Locking processes with flock

Got a cronjob that might overlap if it runs slower than usual and you need to avoid multiple instances running?
Here's how to lock them using flock in bash:

function delicate_process() {
  # the 'locked down' code
  return 0;
}

function main() {
  (
    if ! flock -x --nonblock 200; then
      return 1;
    fi

    delicate_process;

  ) 200>/var/lock/.my.lock
}

main "${@}";

This is essentially opening the file /var/lock/.my.lock and assigning it the FD 200, then inside flock attempts a non blocking exclusive lock on the FD 200, returning `1` on failure.