Add some DIAGNOSTIC checks that panic on some of the common mistakes.

1 files changed, 31 insertions, 7 deletions

diff --git a/sys/kern/kern_timeout.c b/sys/kern/kern_timeout.c
index 04e74fd62c2..a314e2e77e6 100644
--- a/sys/kern/kern_timeout.c
+++ b/sys/kern/kern_timeout.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_timeout.c,v 1.7 2001/03/15 16:47:50 csapuntz Exp $	*/
+/*	$OpenBSD: kern_timeout.c,v 1.8 2001/03/28 07:33:51 art Exp $	*/
 /*
  * Copyright (c) 2000 Artur Grabowski <art@openbsd.org>
  * All rights reserved. 
@@ -92,15 +92,34 @@ timeout_init()
 }
 
 void
-timeout_set(to, fn, arg)
-	struct timeout *to;
+timeout_set(new, fn, arg)
+	struct timeout *new;
 	void (*fn)(void *);
 	void *arg;
 {
 
-	to->to_func = fn;
-	to->to_arg = arg;
-	to->to_flags = TIMEOUT_INITIALIZED;
+#ifdef DIAGNOSTIC
+	struct timeout *to;
+	int s;
+
+	/*
+	 * Be careful. We could be called with random non-zero memory, but
+	 * on the other hand we could be called with a timeout that's
+	 * already queued.
+	 * XXX - this is expensive.
+	 */
+	timeout_list_lock(&s);
+	if (new->to_flags & TIMEOUT_ONQUEUE) {
+		TAILQ_FOREACH(to, &timeout_todo, to_list)
+			if (to == new)
+				panic("timeout_set: on queue");
+	}
+	timeout_list_unlock(s);
+#endif
+
+	new->to_func = fn;
+	new->to_arg = arg;
+	new->to_flags = TIMEOUT_INITIALIZED;
 }
 
 void
@@ -116,6 +135,8 @@ timeout_add(new, to_ticks)
 	 */
 
 #ifdef DIAGNOSTIC
+	if (!(new->to_flags & TIMEOUT_INITIALIZED))
+		panic("timeout_add: not initialized");
 	if (to_ticks < 0)
 		panic("timeout_add: to_ticks < 0");
 #endif
@@ -198,7 +219,10 @@ softclock()
 	timeout_list_lock(&s);
 	while ((to = TAILQ_FIRST(&timeout_todo)) != NULL &&
 	       to->to_time - ticks <= 0) {
-
+#ifdef DIAGNOSTIC
+		if (!(to->to_flags & TIMEOUT_ONQUEUE))
+			panic("softclock: not onqueue");
+#endif
 		TAILQ_REMOVE(&timeout_todo, to, to_list);
 		to->to_flags &= ~TIMEOUT_ONQUEUE;
 		to->to_flags |= TIMEOUT_TRIGGERED;