fsmonitor--daemon: prepare for adding health thread

jeffhostetler · gitster · commit dff74711b2a9 · 2022-03-25T16:06:13.000-07:00
Refactor daemon thread startup to make it easier to start
a third thread class to monitor the health of the daemon.

Signed-off-by: Jeff Hostetler &lt;jeffhost@microsoft.com&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
diff --git a/builtin/fsmonitor--daemon.c b/builtin/fsmonitor--daemon.c
@@ -1174,6 +1174,8 @@ static int fsmonitor_run_daemon_1(struct fsmonitor_daemon_state *state)
 		 */
 		.uds_disallow_chdir = 0
 	};
+	int listener_started = 0;
+	int err = 0;
 
 	/*
 	 * Start the IPC thread pool before the we've started the file
@@ -1194,15 +1196,20 @@ static int fsmonitor_run_daemon_1(struct fsmonitor_daemon_state *state)
 	if (pthread_create(&state->listener_thread, NULL,
 			   fsm_listen__thread_proc, state) < 0) {
 		ipc_server_stop_async(state->ipc_server_data);
-		ipc_server_await(state->ipc_server_data);
-
-		return error(_("could not start fsmonitor listener thread"));
+		err = error(_("could not start fsmonitor listener thread"));
+		goto cleanup;
 	}
+	listener_started = 1;
 
 	/*
 	 * The daemon is now fully functional in background threads.
+	 * Our primary thread should now just wait while the threads
+	 * do all the work.
+	 */
+cleanup:
+	/*
 	 * Wait for the IPC thread pool to shutdown (whether by client
-	 * request or from filesystem activity).
+	 * request, from filesystem activity, or an error).
 	 */
 	ipc_server_await(state->ipc_server_data);
 
@@ -1211,10 +1218,16 @@ static int fsmonitor_run_daemon_1(struct fsmonitor_daemon_state *state)
 	 * event from the IPC thread pool, but it doesn't hurt to tell
 	 * it again.  And wait for it to shutdown.
 	 */
-	fsm_listen__stop_async(state);
-	pthread_join(state->listener_thread, NULL);
+	if (listener_started) {
+		fsm_listen__stop_async(state);
+		pthread_join(state->listener_thread, NULL);
+	}
 
-	return state->error_code;
+	if (err)
+		return err;
+	if (state->error_code)
+		return state->error_code;
+	return 0;
 }
 
 static int fsmonitor_run_daemon(void)
