[src/trunk]: src/sys/sys add another QUEUEDEBUG check: in TAILQ_REMOVE(), if...

[chs <chs%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/126110410343
branches:  trunk
changeset: 538530:126110410343
user:      chs <chs%NetBSD.org@localhost>
date:      Tue Oct 22 04:50:38 2002 +0000

description:
add another QUEUEDEBUG check:  in TAILQ_REMOVE(), if the element we're
removing has no next element, verify that the queue head agrees that
the current element is the last one.  (this is how I found the recent
ppc pmap bugs).

diffstat:

 sys/sys/queue.h |  9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

diffs (37 lines):

diff -r 49304303ed92 -r 126110410343 sys/sys/queue.h
--- a/sys/sys/queue.h   Tue Oct 22 04:34:13 2002 +0000
+++ b/sys/sys/queue.h   Tue Oct 22 04:50:38 2002 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: queue.h,v 1.31 2002/06/01 23:51:05 lukem Exp $ */
+/*     $NetBSD: queue.h,v 1.32 2002/10/22 04:50:38 chs Exp $   */
 
 /*
  * Copyright (c) 1991, 1993
@@ -343,6 +343,11 @@
                panic("TAILQ_* forw %p %s:%d", (elm), __FILE__, __LINE__);\
        if (*(elm)->field.tqe_prev != (elm))                            \
                panic("TAILQ_* back %p %s:%d", (elm), __FILE__, __LINE__);
+#define QUEUEDEBUG_TAILQ_PREREMOVE(head, elm, field)                   \
+       if ((elm)->field.tqe_next == NULL &&                            \
+           (head)->tqh_last != &(elm)->field.tqe_next)                 \
+               panic("TAILQ_PREREMOVE head %p elm %p %s:%d",           \
+                     (head), (elm), __FILE__, __LINE__);
 #define QUEUEDEBUG_TAILQ_POSTREMOVE(elm, field)                                \
        (elm)->field.tqe_next = (void *)1L;                             \
        (elm)->field.tqe_prev = (void *)1L;
@@ -350,6 +355,7 @@
 #define QUEUEDEBUG_TAILQ_INSERT_HEAD(head, elm, field)
 #define QUEUEDEBUG_TAILQ_INSERT_TAIL(head, elm, field)
 #define QUEUEDEBUG_TAILQ_OP(elm, field)
+#define QUEUEDEBUG_TAILQ_PREREMOVE(head, elm, field)
 #define QUEUEDEBUG_TAILQ_POSTREMOVE(elm, field)
 #endif
 
@@ -397,6 +403,7 @@
 } while (/*CONSTCOND*/0)
 
 #define TAILQ_REMOVE(head, elm, field) do {                            \
+       QUEUEDEBUG_TAILQ_PREREMOVE((head), (elm), field)                \
        QUEUEDEBUG_TAILQ_OP((elm), field)                               \
        if (((elm)->field.tqe_next) != NULL)                            \
                (elm)->field.tqe_next->field.tqe_prev =                 \