Fix #280: allow calling initctl restart foo from within foo

Move the stop+start from initctl to the state machine by allowing
stopped tasks to restart once it has been collected.  This should
prevent finit from blocking, allowing it to handle other requests
while waiting for the service's PID to be collected.

Effectively, this will allow a service to call initctl to restart
itself, as reported in issue #280.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

src/api.c

@@ -89,8 +89,7 @@ static int restart(svc_t *svc, void *user_data)
 	if (!svc)
 		return 1;
 
-	svc_mark_dirty(svc);
-	svc_start(svc);
+	service_stop(svc);
 	service_step(svc);
 
 	return 0;
@@ -319,6 +318,10 @@ static void api_cb(uev_t *w, void *arg, int events)
 				if (EAGAIN == errno)
 					break;
 
+				/* we get here when client restarts itself */
+				if (ECONNRESET == errno)
+					break;
+
 				_e("Failed reading initctl request, error %d: %s", errno, strerror(errno));
 			}
 

src/initctl.c

@@ -271,23 +271,10 @@ static int do_reload (char *arg)
 
 static int do_restart(char *arg)
 {
-	size_t retries = 3;
-	svc_t *svc;
-
-	if (do_startstop(INIT_CMD_STOP_SVC, arg))
-		return 1;
-
-	while (retries-- > 0 && (svc = client_svc_find(arg))) {
-		if (!svc_is_running(svc))
-			break;
+	if (do_startstop(INIT_CMD_RESTART_SVC, arg))
+		ERRX(7, "failed restarting %s", arg);
 
-		sleep(1);
-	}
-
-	if (retries == 0)
-		ERRX(7, "failed stopping %s (restart)", arg);
-
-	return do_startstop(INIT_CMD_RESTART_SVC, arg);
+	return 0;
 }
 
 /**

src/service.c

@@ -731,10 +731,14 @@ static void service_cleanup(svc_t *svc)
  * service_stop - Stop service
  * @svc: Service to stop
  *
+ * Called externally by initctl to perform stop/start (restart) of
+ * services.  Internally it is used to bring a run/task/service to
+ * HALTED state.
+ *
  * Returns:
  * 0 if the service was successfully stopped. Non-zero otherwise.
  */
-static int service_stop(svc_t *svc)
+int service_stop(svc_t *svc)
 {
 	char cmdline[CMD_SIZE] = "";
 	int do_progress = 1;

src/service.h

@@ -40,6 +40,7 @@ int       service_timeout_cancel (svc_t *svc);
 
 void      service_forked         (svc_t *svc);
 
+int       service_stop           (svc_t *svc);
 int       service_step           (svc_t *svc);
 void      service_step_all       (int types);
 void      service_worker         (void *unused);