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Commit e3b3907c authored by Konstantin Osipov's avatar Konstantin Osipov
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Backport of: 

------------------------------------------------------------
revno: 2630.4.32
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-6.0-3726-w2
timestamp: Thu 2008-06-19 16:39:58 +0400
message:
  WL#3726 "DDL locking for all metadata objects".

  After-review fixes in progress.

  Ensure that metadata locking subsystem properly handles
  out-of-memory conditions. Clarified MDL interface by
  separating release of locks and removal of lock requests
  from the context.

sql/lock.cc:
  mdl_release_lock(), mdl_acquire_exclusive_locks() and 
  mdl_try_acquire_exclusive_lock() are no longer responsible
  for removal of metadata lock requests from the context.
  One should explicitly call mdl_remove_all_locks() and
  mdl_remove_lock() to do this.
sql/mdl.cc:
  Ensured that metadata locking subsystem properly handles
  out-of-memory conditions.
  Introduced new MDL_INITIALIZED state for metadata lock
  request which is used in all cases when lock is not acquired 
  and we have not associated request with object respesenting 
  lock.
  
  MDL_PENDING is now only used for requests for exclusive locks
  which are added to the MDL_LOCK::waiting_exclusive queue.
  mdl_release_lock(), mdl_acquire_exclusive_locks() and 
  mdl_try_acquire_exclusive_lock() are no longer responsible
  for removal of metadata lock requests from the context.
  One should explicitly call mdl_remove_all_locks() and
  newly introduced mdl_remove_lock() to do this.
  Also renamed mdl_release_all_locks_for_name() to 
  emphasize that it also actually removes lock requests
  from the context.
  
  Finally mdl_try_acquire_exclusive_lock() is now returs
  information about encountered lock conflict in separate
  out parameter since its return value is used for distinguishing
  between error (e.g. due to OOM) and success.
sql/mdl.h:
  Introduced new MDL_INITIALIZED state for metadata lock
  request which is used in all cases when lock is not acquired 
  and we have not associated request with object respesenting 
  lock.
  
  MDL_PENDING is now only used for requests for exclusive locks
  which are added to the MDL_LOCK::waiting_exclusive queue.
  mdl_release_lock(), mdl_acquire_exclusive_locks() and 
  mdl_try_acquire_exclusive_lock() are no longer responsible
  for removal of metadata lock requests from the context.
  One should explicitly call mdl_remove_all_locks() and
  newly introduced mdl_remove_lock() to do this.
  Also renamed mdl_release_all_locks_for_name() to 
  emphasize that it also actually removes lock requests
  from the context.
  
  Finally mdl_try_acquire_exclusive_lock() is now returs
  information about encountered lock conflict in separate
  out parameter since its return value is used for distinguishing
  between error (e.g. due to OOM) and success.
sql/sql_base.cc:
  mdl_release_lock(), mdl_acquire_exclusive_locks() and mdl_try_acquire_exclusive_lock() are no longer responsible
  for removal of metadata lock requests from the context.
  One should explicitly call mdl_remove_all_locks() and
  mdl_remove_lock() to do this.
  Also adjusted open_table() to ensure that it 
  releases/removes metadata locks in case of error 
  after adding/acquiring them (unless keeping these
  lock requests is required for recovering action).
sql/sql_delete.cc:
  mdl_release_lock(), mdl_acquire_exclusive_locks() and mdl_try_acquire_exclusive_lock() are no longer responsible
  for removal of metadata lock requests from the context.
  One should explicitly call mdl_remove_all_locks() and
  mdl_remove_lock() to do this.
sql/sql_handler.cc:
  mdl_release_lock(), mdl_acquire_exclusive_locks() and mdl_try_acquire_exclusive_lock() are no longer responsible
  for removal of metadata lock requests from the context.
  One should explicitly call mdl_remove_all_locks() and
  mdl_remove_lock() to do this.
sql/sql_show.cc:
  mdl_release_lock(), mdl_acquire_exclusive_locks() and mdl_try_acquire_exclusive_lock() are no longer responsible
  for removal of metadata lock requests from the context.
  One should explicitly call mdl_remove_all_locks() and
  mdl_remove_lock() to do this.
sql/sql_table.cc:
  Renamed mdl_release_all_locks_for_name() to emphasize
  that it also actually removes lock requests from the context.
  mdl_release_lock(), mdl_acquire_exclusive_locks() and mdl_try_acquire_exclusive_lock() are no longer responsible
  for removal of metadata lock requests from the context.
  One should explicitly call mdl_remove_all_locks() and
  mdl_remove_lock() to do this.
  Finally mdl_try_acquire_exclusive_lock() is now returs
  information about encountered lock conflict in separate
  out parameter since its return value is used for distinguishing
  between error (e.g. due to OOM) and success.
parent b7e8b016
Show whitespace changes
Inline Side-by-side
Showing with 198 additions and 83 deletions
sql/lock.cc
View file @ e3b3907c
......@@ -965,7 +965,7 @@ bool lock_table_names(THD *thd, TABLE_LIST *table_list)
lock_table->mdl_lock_data= mdl_lock_data;
}
if (mdl_acquire_exclusive_locks(&thd->mdl_context))
return 1;
goto end;
return 0;
end:
......
sql/mdl.cc
View file @ e3b3907c
......@@ -257,7 +257,7 @@ void mdl_context_merge(MDL_CONTEXT *dst, MDL_CONTEXT *src)
Stores the database name, object name and the type in the key
buffer. Initializes mdl_el to point to the key.
We can't simply initialize mdl_el with type, db and name
We can't simply initialize MDL_LOCK_DATA with type, db and name
by-pointer because of the underlying HASH implementation
requires the key to be a contiguous buffer.
......@@ -275,7 +275,7 @@ void mdl_init_lock(MDL_LOCK_DATA *lock_data, char *key, int type,
lock_data->key_length= (uint) (strmov(strmov(key+4, db)+1, name)-key)+1;
lock_data->key= key;
lock_data->type= MDL_SHARED;
lock_data->state= MDL_PENDING;
lock_data->state= MDL_INITIALIZED;
#ifndef DBUG_OFF
lock_data->ctx= 0;
lock_data->lock= 0;
......@@ -336,7 +336,7 @@ MDL_LOCK_DATA *mdl_alloc_lock(int type, const char *db, const char *name,
void mdl_add_lock(MDL_CONTEXT *context, MDL_LOCK_DATA *lock_data)
{
DBUG_ENTER("mdl_add_lock");
DBUG_ASSERT(lock_data->state == MDL_PENDING);
DBUG_ASSERT(lock_data->state == MDL_INITIALIZED);
DBUG_ASSERT(!lock_data->ctx);
lock_data->ctx= context;
context->locks.push_front(lock_data);
......@@ -344,6 +344,36 @@ void mdl_add_lock(MDL_CONTEXT *context, MDL_LOCK_DATA *lock_data)
}
/**
Remove a lock request from the list of lock requests of the context.
Disassociates a lock request from the given context.
@param context The MDL context to remove the lock from.
@param lock_data The lock request to be removed.
@pre The lock request being removed should correspond to lock which
was released or was not acquired.
@note Resets lock request for lock released back to its initial state
(i.e. sets type to MDL_SHARED).
*/
void mdl_remove_lock(MDL_CONTEXT *context, MDL_LOCK_DATA *lock_data)
{
DBUG_ENTER("mdl_remove_lock");
DBUG_ASSERT(lock_data->state == MDL_INITIALIZED);
DBUG_ASSERT(context == lock_data->ctx);
/* Reset lock request back to its initial state. */
lock_data->type= MDL_SHARED;
#ifndef DBUG_OFF
lock_data->ctx= 0;
#endif
context->locks.remove(lock_data);
DBUG_VOID_RETURN;
}
/**
Clear all lock requests in the context (clear the context).
......@@ -629,7 +659,7 @@ bool mdl_acquire_shared_lock(MDL_CONTEXT *context, MDL_LOCK_DATA *lock_data,
MDL_LOCK *lock;
*retry= FALSE;
DBUG_ASSERT(is_shared(lock_data) && lock_data->state == MDL_PENDING);
DBUG_ASSERT(is_shared(lock_data) && lock_data->state == MDL_INITIALIZED);
DBUG_ASSERT(lock_data->ctx == context);
......@@ -654,7 +684,11 @@ bool mdl_acquire_shared_lock(MDL_CONTEXT *context, MDL_LOCK_DATA *lock_data,
if (!(lock= (MDL_LOCK *)my_hash_search(&mdl_locks, (uchar*)lock_data->key,
lock_data->key_length)))
{
lock= get_lock_object();
if (!(lock= get_lock_object()))
{
pthread_mutex_unlock(&LOCK_mdl);
return TRUE;
}
/*
Before inserting MDL_LOCK object into hash we should add at least one
MDL_LOCK_DATA to its lists in order to provide key for this element.
......@@ -662,7 +696,12 @@ bool mdl_acquire_shared_lock(MDL_CONTEXT *context, MDL_LOCK_DATA *lock_data,
*/
lock->active_shared.push_front(lock_data);
lock->lock_data_count= 1;
my_hash_insert(&mdl_locks, (uchar*)lock);
if (my_hash_insert(&mdl_locks, (uchar*)lock))
{
release_lock_object(lock);
pthread_mutex_unlock(&LOCK_mdl);
return TRUE;
}
lock_data->state= MDL_ACQUIRED;
lock_data->lock= lock;
if (lock_data->type == MDL_SHARED_UPGRADABLE)
......@@ -702,9 +741,6 @@ static void release_lock(MDL_LOCK_DATA *lock_data);
@param context A context containing requests for exclusive locks
The context may not have other lock requests.
@note In case of failure (for example, if our thread was killed)
resets lock requests back to their initial state (MDL_SHARED)
@retval FALSE Success
@retval TRUE Failure
*/
......@@ -735,25 +771,32 @@ bool mdl_acquire_exclusive_locks(MDL_CONTEXT *context)
while ((lock_data= it++))
{
DBUG_ASSERT(lock_data->type == MDL_EXCLUSIVE &&
lock_data->state == MDL_PENDING);
lock_data->state == MDL_INITIALIZED);
if (!(lock= (MDL_LOCK *) my_hash_search(&mdl_locks, (uchar*)lock_data->key,
lock_data->key_length)))
{
lock= get_lock_object();
if (!(lock= get_lock_object()))
goto err;
/*
Again before inserting MDL_LOCK into hash provide key for
it by adding MDL_LOCK_DATA to one of its lists.
*/
lock->waiting_exclusive.push_front(lock_data);
lock->lock_data_count= 1;
my_hash_insert(&mdl_locks, (uchar*)lock);
if (my_hash_insert(&mdl_locks, (uchar*)lock))
{
release_lock_object(lock);
goto err;
}
lock_data->lock= lock;
lock_data->state= MDL_PENDING;
}
else
{
lock->waiting_exclusive.push_front(lock_data);
lock->lock_data_count++;
lock_data->lock= lock;
lock_data->state= MDL_PENDING;
}
}
......@@ -806,23 +849,7 @@ bool mdl_acquire_exclusive_locks(MDL_CONTEXT *context)
pthread_cond_timedwait(&COND_mdl, &LOCK_mdl, &abstime);
}
if (thd->killed)
{
/* Remove our pending lock requests from the locks. */
it.rewind();
while ((lock_data= it++))
{
DBUG_ASSERT(lock_data->type == MDL_EXCLUSIVE &&
lock_data->state == MDL_PENDING);
release_lock(lock_data);
/* Return lock request to its initial state. */
lock_data->type= MDL_SHARED;
context->locks.remove(lock_data);
}
/* Pending requests for shared locks can be satisfied now. */
pthread_cond_broadcast(&COND_mdl);
thd->exit_cond(old_msg);
return TRUE;
}
goto err;
}
it.rewind();
while ((lock_data= it++))
......@@ -839,6 +866,22 @@ bool mdl_acquire_exclusive_locks(MDL_CONTEXT *context)
/* As a side-effect THD::exit_cond() unlocks LOCK_mdl. */
thd->exit_cond(old_msg);
return FALSE;
err:
/*
Remove our pending lock requests from the locks.
Ignore those lock requests which were not made MDL_PENDING.
*/
it.rewind();
while ((lock_data= it++) && lock_data->state == MDL_PENDING)
{
release_lock(lock_data);
lock_data->state= MDL_INITIALIZED;
}
/* May be some pending requests for shared locks can be satisfied now. */
pthread_cond_broadcast(&COND_mdl);
thd->exit_cond(old_msg);
return TRUE;
}
......@@ -976,50 +1019,56 @@ bool mdl_upgrade_shared_lock_to_exclusive(MDL_CONTEXT *context,
@param context [in] The context containing the lock request
@param lock [in] The lock request
@param conflict [out] Indicates that conflicting lock exists
@retval FALSE the lock was granted
@retval TRUE there were conflicting locks.
@retval TRUE Failure either conflicting lock exists or some error
occured (probably OOM).
@retval FALSE Success, lock was acquired.
FIXME: Compared to lock_table_name_if_not_cached()
it gives sligthly more false negatives.
*/
bool mdl_try_acquire_exclusive_lock(MDL_CONTEXT *context,
MDL_LOCK_DATA *lock_data)
MDL_LOCK_DATA *lock_data,
bool *conflict)
{
MDL_LOCK *lock;
DBUG_ASSERT(lock_data->type == MDL_EXCLUSIVE &&
lock_data->state == MDL_PENDING);
lock_data->state == MDL_INITIALIZED);
safe_mutex_assert_not_owner(&LOCK_open);
*conflict= FALSE;
pthread_mutex_lock(&LOCK_mdl);
if (!(lock= (MDL_LOCK *)my_hash_search(&mdl_locks, (uchar*)lock_data->key,
lock_data->key_length)))
{
lock= get_lock_object();
if (!(lock= get_lock_object()))
goto err;
lock->active_exclusive.push_front(lock_data);
lock->lock_data_count= 1;
my_hash_insert(&mdl_locks, (uchar*)lock);
if (my_hash_insert(&mdl_locks, (uchar*)lock))
{
release_lock_object(lock);
goto err;
}
lock_data->state= MDL_ACQUIRED;
lock_data->lock= lock;
lock= 0;
global_lock.active_intention_exclusive++;
}
pthread_mutex_unlock(&LOCK_mdl);
return FALSE;
}
/*
FIXME: We can't leave pending MDL_EXCLUSIVE lock request in the list since
for such locks we assume that they have MDL_LOCK_DATA::lock properly set.
Long term we should clearly define relation between lock types,
presence in the context lists and MDL_LOCK_DATA::lock values.
*/
if (lock)
context->locks.remove(lock_data);
/* There is some lock for the object. */
*conflict= TRUE;
return lock;
err:
pthread_mutex_unlock(&LOCK_mdl);
return TRUE;
}
......@@ -1111,11 +1160,12 @@ bool mdl_wait_for_locks(MDL_CONTEXT *context)
it.rewind();
while ((lock_data= it++))
{
DBUG_ASSERT(lock_data->state == MDL_PENDING);
DBUG_ASSERT(lock_data->state == MDL_INITIALIZED);
if (!can_grant_global_lock(lock_data))
break;
/*
To avoid starvation we don't wait if we have pending MDL_EXCLUSIVE lock.
To avoid starvation we don't wait if we have a conflict against
request for MDL_EXCLUSIVE lock.
*/
if (is_shared(lock_data) &&
(lock= (MDL_LOCK *)my_hash_search(&mdl_locks, (uchar*)lock_data->key,
......@@ -1149,6 +1199,9 @@ static void release_lock(MDL_LOCK_DATA *lock_data)
DBUG_PRINT("enter", ("db=%s name=%s", lock_data->key + 4,
lock_data->key + 4 + strlen(lock_data->key + 4) + 1));
DBUG_ASSERT(lock_data->state == MDL_PENDING ||
lock_data->state == MDL_ACQUIRED);
lock= lock_data->lock;
if (lock->has_one_lock_data())
{
......@@ -1184,7 +1237,6 @@ static void release_lock(MDL_LOCK_DATA *lock_data)
}
break;
default:
/* TODO Really? How about problems during lock upgrade ? */
DBUG_ASSERT(0);
}
lock->lock_data_count--;
......@@ -1224,10 +1276,10 @@ void mdl_release_locks(MDL_CONTEXT *context)
lists. Allows us to avoid problems in open_tables() in case of
back-off
*/
if (!(is_shared(lock_data) && lock_data->state == MDL_PENDING))
if (lock_data->state != MDL_INITIALIZED)
{
release_lock(lock_data);
lock_data->state= MDL_PENDING;
lock_data->state= MDL_INITIALIZED;
#ifndef DBUG_OFF
lock_data->lock= 0;
#endif
......@@ -1247,13 +1299,10 @@ void mdl_release_locks(MDL_CONTEXT *context)
/**
Release a lock.
Removes the lock from the context.
@param context Context containing lock in question
@param lock_data Lock to be released
@note Resets lock request for lock released back to its initial state
(i.e. sets type to MDL_SHARED).
*/
void mdl_release_lock(MDL_CONTEXT *context, MDL_LOCK_DATA *lock_data)
......@@ -1263,13 +1312,9 @@ void mdl_release_lock(MDL_CONTEXT *context, MDL_LOCK_DATA *lock_data)
pthread_mutex_lock(&LOCK_mdl);
release_lock(lock_data);
#ifndef DBUG_OFF
lock_data->ctx= 0;
lock_data->lock= 0;
#endif
lock_data->state= MDL_PENDING;
/* Return lock request to its initial state. */
lock_data->type= MDL_SHARED;
context->locks.remove(lock_data);
lock_data->state= MDL_INITIALIZED;
pthread_cond_broadcast(&COND_mdl);
pthread_mutex_unlock(&LOCK_mdl);
}
......@@ -1277,16 +1322,14 @@ void mdl_release_lock(MDL_CONTEXT *context, MDL_LOCK_DATA *lock_data)
/**
Release all locks in the context which correspond to the same name/
object as this lock request.
object as this lock request, remove lock requests from the context.
@param context Context containing locks in question
@param lock_data One of the locks for the name/object for which all
locks should be released.
@see mdl_release_lock()
*/
void mdl_release_all_locks_for_name(MDL_CONTEXT *context,
void mdl_release_and_remove_all_locks_for_name(MDL_CONTEXT *context,
MDL_LOCK_DATA *lock_data)
{
MDL_LOCK *lock;
......@@ -1306,7 +1349,10 @@ void mdl_release_all_locks_for_name(MDL_CONTEXT *context,
{
DBUG_ASSERT(lock_data->state == MDL_ACQUIRED);
if (lock_data->lock == lock)
{
mdl_release_lock(context, lock_data);
mdl_remove_lock(context, lock_data);
}
}
}
......@@ -1418,9 +1464,10 @@ bool mdl_is_lock_owner(MDL_CONTEXT *context, int type, const char *db,
int4store(key, type);
key_length= (uint) (strmov(strmov(key+4, db)+1, name)-key)+1;
while ((lock_data= it++) && (lock_data->key_length != key_length ||
while ((lock_data= it++) &&
(lock_data->key_length != key_length ||
memcmp(lock_data->key, key, key_length) ||
lock_data->state == MDL_PENDING))
lock_data->state != MDL_ACQUIRED))
continue;
return lock_data;
......
sql/mdl.h
View file @ e3b3907c
......@@ -44,7 +44,8 @@ enum enum_mdl_type {MDL_SHARED=0, MDL_SHARED_HIGH_PRIO,
/** States which metadata lock request can have. */
enum enum_mdl_state {MDL_PENDING=0, MDL_ACQUIRED, MDL_PENDING_UPGRADE};
enum enum_mdl_state {MDL_INITIALIZED=0, MDL_PENDING,
MDL_ACQUIRED, MDL_PENDING_UPGRADE};
/**
......@@ -152,6 +153,7 @@ void mdl_init_lock(MDL_LOCK_DATA *lock_data, char *key, int type,
MDL_LOCK_DATA *mdl_alloc_lock(int type, const char *db, const char *name,
MEM_ROOT *root);
void mdl_add_lock(MDL_CONTEXT *context, MDL_LOCK_DATA *lock_data);
void mdl_remove_lock(MDL_CONTEXT *context, MDL_LOCK_DATA *lock_data);
void mdl_remove_all_locks(MDL_CONTEXT *context);
/**
......@@ -160,7 +162,7 @@ void mdl_remove_all_locks(MDL_CONTEXT *context);
inline void mdl_set_lock_type(MDL_LOCK_DATA *lock_data, enum_mdl_type lock_type)
{
DBUG_ASSERT(lock_data->state == MDL_PENDING);
DBUG_ASSERT(lock_data->state == MDL_INITIALIZED);
lock_data->type= lock_type;
}
......@@ -170,13 +172,14 @@ bool mdl_acquire_exclusive_locks(MDL_CONTEXT *context);
bool mdl_upgrade_shared_lock_to_exclusive(MDL_CONTEXT *context,
MDL_LOCK_DATA *lock_data);
bool mdl_try_acquire_exclusive_lock(MDL_CONTEXT *context,
MDL_LOCK_DATA *lock_data);
MDL_LOCK_DATA *lock_data,
bool *conflict);
bool mdl_acquire_global_shared_lock(MDL_CONTEXT *context);
bool mdl_wait_for_locks(MDL_CONTEXT *context);
void mdl_release_locks(MDL_CONTEXT *context);
void mdl_release_all_locks_for_name(MDL_CONTEXT *context,
void mdl_release_and_remove_all_locks_for_name(MDL_CONTEXT *context,
MDL_LOCK_DATA *lock_data);
void mdl_release_lock(MDL_CONTEXT *context, MDL_LOCK_DATA *lock_data);
void mdl_downgrade_exclusive_lock(MDL_CONTEXT *context,
......
sql/sql_base.cc
View file @ e3b3907c
......@@ -2278,7 +2278,7 @@ void table_share_release_hook(void *share)
}
/*
/**
A helper function that acquires an MDL lock for a table
being opened.
*/
......@@ -2304,8 +2304,11 @@ open_table_get_mdl_lock(THD *thd, TABLE_LIST *table_list,
*/
mdl_set_lock_type(mdl_lock_data, MDL_EXCLUSIVE);
if (mdl_acquire_exclusive_locks(&thd->mdl_context))
{
mdl_remove_lock(&thd->mdl_context, mdl_lock_data);
return 1;
}
}
else
{
bool retry;
......@@ -2327,6 +2330,8 @@ open_table_get_mdl_lock(THD *thd, TABLE_LIST *table_list,
{
if (retry)
*action= OT_BACK_OFF_AND_RETRY;
else
mdl_remove_lock(&thd->mdl_context, mdl_lock_data);
return 1;
}
}
......@@ -2833,7 +2838,11 @@ bool open_table(THD *thd, TABLE_LIST *table_list, MEM_ROOT *mem_root,
release_table_share(share);
err_unlock2:
pthread_mutex_unlock(&LOCK_open);
if (! (flags & MYSQL_OPEN_HAS_MDL_LOCK))
{
mdl_release_lock(&thd->mdl_context, mdl_lock_data);
mdl_remove_lock(&thd->mdl_context, mdl_lock_data);
}
DBUG_RETURN(TRUE);
}
......@@ -3497,7 +3506,10 @@ recover_from_failed_open_table_attempt(THD *thd, TABLE_LIST *table,
mdl_set_lock_type(table->mdl_lock_data, MDL_EXCLUSIVE);
mdl_add_lock(&thd->mdl_context, table->mdl_lock_data);
if (mdl_acquire_exclusive_locks(&thd->mdl_context))
{
mdl_remove_lock(&thd->mdl_context, table->mdl_lock_data);
return TRUE;
}
pthread_mutex_lock(&LOCK_open);
tdc_remove_table(thd, TDC_RT_REMOVE_ALL, table->db, table->table_name);
ha_create_table_from_engine(thd, table->db, table->table_name);
......@@ -3506,18 +3518,23 @@ recover_from_failed_open_table_attempt(THD *thd, TABLE_LIST *table,
thd->warning_info->clear_warning_info(thd->query_id);
thd->clear_error(); // Clear error message
mdl_release_lock(&thd->mdl_context, table->mdl_lock_data);
mdl_remove_lock(&thd->mdl_context, table->mdl_lock_data);
break;
case OT_REPAIR:
mdl_set_lock_type(table->mdl_lock_data, MDL_EXCLUSIVE);
mdl_add_lock(&thd->mdl_context, table->mdl_lock_data);
if (mdl_acquire_exclusive_locks(&thd->mdl_context))
{
mdl_remove_lock(&thd->mdl_context, table->mdl_lock_data);
return TRUE;
}
pthread_mutex_lock(&LOCK_open);
tdc_remove_table(thd, TDC_RT_REMOVE_ALL, table->db, table->table_name);
pthread_mutex_unlock(&LOCK_open);
result= auto_repair_table(thd, table);
mdl_release_lock(&thd->mdl_context, table->mdl_lock_data);
mdl_remove_lock(&thd->mdl_context, table->mdl_lock_data);
break;
default:
DBUG_ASSERT(0);
......
sql/sql_delete.cc
View file @ e3b3907c
......@@ -1170,7 +1170,10 @@ bool mysql_truncate(THD *thd, TABLE_LIST *table_list, bool dont_send_ok)
mdl_set_lock_type(mdl_lock_data, MDL_EXCLUSIVE);
mdl_add_lock(&thd->mdl_context, mdl_lock_data);
if (mdl_acquire_exclusive_locks(&thd->mdl_context))
{
mdl_remove_lock(&thd->mdl_context, mdl_lock_data);
DBUG_RETURN(TRUE);
}
pthread_mutex_lock(&LOCK_open);
tdc_remove_table(thd, TDC_RT_REMOVE_ALL, table_list->db,
table_list->table_name);
......@@ -1200,12 +1203,18 @@ bool mysql_truncate(THD *thd, TABLE_LIST *table_list, bool dont_send_ok)
my_ok(thd); // This should return record count
}
if (mdl_lock_data)
{
mdl_release_lock(&thd->mdl_context, mdl_lock_data);
mdl_remove_lock(&thd->mdl_context, mdl_lock_data);
}
}
else if (error)
{
if (mdl_lock_data)
{
mdl_release_lock(&thd->mdl_context, mdl_lock_data);
mdl_remove_lock(&thd->mdl_context, mdl_lock_data);
}
}
DBUG_RETURN(error);
......
sql/sql_handler.cc
View file @ e3b3907c
......@@ -150,6 +150,7 @@ static void mysql_ha_close_table(THD *thd, TABLE_LIST *tables)
}
pthread_mutex_unlock(&LOCK_open);
mdl_release_lock(&thd->handler_mdl_context, mdl_lock_data);
mdl_remove_lock(&thd->handler_mdl_context, mdl_lock_data);
}
else if (tables->table)
{
......
sql/sql_show.cc
View file @ e3b3907c
......@@ -3250,6 +3250,7 @@ static int fill_schema_table_from_frm(THD *thd,TABLE *table,
err:
mdl_release_lock(&thd->mdl_context, &mdl_lock_data);
mdl_remove_lock(&thd->mdl_context, &mdl_lock_data);
thd->clear_error();
return res;
}
......
sql/sql_table.cc
View file @ e3b3907c
......@@ -2208,7 +2208,8 @@ int mysql_rm_table_part2(THD *thd, TABLE_LIST *tables, bool if_exists,
and locked and therefore have to remove several metadata lock
requests associated with them.
*/
mdl_release_all_locks_for_name(&thd->mdl_context, table->mdl_lock_data);
mdl_release_and_remove_all_locks_for_name(&thd->mdl_context,
table->mdl_lock_data);
}
}
}
......@@ -4080,12 +4081,26 @@ static bool lock_table_name_if_not_cached(THD *thd, const char *db,
const char *table_name,
MDL_LOCK_DATA **lock_data)
{
bool conflict;
if (!(*lock_data= mdl_alloc_lock(0, db, table_name, thd->mem_root)))
return TRUE;
mdl_set_lock_type(*lock_data, MDL_EXCLUSIVE);
mdl_add_lock(&thd->mdl_context, *lock_data);
if (mdl_try_acquire_exclusive_lock(&thd->mdl_context, *lock_data))
if (mdl_try_acquire_exclusive_lock(&thd->mdl_context, *lock_data,
&conflict))
{
/*
To simplify our life under LOCK TABLES we remove unsatisfied
lock request from the context.
*/
mdl_remove_lock(&thd->mdl_context, *lock_data);
if (!conflict)
{
/* Probably OOM. */
return TRUE;
}
else
*lock_data= 0;
}
return FALSE;
......@@ -4157,7 +4172,10 @@ bool mysql_create_table(THD *thd, const char *db, const char *table_name,
unlock:
if (target_lock_data)
{
mdl_release_lock(&thd->mdl_context, target_lock_data);
mdl_remove_lock(&thd->mdl_context, target_lock_data);
}
pthread_mutex_lock(&LOCK_lock_db);
if (!--creating_table && creating_database)
pthread_cond_signal(&COND_refresh);
......@@ -4416,7 +4434,10 @@ static int prepare_for_repair(THD *thd, TABLE_LIST *table_list,
mdl_set_lock_type(mdl_lock_data, MDL_EXCLUSIVE);
mdl_add_lock(&thd->mdl_context, mdl_lock_data);
if (mdl_acquire_exclusive_locks(&thd->mdl_context))
{
mdl_remove_lock(&thd->mdl_context, mdl_lock_data);
DBUG_RETURN(0);
}
pthread_mutex_lock(&LOCK_open);
if (!(share= (get_table_share(thd, table_list, key, key_length, 0,
......@@ -4550,7 +4571,10 @@ static int prepare_for_repair(THD *thd, TABLE_LIST *table_list,
}
/* In case of a temporary table there will be no metadata lock. */
if (error && mdl_lock_data)
{
mdl_release_lock(&thd->mdl_context, mdl_lock_data);
mdl_remove_lock(&thd->mdl_context, mdl_lock_data);
}
DBUG_RETURN(error);
}
......@@ -5518,7 +5542,10 @@ goto binlog;
err:
if (target_lock_data)
{
mdl_release_lock(&thd->mdl_context, target_lock_data);
mdl_remove_lock(&thd->mdl_context, target_lock_data);
}
DBUG_RETURN(res);
}
......@@ -6876,7 +6903,9 @@ bool mysql_alter_table(THD *thd,char *new_db, char *new_name,
if (new_name != table_name || new_db != db)
{
mdl_release_lock(&thd->mdl_context, target_lock_data);
mdl_release_all_locks_for_name(&thd->mdl_context, mdl_lock_data);
mdl_remove_lock(&thd->mdl_context, target_lock_data);
mdl_release_and_remove_all_locks_for_name(&thd->mdl_context,
mdl_lock_data);
}
else
mdl_downgrade_exclusive_lock(&thd->mdl_context, mdl_lock_data);
......@@ -7554,7 +7583,9 @@ bool mysql_alter_table(THD *thd,char *new_db, char *new_name,
if ((new_name != table_name || new_db != db))
{
mdl_release_lock(&thd->mdl_context, target_lock_data);
mdl_release_all_locks_for_name(&thd->mdl_context, mdl_lock_data);
mdl_remove_lock(&thd->mdl_context, target_lock_data);
mdl_release_and_remove_all_locks_for_name(&thd->mdl_context,
mdl_lock_data);
}
else
mdl_downgrade_exclusive_lock(&thd->mdl_context, mdl_lock_data);
......@@ -7613,7 +7644,10 @@ bool mysql_alter_table(THD *thd,char *new_db, char *new_name,
thd->abort_on_warning= save_abort_on_warning;
}
if (target_lock_data)
{
mdl_release_lock(&thd->mdl_context, target_lock_data);
mdl_remove_lock(&thd->mdl_context, target_lock_data);
}
DBUG_RETURN(TRUE);
err_with_mdl:
......@@ -7625,8 +7659,11 @@ bool mysql_alter_table(THD *thd,char *new_db, char *new_name,
*/
thd->locked_tables_list.unlink_all_closed_tables();
if (target_lock_data)
{
mdl_release_lock(&thd->mdl_context, target_lock_data);
mdl_release_all_locks_for_name(&thd->mdl_context, mdl_lock_data);
mdl_remove_lock(&thd->mdl_context, target_lock_data);
}
mdl_release_and_remove_all_locks_for_name(&thd->mdl_context, mdl_lock_data);
DBUG_RETURN(TRUE);
}
/* mysql_alter_table */
......
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