WindowManager: launch panel as subprocess

compositor/WindowManager.vala

@@ -201,10 +201,59 @@ namespace GreeterCompositor {
             Idle.add (() => {
                 // let the session manager move to the next phase
                 display.get_context ().notify_ready ();
+                start_command.begin ({ "io.elementary.wingpanel", "-g" });
                 return GLib.Source.REMOVE;
             });
         }
 
+        private async void start_command (string[] command) {
+            if (Meta.Util.is_wayland_compositor ()) {
+                yield start_wayland (command);
+            } else {
+                yield start_x (command);
+            }
+        }
+
+        private async void start_wayland (string[] command) {
+            unowned Meta.Display display = get_display ();
+            var subprocess_launcher = new GLib.SubprocessLauncher (GLib.SubprocessFlags.INHERIT_FDS);
+            try {
+                Meta.WaylandClient daemon_client;
+#if HAS_MUTTER44
+                daemon_client = new Meta.WaylandClient (display.get_context (), subprocess_launcher);
+#else
+                daemon_client = new Meta.WaylandClient (subprocess_launcher);
+#endif
+                var subprocess = daemon_client.spawnv (display, command);
+
+                yield subprocess.wait_async ();
+
+                //Restart the daemon if it crashes
+                Timeout.add_seconds (1, () => {
+                    start_wayland.begin (command);
+                    return Source.REMOVE;
+                });
+            } catch (Error e) {
+                warning ("Failed to create greeter client: %s", e.message);
+                return;
+            }
+        }
+
+        private async void start_x (string[] command) {
+            try {
+                var subprocess = new Subprocess.newv (command, GLib.SubprocessFlags.INHERIT_FDS);
+                yield subprocess.wait_async ();
+
+                //Restart the daemon if it crashes
+                Timeout.add_seconds (1, () => {
+                    start_x.begin (command);
+                    return Source.REMOVE;
+                });
+            } catch (Error e) {
+                warning ("Failed to create greeter subprocess with x: %s", e.message);
+            }
+        }
+
         public uint32[] get_all_xids () {
             unowned Meta.Display display = get_display ();
 

src/Application.vala

@@ -33,7 +33,6 @@ public int main (string[] args) {
     settings_daemon.start ();
 
     Greeter.SubprocessSupervisor compositor;
-    Greeter.SubprocessSupervisor wingpanel;
 
     try {
         compositor = new Greeter.SubprocessSupervisor ({"io.elementary.greeter-compositor"});
@@ -46,12 +45,6 @@ public int main (string[] args) {
     var window = new Greeter.MainWindow ();
     window.show_all ();
 
-    try {
-        wingpanel = new Greeter.SubprocessSupervisor ({"io.elementary.wingpanel", "-g"});
-    } catch (Error e) {
-        critical (e.message);
-    }
-
     Gtk.main ();
 
     return 0;