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, 33 insertions, 13 deletions

diff --git a/usr.bin/tmux/server-client.c b/usr.bin/tmux/server-client.c
index 149fba0e2d3..243e8233ea4 100644
--- a/usr.bin/tmux/server-client.c
+++ b/usr.bin/tmux/server-client.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: server-client.c,v 1.193 2016/10/12 13:03:27 nicm Exp $ */
+/* $OpenBSD: server-client.c,v 1.194 2016/10/16 17:55:14 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -126,8 +126,7 @@ server_client_create(int fd)
 	c->fd = -1;
 	c->cwd = NULL;
 
-	c->cmdq = cmdq_new(c);
-	c->cmdq->client_exit = 1;
+	TAILQ_INIT(&c->queue);
 
 	c->stdin_data = evbuffer_new();
 	c->stdout_data = evbuffer_new();
@@ -244,10 +243,6 @@ server_client_lost(struct client *c)
 	free(c->prompt_string);
 	free(c->prompt_buffer);
 
-	c->cmdq->flags |= CMD_Q_DEAD;
-	cmdq_free(c->cmdq);
-	c->cmdq = NULL;
-
 	environ_free(c->environ);
 
 	proc_remove_peer(c->peer);
@@ -281,6 +276,9 @@ server_client_free(__unused int fd, __unused short events, void *arg)
 
 	log_debug("free client %p (%d references)", c, c->references);
 
+	if (!TAILQ_EMPTY(&c->queue))
+		fatalx("queue not empty");
+
 	if (c->references == 0)
 		free(c);
 }
@@ -1254,6 +1252,29 @@ server_client_dispatch(struct imsg *imsg, void *arg)
 	}
 }
 
+/* Callback when command is done. */
+static enum cmd_retval
+server_client_command_done(struct cmd_q *cmdq, __unused void *data)
+{
+	struct client	*c = cmdq->client;
+
+	if (~c->flags & CLIENT_ATTACHED)
+		c->flags |= CLIENT_EXIT;
+	return (CMD_RETURN_NORMAL);
+}
+
+/* Show an error message. */
+static enum cmd_retval
+server_client_command_error(struct cmd_q *cmdq, void *data)
+{
+	char	*error = data;
+
+	cmdq_error(cmdq, "%s", error);
+	free(error);
+
+	return (CMD_RETURN_NORMAL);
+}
+
 /* Handle command message. */
 static void
 server_client_dispatch_command(struct client *c, struct imsg *imsg)
@@ -1276,7 +1297,7 @@ server_client_dispatch_command(struct client *c, struct imsg *imsg)
 
 	argc = data.argc;
 	if (cmd_unpack_argv(buf, len, argc, &argv) != 0) {
-		cmdq_error(c->cmdq, "command too long");
+		cause = xstrdup("command too long");
 		goto error;
 	}
 
@@ -1287,20 +1308,19 @@ server_client_dispatch_command(struct client *c, struct imsg *imsg)
 	}
 
 	if ((cmdlist = cmd_list_parse(argc, argv, NULL, 0, &cause)) == NULL) {
-		cmdq_error(c->cmdq, "%s", cause);
 		cmd_free_argv(argc, argv);
 		goto error;
 	}
 	cmd_free_argv(argc, argv);
 
-	if (c != cfg_client || cfg_finished)
-		cmdq_run(c->cmdq, cmdlist, NULL);
-	else
-		cmdq_append(c->cmdq, cmdlist, NULL);
+	cmdq_append(c, cmdq_get_command(cmdlist, NULL, NULL, 0));
+	cmdq_append(c, cmdq_get_callback(server_client_command_done, NULL));
 	cmd_list_free(cmdlist);
 	return;
 
 error:
+	cmdq_append(c, cmdq_get_callback(server_client_command_error, cause));
+
 	if (cmdlist != NULL)
 		cmd_list_free(cmdlist);