Terminating a Port Monitor

A port monitor must terminate itself gracefully on receipt of the signal SIGTERM. The termination sequence is the following:

1. The port monitor enters the stopping state; no further service requests are accepted.

2. Any attempt to re-enable the port monitor will be ignored.

3. The port monitor yields control of all ports for which it is responsible. It must be possible for a new instantiation of the port monitor to start correctly while a previous instantiation is stopping.

4. The advisory lock on the process id file is released. Once this lock is released, the contents of the process id file are undefined and a new invocation of the port monitor may be started.