From f0ed73d874d92bd6e21333bcba4b1097db069213 Mon Sep 17 00:00:00 2001
From: unknown <marko@hundin.mysql.fi>
Date: Wed, 13 Oct 2004 22:54:21 +0300
Subject: [PATCH] Added startup option and settable session variable
 innodb_table_locks_old_behavior: do not acquire an InnoDB table lock for LOCK
 TABLES, as in mysql-4.0.18 and earlier.

sql/ha_innodb.cc:
  Do not acquire an InnoDB table lock for LOCK TABLES if
  innodb_table_locks_old_behavior is enabled.
sql/mysqld.cc:
  Added innodb_table_locks_old_behavior
sql/set_var.cc:
  Added innodb_table_locks_old_behavior
sql/sql_class.h:
  Added innodb_table_locks_old_behavior
---
 sql/ha_innodb.cc | 3 ++-
 sql/mysqld.cc    | 7 ++++++-
 sql/set_var.cc   | 4 ++++
 sql/sql_class.h  | 3 +++
 4 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/sql/ha_innodb.cc b/sql/ha_innodb.cc
index fa9537b3217..44d050d14aa 100644
--- a/sql/ha_innodb.cc
+++ b/sql/ha_innodb.cc
@@ -4693,7 +4693,8 @@ ha_innobase::external_lock(
 		}
 
 		if (prebuilt->select_lock_type != LOCK_NONE) {
-			if (thd->in_lock_tables) {
+			if (thd->in_lock_tables &&
+			    !thd->variables.innodb_table_locks_old_behavior) {
 				ulint	error;
 				error = row_lock_table_for_mysql(prebuilt);
 
diff --git a/sql/mysqld.cc b/sql/mysqld.cc
index 89d71ecbfa2..8b478882451 100644
--- a/sql/mysqld.cc
+++ b/sql/mysqld.cc
@@ -3526,6 +3526,7 @@ enum options_mysqld {
   OPT_INNODB_FORCE_RECOVERY,
   OPT_INNODB_STATUS_FILE,
   OPT_INNODB_MAX_DIRTY_PAGES_PCT,
+  OPT_INNODB_TABLE_LOCKS_OLD_BEHAVIOR,
   OPT_BDB_CACHE_SIZE,
   OPT_BDB_LOG_BUFFER_SIZE,
   OPT_BDB_MAX_LOCK,
@@ -3699,7 +3700,11 @@ struct my_option my_long_options[] =
   {"innodb_max_dirty_pages_pct", OPT_INNODB_MAX_DIRTY_PAGES_PCT,
    "Percentage of dirty pages allowed in bufferpool", (gptr*) &srv_max_buf_pool_modified_pct,
    (gptr*) &srv_max_buf_pool_modified_pct, 0, GET_ULONG, REQUIRED_ARG, 90, 0, 100, 0, 0, 0},
-   
+  {"innodb_table_locks_old_behavior", OPT_INNODB_TABLE_LOCKS_OLD_BEHAVIOR,
+   "Disable InnoDB locking in LOCK TABLES",
+   (gptr*) &global_system_variables.innodb_table_locks_old_behavior,
+   (gptr*) &global_system_variables.innodb_table_locks_old_behavior,
+   0, GET_BOOL, OPT_ARG, 0, 0, 0, 0, 0, 0},
 #endif /* End HAVE_INNOBASE_DB */
   {"help", '?', "Display this help and exit", 0, 0, 0, GET_NO_ARG, NO_ARG, 0,
    0, 0, 0, 0, 0},
diff --git a/sql/set_var.cc b/sql/set_var.cc
index 4b66a621f62..9b2db7a0802 100644
--- a/sql/set_var.cc
+++ b/sql/set_var.cc
@@ -263,6 +263,8 @@ sys_var_thd_ulong	sys_net_wait_timeout("wait_timeout",
 #ifdef HAVE_INNOBASE_DB
 sys_var_long_ptr        sys_innodb_max_dirty_pages_pct("innodb_max_dirty_pages_pct",
                                                         &srv_max_buf_pool_modified_pct);
+sys_var_thd_bool	sys_innodb_table_locks_old_behavior("innodb_table_locks_old_behavior",
+							&SV::innodb_table_locks_old_behavior);
 #endif 					     
 
 
@@ -449,6 +451,7 @@ sys_var *sys_variables[]=
   &sys_os,
 #ifdef HAVE_INNOBASE_DB
   &sys_innodb_max_dirty_pages_pct,
+  &sys_innodb_table_locks_old_behavior,
 #endif    
   &sys_unique_checks
 };
@@ -520,6 +523,7 @@ struct show_var_st init_vars[]= {
   {"innodb_log_group_home_dir", (char*) &innobase_log_group_home_dir, SHOW_CHAR_PTR},
   {"innodb_mirrored_log_groups", (char*) &innobase_mirrored_log_groups, SHOW_LONG},
   {sys_innodb_max_dirty_pages_pct.name, (char*) &sys_innodb_max_dirty_pages_pct, SHOW_SYS},
+  {sys_innodb_table_locks_old_behavior.name, (char*) &sys_innodb_table_locks_old_behavior, SHOW_SYS},
 #endif
   {sys_interactive_timeout.name,(char*) &sys_interactive_timeout,   SHOW_SYS},
   {sys_join_buffer_size.name,   (char*) &sys_join_buffer_size,	    SHOW_SYS},
diff --git a/sql/sql_class.h b/sql/sql_class.h
index af53574eeaf..8c383d5848d 100644
--- a/sql/sql_class.h
+++ b/sql/sql_class.h
@@ -338,6 +338,9 @@ struct system_variables
   my_bool low_priority_updates;
   my_bool new_mode;
   my_bool query_cache_wlock_invalidate;
+#ifdef HAVE_INNOBASE_DB
+  my_bool innodb_table_locks_old_behavior;
+#endif /* HAVE_INNOBASE_DB */
 
   CONVERT *convert_set;
 };