bucket debugging. a series of consistency checks for bucket brigades.

to enable, define APR_BUCKET_DEBUG at compile time.  it was suggested that
I should have a --enable-bucket-debug configure option instead, but because
of the way we use APR's rules.mk, it's difficult to add extra CPPFLAGS from
apr-util's configure.in.


git-svn-id: http://svn.apache.org/repos/asf/apr/apr-util/trunk@58918 13f79535-47bb-0310-9956-ffa450edef68

2 files changed, 27 insertions, 0 deletions

diff --git a/buckets/apr_brigade.c b/buckets/apr_brigade.c
index 388b9ae0..eae58f8d 100644
--- a/buckets/apr_brigade.c
+++ b/buckets/apr_brigade.c
@@ -127,6 +127,10 @@ APU_DECLARE(apr_bucket_brigade *) apr_brigade_split(apr_bucket_brigade *b,
         APR_RING_UNSPLICE(e, f, link);
         APR_RING_SPLICE_HEAD(&a->list, e, f, apr_bucket, link);
     }
+
+    APR_BRIGADE_CHECK_CONSISTENCY(a);
+    APR_BRIGADE_CHECK_CONSISTENCY(b);
+
     return a;
 }
 
@@ -148,6 +152,8 @@ APU_DECLARE(apr_status_t) apr_brigade_partition(apr_bucket_brigade *b,
         return APR_SUCCESS;
     }
 
+    APR_BRIGADE_CHECK_CONSISTENCY(b);
+
     APR_BRIGADE_FOREACH(e, b) {
         if ((e->length == (apr_size_t)(-1)) && (point > (apr_size_t)(-1))) {
             /* XXX: point is too far out to simply split this bucket,
diff --git a/buckets/apr_buckets_alloc.c b/buckets/apr_buckets_alloc.c
index ccad531e..884b5347 100644
--- a/buckets/apr_buckets_alloc.c
+++ b/buckets/apr_buckets_alloc.c
@@ -151,12 +151,33 @@ APU_DECLARE_NONSTD(void *) apr_bucket_alloc(apr_size_t size,
     return ((char *)node) + SIZEOF_NODE_HEADER_T;
 }
 
+#ifdef APR_BUCKET_DEBUG
+#if APR_HAVE_STDLIB_H
+#include <stdlib.h>
+#endif
+static void check_not_already_free(node_header_t *node)
+{
+    apr_bucket_alloc_t *list = node->alloc;
+    node_header_t *curr = list->freelist;
+
+    while (curr) {
+        if (node == curr) {
+            abort();
+        }
+        curr = curr->next;
+    }
+}
+#else
+#define check_not_already_free(node)
+#endif
+
 APU_DECLARE_NONSTD(void) apr_bucket_free(void *mem)
 {
     node_header_t *node = (node_header_t *)((char *)mem - SIZEOF_NODE_HEADER_T);
     apr_bucket_alloc_t *list = node->alloc;
 
     if (node->size == SMALL_NODE_SIZE) {
+        check_not_already_free(node);
         node->next = list->freelist;
         list->freelist = node;
     }