Change wait-for to work when the signal comes before the wait, also use

some helper functions and add some logging.

1 files changed, 71 insertions, 36 deletions

diff --git a/usr.bin/tmux/cmd-wait-for.c b/usr.bin/tmux/cmd-wait-for.c
index 8358b5cdbbe..2bdbd594c14 100644
--- a/usr.bin/tmux/cmd-wait-for.c
+++ b/usr.bin/tmux/cmd-wait-for.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-wait-for.c,v 1.7 2014/10/20 22:29:25 nicm Exp $ */
+/* $OpenBSD: cmd-wait-for.c,v 1.8 2015/09/04 12:02:44 nicm Exp $ */
 
 /*
  * Copyright (c) 2013 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -41,6 +41,7 @@ const struct cmd_entry cmd_wait_for_entry = {
 struct wait_channel {
 	const char	       *name;
 	int			locked;
+	int			woken;
 
 	TAILQ_HEAD(, cmd_q)	waiters;
 	TAILQ_HEAD(, cmd_q)	lockers;
@@ -69,8 +70,49 @@ enum cmd_retval	cmd_wait_for_lock(struct cmd_q *, const char *,
 enum cmd_retval	cmd_wait_for_unlock(struct cmd_q *, const char *,
 		    struct wait_channel *);
 
+struct wait_channel	*cmd_wait_for_add(const char *);
+void			 cmd_wait_for_remove(struct wait_channel *wc);
+
+struct wait_channel *
+cmd_wait_for_add(const char *name)
+{
+	struct wait_channel *wc;
+
+	wc = xmalloc(sizeof *wc);
+	wc->name = xstrdup(name);
+
+	wc->locked = 0;
+	wc->woken = 0;
+
+	TAILQ_INIT(&wc->waiters);
+	TAILQ_INIT(&wc->lockers);
+
+	RB_INSERT(wait_channels, &wait_channels, wc);
+
+	log_debug("add wait channel %s", wc->name);
+
+	return (wc);
+}
+
+void
+cmd_wait_for_remove(struct wait_channel *wc)
+{
+
+	if (wc->locked)
+		return;
+	if (!TAILQ_EMPTY(&wc->waiters) || !wc->woken)
+		return;
+
+	log_debug("remove wait channel %s", wc->name);
+
+	RB_REMOVE(wait_channels, &wait_channels, wc);
+
+	free((void *)wc->name);
+	free(wc);
+}
+
 enum cmd_retval
-cmd_wait_for_exec(struct cmd *self, struct cmd_q *cmdq)
+cmd_wait_for_exec(struct cmd *self, unused struct cmd_q *cmdq)
 {
 	struct args     	*args = self->args;
 	const char		*name = args->argv[0];
@@ -89,15 +131,20 @@ cmd_wait_for_exec(struct cmd *self, struct cmd_q *cmdq)
 }
 
 enum cmd_retval
-cmd_wait_for_signal(struct cmd_q *cmdq, const char *name,
+cmd_wait_for_signal(unused struct cmd_q *cmdq, const char *name,
     struct wait_channel *wc)
 {
 	struct cmd_q	*wq, *wq1;
 
-	if (wc == NULL || TAILQ_EMPTY(&wc->waiters)) {
-		cmdq_error(cmdq, "no waiting clients on %s", name);
-		return (CMD_RETURN_ERROR);
+	if (wc == NULL)
+		wc = cmd_wait_for_add(name);
+
+	if (TAILQ_EMPTY(&wc->waiters) && !wc->woken) {
+		log_debug("signal wait channel %s, no waiters", wc->name);
+		wc->woken = 1;
+		return (CMD_RETURN_NORMAL);
 	}
+	log_debug("signal wait channel %s, with waiters", wc->name);
 
 	TAILQ_FOREACH_SAFE(wq, &wc->waiters, waitentry, wq1) {
 		TAILQ_REMOVE(&wc->waiters, wq, waitentry);
@@ -105,12 +152,7 @@ cmd_wait_for_signal(struct cmd_q *cmdq, const char *name,
 			cmdq_continue(wq);
 	}
 
-	if (!wc->locked) {
-		RB_REMOVE(wait_channels, &wait_channels, wc);
-		free((void *)wc->name);
-		free(wc);
-	}
-
+	cmd_wait_for_remove(wc);
 	return (CMD_RETURN_NORMAL);
 }
 
@@ -118,19 +160,23 @@ enum cmd_retval
 cmd_wait_for_wait(struct cmd_q *cmdq, const char *name,
     struct wait_channel *wc)
 {
-	if (cmdq->client == NULL || cmdq->client->session != NULL) {
+	struct client	*c = cmdq->client;
+
+	if (c == NULL || c->session != NULL) {
 		cmdq_error(cmdq, "not able to wait");
 		return (CMD_RETURN_ERROR);
 	}
 
-	if (wc == NULL) {
-		wc = xmalloc(sizeof *wc);
-		wc->name = xstrdup(name);
-		wc->locked = 0;
-		TAILQ_INIT(&wc->waiters);
-		TAILQ_INIT(&wc->lockers);
-		RB_INSERT(wait_channels, &wait_channels, wc);
+	if (wc == NULL)
+		wc = cmd_wait_for_add(name);
+
+	if (wc->woken) {
+		log_debug("wait channel %s already woken (client %d)", wc->name,
+		    c->tty.fd);
+		cmd_wait_for_remove(wc);
+		return (CMD_RETURN_NORMAL);
 	}
+	log_debug("wait channel %s not woken (client %d)", wc->name, c->tty.fd);
 
 	TAILQ_INSERT_TAIL(&wc->waiters, cmdq, waitentry);
 	cmdq->references++;
@@ -147,14 +193,8 @@ cmd_wait_for_lock(struct cmd_q *cmdq, const char *name,
 		return (CMD_RETURN_ERROR);
 	}
 
-	if (wc == NULL) {
-		wc = xmalloc(sizeof *wc);
-		wc->name = xstrdup(name);
-		wc->locked = 0;
-		TAILQ_INIT(&wc->waiters);
-		TAILQ_INIT(&wc->lockers);
-		RB_INSERT(wait_channels, &wait_channels, wc);
-	}
+	if (wc == NULL)
+		wc = cmd_wait_for_add(name);
 
 	if (wc->locked) {
 		TAILQ_INSERT_TAIL(&wc->lockers, cmdq, waitentry);
@@ -183,11 +223,7 @@ cmd_wait_for_unlock(struct cmd_q *cmdq, const char *name,
 			cmdq_continue(wq);
 	} else {
 		wc->locked = 0;
-		if (TAILQ_EMPTY(&wc->waiters)) {
-			RB_REMOVE(wait_channels, &wait_channels, wc);
-			free((void *)wc->name);
-			free(wc);
-		}
+		cmd_wait_for_remove(wc);
 	}
 
 	return (CMD_RETURN_NORMAL);
@@ -210,8 +246,7 @@ cmd_wait_for_flush(void)
 			if (!cmdq_free(wq))
 				cmdq_continue(wq);
 		}
-		RB_REMOVE(wait_channels, &wait_channels, wc);
-		free((void *)wc->name);
-		free(wc);
+		wc->locked = 0;
+		cmd_wait_for_remove(wc);
 	}
 }