From 2a9014d545d81f119e073bff0eac53269aa7ce5e Mon Sep 17 00:00:00 2001
From: sunny <Unknown>
Date: Mon, 20 Aug 2007 21:48:16 +0000
Subject: [PATCH] Add variable "innodb_autoinc_lock_mode" to control the
behavior of the AUTOINC locking. There are three modes, 0 for backward
compatibility, 1 for the new style locking (default, safe for statement-based
replication) and 2 for no AUTOINC locking (unsafe for statement-based
replication).
---
handler/ha_innodb.cc | 80 +++++++++++++++++++++++++++++++++++---------
1 file changed, 65 insertions(+), 15 deletions(-)
diff --git a/handler/ha_innodb.cc b/handler/ha_innodb.cc
index a912c17e1e..f594925e38 100644
--- a/handler/ha_innodb.cc
+++ b/handler/ha_innodb.cc
@@ -92,11 +92,15 @@ extern "C" {
#include "../storage/innobase/include/ha_prototypes.h"
}
+static const long AUTOINC_OLD_STYLE_LOCKING = 0;
+static const long AUTOINC_NEW_STYLE_LOCKING = 1;
+static const long AUTOINC_NO_LOCKING = 2;
+
static long innobase_mirrored_log_groups, innobase_log_files_in_group,
innobase_log_buffer_size, innobase_buffer_pool_awe_mem_mb,
innobase_additional_mem_pool_size, innobase_file_io_threads,
innobase_lock_wait_timeout, innobase_force_recovery,
- innobase_open_files;
+ innobase_open_files, innobase_autoinc_lock_mode;
static long long innobase_buffer_pool_size, innobase_log_file_size;
@@ -3358,24 +3362,46 @@ ha_innobase::innobase_autoinc_lock(void)
{
ulint error = DB_SUCCESS;
- if (thd_sql_command(user_thd) == SQLCOM_INSERT) {
+ switch (innobase_autoinc_lock_mode) {
+ case AUTOINC_NO_LOCKING:
+ /* Acquire only the AUTOINC mutex. */
dict_table_autoinc_lock(prebuilt->table);
+ break;
- /* We peek at the dict_table_t::auto_inc_lock to check if
- another statement has locked it */
- if (prebuilt->trx->auto_inc_lock != NULL) {
- /* Release the mutex to avoid deadlocks */
- dict_table_autoinc_unlock(prebuilt->table);
+ case AUTOINC_NEW_STYLE_LOCKING:
+ /* For simple (single/multi) row INSERTs, we fallback to the
+ old style only if another transaction has already acquired
+ the AUTOINC lock on behalf of a LOAD FILE or INSERT ... SELECT
+ etc. type of statement. */
+ if (thd_sql_command(user_thd) == SQLCOM_INSERT) {
+
+ /* Acquire the AUTOINC mutex. */
+ dict_table_autoinc_lock(prebuilt->table);
+
+ /* We peek at the dict_table_t::auto_inc_lock
+ to check if another statement has locked it. */
+ if (prebuilt->trx->auto_inc_lock != NULL) {
- goto acquire_auto_inc_lock;
+ /* Release the mutex to avoid deadlocks. */
+ dict_table_autoinc_unlock(prebuilt->table);
+ } else {
+ break;
+ }
}
- } else {
-acquire_auto_inc_lock:
+ /* Fall through to old style locking. */
+
+ case AUTOINC_OLD_STYLE_LOCKING:
error = row_lock_table_autoinc_for_mysql(prebuilt);
if (error == DB_SUCCESS) {
+
+ /* Acquire the AUTOINC mutex. */
dict_table_autoinc_lock(prebuilt->table);
}
+ break;
+
+ default:
+ ut_error;
}
return(ulong(error));
@@ -3615,6 +3641,7 @@ no_commit:
if (auto_inc > prebuilt->last_value) {
set_max_autoinc:
+ ut_a(prebuilt->table->autoinc_increment > 0);
auto_inc += prebuilt->table->autoinc_increment;
innobase_set_max_autoinc(auto_inc);
@@ -7416,13 +7443,24 @@ ha_innobase::get_auto_increment(
*nb_reserved_values = prebuilt->trx->n_autoinc_rows;
- /* Compute the last value in the interval */
- prebuilt->last_value = *first_value + (*nb_reserved_values * increment);
+ /* With old style AUTOINC locking we only update the table's
+ AUTOINC counter after attempting to insert the row. */
+ if (innobase_autoinc_lock_mode != AUTOINC_OLD_STYLE_LOCKING) {
- ut_a(prebuilt->last_value >= *first_value);
+ /* Compute the last value in the interval */
+ prebuilt->last_value = *first_value +
+ (*nb_reserved_values * increment);
- /* Update the table autoinc variable */
- dict_table_autoinc_update(prebuilt->table, prebuilt->last_value);
+ ut_a(prebuilt->last_value >= *first_value);
+
+ /* Update the table autoinc variable */
+ dict_table_autoinc_update(
+ prebuilt->table, prebuilt->last_value);
+ } else {
+ /* This will force write_row() into attempting an update
+ of the table's AUTOINC counter. */
+ prebuilt->last_value = 0;
+ }
/* The increment to be used to increase the AUTOINC value, we use
this in write_row() and update_row() to increase the autoinc counter
@@ -8085,6 +8123,17 @@ static MYSQL_SYSVAR_STR(data_file_path, innobase_data_file_path,
"Path to individual files and their sizes.",
NULL, NULL, NULL);
+static MYSQL_SYSVAR_LONG(autoinc_lock_mode, innobase_autoinc_lock_mode,
+ PLUGIN_VAR_RQCMDARG,
+ "The AUTOINC lock modes supported by InnoDB:\n"
+ " 0 => Old style AUTOINC locking (for backward compatibility)\n"
+ " 1 => New style AUTOINC locking\n"
+ " 2 => No AUTOINC locking (unsafe for SBR)",
+ NULL, NULL,
+ AUTOINC_NEW_STYLE_LOCKING, /* Default setting */
+ AUTOINC_OLD_STYLE_LOCKING, /* Minimum value */
+ AUTOINC_NO_LOCKING, 0); /* Maximum value */
+
static struct st_mysql_sys_var* innobase_system_variables[]= {
MYSQL_SYSVAR(additional_mem_pool_size),
MYSQL_SYSVAR(autoextend_increment),
@@ -8123,6 +8172,7 @@ static struct st_mysql_sys_var* innobase_system_variables[]= {
MYSQL_SYSVAR(table_locks),
MYSQL_SYSVAR(thread_concurrency),
MYSQL_SYSVAR(thread_sleep_delay),
+ MYSQL_SYSVAR(autoinc_lock_mode),
NULL
};
--
2.30.9