[Emacs-diffs] master 19f5f7b: Notify systemd in daemon-initialized and kill-emacs (Bug#31498)

[Noam Postavsky]

branch: master
commit 19f5f7b19b0dcdae87476a3fd51c41f840b2b80f
Author: Lucas Werkmeister <address@hidden>
Commit: Noam Postavsky <address@hidden>

    Notify systemd in daemon-initialized and kill-emacs (Bug#31498)
    
    With --[bg-]daemon and Type=forking, systemd will only consider the
    daemon to have fully started up once the original process exits, and
    will wait until then to start units depending on the Emacs service.  To
    get the same functionality with --fg-daemon, use Type=notify instead of
    Type=simple and explicitly send a readiness notification to systemd at
    the point where the forked process would in --bg-daemon mode notify its
    parent process and cause it to exit.  Similarly, notify systemd at the
    beginning of the shutdown process as well.  (Both of these calls are
    successful no-ops if emacs was not started by systemd.)
    * etc/emacs.service: Update Type.
    * src/emacs.c (daemon-initialized) [HAVE_LIBSYSTEMD]:
    * src/emacs.c (kill-emacs) [HAVE_LIBSYSTEMD]: Call sd_notify().
---
 etc/NEWS          |  8 ++++++++
 etc/emacs.service |  2 +-
 src/emacs.c       | 11 +++++++++++
 3 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/etc/NEWS b/etc/NEWS
index 21b648c..995ceb6 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -81,6 +81,14 @@ work right without some adjustment:
 - you can use the new 'package-quickstart' so activation of packages does not
   need to pay attention to 'package-load-list' or 'package-user-dir' any more.
 
+---
+** Emacs now notifies systemd when startup finishes or shutdown begins.
+Units that are ordered after 'emacs.service' will only be started
+after Emacs has finished initialization and is ready for use.
+(If your Emacs is installed in a non-standard location and you copied the
+emacs.service file to eg ~/.config/systemd/user/, you will need to copy
+the new version of the file again.)
+
 
 * Changes in Emacs 27.1
 
diff --git a/etc/emacs.service b/etc/emacs.service
index b29177b..dbcb6bc 100644
--- a/etc/emacs.service
+++ b/etc/emacs.service
@@ -7,7 +7,7 @@ Description=Emacs text editor
 Documentation=info:emacs man:emacs(1) https://gnu.org/software/emacs/
 
 [Service]
-Type=simple
+Type=notify
 ExecStart=emacs --fg-daemon
 ExecStop=emacsclient --eval "(kill-emacs)"
 Environment=SSH_AUTH_SOCK=%t/keyring/ssh
diff --git a/src/emacs.c b/src/emacs.c
index 861d707..130a9f8 100644
--- a/src/emacs.c
+++ b/src/emacs.c
@@ -2019,6 +2019,10 @@ all of which are called before Emacs is actually killed. 
 */
 {
   int exit_code;
 
+#ifdef HAVE_LIBSYSTEMD
+  sd_notify(0, "STOPPING=1");
+#endif /* HAVE_LIBSYSTEMD */
+
   /* Fsignal calls emacs_abort () if it sees that waiting_for_input is
      set.  */
   waiting_for_input = 0;
@@ -2479,6 +2483,13 @@ from the parent process and its tty file descriptors.  
*/)
     error ("This function can only be called after loading the init files");
 #ifndef WINDOWSNT
 
+  if (daemon_type == 1)
+    {
+#ifdef HAVE_LIBSYSTEMD
+      sd_notify(0, "READY=1");
+#endif /* HAVE_LIBSYSTEMD */
+    }
+
   if (daemon_type == 2)
     {
       int nfd;