getworkerid() {
	local i
	for (( i=0 ; i >= 0 ; i++ ))
	do
		if [ -z "${workers[i]}" ]
		then
			echo $i
			return
		fi
	done
	# If we reach this, we have reached the signed long limit
	# (2^63 - 1 = 9223372036854775807 - Got a supercomputer?)
	(( concurrency-- ))
}