+ pid_t pid = -1; // PID of the process. If state is STARTING or STOPPING,
+ // this is PID of the service script; otherwise it is the
+ // PID of the process itself (process service).
+ int exit_status = 0; // Exit status, if the process has exited (pid == -1).
+ int socket_fd = -1; // For socket-activation services, this is the file
+ // descriptor for the socket.
+