Fix #343: handle 'initctl reload' of unmodified non-native services

When 'initctl reload' is called new "configuration generation" is
started by Finit.  This mechanism ensures services reaffirm their
readiness and helps distinguish between their ready before reload
and after.

For native services the pidfile plugin handles this.  The s6 style
services are one-shot only, and thus use a static ready condition.

This patch adds support for stepping the configuration generation
of unmodified systemd style services.

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

src/service.c

@@ -2437,6 +2437,29 @@ int service_completed(void)
 	return 1;
 }
 
+/*
+ * Called in SM_RELOAD_WAIT_STATE to update unmodified non-native
+ * services' READY condition to the current generation.  Similar
+ * to the pidfile_reconf() function for native services.
+ */
+void service_notify_reconf(void)
+{
+	svc_t *svc, *iter = NULL;
+
+	for (svc = svc_iterator(&iter, 1); svc; svc = svc_iterator(&iter, 0)) {
+		if (!svc->notify)
+			continue; /* managed by pidfile plugin */
+
+		if (svc->state != SVC_RUNNING_STATE)
+			continue;
+
+		if (svc_is_changed(svc) || svc_is_starting(svc))
+			continue;
+
+		service_ready(svc);
+	}
+}
+
 /*
  * Called when a service sends readiness notification, or when
  * the service closes its end of the IPC connection.
@@ -2463,7 +2486,19 @@ void service_notify_cb(uev_t *w, void *arg, int events)
 
 	/* systemd and s6, respectively.  The latter then closes the socket */
 	if (!strcmp(buf, "READY=1\n") || !strcmp(buf, "\n")) {
+		/*
+		 * native (pidfile) services are marked as started by
+		 * the pidfile plugin.
+		 */
+		svc_started(svc);
+
+		/*
+		 * On reload, and this svc is unmodified, it is up to
+		 * the service_notify_reconf() function to step the
+		 * generation of the READY condition.
+		 */
 		service_ready(svc);
+
 		/* s6 applications close their socket after notification */
 		if (svc->notify == 2) {
 			uev_io_stop(w);

src/service.h

@@ -49,6 +49,7 @@ void      service_step_all       (int types);
 void      service_worker         (void *unused);
 
 int       service_completed      (void);
+void      service_notify_reconf  (void);
 
 void      service_init           (void);
 

src/sm.c

@@ -256,6 +256,9 @@ restart:
 		dbg("Calling reconf hooks ...");
 		plugin_run_hooks(HOOK_SVC_RECONF);
 
+		dbg("Update configuration generation of unmodified non-native services ...");
+		service_notify_reconf();
+
 		service_step_all(SVC_TYPE_ANY);
 		dbg("Reconfiguration done");