sd-daemon: add notify_start() and notify_on_cleanup() helper function

src/shared/daemon-util.h

@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+
+#include "sd-daemon.h"
+
+#define NOTIFY_READY "READY=1\n" "STATUS=Processing requests..."
+#define NOTIFY_STOPPING "STOPPING=1\n" "STATUS=Shutting down..."
+
+static inline const char *notify_start(const char *start, const char *stop) {
+        if (start)
+                (void) sd_notify(false, start);
+
+        return stop;
+}
+
+/* This is intended to be used with _cleanup_ attribute. */
+static inline void notify_on_cleanup(const char **p) {
+        if (p)
+                (void) sd_notify(false, *p);
+}

src/shared/meson.build

@@ -41,6 +41,7 @@ shared_sources = files('''
         cpu-set-util.h
         crypt-util.c
         crypt-util.h
+        daemon-util.h
         dev-setup.c
         dev-setup.h
         dissect-image.c