Commit graph

209 commits

Author SHA1 Message Date
Alexander Nozdrin
1f1eba3c68 Remove unused enum (enum open_table_mode).
It was added by mistake during backport from 6.0.
2010-08-31 13:53:49 +04:00
Alexander Nozdrin
65c5e8dcbf Bug#27480 (Extend CREATE TEMPORARY TABLES privilege
to allow temp table operations) -- prerequisite patch .

Introduce a new form of find_temporary_table() function:
find_temporary_table() by a table key. It will be used
in further patches.

Replace find_temporary_table(table_list->db, table_list->name)
by more appropiate find_temporary_table(table_list) across
the codebase.
2010-08-31 13:52:56 +04:00
Alexander Nozdrin
2e462c8f99 Bug#27480 (Extend CREATE TEMPORARY TABLES privilege
to allow temp table operations) -- prerequisite patch .

Introduce a new form of find_temporary_table() function:
find_temporary_table() by a table key. It will be used
in further patches.

Replace find_temporary_table(table_list->db, table_list->name)
by more appropiate find_temporary_table(table_list) across
the codebase.
2010-08-31 13:52:56 +04:00
Jon Olav Hauglid
02863b4180 Merge from mysql-5.5-runtime to mysql-5.5-bugfixing. 2010-08-20 10:24:32 +02:00
Jon Olav Hauglid
39ac44d660 Merge from mysql-5.5-runtime to mysql-5.5-bugfixing. 2010-08-20 10:24:32 +02:00
Alfranio Correia
ac6026ce27 BUG#53452 Inconsistent behavior of binlog_direct_non_transactional_updates with
temp table
            
This patch introduces two key changes in the replication's behavior.
            
Firstly, it reverts part of BUG#51894 which puts any update to temporary tables
into the trx-cache. Now, updates to temporary tables are handled according to
the type of their engines as a regular table.
            
Secondly, an unsafe mixed statement, (i.e. a statement that access transactional
table as well non-transactional or temporary table, and writes to any of them),
are written into the trx-cache in order to minimize errors in the execution when
the statement logging format is in use.
            
Such changes has a direct impact on which statements are classified as unsafe
statements and thus part of BUG#53259 is reverted.
2010-08-20 03:59:58 +01:00
Alfranio Correia
c6d4915f3c BUG#53452 Inconsistent behavior of binlog_direct_non_transactional_updates with
temp table
            
This patch introduces two key changes in the replication's behavior.
            
Firstly, it reverts part of BUG#51894 which puts any update to temporary tables
into the trx-cache. Now, updates to temporary tables are handled according to
the type of their engines as a regular table.
            
Secondly, an unsafe mixed statement, (i.e. a statement that access transactional
table as well non-transactional or temporary table, and writes to any of them),
are written into the trx-cache in order to minimize errors in the execution when
the statement logging format is in use.
            
Such changes has a direct impact on which statements are classified as unsafe
statements and thus part of BUG#53259 is reverted.
2010-08-20 03:59:58 +01:00
Jon Olav Hauglid
41caa7f483 Bug Embedded server tests fails with assert in
check_if_table_exists()

This assert was triggered when the server tried to load plugins
while running in embedded server mode. In embedded server mode,
check_if_table_exists() was used to check if mysql.plugin existed
so that ER_NO_SUCH_TABLE could be silently ignored.
The problem was that this check was done without acquiring a metadata
lock on mysql.plugin first. This triggered the assert.

This patch fixes the problem by removing the call to
check_if_table_exists() from plugin_load(). Instead an error handler
which traps ER_NO_SUCH_TABLE is installed before trying to open
mysql.plugin when running in embedded server mode.

No test coverage added since this assert was triggered by 
existing tests running in embedded server mode.


sql/sql_base.cc:
  Renamed Prelock_error_handler to No_such_table_error_handler
  and moved the declaration to sql_base.h to make it usable
  in plugin_load().
sql/sql_base.h:
  Renamed Prelock_error_handler to No_such_table_error_handler
  and moved the declaration to sql_base.h to make it usable
  in plugin_load().
sql/sql_plugin.cc:
  Removed call to check_if_table_exists() used to check for mysql.plugin 
  in plugin_load() for embedded server. Instead install error handler
  which traps ER_NO_SUCH_TABLE during open_and_lock_tables().
2010-08-19 11:33:37 +02:00
Jon Olav Hauglid
b02f5dd8bc Bug Embedded server tests fails with assert in
check_if_table_exists()

This assert was triggered when the server tried to load plugins
while running in embedded server mode. In embedded server mode,
check_if_table_exists() was used to check if mysql.plugin existed
so that ER_NO_SUCH_TABLE could be silently ignored.
The problem was that this check was done without acquiring a metadata
lock on mysql.plugin first. This triggered the assert.

This patch fixes the problem by removing the call to
check_if_table_exists() from plugin_load(). Instead an error handler
which traps ER_NO_SUCH_TABLE is installed before trying to open
mysql.plugin when running in embedded server mode.

No test coverage added since this assert was triggered by 
existing tests running in embedded server mode.
2010-08-19 11:33:37 +02:00
Jon Olav Hauglid
eb498cce4d Manual merge from mysql-5.5-bugfixing to mysql-5.5-runtime. 2010-08-18 13:29:04 +02:00
Jon Olav Hauglid
5139bf6c8f Manual merge from mysql-5.5-bugfixing to mysql-5.5-runtime. 2010-08-18 13:29:04 +02:00
Konstantin Osipov
8ce6e98aa3 Extract reload_acl_and_cache() and flush_tables_with_read_lock()
into an own implementation file.
2010-08-13 13:51:48 +04:00
Konstantin Osipov
4e935a5329 Extract reload_acl_and_cache() and flush_tables_with_read_lock()
into an own implementation file.
2010-08-13 13:51:48 +04:00
Mattias Jonsson
daf0e6b725 Bug#53676: Unexpected errors and possible table
corruption on ADD PARTITION and LOCK TABLE
Bug#53770: Server crash at handler.cc:2076 on
           LOAD DATA after timed out COALESCE PARTITION

5.5 fix for:
Bug#51042: REORGANIZE PARTITION can leave table in an
           inconsistent state in case of crash
Needs to be back-ported to 5.1

5.5 fix for:
Bug#50418: DROP PARTITION does not interact with
           transactions

Main problem was non-persistent operations done
before meta-data lock was taken (53770+53676).
And 53676 needed to keep the table/partitions opened and locked
while copying the data to the new partitions.

Also added thorough tests to spot some additional bugs
in the ddl_log code, which could result in bad state
between the .frm and partitions.

Collapsed patch, includes all fixes required from the reviewers.

mysql-test/r/partition_innodb.result:
  updated result with new test
mysql-test/suite/parts/inc/partition_crash.inc:
  crash test include file
mysql-test/suite/parts/inc/partition_crash_add.inc:
  test all states in fast_alter_partition_table
  ADD PARTITION branch
mysql-test/suite/parts/inc/partition_crash_change.inc:
  test all states in fast_alter_partition_table
  CHANGE PARTITION branch
mysql-test/suite/parts/inc/partition_crash_drop.inc:
  test all states in fast_alter_partition_table
  DROP PARTITION branch
mysql-test/suite/parts/inc/partition_fail.inc:
  recovery test including injecting errors
mysql-test/suite/parts/inc/partition_fail_add.inc:
  test all states in fast_alter_partition_table
  ADD PARTITION branch
mysql-test/suite/parts/inc/partition_fail_change.inc:
  test all states in fast_alter_partition_table
  CHANGE PARTITION branch
mysql-test/suite/parts/inc/partition_fail_drop.inc:
  test all states in fast_alter_partition_table
  DROP PARTITION branch
mysql-test/suite/parts/inc/partition_mgm_crash.inc:
  include file that runs all crash and failure injection tests.
mysql-test/suite/parts/r/partition_debug_innodb.result:
  new test result file
mysql-test/suite/parts/r/partition_debug_myisam.result:
  new test result file
mysql-test/suite/parts/r/partition_special_innodb.result:
  updated result
mysql-test/suite/parts/r/partition_special_myisam.result:
  updated result
mysql-test/suite/parts/t/partition_debug_innodb-master.opt:
  opt file for using with crashing tests of partitioned innodb
mysql-test/suite/parts/t/partition_debug_innodb.test:
  partitioned innodb test that require debug builds
mysql-test/suite/parts/t/partition_debug_myisam-master.opt:
  opt file for using with crashing tests of partitioned myisam
mysql-test/suite/parts/t/partition_debug_myisam.test:
  partitioned myisam test that require debug builds
mysql-test/suite/parts/t/partition_special_innodb-master.opt:
  added innodb-file-per-table to easier verify partition status on disk
mysql-test/suite/parts/t/partition_special_innodb.test:
  added test case
mysql-test/suite/parts/t/partition_special_myisam.test:
  added test case
mysql-test/t/partition_innodb.test:
  added test case
sql/sql_base.cc:
  Moved alter_close_tables to sql_partition.cc
sql/sql_base.h:
  removed some non existing and duplicated functions.
sql/sql_partition.cc:
  fast_alter_partition_table:
  Spletted abort_and_upgrad_lock_and_close_table
  to its parts (wait_while_table_is_used and
  alter_close_tables) and always have
  wait_while_table_is_used before any persistent
  operations (including logs, which will be executed
  on failure) and alter_close_tables after
  create/read/write operations and before
  drop operations.
  
  moved alter_close_tables here from sql_base.cc
  
  Added error injections for better test coverage.
  
  write_log_final_change_partition:
  fixed a log_entry linking bug (delete_frm was not
  linked to change/drop partition)
  and drop partition must be executed before
  change partition (change partition can rename a
  partition to an old name, like REORG p1 INTO (p1,p2).
  
  write_log_add_change_partition:
  need to use drop_frm first, and relinking that entry
  and reusing its execute entry.
sql/sql_table.cc:
  added initialization of next_active_log_entry.
sql/table.h:
  removed a duplicate declaration.
2010-08-13 09:50:25 +02:00
Mattias Jonsson
9a7a64acdb Bug#53676: Unexpected errors and possible table
corruption on ADD PARTITION and LOCK TABLE
Bug#53770: Server crash at handler.cc:2076 on
           LOAD DATA after timed out COALESCE PARTITION

5.5 fix for:
Bug#51042: REORGANIZE PARTITION can leave table in an
           inconsistent state in case of crash
Needs to be back-ported to 5.1

5.5 fix for:
Bug#50418: DROP PARTITION does not interact with
           transactions

Main problem was non-persistent operations done
before meta-data lock was taken (53770+53676).
And 53676 needed to keep the table/partitions opened and locked
while copying the data to the new partitions.

Also added thorough tests to spot some additional bugs
in the ddl_log code, which could result in bad state
between the .frm and partitions.

Collapsed patch, includes all fixes required from the reviewers.
2010-08-13 09:50:25 +02:00
Konstantin Osipov
82759db0cc Remove dead code.
sql/sql_base.h:
  Remove an unused parameter.
sql/sql_servers.cc:
  Remove an unused parameter.
2010-08-12 20:44:41 +04:00
Konstantin Osipov
7349ddae6f Remove dead code. 2010-08-12 20:44:41 +04:00
Konstantin Osipov
29c4873ad5 Commit on behalf of Dmitry Lenev.
Merge his patch for Bug#52044 into 5.5, and apply 
review comments.
2010-08-12 17:50:23 +04:00
Konstantin Osipov
8673d2b20f Commit on behalf of Dmitry Lenev.
Merge his patch for Bug#52044 into 5.5, and apply 
review comments.
2010-08-12 17:50:23 +04:00
Konstantin Osipov
523066987d A fix for Bug#41158 "DROP TABLE holds LOCK_open during unlink()".
Remove acquisition of LOCK_open around file system operations,
since such operations are now protected by metadata locks.
Rework table discovery algorithm to not require LOCK_open.

No new tests added since all MDL locking operations are covered
in lock.test and mdl_sync.test, and as long as these tests
pass despite the increased concurrency, consistency must be
unaffected.

mysql-test/t/disabled.def:
  Disable NDB tests due to Bug#55799.
sql/datadict.cc:
  No longer necessary to protect ha_create_table() with
  LOCK_open. Serial execution is now ensured by metadata
  locks.
sql/ha_ndbcluster.cc:
  Do not manipulate with LOCK_open in cluster code.
sql/ha_ndbcluster_binlog.cc:
  Do not manipulate with LOCK_open in cluster code.
sql/ha_ndbcluster_binlog.h:
  Update function signature.
sql/handler.cc:
  Implement ha_check_if_table_exists().
  @todo: some engines provide ha_table_exists_in_engine()
  handlerton call, for those we perhaps shouldn't
  call ha_discover(), to be more efficient.
  Since currently it's only NDB, postpone till
  integration with NDB.
sql/handler.h:
  Declare ha_check_if_table_exists() function.
sql/mdl.cc:
  Remove an obsolete comment.
sql/sql_base.cc:
  Update to a new signature of close_cached_tables():
  from now on we always call it without LOCK_open.
  Update comments.
  Remove get_table_share_with_create(), we should
  not attempt to create a table under LOCK_open.
  Introduce get_table_share_with_discover() instead,
  which would request a back off action if the table
  exists in engine.
  Remove acquisition of LOCK_open for 
  data dictionary operations, such as check_if_table_exists().
  Do not use get_table_share_with_create/discover for views,
  where it's not needed.
  Make tdc_remove_table() optionally acquire LOCK_open
  to simplify usage of this function.
  Use the right mutex in the partitioning code when
  manipulating with thd->open_tables.
sql/sql_base.h:
  Update signatures of changes functions.
sql/sql_insert.cc:
  Do not wrap quick_rm_table() with LOCK_open acquisition, 
  this is unnecessary.
sql/sql_parse.cc:
  Update to the new calling convention of tdc_remove_table().
  Update to the new signature of close_cached_tables().
  Update comments.
sql/sql_rename.cc:
  Update to the new calling convention of tdc_remove_table().
  Remove acquisition of LOCK_open around filesystem
  operations.
sql/sql_show.cc:
  Remove get_trigger_table_impl().
  Do not acquire LOCK_open for a dirty read of the trigger
  file.
sql/sql_table.cc:
  Do not acquire LOCK_open for filesystem operations.
sql/sql_trigger.cc:
  Do not require LOCK_open for trigger file I/O.
sql/sql_truncate.cc:
  Update to the new signature of tdc_remove_table().
sql/sql_view.cc:
  Do not require LOCK_open for view I/O.
  Use tdc_remove_table() to expel view share.
  Update comments.
sql/sys_vars.cc:
  Update to the new signature of close_cached_tables().
2010-08-09 22:33:47 +04:00
Konstantin Osipov
f8bfa3287d A fix for Bug#41158 "DROP TABLE holds LOCK_open during unlink()".
Remove acquisition of LOCK_open around file system operations,
since such operations are now protected by metadata locks.
Rework table discovery algorithm to not require LOCK_open.

No new tests added since all MDL locking operations are covered
in lock.test and mdl_sync.test, and as long as these tests
pass despite the increased concurrency, consistency must be
unaffected.
2010-08-09 22:33:47 +04:00
Konstantin Osipov
a91a5ee3bf Cleanup: remove unused declarations from sql_base.h.
sql/sql_base.cc:
  Update a comment to not refer to a non-existing
  function.
sql/sql_base.h:
  Remove unused declarations (bad merge with the header
  files split worklog).
sql/sql_test.cc:
  Cleanup: remove unused declarations.
2010-08-04 20:29:13 +04:00
Konstantin Osipov
6a447d1047 Cleanup: remove unused declarations from sql_base.h. 2010-08-04 20:29:13 +04:00
Konstantin Osipov
d85c628180 Merge trunk-bugfixing -> trunk-runtime. 2010-07-29 14:18:13 +04:00
Konstantin Osipov
14b769cfc6 Merge trunk-bugfixing -> trunk-runtime. 2010-07-29 14:18:13 +04:00
Dmitry Lenev
00496b7acd Fix for bug "FLUSH TABLES WITH READ LOCK and FLUSH
TABLES <list> WITH READ LOCK are incompatible".

The problem was that FLUSH TABLES <list> WITH READ LOCK
which was issued when other connection has acquired global
read lock using FLUSH TABLES WITH READ LOCK was blocked
and has to wait until global read lock is released.

This issue stemmed from the fact that FLUSH TABLES <list>
WITH READ LOCK implementation has acquired X metadata locks
on tables to be flushed. Since these locks required acquiring
of global IX lock this statement was incompatible with global
read lock.

This patch addresses problem by using SNW metadata type of
lock for tables to be flushed by FLUSH TABLES <list> WITH
READ LOCK. It is OK to acquire them without global IX lock
as long as we won't try to upgrade those locks. Since SNW
locks allow concurrent statements using same table FLUSH
TABLE <list> WITH READ LOCK now has to wait until old
versions of tables to be flushed go away after acquiring
metadata locks. Since such waiting can lead to deadlock
MDL deadlock detector was extended to take into account
waits for flush and resolve such deadlocks.

As a bonus code in open_tables() which was responsible for
waiting old versions of tables to go away was refactored.
Now when we encounter old version of table in open_table()
we don't back-off and wait for all old version to go away,
but instead wait for this particular table to be flushed.
Such approach supported by deadlock detection should reduce
number of scenarios in which FLUSH TABLES aborts concurrent
multi-statement transactions.

Note that active FLUSH TABLES <list> WITH READ LOCK still
blocks concurrent FLUSH TABLES WITH READ LOCK statement
as the former keeps tables open and thus prevents the
latter statement from doing flush.

mysql-test/include/handler.inc:
  Adjusted test case after changing status which is set
  when FLUSH TABLES waits for tables to be flushed from
  "Flushing tables" to "Waiting for table".
mysql-test/r/flush.result:
  Added test which checks that "flush tables <list> with
  read lock" is compatible with active "flush tables with
  read lock" but not vice-versa. This test also covers
  bug  "FLUSH TABLES WITH READ LOCK and FLUSH TABLES
  <list> WITH READ LOCK are incompatible".
mysql-test/r/mdl_sync.result:
  Added scenarios in which wait for table to be flushed
  causes deadlocks to the coverage of MDL deadlock detector.
mysql-test/suite/perfschema/r/dml_setup_instruments.result:
  Adjusted test results after removal of COND_refresh
  condition variable.
mysql-test/suite/perfschema/r/server_init.result:
  Adjusted test and its results after removal of COND_refresh
  condition variable.
mysql-test/suite/perfschema/t/server_init.test:
  Adjusted test and its results after removal of COND_refresh
  condition variable.
mysql-test/t/flush.test:
  Added test which checks that "flush tables <list> with
  read lock" is compatible with active "flush tables with
  read lock" but not vice-versa. This test also covers
  bug  "FLUSH TABLES WITH READ LOCK and FLUSH TABLES
  <list> WITH READ LOCK are incompatible".
mysql-test/t/kill.test:
  Adjusted test case after changing status which is set
  when FLUSH TABLES waits for tables to be flushed from
  "Flushing tables" to "Waiting for table".
mysql-test/t/lock_multi.test:
  Adjusted test case after changing status which is set
  when FLUSH TABLES waits for tables to be flushed from
  "Flushing tables" to "Waiting for table".
mysql-test/t/mdl_sync.test:
  Added scenarios in which wait for table to be flushed
  causes deadlocks to the coverage of MDL deadlock detector.
sql/ha_ndbcluster.cc:
  Adjusted code after adding one more parameter for
  close_cached_tables() call - timeout for waiting for
  table to be flushed.
sql/ha_ndbcluster_binlog.cc:
  Adjusted code after adding one more parameter for
  close_cached_tables() call - timeout for waiting for
  table to be flushed.
sql/lock.cc:
  Removed COND_refresh condition variable. See comment
  for sql_base.cc for details.
sql/mdl.cc:
  Now MDL deadlock detector takes into account information
  about waits for table flushes when searching for deadlock.
  To implement this change:
  - Declaration of enum_deadlock_weight and
    Deadlock_detection_visitor were moved to mdl.h header
    to make them available to the code in table.cc which
    implements deadlock detector traversal through edges
    of waiters graph representing waiting for flush.
  - Since now MDL_context may wait not only for metadata
    lock but also for table to be flushed an abstract
    Wait_for_edge class was introduced. Its descendants
    MDL_ticket and Flush_ticket incapsulate specifics
    of inspecting waiters graph when following through
    edge representing wait of particular type.
  
  We no longer require global IX metadata lock when acquiring
  SNW or SNRW locks. Such locks are needed only when metadata
  locks of these types are upgraded to X locks. This allows
  to use SNW locks in FLUSH TABLES <list> WITH READ LOCK
  implementation and keep the latter compatible with global
  read lock.
sql/mdl.h:
  Now MDL deadlock detector takes into account information
  about waits for table flushes when searching for deadlock.
  To implement this change:
  - Declaration of enum_deadlock_weight and
    Deadlock_detection_visitor were moved to mdl.h header
    to make them available to the code in table.cc which
    implements deadlock detector traversal through edges
    of waiters graph representing waiting for flush.
  - Since now MDL_context may wait not only for metadata
    lock but also for table to be flushed an abstract
    Wait_for_edge class was introduced. Its descendants
    MDL_ticket and Flush_ticket incapsulate specifics
    of inspecting waiters graph when following through
    edge representing wait of particular type.
  - Deadlock_detection_visitor now has m_table_shares_visited
    member which allows to support recursive locking for
    LOCK_open. This is required when deadlock detector
    inspects waiters graph which contains several edges
    representing waits for flushes or needs to come through
    the such edge more than once.
sql/mysqld.cc:
  Removed COND_refresh condition variable. See comment
  for sql_base.cc for details.
sql/mysqld.h:
  Removed COND_refresh condition variable. See comment
  for sql_base.cc for details.
sql/sql_base.cc:
  Changed approach to how threads are waiting for table
  to be flushed. Now thread that wants to wait for old
  table to go away subscribes for notification by adding
  Flush_ticket to table's share and waits using
  MDL_context::m_wait object. Once table gets flushed
  (i.e. all tables are closed and table share is ready
  to be destroyed) all such waiters are notified
  individually.
  Thanks to this change MDL deadlock detector can take
  such waits into account.
  
  To implement this/as result of this change:
  - tdc_wait_for_old_versions() was replaced with
    tdc_wait_for_old_version() which waits for individual
    old share to go away and which is called by open_table()
    after finding out that share is outdated. We don't
    need to perform back-off before such waiting thanks
    to the fact that deadlock detector now sees such waits.
  - As result Open_table_ctx::m_mdl_requests became
    unnecessary and was removed. We no longer allocate
    copies of MDL_request objects on MEM_ROOT when
    MYSQL_OPEN_FORCE_SHARED/SHARED_HIGH_PRIO flags are
    in effect.
  - close_cached_tables() and tdc_wait_for_old_version()
    share code which implements waiting for share to be
    flushed - the both use TABLE_SHARE::wait_until_flush()
    method. Thanks to this close_cached_tables() supports
    timeouts and has extra parameter for this.
  - Open_table_context::OT_MDL_CONFLICT enum element was
    renamed to OT_CONFLICT as it is now also used in cases
    when back-off is required to resolve deadlock caused
    by waiting for flush and not metadata lock.
  - In cases when we discover that current connection tries
    to open tables from different generation we now simply
    back-off and restart process of opening tables. To
    support this Open_table_context::OT_REOPEN_TABLES enum
    element was added.
  - COND_refresh condition variable became unnecessary and
    was removed.
  - mysql_notify_thread_having_shared_lock() no longer wakes
    up connections waiting for flush as all such connections
    can be waken up by deadlock detector if necessary.
sql/sql_base.h:
  - close_cached_tables() now has one more parameter -
    timeout for waiting for table to be flushed.
  - Open_table_context::OT_MDL_CONFLICT enum element was
    renamed to OT_CONFLICT as it is now also used in cases
    when back-off is required to resolve deadlock caused
    by waiting for flush and not metadata lock.
    Added new OT_REOPEN_TABLES enum element to be used in
    cases when we need to restart open tables process even
    in the middle of transaction.
  - Open_table_ctx::m_mdl_requests became unnecessary and
    was removed.
sql/sql_class.h:
  Added assert ensuring that we won't use LOCK_open mutex
  with THD::enter_cond(). Otherwise deadlocks can arise in
  MDL deadlock detector.
sql/sql_parse.cc:
  Changed FLUSH TABLES <list> WITH READ LOCK to take SNW
  metadata locks instead of X locks on tables to be flushed.
  Since we no longer require global IX lock to be taken
  when SNW locks are taken this makes this statement
  compatible with FLUSH TABLES WITH READ LOCK statement.
  Since SNW locks allow other connections to have table
  opened FLUSH TABLES <list> WITH READ LOCK now has to
  wait during open_tables() for old version to go away.
  Such waits can lead to deadlocks which will be detected
  by MDL deadlock detector which now takes waits for table
  to be flushed into account.
  
  Also adjusted code after adding one more parameter for
  close_cached_tables() call - timeout for waiting for
  table to be flushed.
sql/sql_yacc.yy:
  FLUSH TABLES <list> WITH READ LOCK now needs only SNW
  metadata locks on tables.
sql/sys_vars.cc:
  Adjusted code after adding one more parameter for
  close_cached_tables() call - timeout for waiting for
  table to be flushed.
sql/table.cc:
  Implemented new approach to how threads are waiting for
  table to be flushed. Now thread that wants to wait for
  old table to go away subscribes for notification by
  adding Flush_ticket to table's share and waits using
  MDL_context::m_wait object. Once table gets flushed
  (i.e. all tables are closed and table share is ready
  to be destroyed) all such waiters are notified
  individually. This change allows to make such waits
  visible inside of MDL deadlock detector.
  To do it:
  
  - Added list of waiters/Flush_tickets to TABLE_SHARE
    class.
  - Changed free_table_share() to postpone freeing of
    share memory until last waiter goes away and to
    wake up subscribed waiters.
  - Added TABLE_SHARE::wait_until_flushed() method which
    implements subscription to the list of waiters for
    table to be flushed and waiting for this event.
  
  Implemented interface which allows to expose waits for
  flushes to MDL deadlock detector:
  
  - Introduced Flush_ticket class a descendant of
    Wait_for_edge class.
  - Added TABLE_SHARE::find_deadlock() method which allows
    deadlock detector to find out what contexts are still
    using old version of table in question (i.e. to find
    out what contexts are waited for by owner of
    Flush_ticket).
sql/table.h:
  In order to support new strategy of waiting for table flush
  (see comment for table.cc for details) added list of
  waiters/Flush_tickets to TABLE_SHARE class.
  
  Implemented interface which allows to expose waits for
  flushes to MDL deadlock detector:
  - Introduced Flush_ticket class a descendant of
    Wait_for_edge class.
  - Added TABLE_SHARE::find_deadlock() method which allows
    deadlock detector to find out what contexts are still
    using old version of table in question (i.e. to find
    out what contexts are waited for by owner of
    Flush_ticket).
2010-07-27 17:34:58 +04:00
Dmitry Lenev
5fff906edd Fix for bug "FLUSH TABLES WITH READ LOCK and FLUSH
TABLES <list> WITH READ LOCK are incompatible".

The problem was that FLUSH TABLES <list> WITH READ LOCK
which was issued when other connection has acquired global
read lock using FLUSH TABLES WITH READ LOCK was blocked
and has to wait until global read lock is released.

This issue stemmed from the fact that FLUSH TABLES <list>
WITH READ LOCK implementation has acquired X metadata locks
on tables to be flushed. Since these locks required acquiring
of global IX lock this statement was incompatible with global
read lock.

This patch addresses problem by using SNW metadata type of
lock for tables to be flushed by FLUSH TABLES <list> WITH
READ LOCK. It is OK to acquire them without global IX lock
as long as we won't try to upgrade those locks. Since SNW
locks allow concurrent statements using same table FLUSH
TABLE <list> WITH READ LOCK now has to wait until old
versions of tables to be flushed go away after acquiring
metadata locks. Since such waiting can lead to deadlock
MDL deadlock detector was extended to take into account
waits for flush and resolve such deadlocks.

As a bonus code in open_tables() which was responsible for
waiting old versions of tables to go away was refactored.
Now when we encounter old version of table in open_table()
we don't back-off and wait for all old version to go away,
but instead wait for this particular table to be flushed.
Such approach supported by deadlock detection should reduce
number of scenarios in which FLUSH TABLES aborts concurrent
multi-statement transactions.

Note that active FLUSH TABLES <list> WITH READ LOCK still
blocks concurrent FLUSH TABLES WITH READ LOCK statement
as the former keeps tables open and thus prevents the
latter statement from doing flush.
2010-07-27 17:34:58 +04:00
Konstantin Osipov
36290c0923 A pre-requisite patch for the fix for Bug#52044.
This patch also fixes Bug#55452 "SET PASSWORD is
replicated twice in RBR mode".

The goal of this patch is to remove the release of 
metadata locks from close_thread_tables().
This is necessary to not mistakenly release
the locks in the course of a multi-step
operation that involves multiple close_thread_tables()
or close_tables_for_reopen().

On the same token, move statement commit outside 
close_thread_tables().

Other cleanups:
Cleanup COM_FIELD_LIST.
Don't call close_thread_tables() in COM_SHUTDOWN -- there
are no open tables there that can be closed (we leave
the locked tables mode in THD destructor, and this
close_thread_tables() won't leave it anyway).

Make open_and_lock_tables() and open_and_lock_tables_derived()
call close_thread_tables() upon failure.
Remove the calls to close_thread_tables() that are now
unnecessary.

Simplify the back off condition in Open_table_context.

Streamline metadata lock handling in LOCK TABLES 
implementation.

Add asserts to ensure correct life cycle of 
statement transaction in a session.

Remove a piece of dead code that has also become redundant
after the fix for Bug 37521.

mysql-test/r/variables.result:
  Update results: set @@autocommit and statement transaction/
  prelocked mode.
mysql-test/r/view.result:
  A harmless change in CHECK TABLE <view> status for a broken view.
  If previously a failure to prelock all functions used in a view 
  would leave the connection in LTM_PRELOCKED mode, now we call
  close_thread_tables() from open_and_lock_tables()
  and leave prelocked mode, thus some check in mysql_admin_table() that
  works only in prelocked/locked tables mode is no longer activated.
mysql-test/suite/rpl/r/rpl_row_implicit_commit_binlog.result:
  Fixed Bug#55452 "SET PASSWORD is replicated twice in
  RBR mode": extra binlog events are gone from the
  binary log.
mysql-test/t/variables.test:
  Add a test case: set autocommit and statement transaction/prelocked
  mode.
sql/event_data_objects.cc:
  Simplify code in Event_job_data::execute().
  Move sp_head memory management to lex_end().
sql/event_db_repository.cc:
  Move the release of metadata locks outside
  close_thread_tables().
  Make sure we call close_thread_tables() when
  open_and_lock_tables() fails and remove extra
  code from the events data dictionary.
  Use close_mysql_tables(), a new internal
  function to properly close mysql.* tables
  in the data dictionary.
  Contract Event_db_repository::drop_events_by_field,
  drop_schema_events into one function.
  When dropping all events in a schema,
  make sure we don't mistakenly release all
  locks acquired by DROP DATABASE. These
  include locks on the database name
  and the global intention exclusive
  metadata lock.
sql/event_db_repository.h:
  Function open_event_table() does not require an instance 
  of Event_db_repository.
sql/events.cc:
  Use close_mysql_tables() instead of close_thread_tables()
  to bootstrap events, since the latter no longer
  releases metadata locks.
sql/ha_ndbcluster.cc:
  - mysql_rm_table_part2 no longer releases
  acquired metadata locks. Do it in the caller.
sql/ha_ndbcluster_binlog.cc:
  Deploy the new protocol for closing thread
  tables in run_query() and ndb_binlog_index
  code.
sql/handler.cc:
  Assert that we never call ha_commit_trans/
  ha_rollback_trans in sub-statement, which
  is now the case.
sql/handler.h:
  Add an accessor to check whether THD_TRANS object
  is empty (has no transaction started).
sql/log.cc:
  Update a comment.
sql/log_event.cc:
  Since now we commit/rollback statement transaction in 
  mysql_execute_command(), we need a mechanism to communicate
  from Query_log_event::do_apply_event() to mysql_execute_command()
  that the statement transaction should be rolled back, not committed.
  Ideally it would be a virtual method of THD. I hesitate
  to make THD a virtual base class in this already large patch.
  Use a thd->variables.option_bits for now.
  
  Remove a call to close_thread_tables() from the slave IO
  thread. It doesn't open any tables, and the protocol
  for closing thread tables is more complicated now.
  
  Make sure we properly close thread tables, however, 
  in Load_data_log_event, which doesn't
  follow the standard server execution procedure
  with mysql_execute_command().
  @todo: this piece should use Server_runnable
  framework instead.
  Remove an unnecessary call to mysql_unlock_tables().
sql/rpl_rli.cc:
  Update Relay_log_info::slave_close_thread_tables()
  to follow the new close protocol.
sql/set_var.cc:
  Remove an unused header.
sql/slave.cc:
  Remove an unnecessary call to
  close_thread_tables().
sql/sp.cc:
  Remove unnecessary calls to close_thread_tables()
  from SP DDL implementation. The tables will
  be closed by the caller, in mysql_execute_command().
  When dropping all routines in a database, make sure
  to not mistakenly drop all metadata locks acquired
  so far, they include the scoped lock on the schema.
sql/sp_head.cc:
  Correct the protocol that closes thread tables
  in an SP instruction.
  Clear lex->sphead before cleaning up lex
  with lex_end to make sure that we don't
  delete the sphead twice. It's considered
  to be "cleaner" and more in line with
  future changes than calling delete lex->sphead
  in other places that cleanup the lex.
sql/sp_head.h:
  When destroying m_lex_keeper of an instruction,
  don't delete the sphead that all lex objects
  share. 
  @todo: don't store a reference to routine's sp_head
  instance in instruction's lex.
sql/sql_acl.cc:
  Don't call close_thread_tables() where the caller will
  do that for us.
  Fix Bug#55452 "SET PASSWORD is replicated twice in RBR 
  mode" by disabling RBR replication in change_password()
  function.
  Use close_mysql_tables() in bootstrap and ACL reload
  code to make sure we release all metadata locks.
sql/sql_base.cc:
  This is the main part of the patch:
  - remove manipulation with thd->transaction
  and thd->mdl_context from close_thread_tables().
  Now this function is only responsible for closing
  tables, nothing else.
  This is necessary to be able to easily use
  close_thread_tables() in procedures, that
  involve multiple open/close tables, which all
  need to be protected continuously by metadata
  locks.
  Add asserts ensuring that TABLE object
  is only used when is protected by a metadata lock.
  Simplify the back off condition of Open_table_context,
  we no longer need to look at the autocommit mode.
  Make open_and_lock_tables() and open_normal_and_derived_tables()
  close thread tables and release metadata locks acquired so-far 
  upon failure. This simplifies their usage.
  Implement close_mysql_tables().
sql/sql_base.h:
  Add declaration for close_mysql_tables().
sql/sql_class.cc:
  Remove a piece of dead code that has also become redundant
  after the fix for Bug 37521.
  The code became dead when my_eof() was made a non-protocol method,
  but a method that merely modifies the diagnostics area.
  The code became redundant with the fix for Bug#37521, when 
  we started to cal close_thread_tables() before
  Protocol::end_statement().
sql/sql_do.cc:
  Do nothing in DO if inside a substatement
  (the assert moved out of trans_rollback_stmt).
sql/sql_handler.cc:
  Add comments.
sql/sql_insert.cc:
  Remove dead code. 
  Release metadata locks explicitly at the
  end of the delayed insert thread.
sql/sql_lex.cc:
  Add destruction of lex->sphead to lex_end(),
  lex "reset" method called at the end of each statement.
sql/sql_parse.cc:
  Move close_thread_tables() and other related
  cleanups to mysql_execute_command()
  from dispatch_command(). This has become
  possible after the fix for Bug#37521.
  Mark federated SERVER statements as DDL.
  
  Next step: make sure that we don't store
  eof packet in the query cache, and move
  the query cache code outside mysql_parse.
  
  Brush up the code of COM_FIELD_LIST.
  Remove unnecessary calls to close_thread_tables().
  
  When killing a query, don't report "OK"
  if it was a suicide.
sql/sql_parse.h:
  Remove declaration of a function that is now static.
sql/sql_partition.cc:
  Remove an unnecessary call to close_thread_tables().
sql/sql_plugin.cc:
  open_and_lock_tables() will clean up
  after itself after a failure.
  Move close_thread_tables() above
  end: label, and replace with close_mysql_tables(),
  which will also release the metadata lock
  on mysql.plugin.
sql/sql_prepare.cc:
  Now that we no longer release locks in close_thread_tables()
  statement prepare code has become more straightforward.
  Remove the now redundant check for thd->killed() (used
  only by the backup project) from Execute_server_runnable.
  Reorder code to take into account that now mysql_execute_command()
  performs lex->unit.cleanup() and close_thread_tables().
sql/sql_priv.h:
  Add a new option to server options to interact
  between the slave SQL thread and execution
  framework (hack). @todo: use a virtual
  method of class THD instead.
sql/sql_servers.cc:
  Due to Bug 25705 replication of 
  DROP/CREATE/ALTER SERVER is broken.
  Make sure at least we do not attempt to 
  replicate these statements using RBR,
  as this violates the assert in close_mysql_tables().
sql/sql_table.cc:
  Do not release metadata locks in mysql_rm_table_part2,
  this is done by the caller.
  Do not call close_thread_tables() in mysql_create_table(),
  this is done by the caller. 
  Fix a bug in DROP TABLE under LOCK TABLES when,
  upon error in wait_while_table_is_used() we would mistakenly
  release the metadata lock on a non-dropped table.
  Explicitly release metadata locks when doing an implicit
  commit.
sql/sql_trigger.cc:
  Now that we delete lex->sphead in lex_end(),
  zero the trigger's sphead in lex after loading
  the trigger, to avoid double deletion.
sql/sql_udf.cc:
  Use close_mysql_tables() instead of close_thread_tables().
sql/sys_vars.cc:
  Remove code added in scope of WL#4284 which would
  break when we perform set @@session.autocommit along
  with setting other variables and using tables or functions.
  A test case added to variables.test.
sql/transaction.cc:
  Add asserts.
sql/tztime.cc:
  Use close_mysql_tables() rather than close_thread_tables().
2010-07-27 14:25:53 +04:00
Konstantin Osipov
ec2c3bf2c1 A pre-requisite patch for the fix for Bug#52044.
This patch also fixes Bug#55452 "SET PASSWORD is
replicated twice in RBR mode".

The goal of this patch is to remove the release of 
metadata locks from close_thread_tables().
This is necessary to not mistakenly release
the locks in the course of a multi-step
operation that involves multiple close_thread_tables()
or close_tables_for_reopen().

On the same token, move statement commit outside 
close_thread_tables().

Other cleanups:
Cleanup COM_FIELD_LIST.
Don't call close_thread_tables() in COM_SHUTDOWN -- there
are no open tables there that can be closed (we leave
the locked tables mode in THD destructor, and this
close_thread_tables() won't leave it anyway).

Make open_and_lock_tables() and open_and_lock_tables_derived()
call close_thread_tables() upon failure.
Remove the calls to close_thread_tables() that are now
unnecessary.

Simplify the back off condition in Open_table_context.

Streamline metadata lock handling in LOCK TABLES 
implementation.

Add asserts to ensure correct life cycle of 
statement transaction in a session.

Remove a piece of dead code that has also become redundant
after the fix for Bug 37521.
2010-07-27 14:25:53 +04:00
Luis Soares
9a714c935f BUG#55387: binlog.binlog_tmp_table crashes the server
sporadically

There are two problems:

1. When closing temporary tables, during the THD clean up - and
   after the session connection was already closed, there is a
   chance we can push an error into the THD diagnostics area, if
   the writing of the implicit DROP event to the binary log fails
   for some reason. As a consequence an assertion can be
   triggered, because at that point the diagnostics area is
   already set.

2. Using push_warning with MYSQL_ERROR::WARN_LEVEL_ERROR is a 
   bug.

Given that close_temporary_tables is mostly called from
THD::cleanup - ie, with the session already closed, we fix
problem  by allowing the diagnostics area to be
overwritten. There is one other place in the code that calls
close_temporary_tables - while applying Start_log_event_v3. To
cover that case, we make close_temporary_tables to return the
error, thus, propagating upwards in the stack.

To fix problem , we replace push_warning with sql_print_error.

sql/log_event.cc:
  Added handling of error returned by close_temporary_tables to
  Start_log_event_v3::do_apply_event.
sql/sql_base.cc:
  Three changes to close_temporary_tables:
  1. it returns a boolean now (instead of void)
  2. it uses sql_print_error instead of push_warning when writing to
     binary log fails
  3. we set can_overwrite_status before writing to the binary log,
     thence not risking triggering an assertion by any other push
     into diagnostics area happening inside mysql_bin_log.write.
sql/sql_base.h:
  Changed the interface of close_temporary_tables so that it returns
  bool instead of void.
2010-07-22 16:56:50 +01:00
Luis Soares
2773385dd7 BUG#55387: binlog.binlog_tmp_table crashes the server
sporadically

There are two problems:

1. When closing temporary tables, during the THD clean up - and
   after the session connection was already closed, there is a
   chance we can push an error into the THD diagnostics area, if
   the writing of the implicit DROP event to the binary log fails
   for some reason. As a consequence an assertion can be
   triggered, because at that point the diagnostics area is
   already set.

2. Using push_warning with MYSQL_ERROR::WARN_LEVEL_ERROR is a 
   bug.

Given that close_temporary_tables is mostly called from
THD::cleanup - ie, with the session already closed, we fix
problem  by allowing the diagnostics area to be
overwritten. There is one other place in the code that calls
close_temporary_tables - while applying Start_log_event_v3. To
cover that case, we make close_temporary_tables to return the
error, thus, propagating upwards in the stack.

To fix problem , we replace push_warning with sql_print_error.
2010-07-22 16:56:50 +01:00
Dmitry Lenev
10582e2abe A follow-up for 5.5 version of fix for bug#54360 "Deadlock
DROP/ALTER/CREATE DATABASE with open HANDLER".

Remove wait_for_condition() which became unused after 
database locks were replaced with MDL scoped locks.
If one needs functionality provided by this call one can 
always use THD::enter_cond()/exit_cond() methods.

Also removed an unused include from sql_db.cc and updated 
comment describing one of used includes to reflect current
situation.
2010-07-01 18:58:47 +04:00
Dmitry Lenev
8ad1aa562f A follow-up for 5.5 version of fix for bug#54360 "Deadlock
DROP/ALTER/CREATE DATABASE with open HANDLER".

Remove wait_for_condition() which became unused after 
database locks were replaced with MDL scoped locks.
If one needs functionality provided by this call one can 
always use THD::enter_cond()/exit_cond() methods.

Also removed an unused include from sql_db.cc and updated 
comment describing one of used includes to reflect current
situation.
2010-07-01 18:58:47 +04:00
Jon Olav Hauglid
9ff272fbbd A 5.5 version of the fix for Bug "Deadlock DROP/ALTER/CREATE
DATABASE with open HANDLER"

Remove LOCK_create_db, database name locks, and use metadata locks instead.
This exposes CREATE/DROP/ALTER DATABASE statements to the graph-based
deadlock detector in MDL, and paves the way for a safe, deadlock-free
implementation of RENAME DATABASE.

Database DDL statements will now take exclusive metadata locks on
the database name, while table/view/routine DDL statements take
intention exclusive locks on the database name. This prevents race
conditions between database DDL and table/view/routine DDL.
(e.g. DROP DATABASE with concurrent CREATE/ALTER/DROP TABLE)

By adding database name locks, this patch implements
WL#4450 "DDL locking: CREATE/DROP DATABASE must use database locks" and
WL#4985 "DDL locking: namespace/hierarchical locks".

The patch also changes code to use init_one_table() where appropriate.
The new lock_table_names() function requires TABLE_LIST::db_length to
be set correctly, and this is taken care of by init_one_table().

This patch also adds a simple template to help work with 
the mysys HASH data structure.

Most of the patch was written by Konstantin Osipov.
2010-07-01 15:53:46 +02:00
Jon Olav Hauglid
41a3dfe490 A 5.5 version of the fix for Bug "Deadlock DROP/ALTER/CREATE
DATABASE with open HANDLER"

Remove LOCK_create_db, database name locks, and use metadata locks instead.
This exposes CREATE/DROP/ALTER DATABASE statements to the graph-based
deadlock detector in MDL, and paves the way for a safe, deadlock-free
implementation of RENAME DATABASE.

Database DDL statements will now take exclusive metadata locks on
the database name, while table/view/routine DDL statements take
intention exclusive locks on the database name. This prevents race
conditions between database DDL and table/view/routine DDL.
(e.g. DROP DATABASE with concurrent CREATE/ALTER/DROP TABLE)

By adding database name locks, this patch implements
WL#4450 "DDL locking: CREATE/DROP DATABASE must use database locks" and
WL#4985 "DDL locking: namespace/hierarchical locks".

The patch also changes code to use init_one_table() where appropriate.
The new lock_table_names() function requires TABLE_LIST::db_length to
be set correctly, and this is taken care of by init_one_table().

This patch also adds a simple template to help work with 
the mysys HASH data structure.

Most of the patch was written by Konstantin Osipov.
2010-07-01 15:53:46 +02:00
Konstantin Osipov
33c57e2f9e WL#5419 "LOCK_open scalability: make tdc_refresh_version
an atomic counter"

Split the large LOCK_open section in open_table(). 
Do not call open_table_from_share() under LOCK_open.
Remove thd->version.

This fixes
Bug#50589 "Server hang on a query evaluated using a temporary 
table"
Bug#51557 "LOCK_open and kernel_mutex are not happy together"
Bug#49463 "LOCK_table and innodb are not nice when handler 
instances are created".

This patch has effect on storage engines that rely on
ha_open() PSEA method being called under LOCK_open.
In particular:

1) NDB is broken and left unfixed. NDB relies on LOCK_open
being kept as part of ha_open(), since it uses auto-discovery.
While previously the NDB open code was race-prone, now
it simply fails on asserts.

2) HEAP engine had a race in ha_heap::open() when
a share for the same table could be added twice
to the list of shares, or a dangling reference to a share
stored in HEAP handler. This patch aims to address this
problem by 'pinning' the newly created share in the 
internal HEAP engine share list until at least one
handler instance is created using that share.


include/heap.h:
  Add members to HP_CREATE_INFO.
  Declare heap_release_share().
sql/lock.cc:
  Remove thd->version, use thd->open_tables->s->version instead.
sql/repl_failsafe.cc:
  Remove thd->version.
sql/sql_base.cc:
  - close_thread_table(): move handler cleanup code outside the critical section protected by LOCK_open.
  - remove thd->version
  - split the large critical section in open_table() that
  opens a new table from share and is protected by LOCK_open
  into 2 critical sections, thus reducing the critical path.
  - make check_if_table_exists() acquire LOCK_open internally.
  - use thd->open_tables->s->version instead of thd->refresh_version to make sure that all tables in
  thd->open_tables are in the same refresh series.
sql/sql_base.h:
  Add declaration for check_if_table_exists().
sql/sql_class.cc:
  Remove init_open_tables_state(), it's now equal to
  reset_open_tables_state().
sql/sql_class.h:
  Remove thd->version, THD::init_open_tables_state().
sql/sql_plugin.cc:
  Use table->m_needs_reopen to mark the table as stale
  rather than manipulate with thd->version, which is no more.
sql/sql_udf.cc:
  Use table->m_needs_reopen to mark the table as stale
  rather than manipulate with thd->version, which is no more.
sql/table.h:
  Remove an unused variable.
sql/tztime.cc:
  Use table->m_needs_reopen to mark the table as stale
  rather than manipulate with thd->version, which is no more.
storage/heap/CMakeLists.txt:
  Add heap tests to cmake build files.
storage/heap/ha_heap.cc:
  Fix a race when ha_heap::ha_open() could insert two 
  HP_SHARE objects into the internal share list or store
  a dangling reference to a share in ha_heap instance,
  or wrongly set implicit_emptied.
storage/heap/hp_create.c:
  Optionally pin a newly created share in the list of shares
  by increasing its open_count. This is necessary to 
  make sure that a newly created share doesn't disappear while
  a HP_INFO object is being created to reference it.
storage/heap/hp_open.c:
  When adding a new HP_INFO object to the list of objects
  in the heap share, make sure the open_count is not increased
  twice.
storage/heap/hp_test1.c:
  Adjust the test to new function signatures.
storage/heap/hp_test2.c:
  Adjust the test to new function signatures.
2010-06-11 19:28:18 +04:00
Konstantin Osipov
b140456601 WL#5419 "LOCK_open scalability: make tdc_refresh_version
an atomic counter"

Split the large LOCK_open section in open_table(). 
Do not call open_table_from_share() under LOCK_open.
Remove thd->version.

This fixes
Bug#50589 "Server hang on a query evaluated using a temporary 
table"
Bug#51557 "LOCK_open and kernel_mutex are not happy together"
Bug#49463 "LOCK_table and innodb are not nice when handler 
instances are created".

This patch has effect on storage engines that rely on
ha_open() PSEA method being called under LOCK_open.
In particular:

1) NDB is broken and left unfixed. NDB relies on LOCK_open
being kept as part of ha_open(), since it uses auto-discovery.
While previously the NDB open code was race-prone, now
it simply fails on asserts.

2) HEAP engine had a race in ha_heap::open() when
a share for the same table could be added twice
to the list of shares, or a dangling reference to a share
stored in HEAP handler. This patch aims to address this
problem by 'pinning' the newly created share in the 
internal HEAP engine share list until at least one
handler instance is created using that share.
2010-06-11 19:28:18 +04:00
Konstantin Osipov
90a87cd52d A pre-requisite for WL#5419 "LOCK_open scalability:
make tdc_refresh_version an 
atomic counter".
Backport the trivial changes from mysql-trunk-iplus.
2010-06-10 15:43:32 +04:00
Konstantin Osipov
41d95c5049 A pre-requisite for WL#5419 "LOCK_open scalability:
make tdc_refresh_version an 
atomic counter".
Backport the trivial changes from mysql-trunk-iplus.
2010-06-10 15:43:32 +04:00
Dmitry Lenev
9dbd9ce185 Patch that changes approach to how we acquire metadata
locks for DML statements and changes the way MDL locks
are acquired/granted in contended case.

Instead of backing-off when a lock conflict is encountered
and waiting for it to go away before restarting open_tables()
process we now wait for lock to be released without releasing
any previously acquired locks. If conflicting lock goes away
we resume opening tables. If waiting leads to a deadlock we
try to resolve it by backing-off and restarting open_tables()
immediately.

As result both waiting for possibility to acquire and
acquiring of a metadata lock now always happen within the
same MDL API call. This has allowed to make release of a lock
and granting it to the most appropriate pending request an
atomic operation.
Thanks to this it became possible to wake up during release
of lock only those waiters which requests can be satisfied
at the moment as well as wake up only one waiter in case
when granting its request would prevent all other requests
from being satisfied. This solves thundering herd problem
which occured in cases when we were releasing some lock and
woke up many waiters for SNRW or X locks (this was the issue
in bug#52289 "performance regression for MyISAM in sysbench
OLTP_RW test".
This also allowed to implement more fair (FIFO) scheduling
among waiters with the same priority.
It also opens the door for introducing new types of requests
for metadata locks such as low-prio SNRW lock which is
necessary in order to support LOCK TABLES LOW_PRIORITY WRITE.

Notice that after this sometimes can report ER_LOCK_DEADLOCK
error in cases in which it has not happened before.
Particularly we will always report this error if waiting for
conflicting lock has happened in the middle of transaction
and resulted in a deadlock. Before this patch the error was
not reported if deadlock could have been resolved by backing
off all metadata locks acquired by the current statement.

mysql-test/r/mdl_sync.result:
  Added test coverage for some aspects of deadlock handling in
  metadata locking subsystem.
  Adjusted test case after removing back-off in general case
  when conflicting metadata lock is encountered during
  open_tables() (now this happens only if waiting for
  conflicting lock to go away leads to a deadlock).
mysql-test/r/sp_sync.result:
  Adjusted test case after removing back-off in general case
  when conflicting metadata lock is encountered during
  open_tables() (now this happens only if waiting for
  conflicting lock to go away leads to a deadlock).
mysql-test/suite/perfschema/r/dml_setup_instruments.result:
  Adjusted test results after renaming MDL_context::
  m_waiting_for_lock rwlock to m_LOCK_waiting_for.
mysql-test/suite/rpl/r/rpl_sp.result:
  Adjusted test case after implementing new approach to
  acquiring metadata locks in open_tables(). We no longer
  release all MDL locks acquired by statement before waiting
  for conflicting lock to go away. As result DROP FUNCTION
  statement has to wait for DML statement which managed to
  acquire metadata lock on function being dropped and now
  waits for other conflicting metadata lock to go away.
mysql-test/suite/rpl/t/rpl_sp.test:
  Adjusted test case after implementing new approach to
  acquiring metadata locks in open_tables(). We no longer
  release all MDL locks acquired by statement before waiting
  for conflicting lock to go away. As result DROP FUNCTION
  statement has to wait for DML statement which managed to
  acquire metadata lock on function being dropped and now
  waits for other conflicting metadata lock to go away.
mysql-test/t/mdl_sync.test:
  Added test coverage for some aspects of deadlock handling in
  metadata locking subsystem.
  Adjusted test case after removing back-off in general case
  when conflicting metadata lock is encountered during
  open_tables() (now this happens only if waiting for
  conflicting lock to go away leads to a deadlock).
mysql-test/t/sp_sync.test:
  Adjusted test case after removing back-off in general case
  when conflicting metadata lock is encountered during
  open_tables() (now this happens only if waiting for
  conflicting lock to go away leads to a deadlock).
sql/mdl.cc:
  Changed MDL subsystem to support new approach to acquring
  metadata locks in open tables and more fair and efficient
  scheduling of metadata locks. To implement this:
  - Made releasing of the lock and granting it to the most
    appropriate pending request atomic operation. As result it
    became possible to wake up only those waiters requests from
    which can be satisfied at the moment as well as wake-up
    only one waiter in case when granting its request would
    prevent all other requests from being satisfied.
    This solved thundering herd problem which occured in cases
    when we were releasing some lock and woke up many waiters
    for SNRW or X locks (this was the issue in Bug 
    "performance regression for MyISAM in sysbench OLTP_RW
    test".
    To emphasize above changes wake_up_waiters() was renamed
    to MDL_context::reschedule_waiters().
  - Changed code to add tickets for new requests to the back of
    waiters queue and to select tickets to be satisfied from
    the head of the queue if possible (this makes scheduling of
    requests with the same priority fair). To be able to do
    this efficiently we now use for waiting and granted queues
    version of I_P_List class which provides fast push_back()
    method.
  - Members and methods of MDL_context related to sending
    and waiting for signal were moved to separate MDL_wait
    class.
  - Since in order to avoid race conditions we must grant the
    lock only to the context which was not chosen as a victim
    of deadlock, killed or aborted due to timeout
    MDL_wait::set_status() (former awake()) was changed not to
    send signal if signal slot is already occupied and to
    indicate this fact through its return value. As another
    consequence MDL_wait::timed_wait() method was changed to
    handle timeout (optionally) and abort due to kill as
    signals which make signal slot occupied.
  - Renamed MDL_context::acquire_lock_impl() to acquire_lock().
    Changed it to be able correctly process requests for shared
    locks when there are open HANDLERs, made this method more
    optimized for acquisition of shared locks. As part of this
    change moved code common between try_acquire_lock() and
    acquire_lock() to new try_acquire_lock_impl() method.
    Also adjusted acquire_lock()'s code to take into account
    the fact that in cases when lock is granted as result of
    MDL_context::reschedule_waiters() call (i.e. when it is
    granted after waiting for lock conflict to go away)
    updating MDL_lock state is responsibility of the thread
    calling reschedule_waiters().
  - Changed MDL_context::find_deadlock() to send VICTIM
    signal even if victim is the context which has initiated
    deadlock detection. This is required in order to avoid
    races in cases when the same context simultaneously is
    chosen as a victim and its request for lock is satisfied.
    As result return value of this method became unnecessary
    and it was changed to return void.
    Adjusted MDL_lock::find_deadlock() method to take into
    account that now there can be a discrepancy between
    MDL_context::m_waiting_for value being set and real state
    of the ticket this member points to.
  - Renamed MDL_context::m_waiting_for_lock to m_LOCK_waiting_for
    and MDL_context::stop_waiting() to done_waiting_for().
  - Finally, removed MDL_context::wait_for_lock() method.
sql/mdl.h:
  Changed MDL subsystem to support new approach to acquring
  metadata locks in open tables and more fair and efficient
  scheduling of metadata locks. To implement this:
  - Members and methods of MDL_context related to sending
    and waiting for signal were moved to separate MDL_wait
    class.
  - Since now in order to avoid race conditions we must grant
    the lock only to the context which was not chosen as a
    victim of deadlock, killed or aborted due to timeout
    MDL_wait::set_status (former awake()) was changed not to
    send signal if signal slot is already occupied and to
    indicate this fact through its return value.
    Also NORMAL_WAKE_UP signal became GRANTED, and timeouts
    and aborts due to kill became full blown signals rather
    than simple return values.
  - MDL_wait::timed_wait() now takes extra parameter that
    indicates whether signal should be set if timeout is
    reached.
  - Enabled fast push_back() operation in MDL_context::m_tickets
    list to make move_ticket_after_trans_sentinel() method more
    efficient.
  - Removed MDL_context::wait_for_lock() method.
  - Renamed MDL_context::m_waiting_for_lock to m_LOCK_waiting_for
    and MDL_context::stop_waiting() to done_waiting_for().
  - MDL_context::acquire_lock_impl() became acquire_lock().
  - Introduced MDL_context::try_acquire_lock_impl() as a
    place for code shared by try_acquire_lock and
    acquire_lock().
  - Due to fact that now VICTIM signal is sent even if victim
    is the context which has initiated deadlock detection
    find_deadlock() no longer needs a return value.
sql/sql_base.cc:
  Implemented new approach to acquiring metadata locks in
  open_tables(). We no longer perform back-off when conflicting
  metadata lock is encountered. Instead we wait for this lock
  to go away while holding all locks which were acquired so
  far. Back-off is only used in situation when further waiting
  will cause a deadlock which could be avoided by performing
  back-off and restarting open_tables() process. Absence of
  waiting between back-off and restart of acquiring metadata
  locks can't lead to livelocks as MDL subsystem was changed
  to make release of lock and granting it to waiting lock
  an atomic action, so back-off will automatically give way
  to other participants of deadlock loop.
  Accordingly:
  - open_table_get_mdl_lock() and open_and_process_routine()
    were changed to wait for conflicting metadata lock to
    go away without back-off. Only if such wait leads to a
    deadlock back-off is requested. As part of this change
    new error handler class was introduced which converts,
    if possible, ER_LOCK_DEADLOCK error to a request for
    back-off and re-start of open_tables() process.
  - Open_table_context::recover_from_failed_open() was changed
    not to wait in case of metadata lock conflict. Instead we
    immediately proceed to re-acquiring locks.
  - Open_table_context::request_backoff_action() now always
    emits error if back-off is requested in the middle of
    transaction as we can't be sure that releasing lock
    which were acquired only by current statement will
    resolve a deadlock. Before this patch such situations were
    successfully detected thanks to the fact that we called
    MDL_context::wait_for_lock() method in
    recover_from_failed_open().
  - In order to avoid deadlocks open_tables() code was adjusted
    to flush open HANDLERs for which there are pending requests
    for X locks before restarting the process of acquiring
    metadata locks.
  - Changed close_tables_for_reopen() not to reset MDL_request
    for tables belonging to the tail of prelocking list. It is
    no longer necessary as these MDL_request objects won't be
    used for any waiting.
  - Adjusted comment in tdc_wait_for_old_version() to avoid
    mentioning removed MDL_context::wait_for_lock() method.
sql/sql_base.h:
  As we no longer wait for conflicting metadata lock away in
  Open_table_context::recover_from_failed_open() method,
  Open_table_context::OT_WAIT_MDL_LOCK action was renamed to
  OT_MDL_CONFLICT.
  Also Open_table_context::m_failed_mdl_request became
  unnecessary and was removed.
sql/sql_plist.h:
  Extended I_P_List template to support efficient push_back()
  operation if it is parameterized with an appropriate policy
  class.
sql/sql_show.cc:
  Adjusted code after removal of MDL_context::wait_for_lock()
  method. Now if one needs to acquire metadata lock with waiting
  one has to use a variant of MDL_context::acquire_lock() method.
2010-06-07 11:06:55 +04:00
Dmitry Lenev
571acc878b Patch that changes approach to how we acquire metadata
locks for DML statements and changes the way MDL locks
are acquired/granted in contended case.

Instead of backing-off when a lock conflict is encountered
and waiting for it to go away before restarting open_tables()
process we now wait for lock to be released without releasing
any previously acquired locks. If conflicting lock goes away
we resume opening tables. If waiting leads to a deadlock we
try to resolve it by backing-off and restarting open_tables()
immediately.

As result both waiting for possibility to acquire and
acquiring of a metadata lock now always happen within the
same MDL API call. This has allowed to make release of a lock
and granting it to the most appropriate pending request an
atomic operation.
Thanks to this it became possible to wake up during release
of lock only those waiters which requests can be satisfied
at the moment as well as wake up only one waiter in case
when granting its request would prevent all other requests
from being satisfied. This solves thundering herd problem
which occured in cases when we were releasing some lock and
woke up many waiters for SNRW or X locks (this was the issue
in bug#52289 "performance regression for MyISAM in sysbench
OLTP_RW test".
This also allowed to implement more fair (FIFO) scheduling
among waiters with the same priority.
It also opens the door for introducing new types of requests
for metadata locks such as low-prio SNRW lock which is
necessary in order to support LOCK TABLES LOW_PRIORITY WRITE.

Notice that after this sometimes can report ER_LOCK_DEADLOCK
error in cases in which it has not happened before.
Particularly we will always report this error if waiting for
conflicting lock has happened in the middle of transaction
and resulted in a deadlock. Before this patch the error was
not reported if deadlock could have been resolved by backing
off all metadata locks acquired by the current statement.
2010-06-07 11:06:55 +04:00
Jon Olav Hauglid
142a162c66 manual merge from mysql-trunk-bugfixing
Conflicts:
Text conflict in mysql-test/r/archive.result
Contents conflict in mysql-test/r/innodb_bug38231.result
Text conflict in mysql-test/r/mdl_sync.result
Text conflict in mysql-test/suite/binlog/t/disabled.def
Text conflict in mysql-test/suite/rpl_ndb/r/rpl_ndb_binlog_format_errors.result
Text conflict in mysql-test/t/archive.test
Contents conflict in mysql-test/t/innodb_bug38231.test
Text conflict in mysql-test/t/mdl_sync.test
Text conflict in sql/sp_head.cc
Text conflict in sql/sql_show.cc
Text conflict in sql/table.cc
Text conflict in sql/table.h
2010-06-06 13:19:29 +02:00
Jon Olav Hauglid
1af11051bf manual merge from mysql-trunk-bugfixing
Conflicts:
Text conflict in mysql-test/r/archive.result
Contents conflict in mysql-test/r/innodb_bug38231.result
Text conflict in mysql-test/r/mdl_sync.result
Text conflict in mysql-test/suite/binlog/t/disabled.def
Text conflict in mysql-test/suite/rpl_ndb/r/rpl_ndb_binlog_format_errors.result
Text conflict in mysql-test/t/archive.test
Contents conflict in mysql-test/t/innodb_bug38231.test
Text conflict in mysql-test/t/mdl_sync.test
Text conflict in sql/sp_head.cc
Text conflict in sql/sql_show.cc
Text conflict in sql/table.cc
Text conflict in sql/table.h
2010-06-06 13:19:29 +02:00
Konstantin Osipov
5fa66315e9 A follow up patch for the fix for Bug#51263 "Deadlock between
transactional SELECT and ALTER TABLE ...  REBUILD PARTITION".

Make open flags part of Open_table_context.
This allows to simplify some code and (in future)
enforce the invariant that we don't, say, request a back 
off on the table when there is MYSQL_OPEN_IGNORE_FLUSH 
flag.



sql/sql_base.cc:
  open_table() flags are part of Open_table_context.
  Remove dead code that would check for OPEN_VIEW_NO_PARSE,
  which is not an open table flag.
sql/sql_base.h:
  Move flags to Open_table_context. Reorder Open_table_context
  members to compact the structure footprint.
sql/sql_insert.cc:
  Update with a new calling signature of open_table().
sql/sql_table.cc:
  Update with a new calling signature of open_table().
2010-06-01 14:49:35 +04:00
Konstantin Osipov
559e3889f2 A follow up patch for the fix for Bug#51263 "Deadlock between
transactional SELECT and ALTER TABLE ...  REBUILD PARTITION".

Make open flags part of Open_table_context.
This allows to simplify some code and (in future)
enforce the invariant that we don't, say, request a back 
off on the table when there is MYSQL_OPEN_IGNORE_FLUSH 
flag.
2010-06-01 14:49:35 +04:00
Konstantin Osipov
a96d23a57a A follow up patch for the fix for Bug#51263 "Deadlock between
transactional SELECT and ALTER TABLE ...  REBUILD PARTITION".

Move declarations of sql_base.cc classes to sql_base.h
(previously declared in sql_class.h).
Became possible after a header file split.





sql/sql_base.cc:
  Make sql_base.h the first include in sql_base.cc.
sql/sql_base.h:
  Add declarations of Prelocking_strategy and Open_table_context.
sql/sql_class.h:
  Remove declarations of Prelocking_strategy and Open_table_context
  (moved).
2010-06-01 14:19:05 +04:00
Konstantin Osipov
8b0c705c39 A follow up patch for the fix for Bug#51263 "Deadlock between
transactional SELECT and ALTER TABLE ...  REBUILD PARTITION".

Move declarations of sql_base.cc classes to sql_base.h
(previously declared in sql_class.h).
Became possible after a header file split.
2010-06-01 14:19:05 +04:00
Alexander Nozdrin
59a9912963 Auto-merge from mysql-trunk. 2010-05-28 09:47:58 +04:00
Alexander Nozdrin
4e633ec234 Auto-merge from mysql-trunk. 2010-05-28 09:47:58 +04:00
Dmitry Lenev
94ee84548d Small clean-up. Removed standalone enum_open_table_action enum
type, which some time ago became part of Open_table_context class.
Apparently standalone enum type was erroneously re-introduced
during one of merges.
2010-05-13 13:36:49 +04:00