Rewrite command queue handling. Each client still has a command queue,

but there is also now a global command queue. Instead of command queues
being dispatched on demand from wherever the command happens to be
added, they are now all dispatched from the top level server
loop. Command queues may now also include callbacks as well as commands,
and items may be inserted after the current command as well as at the end.

This all makes command queues significantly more predictable and easier
to use, and avoids the complex multiple nested command queues used by
source-file, if-shell and friends.

A mass rename of struct cmdq to a better name (cmdq_item probably) is
coming.

1 files changed, 25 insertions, 45 deletions

diff --git a/cfg.c b/cfg.c
index 801056db..62cca179 100644
--- a/cfg.c
+++ b/cfg.c
@@ -29,14 +29,25 @@
 #include "tmux.h"
 
 char			 *cfg_file;
-static struct cmd_q	 *cfg_cmd_q;
 int			  cfg_finished;
-int			  cfg_references;
 static char		**cfg_causes;
 static u_int		  cfg_ncauses;
 struct client		 *cfg_client;
 
-static void	  cfg_default_done(struct cmd_q *);
+static enum cmd_retval
+cfg_done(__unused struct cmd_q *cmdq, __unused void *data)
+{
+	if (cfg_finished)
+		return (CMD_RETURN_NORMAL);
+	cfg_finished = 1;
+
+	if (!RB_EMPTY(&sessions))
+		cfg_show_causes(RB_MIN(sessions, &sessions));
+
+	if (cfg_client != NULL)
+		server_client_unref(cfg_client);
+	return (CMD_RETURN_NORMAL);
+}
 
 void
 set_cfg_file(const char *path)
@@ -51,30 +62,24 @@ start_cfg(void)
 	const char	*home;
 	int		 quiet = 0;
 
-	cfg_cmd_q = cmdq_new(NULL);
-	cfg_cmd_q->emptyfn = cfg_default_done;
-
-	cfg_finished = 0;
-	cfg_references = 1;
-
 	cfg_client = TAILQ_FIRST(&clients);
 	if (cfg_client != NULL)
 		cfg_client->references++;
 
-	load_cfg(TMUX_CONF, cfg_cmd_q, 1);
+	load_cfg(TMUX_CONF, cfg_client, NULL, 1);
 
 	if (cfg_file == NULL && (home = find_home()) != NULL) {
 		xasprintf(&cfg_file, "%s/.tmux.conf", home);
 		quiet = 1;
 	}
 	if (cfg_file != NULL)
-		load_cfg(cfg_file, cfg_cmd_q, quiet);
+		load_cfg(cfg_file, cfg_client, NULL, quiet);
 
-	cmdq_continue(cfg_cmd_q);
+	cmdq_append(cfg_client, cmdq_get_callback(cfg_done, NULL));
 }
 
 int
-load_cfg(const char *path, struct cmd_q *cmdq, int quiet)
+load_cfg(const char *path, struct client *c, struct cmd_q *cmdq, int quiet)
 {
 	FILE		*f;
 	char		 delim[3] = { '\\', '\\', '\0' };
@@ -82,6 +87,7 @@ load_cfg(const char *path, struct cmd_q *cmdq, int quiet)
 	size_t		 line = 0;
 	char		*buf, *cause1, *p;
 	struct cmd_list	*cmdlist;
+	struct cmd_q	*new_cmdq;
 
 	log_debug("loading %s", path);
 	if ((f = fopen(path, "rb")) == NULL) {
@@ -117,8 +123,13 @@ load_cfg(const char *path, struct cmd_q *cmdq, int quiet)
 
 		if (cmdlist == NULL)
 			continue;
-		cmdq_append(cmdq, cmdlist, NULL);
+		new_cmdq = cmdq_get_command(cmdlist, NULL, NULL, 0);
+		if (cmdq != NULL)
+			cmdq_insert_after(cmdq, new_cmdq);
+		else
+			cmdq_append(c, new_cmdq);
 		cmd_list_free(cmdlist);
+
 		found++;
 	}
 	fclose(f);
@@ -126,37 +137,6 @@ load_cfg(const char *path, struct cmd_q *cmdq, int quiet)
 	return (found);
 }
 
-static void
-cfg_default_done(__unused struct cmd_q *cmdq)
-{
-	log_debug("%s: %u references%s", __func__, cfg_references,
-	    cfg_finished ? " (finished)" : "");
-
-	if (cfg_finished || --cfg_references != 0)
-		return;
-	cfg_finished = 1;
-
-	if (!RB_EMPTY(&sessions))
-		cfg_show_causes(RB_MIN(sessions, &sessions));
-
-	cmdq_free(cfg_cmd_q);
-	cfg_cmd_q = NULL;
-
-	if (cfg_client != NULL) {
-		/*
-		 * The client command queue starts with client_exit set to 1 so
-		 * only continue if not empty (that is, we have been delayed
-		 * during configuration parsing for long enough that the
-		 * MSG_COMMAND has arrived), else the client will exit before
-		 * the MSG_COMMAND which might tell it not to.
-		 */
-		if (!TAILQ_EMPTY(&cfg_client->cmdq->queue))
-			cmdq_continue(cfg_client->cmdq);
-		server_client_unref(cfg_client);
-		cfg_client = NULL;
-	}
-}
-
 void
 cfg_add_cause(const char *fmt, ...)
 {