This bug occurs when some trigger for table used by DML statement is created
or changed while statement was waiting in lock_tables(). In this situation
prelocking set which we have calculated becames invalid which can easily lead
to errors and even in some cases to crashes.
With proposed patch we no longer silently reopen tables in lock_tables(),
instead caller of lock_tables() becomes responsible for reopening tables and
recalculation of prelocking set.
Bug was introduced by cset 1.1659.14.1. Before it server was silently
ignoring that lock can't be acquired because it already acquired.
This patch makes make_global_read_lock_block_commit() return without error
if lock already acquired.
Fixed portability problem with bool in C programs
Moved close_thread_tables out from LOCK_thread_count mutex (safety fix)
my_sleep() -> pthread_cond_timedwait()
The idea of the patch
is that every cursor gets its own lock id for table level locking.
Thus cursors are protected from updates performed within the same
connection. Additionally a list of transient (must be closed at
commit) cursors is maintained and all transient cursors are closed
when necessary. Lastly, this patch adds support for deadlock
timeouts to TLL locking when using cursors.
+ post-review fixes.
of stored routines definitions even if we already have some tables open and
locked. To avoid deadlocks in this case we have to put certain restrictions
on locking of mysql.proc table.
This allows to use stored routines safely under LOCK TABLES without explicitly
mentioning mysql.proc in the list of locked tables. It also fixes bug #11554
"Server crashes on statement indirectly using non-cached function".
1.) Added a new option to mysql_lock_tables() for ignoring FLUSH TABLES.
Used the new option in create_table_from_items().
It is necessary to prevent the SELECT table from being reopend.
It would get new storage assigned for its fields, while the
SELECT part of the command would still use the old (freed) storage.
2.) Protected the CREATE TABLE and CREATE TABLE ... SELECT commands
against a global read lock. This prevents a deadlock in
CREATE TABLE ... SELECT in conjunction with FLUSH TABLES WITH READ LOCK
and avoids the creation of new tables during a global read lock.
3.) Replaced set_protect_against_global_read_lock() and
unset_protect_against_global_read_lock() by
wait_if_global_read_lock() and start_waiting_global_read_lock()
in the INSERT DELAYED handling.
to read and write
Changed Server code, added new interface to handler and changed the
NDB handler, InnoDB handler and Federated handler that previously used
query_id
Bug#10202 fix (one-liner fix for memory leak)
Added protection against global read lock while creating and
initializing a delayed insert handler.
Allowed to ignore a global read lock when locking the table
inside the delayed insert handler.
Added some minor improvements.
(otherwise a deadlock when ALTER writes to
binlog holding LOCK_open, it causes binlog rotation,
binlog waits for prepared transactions to commit, and commit
needs LOCK_open to check for global read lock)
start_waiting_global_read_lock() should wake up all those who are waiting
for protect_against_global_read_lock to go down to 0: those registered in waiting_for_read_lock
AND those registered in global_read_lock_blocks_commit.
Split TABLE to TABLE and TABLE_SHARE (TABLE_SHARE is still allocated as part of table, will be fixed soon)
Created Field::make_field() and made Field_num::make_field() to call this
Added 'TABLE_SHARE->db' that points to database name; Changed all usage of table_cache_key as database name to use this instead
Changed field->table_name to point to pointer to alias. This allows us to change alias for a table by just updating one pointer.
Renamed TABLE_SHARE->real_name to table_name
Renamed TABLE->table_name to alias
Renamed TABLE_LIST->real_name to table_name
transactional table locks to tables mentioned in the query. These locks
are released at the end of the transaction automatically.
This is fix for bugs #5655, #5998 and issue #3762.
(originally reported as "second run of innobackup hangs forever and can even hang server").
Plus testcase for the bugfix and comments about global read locks.
