting for jobs to complete ..."
jsc resume
wait_for_jobs
#while [ $(jsq | egrep -c '^[0-9]+ +(running|pending)') != 0 ]; do
#    sleep 5
#done

echo "cleaning up ..."
jsc quit
wait $JSD_PID

echo "all done"