WIP: Try to really force the fsmonitor--daemon to quit

builtin/fsmonitor--daemon.c

@@ -67,6 +67,9 @@ static int handle_client(struct ipc_command_listener *data,
 	trace2_data_string("fsmonitor", the_repository, "command", command);
 
 	if (!strcmp(command, "quit")) {
+		if (fsmonitor_listen_stop(state))
+			error("Could not terminate watcher thread");
+		sleep_millisec(50);
 		return SIMPLE_IPC_QUIT;
 	}
 
@@ -165,7 +168,6 @@ int fsmonitor_queue_path(struct fsmonitor_daemon_state *state,
 
 static int fsmonitor_run_daemon(int background)
 {
-	pthread_t thread;
 	struct fsmonitor_daemon_state state = { { 0 } };
 	struct ipc_data ipc_data = {
 		.data = {
@@ -183,7 +185,7 @@ static int fsmonitor_run_daemon(int background)
 	pthread_mutex_init(&state.initial_mutex, NULL);
 	pthread_mutex_lock(&state.initial_mutex);
 
-	if (pthread_create(&thread, NULL,
+	if (pthread_create(&state.watcher_thread, NULL,
 			   (void *(*)(void *)) fsmonitor_listen, &state) < 0)
 		return error(_("could not start fsmonitor listener thread"));
 

compat/fsmonitor/win32.c

@@ -30,6 +30,14 @@ static int process_entry(struct fsmonitor_daemon_state *state,
 	return 0;
 }
 
+int fsmonitor_listen_stop(struct fsmonitor_daemon_state *state)
+{
+	if (!TerminateThread(state->watcher_thread.handle, 1))
+		return -1;
+
+	return 0;
+}
+
 struct fsmonitor_daemon_state *fsmonitor_listen(struct fsmonitor_daemon_state *state)
 {
 	HANDLE dir;

fsmonitor.h

@@ -111,6 +111,7 @@ struct fsmonitor_daemon_state {
 	struct fsmonitor_queue_item *first;
 	struct fsmonitor_queue_item *last;
 	uint64_t latest_update;
+	pthread_t watcher_thread;
 	pthread_mutex_t queue_update_lock, initial_mutex;
 	int error_code;
 };
@@ -124,6 +125,7 @@ int fsmonitor_queue_path(struct fsmonitor_daemon_state *state,
 
 /* This needs to be implemented by the backend */
 struct fsmonitor_daemon_state *fsmonitor_listen(struct fsmonitor_daemon_state *state);
+int fsmonitor_listen_stop(struct fsmonitor_daemon_state *state);
 #endif
 
 #endif

t/t7527-internal-fsmonitor.sh

@@ -9,6 +9,13 @@ git fsmonitor--daemon --is-supported || {
 	test_done
 }
 
+# Tell the fsmonitor--daemon to stop, even if `--stop` failed
+test_atexit '
+	git fsmonitor--daemon --stop ||
+	test -n "$debug" ||
+	rm -r .git
+'
+
 test_expect_success 'can start and stop the daemon' '
 	test_when_finished \
 		"test_might_fail git -C test fsmonitor--daemon --stop" &&