Better take on reducing the name timer. Again check for name changes in

the main loop after events that may have changed the pane, but do so at
most once every 500 millis. If the pane changed too soon, use a timer to
ensure that a check happens later.

cmd-set-option.c

@@ -180,9 +180,7 @@ cmd_set_option_exec(struct cmd *self, struct cmd_q *cmdq)
 	if (strcmp(oe->name, "automatic-rename") == 0) {
 		RB_FOREACH(w, windows, &windows) {
 			if (options_get_number(&w->options, "automatic-rename"))
-				queue_window_name(w);
-			else if (event_initialized(&w->name_timer))
-				evtimer_del(&w->name_timer);
+				w->active->flags |= PANE_CHANGED;
 		}
 	}
 	if (strcmp(oe->name, "status") == 0 ||

names.c

@@ -25,47 +25,76 @@
 
 #include "tmux.h"
 
-void	 window_name_callback(unused int, unused short, void *);
+void	name_time_callback(int, short, void *);
+int	name_time_expired(struct window *, struct timeval *);
 
 void
-queue_window_name(struct window *w)
+name_time_callback(unused int fd, unused short events, void *arg)
 {
-	struct timeval	tv;
+	struct window	*w = arg;
 
-	tv.tv_sec = 0;
-	tv.tv_usec = NAME_INTERVAL * 1000L;
+	/* The event loop will call check_window_name for us on the way out. */
+	log_debug("@%u name timer expired", w->id);
+}
 
-	if (event_initialized(&w->name_timer))
-		evtimer_del(&w->name_timer);
-	evtimer_set(&w->name_timer, window_name_callback, w);
-	evtimer_add(&w->name_timer, &tv);
+int
+name_time_expired(struct window *w, struct timeval *tv)
+{
+	struct timeval	offset;
+
+	timersub(tv, &w->name_time, &offset);
+	if (offset.tv_sec != 0 || offset.tv_usec > NAME_INTERVAL)
+		return (0);
+	return (NAME_INTERVAL - offset.tv_usec);
 }
 
 void
-window_name_callback(unused int fd, unused short events, void *data)
+check_window_name(struct window *w)
 {
-	struct window	*w = data;
+	struct timeval	 tv, next;
 	char		*name;
+	int		 left;
 
 	if (w->active == NULL)
 		return;
 
-	if (!options_get_number(&w->options, "automatic-rename")) {
-		if (event_initialized(&w->name_timer))
-			event_del(&w->name_timer);
+	if (!options_get_number(&w->options, "automatic-rename"))
+		return;
+
+	if (~w->active->flags & PANE_CHANGED) {
+		log_debug("@%u active pane not changed", w->id);
 		return;
 	}
-	queue_window_name(w);
+	log_debug("@%u active pane changed", w->id);
 
-	if (~w->active->flags & PANE_CHANGED)
+	gettimeofday(&tv, NULL);
+	left = name_time_expired(w, &tv);
+	if (left != 0) {
+		if (!event_initialized(&w->name_event))
+			evtimer_set(&w->name_event, name_time_callback, w);
+		if (!evtimer_pending(&w->name_event, NULL)) {
+			log_debug("@%u name timer queued (%d left)", w->id, left);
+			timerclear(&next);
+			next.tv_usec = left;
+			event_add(&w->name_event, &next);
+		} else
+			log_debug("@%u name timer already queued (%d left)", w->id, left);
 		return;
+	}
+	memcpy(&w->name_time, &tv, sizeof w->name_time);
+	if (event_initialized(&w->name_event))
+		evtimer_del(&w->name_event);
+
 	w->active->flags &= ~PANE_CHANGED;
 
 	name = format_window_name(w);
 	if (strcmp(name, w->name) != 0) {
+		log_debug("@%u new name %s (was %s)", w->id, name, w->name);
 		window_set_name(w, name);
 		server_status_window(w);
-	}
+	} else
+		log_debug("@%u name not changed (still %s)", w->id, w->name);
+
 	free(name);
 }
 

server-window.c

@@ -49,6 +49,7 @@ server_window_loop(void)
 					server_status_session(s);
 			}
 		}
+		check_window_name(w);
 	}
 }
 

tmux.h

@@ -47,8 +47,8 @@ extern char   **environ;
  */
 #define PANE_MINIMUM 2
 
-/* Automatic name refresh interval, in milliseconds. */
-#define NAME_INTERVAL 500
+/* Automatic name refresh interval, in microseconds. Must be < 1 second. */
+#define NAME_INTERVAL 500000
 
 /*
  * UTF-8 data size. This must be big enough to hold combined characters as well
@@ -869,8 +869,11 @@ RB_HEAD(window_pane_tree, window_pane);
 /* Window structure. */
 struct window {
 	u_int		 id;
+
 	char		*name;
-	struct event	 name_timer;
+	struct event	 name_event;
+	struct timeval	 name_time;
+
 	struct timeval	 silence_timer;
 	struct timeval	 activity_time;
 
@@ -2209,7 +2212,7 @@ void	window_choose_collapse_all(struct window_pane *);
 void	window_choose_set_current(struct window_pane *, u_int);
 
 /* names.c */
-void	 queue_window_name(struct window *);
+void	 check_window_name(struct window *);
 char	*default_window_name(struct window *);
 char	*format_window_name(struct window *);
 char	*parse_window_name(const char *);

window.c

@@ -299,8 +299,6 @@ window_create1(u_int sx, u_int sy)
 		fatal("gettimeofday failed");
 
 	options_init(&w->options, &global_w_options);
-	if (options_get_number(&w->options, "automatic-rename"))
-		queue_window_name(w);
 
 	w->references = 0;
 
@@ -349,8 +347,8 @@ window_destroy(struct window *w)
 		layout_free_cell(w->saved_layout_root);
 	free(w->old_layout);
 
-	if (event_initialized(&w->name_timer))
-		evtimer_del(&w->name_timer);
+	if (event_initialized(&w->name_event))
+		evtimer_del(&w->name_event);
 
 	options_free(&w->options);