In order that people can use formats like #D in #() in the status line

and not have to wait for an update when they change pane, we allow
commands to run more than once a second if the expanded form
changes. Unfortunately this can mean them being run far too often
(pretty much continually) when multiple clients exist, because some
formats (including #D) will always differ between clients.

To avoid this, give each client its own tree of jobs which means that
the same command will be different instances for each client - similar
to how we have the tag to separate commands for different panes.

GitHub issue 889; test case reported by Paul Johnson.

cfg.c

@@ -148,7 +148,8 @@ load_cfg(const char *path, struct client *c, struct cmdq_item *item, int quiet)
 				    line);
 				continue;
 			}
-			ft = format_create(NULL, FORMAT_NONE, FORMAT_NOJOBS);
+			ft = format_create(NULL, NULL, FORMAT_NONE,
+			    FORMAT_NOJOBS);
 
 			s = p + 3;
 			while (isspace((u_char)*s))

cmd-display-message.c

@@ -73,7 +73,7 @@ cmd_display_message_exec(struct cmd *self, struct cmdq_item *item)
 	if (template == NULL)
 		template = DISPLAY_MESSAGE_TEMPLATE;
 
-	ft = format_create(item, FORMAT_NONE, 0);
+	ft = format_create(item->client, item, FORMAT_NONE, 0);
 	format_defaults(ft, c, s, wl, wp);
 
 	msg = format_expand_time(ft, template, time(NULL));

cmd-list-buffers.c

@@ -57,7 +57,7 @@ cmd_list_buffers_exec(struct cmd *self, struct cmdq_item *item)
 
 	pb = NULL;
 	while ((pb = paste_walk(pb)) != NULL) {
-		ft = format_create(item, FORMAT_NONE, 0);
+		ft = format_create(item->client, item, FORMAT_NONE, 0);
 		format_defaults_paste_buffer(ft, pb);
 
 		line = format_expand(ft, template);

cmd-list-clients.c

@@ -72,7 +72,7 @@ cmd_list_clients_exec(struct cmd *self, struct cmdq_item *item)
 		if (c->session == NULL || (s != NULL && s != c->session))
 			continue;
 
-		ft = format_create(item, FORMAT_NONE, 0);
+		ft = format_create(item->client, item, FORMAT_NONE, 0);
 		format_add(ft, "line", "%u", idx);
 		format_defaults(ft, c, NULL, NULL, NULL);
 

cmd-list-keys.c

@@ -144,7 +144,7 @@ cmd_list_keys_commands(struct cmd *self, struct cmdq_item *item)
 		    "#{command_list_usage}";
 	}
 
-	ft = format_create(item, FORMAT_NONE, 0);
+	ft = format_create(item->client, item, FORMAT_NONE, 0);
 	format_defaults(ft, NULL, NULL, NULL, NULL);
 
 	for (entryp = cmd_table; *entryp != NULL; entryp++) {

cmd-list-panes.c

@@ -123,7 +123,7 @@ cmd_list_panes_window(struct cmd *self, struct session *s, struct winlink *wl,
 
 	n = 0;
 	TAILQ_FOREACH(wp, &wl->window->panes, entry) {
-		ft = format_create(item, FORMAT_NONE, 0);
+		ft = format_create(item->client, item, FORMAT_NONE, 0);
 		format_add(ft, "line", "%u", n);
 		format_defaults(ft, NULL, s, wl, wp);
 

cmd-list-sessions.c

@@ -65,7 +65,7 @@ cmd_list_sessions_exec(struct cmd *self, struct cmdq_item *item)
 
 	n = 0;
 	RB_FOREACH(s, sessions, &sessions) {
-		ft = format_create(item, FORMAT_NONE, 0);
+		ft = format_create(item->client, item, FORMAT_NONE, 0);
 		format_add(ft, "line", "%u", n);
 		format_defaults(ft, NULL, s, NULL, NULL);
 

cmd-list-windows.c

@@ -86,7 +86,7 @@ cmd_list_windows_session(struct cmd *self, struct session *s,
 {
 	struct args		*args = self->args;
 	struct winlink		*wl;
-	u_int			n;
+	u_int			 n;
 	struct format_tree	*ft;
 	const char		*template;
 	char			*line;
@@ -105,7 +105,7 @@ cmd_list_windows_session(struct cmd *self, struct session *s,
 
 	n = 0;
 	RB_FOREACH(wl, winlinks, &s->windows) {
-		ft = format_create(item, FORMAT_NONE, 0);
+		ft = format_create(item->client, item, FORMAT_NONE, 0);
 		format_add(ft, "line", "%u", n);
 		format_defaults(ft, NULL, s, wl, NULL);
 

cmd-pipe-pane.c

@@ -90,7 +90,7 @@ cmd_pipe_pane_exec(struct cmd *self, struct cmdq_item *item)
 	}
 
 	/* Expand the command. */
-	ft = format_create(item, FORMAT_NONE, 0);
+	ft = format_create(item->client, item, FORMAT_NONE, 0);
 	format_defaults(ft, c, s, wl, wp);
 	cmd = format_expand_time(ft, args->argv[0], time(NULL));
 	format_free(ft);

cmd-queue.c

@@ -299,7 +299,7 @@ cmdq_format(struct cmdq_item *item, const char *key, const char *fmt, ...)
 	va_end(ap);
 
 	if (shared->formats == NULL)
-		shared->formats = format_create(NULL, FORMAT_NONE, 0);
+		shared->formats = format_create(NULL, NULL, FORMAT_NONE, 0);
 	format_add(shared->formats, key, "%s", value);
 
 	free(value);

format.c

@@ -76,6 +76,7 @@ static void	 format_defaults_winlink(struct format_tree *,
 
 /* Entry in format job tree. */
 struct format_job {
+	struct client		*client;
 	u_int			 tag;
 	const char		*cmd;
 	const char		*expanded;
@@ -128,6 +129,7 @@ struct format_tree {
 	struct session		*s;
 	struct window_pane	*wp;
 
+	struct client		*client;
 	u_int			 tag;
 	int			 flags;
 
@@ -236,7 +238,6 @@ format_job_complete(struct job *job)
 	struct format_job	*fj = job->data;
 	char			*line, *buf;
 	size_t			 len;
-	struct client		*c;
 
 	fj->job = NULL;
 
@@ -258,8 +259,8 @@ format_job_complete(struct job *job)
 		free(buf);
 
 	if (fj->status) {
-		TAILQ_FOREACH(c, &clients, entry)
-		    server_status_client(c);
+		if (fj->client != NULL)
+			server_status_client(fj->client);
 		fj->status = 0;
 	}
 }
@@ -268,22 +269,33 @@ format_job_complete(struct job *job)
 static char *
 format_job_get(struct format_tree *ft, const char *cmd)
 {
+	struct format_job_tree	*jobs;
 	struct format_job	 fj0, *fj;
 	time_t			 t;
 	char			*expanded;
 	int			 force;
 
+	if (ft->client == NULL)
+		jobs = &format_jobs;
+	else if (ft->client->jobs != NULL)
+		jobs = ft->client->jobs;
+	else {
+		jobs = ft->client->jobs = xmalloc(sizeof *ft->client->jobs);
+		RB_INIT(jobs);
+	}
+
 	fj0.tag = ft->tag;
 	fj0.cmd = cmd;
-	if ((fj = RB_FIND(format_job_tree, &format_jobs, &fj0)) == NULL) {
+	if ((fj = RB_FIND(format_job_tree, jobs, &fj0)) == NULL) {
 		fj = xcalloc(1, sizeof *fj);
+		fj->client = ft->client;
 		fj->tag = ft->tag;
 		fj->cmd = xstrdup(cmd);
 		fj->expanded = NULL;
 
 		xasprintf(&fj->out, "<'%s' not ready>", fj->cmd);
 
-		RB_INSERT(format_job_tree, &format_jobs, fj);
+		RB_INSERT(format_job_tree, jobs, fj);
 	}
 
 	expanded = format_expand(ft, cmd);
@@ -314,17 +326,16 @@ format_job_get(struct format_tree *ft, const char *cmd)
 
 /* Remove old jobs. */
 static void
-format_job_timer(__unused int fd, __unused short events, __unused void *arg)
+format_job_tidy(struct format_job_tree *jobs, int force)
 {
 	struct format_job	*fj, *fj1;
 	time_t			 now;
-	struct timeval		 tv = { .tv_sec = 60 };
 
 	now = time(NULL);
-	RB_FOREACH_SAFE(fj, format_job_tree, &format_jobs, fj1) {
-		if (fj->last > now || now - fj->last < 3600)
+	RB_FOREACH_SAFE(fj, format_job_tree, jobs, fj1) {
+		if (!force && (fj->last > now || now - fj->last < 3600))
 			continue;
-		RB_REMOVE(format_job_tree, &format_jobs, fj);
+		RB_REMOVE(format_job_tree, jobs, fj);
 
 		log_debug("%s: %s", __func__, fj->cmd);
 
@@ -337,6 +348,29 @@ format_job_timer(__unused int fd, __unused short events, __unused void *arg)
 
 		free(fj);
 	}
+}
+
+/* Remove old jobs for client. */
+void
+format_lost_client(struct client *c)
+{
+	if (c->jobs != NULL)
+		format_job_tidy(c->jobs, 1);
+	free(c->jobs);
+}
+
+/* Remove old jobs periodically. */
+static void
+format_job_timer(__unused int fd, __unused short events, __unused void *arg)
+{
+	struct client	*c;
+	struct timeval	 tv = { .tv_sec = 60 };
+
+	format_job_tidy(&format_jobs, 0);
+	TAILQ_FOREACH(c, &clients, entry) {
+		if (c->jobs != NULL)
+			format_job_tidy(c->jobs, 0);
+	}
 
 	evtimer_del(&format_job_event);
 	evtimer_add(&format_job_event, &tv);
@@ -533,7 +567,7 @@ format_merge(struct format_tree *ft, struct format_tree *from)
 
 /* Create a new tree. */
 struct format_tree *
-format_create(struct cmdq_item *item, int tag, int flags)
+format_create(struct client *c, struct cmdq_item *item, int tag, int flags)
 {
 	struct format_tree	*ft;
 
@@ -545,6 +579,11 @@ format_create(struct cmdq_item *item, int tag, int flags)
 	ft = xcalloc(1, sizeof *ft);
 	RB_INIT(&ft->tree);
 
+	if (c != NULL) {
+		ft->client = c;
+		ft->client->references++;
+	}
+
 	ft->tag = tag;
 	ft->flags = flags;
 
@@ -577,6 +616,8 @@ format_free(struct format_tree *ft)
 		free(fe);
 	}
 
+	if (ft->client != NULL)
+		server_client_unref(ft->client);
 	free(ft);
 }
 
@@ -1099,7 +1140,10 @@ format_single(struct cmdq_item *item, const char *fmt, struct client *c,
 	struct format_tree	*ft;
 	char			*expanded;
 
-	ft = format_create(item, FORMAT_NONE, 0);
+	if (item != NULL)
+		ft = format_create(item->client, item, FORMAT_NONE, 0);
+	else
+		ft = format_create(NULL, item, FORMAT_NONE, 0);
 	format_defaults(ft, c, s, wl, wp);
 
 	expanded = format_expand(ft, fmt);

names.c

@@ -124,7 +124,7 @@ format_window_name(struct window *w)
 	const char		*fmt;
 	char			*name;
 
-	ft = format_create(NULL, FORMAT_WINDOW|w->id, 0);
+	ft = format_create(NULL, NULL, FORMAT_WINDOW|w->id, 0);
 	format_defaults_window(ft, w);
 	format_defaults_pane(ft, w->active);
 

screen-redraw.c

@@ -280,7 +280,7 @@ screen_redraw_make_pane_status(struct client *c, struct window *w,
 
 	fmt = options_get_string(w->options, "pane-border-format");
 
-	ft = format_create(NULL, FORMAT_PANE|wp->id, 0);
+	ft = format_create(c, NULL, FORMAT_PANE|wp->id, 0);
 	format_defaults(ft, c, NULL, NULL, wp);
 
 	memcpy(&old, &wp->status_screen, sizeof old);

server-client.c

@@ -283,6 +283,7 @@ server_client_lost(struct client *c)
 	free(c->prompt_string);
 	free(c->prompt_buffer);
 
+	format_lost_client(c);
 	environ_free(c->environ);
 
 	proc_remove_peer(c->peer);
@@ -1326,7 +1327,7 @@ server_client_set_title(struct client *c)
 
 	template = options_get_string(s->options, "set-titles-string");
 
-	ft = format_create(NULL, FORMAT_NONE, 0);
+	ft = format_create(c, NULL, FORMAT_NONE, 0);
 	format_defaults(ft, c, NULL, NULL, NULL);
 
 	title = format_expand_time(ft, template, time(NULL));

status.c

@@ -519,9 +519,9 @@ status_replace(struct client *c, struct winlink *wl, const char *fmt, time_t t)
 	else
 		tag = FORMAT_NONE;
 	if (c->flags & CLIENT_STATUSFORCE)
-		ft = format_create(NULL, tag, FORMAT_STATUS|FORMAT_FORCE);
+		ft = format_create(c, NULL, tag, FORMAT_STATUS|FORMAT_FORCE);
 	else
-		ft = format_create(NULL, tag, FORMAT_STATUS);
+		ft = format_create(c, NULL, tag, FORMAT_STATUS);
 	format_defaults(ft, c, NULL, wl, NULL);
 
 	expanded = format_expand_time(ft, fmt, t);
@@ -663,7 +663,7 @@ status_prompt_set(struct client *c, const char *msg, const char *input,
 	time_t			 t;
 	char			*tmp;
 
-	ft = format_create(NULL, FORMAT_NONE, 0);
+	ft = format_create(c, NULL, FORMAT_NONE, 0);
 	format_defaults(ft, c, NULL, NULL, NULL);
 
 	t = time(NULL);
@@ -724,7 +724,7 @@ status_prompt_update(struct client *c, const char *msg, const char *input)
 	time_t			 t;
 	char			*tmp;
 
-	ft = format_create(NULL, FORMAT_NONE, 0);
+	ft = format_create(c, NULL, FORMAT_NONE, 0);
 	format_defaults(ft, c, NULL, NULL, NULL);
 
 	t = time(NULL);

tmux.h

@@ -43,6 +43,7 @@ struct client;
 struct cmdq_item;
 struct cmdq_list;
 struct environ;
+struct format_job_tree;
 struct input_ctx;
 struct mode_key_cmdstr;
 struct mouse_event;
@@ -1290,6 +1291,7 @@ struct client {
 	struct timeval	 activity_time;
 
 	struct environ	*environ;
+	struct format_job_tree	*jobs;
 
 	char		*title;
 	const char	*cwd;
@@ -1501,7 +1503,8 @@ char		*paste_make_sample(struct paste_buffer *);
 #define FORMAT_PANE 0x80000000U
 #define FORMAT_WINDOW 0x40000000U
 struct format_tree;
-struct format_tree *format_create(struct cmdq_item *, int, int);
+struct format_tree *format_create(struct client *, struct cmdq_item *, int,
+		     int);
 void		 format_free(struct format_tree *);
 void printflike(3, 4) format_add(struct format_tree *, const char *,
 		     const char *, ...);
@@ -1517,6 +1520,7 @@ void		 format_defaults_pane(struct format_tree *,
 		     struct window_pane *);
 void		 format_defaults_paste_buffer(struct format_tree *,
 		     struct paste_buffer *);
+void		 format_lost_client(struct client *);
 
 /* hooks.c */
 struct hook;

window-choose.c

@@ -202,7 +202,7 @@ window_choose_data_create(int type, struct client *c, struct session *s)
 	wcd = xmalloc(sizeof *wcd);
 	wcd->type = type;
 
-	wcd->ft = format_create(NULL, FORMAT_NONE, 0);
+	wcd->ft = format_create(c, NULL, FORMAT_NONE, 0);
 	wcd->ft_template = NULL;
 
 	wcd->command = NULL;