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refs #5862 support MDL X during alter prepare for various locking protocols

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git-svn-id: file:///svn/mysql/tokudb-engine/tokudb-engine@51654 c7de825b-a66e-492c-adef-691d508d4ae1
This commit is contained in:
Rich Prohaska 2013-01-03 12:17:26 +00:00 committed by Yoni Fogel
parent e10c7fe451
commit 86488ae108
1 changed files with 10 additions and 4 deletions
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14
storage/tokudb/ha_tokudb_alter_56.cc
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@ -169,13 +169,19 @@ static bool only_flags(ulong bits, ulong mask) {
// Check if an alter table operation on this table and described by the alter table parameters is supported inplace
// and if so, what type of locking is needed to execute it.
// return values:
// HA_ALTER_INPLACE_NOT_SUPPORTED: alter operation is not supported as an inplace operation, a table copy is required
// HA_ALTER_INPLACE_NOT_SUPPORTED: alter operation is not supported as an inplace operation, a table copy is required
// HA_ALTER_ERROR: the alter table operation should fail
// HA_ALTER_INPLACE_EXCLUSIVE_LOCK: prepare and alter runs with MDL X
// HA_ALTER_INPLACE_SHARED_LOCK_AFTER_PREPARE: prepare runs with MDL X, alter runs with MDL SNW
// HA_ALTER_INPLACE_SHARED_LOCK: prepare and alter methods called with MDL SNW, concurrent reads, no writes
// HA_ALTER_INPLACE_NO_LOCK_AFTER_PREPARE: prepare runs with MDL X, alter runs with MDL SW
// HA_ALTER_INPLACE_NO_LOCK: prepare and alter methods called with MDL SW, concurrent reads, writes.
// must set WRITE_ALLOW_WRITE lock type in the external lock method to avoid deadlocks
// with the MDL lock and the table lock
// HA_ALTER_INPLACE_EXCLUSIVE_LOCK: the alter operation requires an exclusive MDL no concurrent reads, no writes
enum_alter_inplace_result ha_tokudb::check_if_supported_inplace_alter(TABLE *altered_table, Alter_inplace_info *ha_alter_info) {
TOKUDB_DBUG_ENTER("check_if_supported_alter");
@ -209,14 +215,14 @@ enum_alter_inplace_result ha_tokudb::check_if_supported_inplace_alter(TABLE *alt
// we grab an exclusive MDL for the drop index.
result = HA_ALTER_INPLACE_EXCLUSIVE_LOCK;
} else {
result = HA_ALTER_INPLACE_SHARED_LOCK;
result = HA_ALTER_INPLACE_SHARED_LOCK_AFTER_PREPARE;
// someday, allow multiple hot indexes via alter table add key. don't forget to change the store_lock function.
// for now, hot indexing is only supported via session variable with the create index sql command
if (ha_alter_info->index_add_count == 1 && ha_alter_info->index_drop_count == 0 &&
get_create_index_online(thd) && thd_sql_command(thd) == SQLCOM_CREATE_INDEX) {
// external_lock set WRITE_ALLOW_WRITE which allows writes concurrent with the index creation
result = HA_ALTER_INPLACE_NO_LOCK;
result = HA_ALTER_INPLACE_NO_LOCK_AFTER_PREPARE;
}
}
}