ctld rewrites its pidfile in the main_loop function. And it will exit and reenter that function every time that select gets interrupted by EINTR due to SIGCHLD. That will happen whenever a child process exits, and that will happen every time it gets a new connection attempt. On a production server, I saw that ctld was rewriting its pidfile about 20 times per second, due to a misconfigured iSCSI client that kept trying to connect to a nonexistent target over and over. Yet when the pidfile didn't exist, a concurrent "service ctld reload" would fail. Such a failure would cause higher level code to restart ctld, which can cause various other problems. To prevent the need to restart ctld unnecessarily, the pidfile open/close logic should be moved out of main_loop and into main.