manual merge fix of bug#42438 in mysql-next-mr-merge

mysql-test/r/partition_debug_sync.result

@@ -4,6 +4,8 @@ SET DEBUG_SYNC= 'RESET';
 # Bug#42438: Crash ha_partition::change_table_ptr
 # Test when remove partitioning is done while drop table is waiting
 # for the table.
+# After MDL was introduced, there is no longer any race, so test is done
+# by adding a small sleep to verify that the delete waits.
 # Con 1
 SET DEBUG_SYNC= 'RESET';
 CREATE TABLE t1
@@ -16,21 +18,25 @@ ENGINE = MYISAM
 PARTITION p1 VALUES LESS THAN (20),
 PARTITION p2 VALUES LESS THAN (100),
 PARTITION p3 VALUES LESS THAN MAXVALUE ) */;
+SET SESSION debug= "+d,sleep_before_create_table_no_lock";
 SET DEBUG_SYNC= 'alter_table_before_create_table_no_lock SIGNAL removing_partitioning WAIT_FOR waiting_for_alter';
 SET DEBUG_SYNC= 'alter_table_before_main_binlog SIGNAL partitioning_removed';
 ALTER TABLE t1 REMOVE PARTITIONING;
 # Con default
 SET DEBUG_SYNC= 'now WAIT_FOR removing_partitioning';
-SET DEBUG_SYNC= 'waiting_for_table SIGNAL waiting_for_alter';
+SET DEBUG_SYNC= 'mdl_acquire_lock_wait SIGNAL waiting_for_alter';
 SET DEBUG_SYNC= 'rm_table_part2_before_delete_table WAIT_FOR partitioning_removed';
 DROP TABLE IF EXISTS t1;
 # Con 1
+SET SESSION debug= "-d,sleep_before_create_table_no_lock";
 SET DEBUG_SYNC= 'RESET';
 SET DEBUG_SYNC= 'RESET';
 #
 # Bug#42438: Crash ha_partition::change_table_ptr
 # Test when remove partitioning is failing due to drop table is already
 # in progress.
+# After MDL was introduced, there is no longer any race, so test is done
+# by adding a small sleep to verify that the alter waits.
 CREATE TABLE t2
 (a INTEGER,
 b INTEGER NOT NULL,
@@ -41,14 +47,16 @@ ENGINE = MYISAM
 PARTITION p1 VALUES LESS THAN (20),
 PARTITION p2 VALUES LESS THAN (100),
 PARTITION p3 VALUES LESS THAN MAXVALUE ) */;
-SET DEBUG_SYNC= 'before_lock_tables_takes_lock SIGNAL removing_partitions WAIT_FOR waiting_for_alter';
+SET DEBUG_SYNC= 'open_tables_acquire_upgradable_mdl SIGNAL removing_partitions WAIT_FOR waiting_for_alter';
 SET DEBUG_SYNC= 'alter_table_before_rename_result_table WAIT_FOR delete_done';
 ALTER TABLE t2 REMOVE PARTITIONING;
 # Con default
+SET SESSION debug= "+d,sleep_before_part2_delete_table";
 SET DEBUG_SYNC= 'now WAIT_FOR removing_partitions';
-SET DEBUG_SYNC= 'waiting_for_table SIGNAL waiting_for_alter';
+SET DEBUG_SYNC= 'rm_table_part2_before_delete_table SIGNAL waiting_for_alter';
 SET DEBUG_SYNC= 'rm_table_part2_before_binlog SIGNAL delete_done';
 DROP TABLE IF EXISTS t2;
+SET SESSION debug= "-d,sleep_before_part2_delete_table";
 # Con 1
 ERROR 42S02: Table 'test.t2' doesn't exist
 SET DEBUG_SYNC= 'RESET';

mysql-test/t/disabled.def

@@ -15,4 +15,3 @@ sp_sync                  : Bug#48157 2010-02-06 5.5-m3 demands a differnt soluti
 innodb-autoinc           : Bug#49267 2009-12-02 test fails on windows because of different case mode
 innodb                   : Bug#49396 2009-12-03 test fails in embedded mode
 plugin_load              : Bug#42144 2009-12-21 alik plugin_load fails
-partition_debug_sync     : 2010-03-01 alik Disable partition_debug_sync temporarily awaiting a patch from Mattias

mysql-test/t/partition_debug_sync.test

@@ -15,6 +15,8 @@ SET DEBUG_SYNC= 'RESET';
 --echo # Bug#42438: Crash ha_partition::change_table_ptr
 --echo # Test when remove partitioning is done while drop table is waiting
 --echo # for the table.
+--echo # After MDL was introduced, there is no longer any race, so test is done
+--echo # by adding a small sleep to verify that the delete waits.
 connect(con1, localhost, root,,);
 --echo # Con 1
 SET DEBUG_SYNC= 'RESET';
@@ -28,18 +30,20 @@ ENGINE = MYISAM
  PARTITION p1 VALUES LESS THAN (20),
  PARTITION p2 VALUES LESS THAN (100),
  PARTITION p3 VALUES LESS THAN MAXVALUE ) */;
+SET SESSION debug= "+d,sleep_before_create_table_no_lock";
 SET DEBUG_SYNC= 'alter_table_before_create_table_no_lock SIGNAL removing_partitioning WAIT_FOR waiting_for_alter';
 SET DEBUG_SYNC= 'alter_table_before_main_binlog SIGNAL partitioning_removed';
 --send ALTER TABLE t1 REMOVE PARTITIONING
 connection default;
 --echo # Con default
 SET DEBUG_SYNC= 'now WAIT_FOR removing_partitioning';
-SET DEBUG_SYNC= 'waiting_for_table SIGNAL waiting_for_alter';
+SET DEBUG_SYNC= 'mdl_acquire_lock_wait SIGNAL waiting_for_alter';
 SET DEBUG_SYNC= 'rm_table_part2_before_delete_table WAIT_FOR partitioning_removed';
 DROP TABLE IF EXISTS t1;
 --echo # Con 1
 connection con1;
 --reap
+SET SESSION debug= "-d,sleep_before_create_table_no_lock";
 connection default;
 SET DEBUG_SYNC= 'RESET';
 connection con1;
@@ -49,6 +53,8 @@ SET DEBUG_SYNC= 'RESET';
 --echo # Bug#42438: Crash ha_partition::change_table_ptr
 --echo # Test when remove partitioning is failing due to drop table is already
 --echo # in progress.
+--echo # After MDL was introduced, there is no longer any race, so test is done
+--echo # by adding a small sleep to verify that the alter waits.
 CREATE TABLE t2
 (a INTEGER,
  b INTEGER NOT NULL,
@@ -59,15 +65,17 @@ ENGINE = MYISAM
  PARTITION p1 VALUES LESS THAN (20),
  PARTITION p2 VALUES LESS THAN (100),
  PARTITION p3 VALUES LESS THAN MAXVALUE ) */;
-SET DEBUG_SYNC= 'before_lock_tables_takes_lock SIGNAL removing_partitions WAIT_FOR waiting_for_alter';
+SET DEBUG_SYNC= 'open_tables_acquire_upgradable_mdl SIGNAL removing_partitions WAIT_FOR waiting_for_alter';
 SET DEBUG_SYNC= 'alter_table_before_rename_result_table WAIT_FOR delete_done';
 --send ALTER TABLE t2 REMOVE PARTITIONING
 connection default;
 --echo # Con default
+SET SESSION debug= "+d,sleep_before_part2_delete_table";
 SET DEBUG_SYNC= 'now WAIT_FOR removing_partitions';
-SET DEBUG_SYNC= 'waiting_for_table SIGNAL waiting_for_alter';
+SET DEBUG_SYNC= 'rm_table_part2_before_delete_table SIGNAL waiting_for_alter';
 SET DEBUG_SYNC= 'rm_table_part2_before_binlog SIGNAL delete_done';
 DROP TABLE IF EXISTS t2;
+SET SESSION debug= "-d,sleep_before_part2_delete_table";
 --echo # Con 1
 connection con1;
 --error ER_NO_SUCH_TABLE

sql/sql_base.cc

@@ -4377,6 +4377,8 @@ open_tables_acquire_upgradable_mdl(THD *thd, TABLE_LIST *tables_start,
   MDL_request_list mdl_requests;
   TABLE_LIST *table;
 
+  DEBUG_SYNC(thd, "open_tables_acquire_upgradable_mdl");
+
   for (table= tables_start; table && table != tables_end;
        table= table->next_global)
   {

sql/sql_table.cc

@@ -1897,18 +1897,15 @@ int mysql_rm_table_part2(THD *thd, TABLE_LIST *tables, bool if_exists,
   mysql_ha_rm_tables(thd, tables);
 
   /* Disable drop of enabled log tables, must be done before name locking */
-  mysql_mutex_lock(&LOCK_open);
   for (table= tables; table; table= table->next_local)
   {
     if (check_if_log_table(table->db_length, table->db,
                            table->table_name_length, table->table_name, 1))
     {
-      mysql_mutex_unlock(&LOCK_open);
       my_error(ER_BAD_LOG_STATEMENT, MYF(0), "DROP");
       DBUG_RETURN(1);
     }
   }
-  mysql_mutex_unlock(&LOCK_open);
 
   if (!drop_temporary)
   {
@@ -2061,6 +2058,8 @@ int mysql_rm_table_part2(THD *thd, TABLE_LIST *tables, bool if_exists,
             Is exclusive meta-data lock enough ?
     */
     DEBUG_SYNC(thd, "rm_table_part2_before_delete_table");
+    DBUG_EXECUTE_IF("sleep_before_part2_delete_table",
+                    my_sleep(100000););
     mysql_mutex_lock(&LOCK_open);
     if (drop_temporary ||
         ((access(path, F_OK) &&
@@ -7128,6 +7127,8 @@ view_err:
     create_info->data_file_name=create_info->index_file_name=0;
 
   DEBUG_SYNC(thd, "alter_table_before_create_table_no_lock");
+  DBUG_EXECUTE_IF("sleep_before_create_table_no_lock",
+                  my_sleep(100000););
   /*
     Create a table with a temporary name.
     With create_info->frm_only == 1 this creates a .frm file only.