Functions
static void	drizzled::print_lock_error (int error, const char *)
static void	drizzled::reset_lock_data_and_free (DrizzleLock *&lock)
static bool	drizzled::locked_named_table (TableList *table_list)
static bool	drizzled::must_wait (bool is_not_commit)
DrizzleLock *	drizzled::Session::lockTables (Table **tables, uint32_t count, uint32_t flags)
int	drizzled::Session::lock_external (Table **tables, uint32_t count)
void	drizzled::Session::unlockTables (DrizzleLock *sql_lock)
void	drizzled::Session::unlockSomeTables (Table **table, uint32_t count)
void	drizzled::Session::unlockReadTables (DrizzleLock *sql_lock)
void	drizzled::Session::removeLock (Table *table)
void	drizzled::Session::abortLock (Table *table)
bool	drizzled::Session::abortLockForThread (Table *table)
int	drizzled::Session::unlock_external (Table **table, uint32_t count)
DrizzleLock *	drizzled::Session::get_lock_data (Table table_ptr, uint32_t count, bool should_lock, Table write_lock_used)
int	drizzled::Session::lock_table_name (TableList *table_list)
void	drizzled::TableList::unlock_table_name ()
bool	drizzled::Session::wait_for_locked_table_names (TableList *table_list)
bool	drizzled::Session::lock_table_names (TableList *table_list)
bool	drizzled::Session::lock_table_names_exclusively (TableList *table_list)
void	drizzled::TableList::unlock_table_names (TableList *last_table=NULL)
bool	drizzled::Session::lockGlobalReadLock ()
void	drizzled::Session::unlockGlobalReadLock ()
bool	drizzled::Session::wait_if_global_read_lock (bool abort_on_refresh, bool is_not_commit)
void	drizzled::Session::startWaitingGlobalReadLock ()
bool	drizzled::Session::makeGlobalReadLockBlockCommit ()
void	drizzled::locking::broadcast_refresh (void)

Variables
static drizzled::error_t	drizzled::thr_lock_errno_to_mysql []
volatile uint32_t	drizzled::global_read_lock = 0
volatile uint32_t	drizzled::global_read_lock_blocks_commit = 0
static volatile uint32_t	drizzled::protect_against_global_read_lock = 0
static volatile uint32_t	drizzled::waiting_for_read_lock = 0

Detailed Description

Function Documentation

void drizzled::Session::abortLock ( Table * table )

Abort all other threads waiting to get lock in table.

Definition at line 429 of file global.cc.

bool drizzled::Session::abortLockForThread ( Table * table )

Abort one thread / table combination.

Parameters:

session	Thread handler
table	Table that should be removed from lock queue

Return values:

0	Table was not locked by another thread
1	Table was locked by at least one other thread

Definition at line 456 of file global.cc.

References drizzled::Table::in_use.

void drizzled::locking::broadcast_refresh ( void )

Broadcast COND_refresh and COND_global_read_lock.

Due to a bug in a threading library it could happen that a signal did not reach its target. A condition for this was that the same condition variable was used with different mutexes in pthread_cond_wait(). Some time ago we changed table::Cache::mutex() to LOCK_global_read_lock in global read lock handling. So COND_refresh was used with table::Cache::mutex() and LOCK_global_read_lock.

We did now also change from COND_refresh to COND_global_read_lock in global read lock handling. But now it is necessary to signal both conditions at the same time.

Note:: When signalling COND_global_read_lock within the global read lock handling, it is not necessary to also signal COND_refresh.

Definition at line 1109 of file global.cc.

Referenced by drizzled::Session::close_old_data_files(), drizzled::Open_tables_state::close_open_tables(), drizzled::Session::reopen_tables(), drizzled::Session::unlink_open_table(), and drizzled::TableList::unlock_table_names().

DrizzleLock * drizzled::Session::get_lock_data	(	Table **	table_ptr,
		uint32_t	count,
		bool	should_lock,
		Table **	write_lock_used
	)

private

Get lock structures from table structs and initialize locks.

Parameters:

session	Thread handler
table_ptr	Pointer to tables that should be locks
should_lock	One of: false : If we should send TL_IGNORE to store lock true : Store lock info in Table
write_lock_used	Store pointer to last table with WRITE_ALLOW_WRITE

Definition at line 507 of file global.cc.

References drizzled::Table::cursor, drizzled::Table::db_stat, drizzled::Table::lock_count, drizzled::Table::lock_data_start, drizzled::Table::lock_position, drizzled::reset_lock_data_and_free(), and drizzled::Cursor::store_lock().

int drizzled::Session::lock_table_name ( TableList * table_list )

Put a not open table with an old refresh version in the table cache.

Parameters:

table_list	Lock first table in this list
check_in_use	Do we need to check if table already in use by us

Note:: One must have a lock on table::Cache::mutex()!

Warning:: If you are going to update the table, you should use lock_and_wait_for_table_name(removed) instead of this function as this works together with 'FLUSH TABLES WITH READ LOCK'

Note:: This will force any other threads that uses the table to release it as soon as possible.

Returns:: < 0 error; == 0 table locked; 0 table locked, but someone is using it

Definition at line 619 of file global.cc.

References drizzled::Table::in_use, and drizzled::TableList::table.

bool drizzled::Session::lock_table_names ( TableList * table_list )

Lock all tables in list with a name lock.

REQUIREMENTS

One must have a lock on table::Cache::mutex() when calling this

Parameters:

table_list Names of tables to lock

Return values:

0	ok
1	Fatal error (end of memory ?)

Definition at line 712 of file global.cc.

References lock_table(), and drizzled::TableList::unlock_table_names().

bool drizzled::Session::lock_table_names_exclusively ( TableList * table_list )

Unlock all tables in list with a name lock.

Parameters:

table_list Names of tables to lock.

Note:: This function needs to be protected by table::Cache::mutex(). If we're under LOCK TABLES, this function does not work as advertised. Namely, it does not exclude other threads from using this table and does not put an exclusive name lock on this table into the table cache.

See also:: lock_table_names; unlock_table_names

Return values:

TRUE	An error occured.
FALSE	Name lock successfully acquired.

Definition at line 755 of file global.cc.

References drizzled::TableList::next_global.

void drizzled::Session::removeLock ( Table * table )

Try to find the table in the list of locked tables. In case of success, unlock the table and remove it from this list.

Note:: This function has a legacy side effect: the table is unlocked even if it is not found in the locked list. It's not clear if this side effect is intentional or still desirable. It might lead to unmatched calls to unlock_external(). Moreover, a discrepancy can be left unnoticed by the storage engine, because in unlock_external() we call handler::external_lock(F_UNLCK) only if table->current_lock is not F_UNLCK.

Parameters:

session	thread context
locked	list of locked tables
table	the table to unlock
always_unlock	specify explicitly if the legacy side effect is desired.

Definition at line 421 of file global.cc.

static void drizzled::reset_lock_data_and_free ( DrizzleLock *& lock )

static

Reset lock type in lock data and free.

Parameters:

mysql_lock Lock structures to reset.

Note:

After a locking error we want to quit the locking of the table(s). The test case in the bug report for Bug #18544 has the following cases: 1. Locking error in lock_external() due to InnoDB timeout.

Locking error in get_lock_data() due to missing write permission.
Locking error in wait_if_global_read_lock() due to lock conflict.

In all these cases we have already set the lock type into the lock data of the open table(s). If the table(s) are in the open table cache, they could be reused with the non-zero lock type set. This could lead to ignoring a different lock type with the next lock.

Clear the lock type of all lock data. This ensures that the next lock request will set its lock type properly.

Definition at line 166 of file global.cc.

Referenced by drizzled::Session::get_lock_data().

int drizzled::Session::unlock_external	(	Table **	table,
		uint32_t	count
	)

private

Unlock a set of external.

Definition at line 474 of file global.cc.

References drizzled::Table::current_lock.

void drizzled::TableList::unlock_table_names ( TableList * last_table = NULL )

Unlock all tables in list with a name lock.

Parameters:

table_list	Names of tables to unlock
last_table	Don't unlock any tables after this one. (default 0, which will unlock all tables)

Note:: One must have a lock on table::Cache::mutex() when calling this.; This function will broadcast refresh signals to inform other threads that the name locks are removed.

Return values: