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| author | Sergey Vojtovich <svoj@mariadb.org> | 2014-02-13 10:44:10 +0400 |
|---|---|---|
| committer | Sergey Vojtovich <svoj@mariadb.org> | 2014-02-13 10:44:10 +0400 |
| commit | 048e9c40a661476d1b742f61d692f211acbd24d2 (patch) | |
| tree | 8f54dde52aa39fd3a5ac523764820747508b0975 /sql/table_cache.h | |
| parent | a25d87e50f2636263d03246ba8a7ca827f43c48b (diff) | |
| download | mariadb-git-048e9c40a661476d1b742f61d692f211acbd24d2.tar.gz | |
MDEV-5492 - Reduce usage of LOCK_open: TABLE::in_use
Move TABLE::in_use out of LOCK_open.
This is done with assumtion that foreign threads accessing TABLE::in_use
will only need consistent value _after_ marking table for flush and purging
unused table instances. In this case TABLE::in_use will always point to a
valid thread object.
Previously FLUSH TABLES thread may wait for tables flushed subsequently by
concurrent threads which breaks the above assumption, e.g.:
open tables: t1 (version= 1)
thr1 (FLUSH TABLES): refresh_version++
thr1 (FLUSH TABLES): purge table cache
open tables: none
thr2 (SELECT * FROM t1): open tables: t1
open tables: t1 (version= 2)
thr2 (FLUSH TABLES): refresh_version++
thr2 (FLUSH TABLES): purge table cache
thr1 (FLUSH TABLES): wait for old tables (including t1 with version 2)
It is fixed so that FLUSH TABLES waits only for tables that were open
heretofore.
Diffstat (limited to 'sql/table_cache.h')
| -rw-r--r-- | sql/table_cache.h | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/sql/table_cache.h b/sql/table_cache.h index 7b7fb239131..a30a07b8357 100644 --- a/sql/table_cache.h +++ b/sql/table_cache.h @@ -47,13 +47,14 @@ extern bool tdc_remove_table(THD *thd, enum_tdc_remove_table_type remove_type, bool kill_delayed_threads); extern int tdc_wait_for_old_version(THD *thd, const char *db, const char *table_name, - ulong wait_timeout, uint deadlock_weight); + ulong wait_timeout, uint deadlock_weight, + ulong refresh_version= ULONG_MAX); extern ulong tdc_refresh_version(void); -extern void tdc_increment_refresh_version(void); +extern ulong tdc_increment_refresh_version(void); extern void tdc_assign_new_table_id(TABLE_SHARE *share); extern uint tc_records(void); -extern void tc_purge(void); +extern void tc_purge(bool mark_flushed= false); extern void tc_add_table(THD *thd, TABLE *table); extern bool tc_release_table(TABLE *table); |