This is by far te best way to go, it resolves issues where the system is powered down fast of the application is terminated without its own end block executing to clean up a pid file or lock file. The OS level lock will get cleared if the application is not running or on a reboot. One of the only reasons to use a PDI file (and there are better ways to do this if need be) is to have a way for other applications to actualy start, stop or send interupts etc to a running proccess.

-Waswas