Pull format allocation outside of loop for control subs, from Conor

Taylor in GitHub issue 4848.

control.c

@@ -847,15 +847,13 @@ control_stop(struct client *c)
 
 /* Check session subscription. */
 static void
-control_check_subs_session(struct client *c, struct control_sub *csub)
+control_check_subs_session(struct client *c, struct control_sub *csub,
+    struct format_tree *ft)
 {
 	struct session		*s = c->session;
-	struct format_tree	*ft;
 	char			*value;
 
-	ft = format_create_defaults(NULL, c, s, NULL, NULL);
 	value = format_expand(ft, csub->format);
-	format_free(ft);
 
 	if (csub->last != NULL && strcmp(value, csub->last) == 0) {
 		free(value);
@@ -916,24 +914,17 @@ control_check_subs_pane(struct client *c, struct control_sub *csub)
 	}
 }
 
-/* Check all panes subscription. */
+/* Check all-panes subscription for a pane. */
 static void
-control_check_subs_all_panes(struct client *c, struct control_sub *csub)
+control_check_subs_all_panes_one(struct client *c, struct control_sub *csub,
+    struct format_tree *ft, struct winlink *wl, struct window_pane *wp)
 {
 	struct session		*s = c->session;
-	struct window_pane	*wp;
+	struct window		*w = wl->window;
-	struct window		*w;
-	struct winlink		*wl;
-	struct format_tree	*ft;
 	char			*value;
 	struct control_sub_pane	*csp, find;
 
-	RB_FOREACH(wl, winlinks, &s->windows) {
-		w = wl->window;
-		TAILQ_FOREACH(wp, &w->panes, entry) {
-			ft = format_create_defaults(NULL, c, s, wl, wp);
 	value = format_expand(ft, csub->format);
-			format_free(ft);
 
 	find.pane = wp->id;
 	find.idx = wl->idx;
@@ -946,18 +937,15 @@ control_check_subs_all_panes(struct client *c, struct control_sub *csub)
 		RB_INSERT(control_sub_panes, &csub->panes, csp);
 	}
 
-			if (csp->last != NULL &&
+	if (csp->last != NULL && strcmp(value, csp->last) == 0) {
-			    strcmp(value, csp->last) == 0) {
 		free(value);
-				continue;
+		return;
 	}
 	control_write(c,
 	    "%%subscription-changed %s $%u @%u %u %%%u : %s",
 	    csub->name, s->id, w->id, wl->idx, wp->id, value);
 	free(csp->last);
 	csp->last = value;
-		}
-	}
 }
 
 /* Check window subscription. */
@@ -1006,23 +994,17 @@ control_check_subs_window(struct client *c, struct control_sub *csub)
 	}
 }
 
-/* Check all windows subscription. */
+/* Check all-windows subscription for a window. */
 static void
-control_check_subs_all_windows(struct client *c, struct control_sub *csub)
+control_check_subs_all_windows_one(struct client *c, struct control_sub *csub,
+    struct format_tree *ft, struct winlink *wl)
 {
 	struct session			*s = c->session;
-	struct window			*w;
+	struct window			*w = wl->window;
-	struct winlink			*wl;
-	struct format_tree		*ft;
 	char				*value;
 	struct control_sub_window	*csw, find;
 
-	RB_FOREACH(wl, winlinks, &s->windows) {
-		w = wl->window;
-
-		ft = format_create_defaults(NULL, c, s, wl, NULL);
 	value = format_expand(ft, csub->format);
-		format_free(ft);
 
 	find.window = w->id;
 	find.idx = wl->idx;
@@ -1037,14 +1019,13 @@ control_check_subs_all_windows(struct client *c, struct control_sub *csub)
 
 	if (csw->last != NULL && strcmp(value, csw->last) == 0) {
 		free(value);
-			continue;
+		return;
 	}
 	control_write(c,
 	    "%%subscription-changed %s $%u @%u %u - : %s",
 	    csub->name, s->id, w->id, wl->idx, value);
 	free(csw->last);
 	csw->last = value;
-	}
 }
 
 /* Check subscriptions timer. */
@@ -1054,30 +1035,91 @@ control_check_subs_timer(__unused int fd, __unused short events, void *data)
 	struct client		*c = data;
 	struct control_state	*cs = c->control_state;
 	struct control_sub	*csub, *csub1;
+	struct session		*s = c->session;
+	struct format_tree	*ft;
+	struct winlink		*wl;
+	struct window_pane	*wp;
 	struct timeval		 tv = { .tv_sec = 1 };
+	int			 have_session = 0, have_all_panes = 0;
+	int			 have_all_windows = 0;
 
 	log_debug("%s: timer fired", __func__);
 	evtimer_add(&cs->subs_timer, &tv);
 
-	RB_FOREACH_SAFE(csub, control_subs, &cs->subs, csub1) {
+	/* Find which subscription types are present. */
+	RB_FOREACH(csub, control_subs, &cs->subs) {
 		switch (csub->type) {
 		case CONTROL_SUB_SESSION:
-			control_check_subs_session(c, csub);
+			have_session = 1;
-			break;
-		case CONTROL_SUB_PANE:
-			control_check_subs_pane(c, csub);
 			break;
 		case CONTROL_SUB_ALL_PANES:
-			control_check_subs_all_panes(c, csub);
+			have_all_panes = 1;
+			break;
+		case CONTROL_SUB_ALL_WINDOWS:
+			have_all_windows = 1;
+			break;
+		default:
+			break;
+		}
+	}
+
+	/* Check session subscriptions. */
+	if (have_session) {
+		ft = format_create_defaults(NULL, c, s, NULL, NULL);
+		RB_FOREACH_SAFE(csub, control_subs, &cs->subs, csub1) {
+			if (csub->type == CONTROL_SUB_SESSION)
+				control_check_subs_session(c, csub, ft);
+		}
+		format_free(ft);
+	}
+
+	/* Check pane and window subscriptions. */
+	RB_FOREACH_SAFE(csub, control_subs, &cs->subs, csub1) {
+		switch (csub->type) {
+		case CONTROL_SUB_PANE:
+			control_check_subs_pane(c, csub);
 			break;
 		case CONTROL_SUB_WINDOW:
 			control_check_subs_window(c, csub);
 			break;
+		case CONTROL_SUB_SESSION:
+		case CONTROL_SUB_ALL_PANES:
 		case CONTROL_SUB_ALL_WINDOWS:
-			control_check_subs_all_windows(c, csub);
 			break;
 		}
 	}
+
+	/* Check all-panes subscriptions. */
+	if (have_all_panes) {
+		RB_FOREACH(wl, winlinks, &s->windows) {
+			TAILQ_FOREACH(wp, &wl->window->panes, entry) {
+				ft = format_create_defaults(NULL, c, s, wl, wp);
+				RB_FOREACH_SAFE(csub, control_subs, &cs->subs,
+				    csub1) {
+					if (csub->type != CONTROL_SUB_ALL_PANES)
+						continue;
+					control_check_subs_all_panes_one(c,
+					    csub, ft, wl, wp);
+				}
+				format_free(ft);
+			}
+		}
+	}
+
+	/* Check all-windows subscriptions. */
+	if (have_all_windows) {
+		RB_FOREACH(wl, winlinks, &s->windows) {
+			ft = format_create_defaults(NULL, c, s, wl, NULL);
+			RB_FOREACH_SAFE(csub, control_subs, &cs->subs,
+			    csub1) {
+				if (csub->type != CONTROL_SUB_ALL_WINDOWS)
+					continue;
+				control_check_subs_all_windows_one(c, csub, ft,
+				    wl);
+			}
+			format_free(ft);
+		}
+	}
 }
 
 /* Add a subscription. */