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Code Activity

Backport of:

Browse Source 
------------------------------------------------------------
revno: 2630.9.3
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-6.0-3726-w3
timestamp: Wed 2008-06-11 08:33:36 +0400
message:
  WL#3726 "DDL locking for all metadata objects".

  After review fixes in progress.

  Changed close_cached_tables() not to flush all unused TABLE
  instances when flushing individual table.
  Renamed expel_table_from_cache() to tdc_remove_table() and
  added enum parameter to be able more explicitly specify type
  of removal, rewrote its code to be more efficient.

******
Backport of:
------------------------------------------------------------
revno: 2630.9.4
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-6.0-3726-w3
timestamp: Wed 2008-06-11 15:53:53 +0400
message:
  WL#3726 "DDL locking for all metadata objects".

  After-review fixes in progress.

  Minor changes in order to improve code readability
  and simplify debugging.
This commit is contained in:
Konstantin Osipov
2009-12-01 22:13:01 +03:00
parent b474ad262b
commit cf4a4ba6fd
9 changed files with 155 additions and 99 deletions
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79
sql/sql_show.cc
View File

@ -3075,6 +3075,56 @@ uint get_table_open_method(TABLE_LIST *tables,
}
/**
Acquire high priority share metadata lock on a table.
@param thd Thread context.
@param mdl_lock_data Pointer to memory to be used for MDL_LOCK_DATA
object for a lock request.
@param mdlkey Pointer to the buffer for key for the lock request
(should be at least strlen(db) + strlen(name) + 2
bytes, or, if the lengths are not known,
MAX_DBNAME_LENGTH)
@param table Table list element for the table
@note This is an auxiliary function to be used in cases when we want to
access table's description by looking up info in TABLE_SHARE without
going through full-blown table open.
@note This function assumes that there are no other metadata lock requests
in the current metadata locking context.
@retval FALSE Success
@retval TRUE Some error occured (probably thread was killed).
*/
static bool
acquire_high_prio_shared_mdl_lock(THD *thd, MDL_LOCK_DATA *mdl_lock_data,
char *mdlkey, TABLE_LIST *table)
{
bool retry;
mdl_init_lock(mdl_lock_data, mdlkey, 0, table->db, table->table_name);
table->mdl_lock_data= mdl_lock_data;
mdl_add_lock(&thd->mdl_context, mdl_lock_data);
mdl_set_lock_type(mdl_lock_data, MDL_SHARED_HIGH_PRIO);
while (1)
{
if (mdl_acquire_shared_lock(&thd->mdl_context, mdl_lock_data, &retry))
{
if (!retry || mdl_wait_for_locks(&thd->mdl_context))
{
mdl_remove_all_locks(&thd->mdl_context);
return TRUE;
}
continue;
}
break;
}
return FALSE;
}
/**
@brief Fill I_S table with data from FRM file only
@ -3108,7 +3158,6 @@ static int fill_schema_table_from_frm(THD *thd,TABLE *table,
char db_name_buff[NAME_LEN + 1], table_name_buff[NAME_LEN + 1];
MDL_LOCK_DATA mdl_lock_data;
char mdlkey[MAX_DBKEY_LENGTH];
bool retry;
bzero((char*) &table_list, sizeof(TABLE_LIST));
bzero((char*) &tbl, sizeof(TABLE));
@ -3133,32 +3182,20 @@ static int fill_schema_table_from_frm(THD *thd,TABLE *table,
table_list.db= db_name->str;
}
mdl_init_lock(&mdl_lock_data, mdlkey, 0, db_name->str, table_name->str);
table_list.mdl_lock_data= &mdl_lock_data;
mdl_add_lock(&thd->mdl_context, &mdl_lock_data);
mdl_set_lock_type(&mdl_lock_data, MDL_SHARED_HIGH_PRIO);
/*
TODO: investigate if in this particular situation we can get by
simply obtaining internal lock of data-dictionary (ATM it
is LOCK_open) instead of obtaning full-blown metadata lock.
*/
while (1)
if (acquire_high_prio_shared_mdl_lock(thd, &mdl_lock_data, mdlkey,
&table_list))
{
if (mdl_acquire_shared_lock(&thd->mdl_context, &mdl_lock_data, &retry))
{
if (!retry || mdl_wait_for_locks(&thd->mdl_context))
{
/*
Some error occured or we have been killed while waiting
for conflicting locks to go away, let the caller to handle
the situation.
*/
return 1;
}
continue;
}
break;
/*
Some error occured (most probably we have been killed while
waiting for conflicting locks to go away), let the caller to
handle the situation.
*/
return 1;
}
key_length= create_table_def_key(thd, key, &table_list, 0);