Add "grouped sessions" which have independent name, options, current window and

so on but where the linked windows are synchronized (ie creating, killing
windows and so on are mirrored between the sessions). A grouped session may be
created by passing -t to new-session.

Had this around for a while, tested by a couple of people.

1 files changed, 181 insertions, 8 deletions

diff --git a/session.c b/session.c
index 62c5b746..a477634e 100644
--- a/session.c
+++ b/session.c
@@ -30,6 +30,7 @@
 /* Global session list. */
 struct sessions	sessions;
 struct sessions dead_sessions;
+struct session_groups session_groups;
 
 struct winlink *session_next_activity(struct session *, struct winlink *);
 struct winlink *session_previous_activity(struct session *, struct winlink *);
@@ -131,7 +132,7 @@ session_create(const char *name, const char *cmd, const char *cwd,
 		fatal("gettimeofday failed");
 
 	s->curw = NULL;
-	SLIST_INIT(&s->lastw);
+	TAILQ_INIT(&s->lastw);
 	RB_INIT(&s->windows);
 	SLIST_INIT(&s->alerts);
 
@@ -164,11 +165,14 @@ session_create(const char *name, const char *cmd, const char *cwd,
 		s->name = xstrdup(name);
 	else
 		xasprintf(&s->name, "%u", i);
-	if (session_new(s, NULL, cmd, cwd, idx, cause) == NULL) {
-		session_destroy(s);
-		return (NULL);
+	
+	if (cmd != NULL) {
+		if (session_new(s, NULL, cmd, cwd, idx, cause) == NULL) {
+			session_destroy(s);
+			return (NULL);
+		}
+		session_select(s, RB_ROOT(&s->windows)->idx);
 	}
-	session_select(s, RB_ROOT(&s->windows)->idx);
 
 	log_debug("session %s created", s->name);
 
@@ -192,13 +196,14 @@ session_destroy(struct session *s)
 	if (s->tio != NULL)
 		xfree(s->tio);
 
+	session_group_remove(s);
 	session_alert_cancel(s, NULL);
 	environ_free(&s->environ);
 	options_free(&s->options);
 	paste_free_stack(&s->buffers);
 
-	while (!SLIST_EMPTY(&s->lastw))
-		winlink_stack_remove(&s->lastw, SLIST_FIRST(&s->lastw));
+	while (!TAILQ_EMPTY(&s->lastw))
+		winlink_stack_remove(&s->lastw, TAILQ_FIRST(&s->lastw));
 	while (!RB_EMPTY(&s->windows))
 		winlink_remove(&s->windows, RB_ROOT(&s->windows));
 
@@ -268,6 +273,7 @@ session_attach(struct session *s, struct window *w, int idx, char **cause)
 
 	if ((wl = winlink_add(&s->windows, w, idx)) == NULL)
 		xasprintf(cause, "index in use: %d", idx);
+	session_group_synchronize_from(s);
 	return (wl);
 }
 
@@ -282,6 +288,7 @@ session_detach(struct session *s, struct winlink *wl)
 	session_alert_cancel(s, wl);
 	winlink_stack_remove(&s->lastw, wl);
 	winlink_remove(&s->windows, wl);
+	session_group_synchronize_from(s);
 	if (RB_EMPTY(&s->windows)) {
 		session_destroy(s);
 		return (1);
@@ -408,7 +415,7 @@ session_last(struct session *s)
 {
 	struct winlink	*wl;
 
-	wl = SLIST_FIRST(&s->lastw);
+	wl = TAILQ_FIRST(&s->lastw);
 	if (wl == NULL)
 		return (-1);
 	if (wl == s->curw)
@@ -420,3 +427,169 @@ session_last(struct session *s)
 	session_alert_cancel(s, wl);
 	return (0);
 }
+
+/* Find the session group containing a session. */
+struct session_group *
+session_group_find(struct session *target)
+{
+	struct session_group	*sg;
+	struct session		*s;
+
+	TAILQ_FOREACH(sg, &session_groups, entry) {
+		TAILQ_FOREACH(s, &sg->sessions, gentry) {
+			if (s == target)
+				return (sg);
+		}
+	}
+	return (NULL);
+}
+
+/* Find session group index. */
+u_int
+session_group_index(struct session_group *sg)
+{
+	struct session_group   *sg2;
+	u_int			i;
+
+	i = 0;
+	TAILQ_FOREACH(sg2, &session_groups, entry) {
+		if (sg == sg2)
+			return (i);
+		i++;
+	}
+
+	fatalx("session group not found");
+}
+
+/*
+ * Add a session to the session group containing target, creating it if
+ * necessary. 
+ */
+void
+session_group_add(struct session *target, struct session *s)
+{
+	struct session_group	*sg;
+
+	if ((sg = session_group_find(target)) == NULL) {
+		sg = xmalloc(sizeof *sg);
+		TAILQ_INSERT_TAIL(&session_groups, sg, entry);
+		TAILQ_INIT(&sg->sessions);
+		TAILQ_INSERT_TAIL(&sg->sessions, target, gentry);
+	}
+	TAILQ_INSERT_TAIL(&sg->sessions, s, gentry);
+}
+
+/* Remove a session from its group and destroy the group if empty. */
+void
+session_group_remove(struct session *s)
+{
+	struct session_group	*sg;
+
+	if ((sg = session_group_find(s)) == NULL)
+		return;
+	TAILQ_REMOVE(&sg->sessions, s, gentry);
+	if (TAILQ_NEXT(TAILQ_FIRST(&sg->sessions), gentry) == NULL)
+		TAILQ_REMOVE(&sg->sessions, TAILQ_FIRST(&sg->sessions), gentry);
+	if (TAILQ_EMPTY(&sg->sessions)) {
+		TAILQ_REMOVE(&session_groups, sg, entry);
+		xfree(sg);
+	}
+}
+
+/* Synchronize a session to its session group. */
+void
+session_group_synchronize_to(struct session *s)
+{
+	struct session_group	*sg;
+	struct session		*target;
+
+	if ((sg = session_group_find(s)) == NULL)
+		return;
+
+	target = NULL;
+	TAILQ_FOREACH(target, &sg->sessions, gentry) {
+		if (target != s)
+			break;
+	}
+	session_group_synchronize1(target, s);
+}
+
+/* Synchronize a session group to a session. */
+void
+session_group_synchronize_from(struct session *target)
+{
+	struct session_group	*sg;
+	struct session		*s;
+
+	if ((sg = session_group_find(target)) == NULL)
+		return;
+
+	TAILQ_FOREACH(s, &sg->sessions, gentry) {
+		if (s != target)
+			session_group_synchronize1(target, s);
+	}
+}
+
+/*
+ * Synchronize a session with a target session. This means destroying all
+ * winlinks then recreating them, then updating the current window, last window
+ * stack and alerts.
+ */
+void
+session_group_synchronize1(struct session *target, struct session *s)
+{
+	struct winlinks		 old_windows, *ww;
+	struct winlink_stack	 old_lastw;
+	struct winlink		*wl, *wl2;
+	struct session_alert	*sa;
+
+	/* Don't do anything if the session is empty (it'll be destroyed). */
+	ww = &target->windows;
+	if (RB_EMPTY(ww))
+		return;
+
+	/* If the current window has vanished, move to the next now. */
+	if (s->curw != NULL) {
+		while (winlink_find_by_index(ww, s->curw->idx) == NULL)
+			session_next(s, 0);
+	}
+
+	/* Save the old pointer and reset it. */
+	memcpy(&old_windows, &s->windows, sizeof old_windows);
+	RB_INIT(&s->windows);
+
+	/* Link all the windows from the target. */
+	RB_FOREACH(wl, winlinks, ww)
+		winlink_add(&s->windows, wl->window, wl->idx);
+
+	/* Fix up the current window. */
+	if (s->curw != NULL)
+		s->curw = winlink_find_by_index(&s->windows, s->curw->idx);
+	else
+		s->curw = winlink_find_by_index(&s->windows, target->curw->idx);
+
+	/* Fix up the last window stack. */
+	memcpy(&old_lastw, &s->lastw, sizeof old_lastw);
+	TAILQ_INIT(&s->lastw);
+	TAILQ_FOREACH(wl, &old_lastw, sentry) {
+		wl2 = winlink_find_by_index(&s->windows, wl->idx);
+		if (wl2 != NULL)
+			TAILQ_INSERT_TAIL(&s->lastw, wl2, sentry);
+	}
+
+	/* And update the alerts list. */
+	SLIST_FOREACH(sa, &s->alerts, entry) {
+		wl = winlink_find_by_index(&s->windows, sa->wl->idx);
+		if (wl == NULL)
+			session_alert_cancel(s, sa->wl);
+		else
+			sa->wl = wl;
+	}
+
+	/* Then free the old winlinks list. */
+	while (!RB_EMPTY(&old_windows)) {
+		wl = RB_ROOT(&old_windows);
+		RB_REMOVE(winlinks, &old_windows, wl);
+		xfree(wl);
+	}
+}