Just replaced tabs with spaces to follow guidelines.
>>> [EMAIL PROTECTED] 12/11/2003 5:00:31 PM >>>
Bugzilla Defect #21285
This is a rework of the already posted patch.
It address the following situation;
1- request comes in for streaming response
2- before that request could be completed, the entry is ejected from the cache
3- when completing the write body step, the incomplete entry is removed
before inserting the correct entry.
The problem is that the incomplete entry was already removed/replaced
in the cache. The cache_remove() will then seg fault.
I don't think it has something to do with the cache size has stated
in the bug description. I will follow with a patch removing the deprecated
cache_size and object_cnt from the mem_cache_conf struct.
@@ -1028,7 +1029,18 @@
if (sconf->lock) {
apr_thread_mutex_lock(sconf->lock);
}
- cache_remove(sconf->cache_cache, obj);
+ /* We need to check if the object has been removed/replaced
+ * from/in the cache, this could happen in some cases, because
+ * the current request is a streaming response that is handled
+ * in multiple individual pieces. - fixing Bugzilla Defect 21285
+ */
+ if((tmp_obj = (cache_object_t *) cache_find(sconf->cache_cache, obj->key)) &&
+ (tmp_obj == obj)) {
+ cache_remove(sconf->cache_cache, obj);
+ }
+ else {
+ obj->cleanup = 0;
+ }
I added the patch to the bug list of attachment.
Thank you,
Jean-Jacques
I've not had time to test this but I believe it is a bit cleaner and altogether avoids the issue of duplicate entries in the cache. What do you think?
Index: mod_mem_cache.c
===================================================================
RCS file: /home/cvs/httpd-2.0/modules/experimental/mod_mem_cache.c,v
retrieving revision 1.99
diff -u -r1.99 mod_mem_cache.c
--- mod_mem_cache.c 10 Dec 2003 03:22:32 -0000 1.99
+++ mod_mem_cache.c 16 Dec 2003 00:02:56 -0000
@@ -1043,7 +1043,25 @@
if (sconf->lock) {
apr_thread_mutex_lock(sconf->lock);
}
- cache_remove(sconf->cache_cache, obj);
+ if (obj->cleanup) {
+ /* If obj->cleanup is set, the object has been prematurly
+ * ejected from the cache by the garbage collector. Add the
+ * object back to the cache. If an object with the same key is
+ * found in the cache, eject it in favor of the completed obj.
+ */
+ cache_object_t *tmp_obj =
+ (cache_object_t *) cache_find(sconf->cache_cache, obj->key);
+ if (tmp_obj) {
+ cache_remove(sconf->cache_cache, tmp_obj);
+ sconf->object_cnt--;
+ sconf->cache_size -= mobj->m_len;
+ tmp_obj->cleanup = 1;
+ }
+ obj->cleanup = 0;
+ }
+ else {
+ cache_remove(sconf->cache_cache, obj);
+ }
mobj->m_len = obj->count;
cache_insert(sconf->cache_cache, obj);
sconf->cache_size -= (mobj->m_len - obj->count);