watchdog in bash

control.sh

#!/usr/bin/bash
MYPID=$$
watchdog () { 
( PID=$1
DONE=0
while [[ $DONE == 0  ]]; do
	echo "watchdog running"
	if $( kill -0 $PID ); then
		sleep 1;
	else 
		kill -s SIGUSR1 $MYPID;
		DONE=1;
	fi
done ) &
};
RUNNING="RUNNING"
watchdog $( pgrep this.sh )

on_end () { echo "Singal launched"; RUNNING="STOPPED"; }

trap on_end SIGUSR1

while [ 1 ]; do
	sleep 1;
	echo "JOB is " $RUNNING
done