database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-12-24 11:21:21 +03:00
Code Activity

Making FLUSH TABLES WITH READ LOCK block COMMITs of existing transactions,

Browse Source 
in a deadlock-free manner. This splits locking the global read lock in two steps.
This fixes a consequence of this bug, known as:
BUG#4953 'mysqldump --master-data may report incorrect binlog position if using InnoDB'
And a test.


sql/handler.cc:
  making COMMIT wait if FLUSH TABLES WITH READ LOCK happened.
sql/lock.cc:
  an additional stage so that FLUSH TABLES WITH READ LOCK blocks COMMIT:
  make_global_read_lock_block_commit():
  taking the global read lock is TWO steps (2nd step is optional; without
  it, COMMIT of existing transactions will be allowed):
  lock_global_read_lock() THEN make_global_read_lock_block_commit().
sql/mysql_priv.h:
  new argument to wait_if_global_read_lock()
sql/sql_class.h:
  THD::global_read_lock now an uint to reflect the 2 steps of global read lock (does not block COMMIT / does)
sql/sql_db.cc:
  update for new prototype
sql/sql_parse.cc:
  implementing the two steps of global read lock so that FLUSH TABLES WITH READ LOCK can block COMMIT without deadlocking with COMMITs.
This commit is contained in:
unknown
2004-08-20 16:35:23 +02:00
parent f758ada4bc
commit cd8054d431
9 changed files with 154 additions and 21 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
sql/sql_parse.cc
View File

@@ -3708,8 +3708,12 @@ bool reload_acl_and_cache(THD *thd, ulong options, TABLE_LIST *tables)
{
if (lock_global_read_lock(thd))
return 1;
result=close_cached_tables(thd,(options & REFRESH_FAST) ? 0 : 1,
tables);
make_global_read_lock_block_commit(thd);
}
result=close_cached_tables(thd,(options & REFRESH_FAST) ? 0 : 1, tables);
else
result=close_cached_tables(thd,(options & REFRESH_FAST) ? 0 : 1, tables);
}
if (options & REFRESH_HOSTS)
hostname_cache_refresh();