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| author | Thirunarayanan Balathandayuthapani <thirunarayanan.balathandayuth@oracle.com> | 2015-03-24 14:09:18 +0530 |
|---|---|---|
| committer | Thirunarayanan Balathandayuthapani <thirunarayanan.balathandayuth@oracle.com> | 2015-03-24 14:09:18 +0530 |
| commit | f8eacccf2a56e86ed5c6413481d5ea918b9eca1d (patch) | |
| tree | f7dba1b06defacd4e0840cf25d3e5d51579b487d /storage | |
| parent | 26e845c19d5387a13cf30c9bd6c58e9e819fb2b2 (diff) | |
| download | mariadb-git-f8eacccf2a56e86ed5c6413481d5ea918b9eca1d.tar.gz | |
Bug#20422680 BUF_POOL_WATCH_SET WOULD CRASH TRYING
TO USE A SECOND WATCH PAGE PER INSTANCE
Description:
BUF_POOL_WATCH_SIZE is also initialized to number of purge threads.
so BUF_POOL_WATCH_SIZE will never be lesser than number of purge threads.
From the code, there is no scope for purge thread to skip buf_pool_watch_unset.
So there can be at most one buffer pool watch active per purge thread.
In other words, there is no chance for purge thread instance to hold a watch
when setting another watch.
Solution:
Adding code comments to clarify the issue.
Reviewed-by: Marko Mäkelä <marko.makela@oracle.com>
Approved via Bug page.
Diffstat (limited to 'storage')
| -rw-r--r-- | storage/innobase/buf/buf0buf.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/storage/innobase/buf/buf0buf.c b/storage/innobase/buf/buf0buf.c index b6bfcc3dbc0..4963f1c30c3 100644 --- a/storage/innobase/buf/buf0buf.c +++ b/storage/innobase/buf/buf0buf.c @@ -1,6 +1,6 @@ /***************************************************************************** -Copyright (c) 1995, 2014, Oracle and/or its affiliates. All Rights Reserved. +Copyright (c) 1995, 2015, Oracle and/or its affiliates. All Rights Reserved. Copyright (c) 2008, Google Inc. Portions of this file contain modifications contributed and copyrighted by @@ -1528,6 +1528,9 @@ buf_pool_watch_set( return(NULL); } + /* The maximum number of purge threads should never exceed + BUF_POOL_WATCH_SIZE. So there is no way for purge thread + instance to hold a watch when setting another watch. */ for (i = 0; i < BUF_POOL_WATCH_SIZE; i++) { bpage = &buf_pool->watch[i]; |