mirror/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-01-22 06:44:16 +01:00
Code Issues Projects Releases Packages Wiki Activity Actions

branches/zip: buf_LRU_free_block(): When buf_page_is_old(b), we incremented

Browse source 
buf_pool->LRU_old_len.  However, we forgot to check if buf_pool->LRU_old
happens to point to b's successor in the LRU list.  If it does, we must
assign buf_pool->LRU_old = b.  The following invariants hold:

In the LRU list, the "old" flag should grow monotonically, i.e., it is 0
for the first few items and 1 from thereafter.

If buf_pool->LRU_old != NULL, it must point to the first item with old=1
in the LRU list, and there must be buf_pool->LRU_old_len old items in the list.

This should fix Mantis issue#50 and issue#68.
This commit is contained in:
marko 2008-08-08 13:01:02 +00:00
parent 9bbd5454db
commit 7d69d45534
2 changed files with 12 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
buf/buf0lru.c
View file

@ -1246,6 +1246,12 @@ alloc:
if (buf_page_is_old(b)) {
buf_pool->LRU_old_len++;
if (UNIV_UNLIKELY
(buf_pool->LRU_old
== UT_LIST_GET_NEXT(LRU, b))) {
buf_pool->LRU_old = b;
}
}
lru_len = UT_LIST_GET_LEN(buf_pool->LRU);

8
include/buf0buf.h
View file

@ -1277,13 +1277,17 @@ struct buf_pool_struct{
/* base node of the LRU list */
buf_page_t* LRU_old; /* pointer to the about 3/8 oldest
blocks in the LRU list; NULL if LRU
length less than BUF_LRU_OLD_MIN_LEN */
length less than BUF_LRU_OLD_MIN_LEN;
NOTE: when LRU_old != NULL, its length
should always equal LRU_old_len */
ulint LRU_old_len; /* length of the LRU list from
the block to which LRU_old points
onward, including that block;
see buf0lru.c for the restrictions
on this value; not defined if
LRU_old == NULL */
LRU_old == NULL;
NOTE: LRU_old_len must be adjusted
whenever LRU_old shrinks or grows! */
UT_LIST_BASE_NODE_T(buf_block_t) unzip_LRU;
/* base node of the unzip_LRU list */