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ha_innodb.cc:

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Weaken InnoDB table locking at the start of a stored procedure call: this will make multi-transaction stored procedures less deterministic for binlogging, but since they are non-deterministic anyway, it is not that bad; this fix will remove the huge amount of InnoDB tranasctional deadlocks caused by table locking at the start of a stored procedure
This commit is contained in:
heikki@hundin.mysql.fi
2005-06-02 18:10:32 +03:00
parent cdb1474dae
commit 894de1686a
1 changed files with 19 additions and 3 deletions
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22
sql/ha_innodb.cc
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@ -5963,11 +5963,14 @@ ha_innobase::external_lock(
TABLES if AUTOCOMMIT=1. It does not make much sense to acquire
an InnoDB table lock if it is released immediately at the end
of LOCK TABLES, and InnoDB's table locks in that case cause
VERY easily deadlocks. */
VERY easily deadlocks. We do not set InnoDB table locks when
MySQL sets them at the start of a stored procedure call
(MySQL does have thd->in_lock_tables TRUE there). */
if (prebuilt->select_lock_type != LOCK_NONE) {
if (thd->in_lock_tables &&
thd->lex->sql_command != SQLCOM_CALL &&
thd->variables.innodb_table_locks &&
(thd->options & OPTION_NOT_AUTOCOMMIT)) {
@ -6478,11 +6481,21 @@ ha_innobase::store_lock(
if (lock_type != TL_IGNORE && lock.type == TL_UNLOCK) {
/* Starting from 5.0.7, we weaken also the table locks
set at the start of a MySQL stored procedure call, just like
we weaken the locks set at the start of an SQL statement.
MySQL does set thd->in_lock_tables TRUE there, but in reality
we do not need table locks to make the execution of a
single transaction stored procedure call deterministic
(if it does not use a consistent read). */
/* If we are not doing a LOCK TABLE or DISCARD/IMPORT
TABLESPACE or TRUNCATE TABLE, then allow multiple writers */
if ((lock_type >= TL_WRITE_CONCURRENT_INSERT &&
lock_type <= TL_WRITE) && !thd->in_lock_tables
lock_type <= TL_WRITE)
&& (!thd->in_lock_tables
|| thd->lex->sql_command == SQLCOM_CALL)
&& !thd->tablespace_op
&& thd->lex->sql_command != SQLCOM_TRUNCATE
&& thd->lex->sql_command != SQLCOM_CREATE_TABLE) {
@ -6496,7 +6509,10 @@ ha_innobase::store_lock(
to t2. Convert the lock to a normal read lock to allow
concurrent inserts to t2. */
if (lock_type == TL_READ_NO_INSERT && !thd->in_lock_tables) {
if (lock_type == TL_READ_NO_INSERT
&& (!thd->in_lock_tables
|| thd->lex->sql_command == SQLCOM_CALL)) {
lock_type = TL_READ;
}