parallelLimit

#!/bin/sh

rundir=/var/run/parallelLimit
pause_file="$rundir/paused"
harakiri_file="$rundir/good-day-to-die"

is-paused() {
    [ -f "$pause_file" ]
}

is-time-to-die() {
    [ -f "$harakiri_file" ]
}

run() {
    for i in $(seq 1 16); do
        (
            while true; do
                is-time-to-die && exit

                if is-paused; then
                    sleep 60
                else
                    /path/to/do-job
                fi
            done
        ) &
    done

    wait
}

pause() {
    touch "$pause_file"
}

unpause() {
    rm -f "$pause_file"
}

stop() {
    touch "$harakiri_file"
}