1. 12 Feb, 2010 1 commit
    • Dmitry Lenev's avatar
      Fix for bug #50908 "Assertion `handler_tables_hash.records == 0' · d5a498ab
      Dmitry Lenev authored
      failed in enter_locked_tables_mode".
      
      Server was aborted due to assertion failure when one tried to 
      execute statement requiring prelocking (i.e. firing triggers
      or using stored functions) while having open HANDLERs.
      
      The problem was that THD::enter_locked_tables_mode() method
      which was called at the beginning of execution of prelocked 
      statement assumed there are no open HANDLERs. It had to do 
      so because corresponding THD::leave_locked_tables_mode()
      method was unable to properly restore MDL sentinel when
      leaving LOCK TABLES/prelocked mode in the presence of open 
      HANDLERs.
      
      This patch solves this problem by changing the latter method
      to properly restore MDL sentinel and thus removing need for 
      this assumption. As a side-effect, it lifts unjustified
      limitation by allowing to keep HANDLERs open when entering 
      LOCK TABLES mode.
      
      mysql-test/include/handler.inc:
        Adjusted tests after making LOCK TABLES not to close
        open HANDLERs. Added coverage for bug #50908
        "Assertion `handler_tables_hash.records == 0' failed
        in enter_locked_tables_mode".
      mysql-test/r/handler_innodb.result:
        Updated test results (see include/handler.inc).
      mysql-test/r/handler_myisam.result:
        Updated test results (see include/handler.inc).
      sql/mysql_priv.h:
        Introduced mysql_ha_move_tickets_after_trans_sentinel()
        routine which allows to move tickets for metadata locks
        corresponding to open HANDLERs after transaction sentinel.
      sql/sql_class.cc:
        Changed THD::leave_locked_tables_mode() to correctly restore 
        MDL sentinel value in the presence of open HANDLERs.
      sql/sql_class.h:
        Removed assert from THD::enter_locked_tables_mode() as we
        no longer have to close HANDLERs when entering LOCK TABLES 
        or prelocked modes. Instead we keep them open and correctly
        restore MDL sentinel value after leaving them.
        Removal of assert also fixes problem from the bug report.
      sql/sql_handler.cc:
        Introduced mysql_ha_move_tickets_after_trans_sentinel()
        routine which allows to move tickets for metadata locks
        corresponding to open HANDLERs after transaction sentinel.
      sql/sql_parse.cc:
        We no longer have to close HANDLERs when entering LOCK TABLES 
        mode. Instead we keep them open and simply correctly restore 
        MDL sentinel value after leaving this mode.
      d5a498ab
  2. 11 Feb, 2010 5 commits
    • Konstantin Osipov's avatar
      next-4284 tree: · e6cb88eb
      Konstantin Osipov authored
      fix lock_sync.test failure in row based replication mode.
      e6cb88eb
    • Konstantin Osipov's avatar
      Fix a sporadic failure of rpl_sp.test in next-4284 tree: when doing · c48c21eb
      Konstantin Osipov authored
      SELECT * FROM t1 on slave, first make sure that the slave has received
      the CREATE TABLE from the master.
      c48c21eb
    • Konstantin Osipov's avatar
      next-4284 tree: fix the failures of processlist_val_* tests, · 6cf17332
      Konstantin Osipov authored
      update the condition to wait for in wait_condition
      to reflect type-of-operation aware metadata locks.
      6cf17332
    • Jon Olav Hauglid's avatar
      Followup to Bug#34604 handler::ha_rnd_end(): Assertion `inited==RND' failed. · c9e4b1bb
      Jon Olav Hauglid authored
      The test case for this bug relies on getting a ER_LOCK_WAIT_TIMEOUT
      error. However with the introduction of MDL, the test would hang
      forever since the metadata locks would not timeout.
      
      MDL timeouts are now introduced in the scope of Bug#45225. This
      patch changes the testcase for Bug#34604 to set the new server
      variable "lock_wait_timeout" to one second which makes the test
      generate the necessary timeout again.
      c9e4b1bb
    • Jon Olav Hauglid's avatar
      Bug #45225 Locking: hang if drop table with no timeout · 3d6a89e7
      Jon Olav Hauglid authored
      This patch introduces timeouts for metadata locks. 
      
      The timeout is specified in seconds using the new dynamic system 
      variable  "lock_wait_timeout" which has both GLOBAL and SESSION
      scopes. Allowed values range from 1 to 31536000 seconds (= 1 year). 
      The default value is 1 year.
      
      The new server parameter "lock-wait-timeout" can be used to set
      the default value parameter upon server startup.
      
      "lock_wait_timeout" applies to all statements that use metadata locks.
      These include DML and DDL operations on tables, views, stored procedures
      and stored functions. They also include LOCK TABLES, FLUSH TABLES WITH
      READ LOCK and HANDLER statements.
      
      The patch also changes thr_lock.c code (table data locks used by MyISAM
      and other simplistic engines) to use the same system variable.
      InnoDB row locks are unaffected.
      
      One exception to the handling of the "lock_wait_timeout" variable
      is delayed inserts. All delayed inserts are executed with a timeout
      of 1 year regardless of the setting for the global variable. As the
      connection issuing the delayed insert gets no notification of 
      delayed insert timeouts, we want to avoid unnecessary timeouts.
      
      It's important to note that the timeout value is used for each lock
      acquired and that one statement can take more than one lock.
      A statement can therefore block for longer than the lock_wait_timeout 
      value before reporting a timeout error. When lock timeout occurs, 
      ER_LOCK_WAIT_TIMEOUT is reported.
      
      Test case added to lock_multi.test.
      
      
      include/my_pthread.h:
        Added macros for comparing two timespec structs.
      include/thr_lock.h:
        Introduced timeouts for thr_lock.c locks.
      mysql-test/r/mysqld--help-notwin.result:
        Updated result file with the new server variable.
      mysql-test/r/mysqld--help-win.result:
        Updated result file with the new server variable.
      mysql-test/suite/sys_vars/r/lock_wait_timeout_basic.result:
        Added basic test for the new server variable.
      mysql-test/suite/sys_vars/t/lock_wait_timeout_basic.test:
        Added basic test for the new server variable.
      mysys/thr_lock.c:
        Introduced timeouts for thr_lock.c locks.
      sql/mdl.cc:
        Introduced timeouts for metadata locks.
      sql/mdl.h:
        Introduced timeouts for metadata locks.
      sql/sql_base.cc:
        Introduced timeouts in tdc_wait_for_old_versions().
      sql/sql_class.h:
        Added new server variable lock_wait_timeout.
      sql/sys_vars.cc:
        Added new server variable lock_wait_timeout.
      3d6a89e7
  3. 10 Feb, 2010 2 commits
    • Alexander Nozdrin's avatar
      Update result file. · d7f203c7
      Alexander Nozdrin authored
      d7f203c7
    • Dmitry Lenev's avatar
      Fix for bug #50998 "Deadlock in MDL code during test · 96344bef
      Dmitry Lenev authored
      rqg_mdl_stability".
      
      When start of statement's waiting on a metadata lock 
      created more than one loop in waiters graph server might 
      have entered deadlock condition.
      
      The problem was that in the case described above MDL deadlock 
      detector had to perform several searches for deadlock but
      forgot to reset Deadlock_detection_context before performing 
      new search. 
      Failure to do so has broken assumption in code resposible for 
      choosing victim that if Deadlock_detection_context::victim
      is set we also have read lock on m_waiting_for_lock for this
      context. As result this lock could have been unlocked more
      times than it was acquired which corrupted rwlock's state
      which led to server deadlock.
      
      This fix ensures that such reset is done before each attempt
      to find a deadlock.
      
      mysql-test/r/mdl_sync.result:
        Added test for bug #50998 "Deadlock in MDL code during test
        rqg_mdl_stability" as well as coverage for the case when
        addition of statement waiting for metadata lock adds several
        loops in the waiters graph and therefore several searches
        for deadlock should be performed by MDL deadlock detector.
      mysql-test/t/mdl_sync.test:
        Added test for bug #50998 "Deadlock in MDL code during test
        rqg_mdl_stability" as well as coverage for the case when
        addition of statement waiting for metadata lock adds several
        loops in the waiters graph and therefore several searches
        for deadlock should be performed by MDL deadlock detector.
      sql/mdl.cc:
        Ensure that in cases when MDL deadlock detector had to
        perform several searches for deadlock because several loops
        in waiters graph are possible we reset
        Deadlock_detection_context before performing each search.
        Failure to do so has broken assumption in code resposible
        for choosing victim that if Deadlock_detection_context::victim
        is set we also have read lock on m_waiting_for_lock for this
        context. As result this lock could have been unlocked more
        times than it was acquired which corrupted rwlock's state
        (no one was able to acquire write lock on it anymore).
      96344bef
  4. 09 Feb, 2010 5 commits
  5. 08 Feb, 2010 4 commits
    • Joerg Bruehe's avatar
      Upmerge "configure.in" text change from 5.1 to 5.5 ("trunk"), · 5d115bbe
      Joerg Bruehe authored
      fixing bug#50950.
      5d115bbe
    • Joerg Bruehe's avatar
      Upmerge "configure.in" text change from 5.0 to 5.1, · ed75cda3
      Joerg Bruehe authored
      fixing bug#50950.
      ed75cda3
    • Dmitry Lenev's avatar
      Fix for bug #50913 "Deadlock between open_and_lock_tables_derived · 8018ec5a
      Dmitry Lenev authored
      and MDL".
      
      Concurrent execution of a multi-DELETE statement and ALTER
      TABLE statement which affected one of the tables used in
      the multi-DELETE sometimes led to deadlock.
      Similar deadlocks might have occured when one performed
      INSERT/UPDATE/DELETE on a view and concurrently executed
      ALTER TABLE for the view's underlying table, or when one
      concurrently executed TRUNCATE TABLE for InnoDB table and
      ALTER TABLE for the same table.
      
      These deadlocks were caused by a discrepancy between types of
      metadata and thr_lock.cc locks acquired by those statements.
      
      What happened was that multi-DELETE/TRUNCATE/DML-through-the-
      view statement in the first connection acquired SR lock on a
      table, then ALTER TABLE would come in in the second connection
      and acquire SNW metadata lock and TL_WRITE_ALLOW_READ
      thr_lock.c lock and then would start waiting for the first
      connection during lock upgrade. After that the statement in
      the first connection would try to acquire TL_WRITE lock on
      table and would start waiting for the second connection,
      creating a deadlock.
      
      This patch solves this problem by ensuring that we acquire
      SW metadata lock in all cases in which we acquiring write
      thr_lock.c lock. This guarantees that deadlocks like the
      one described above won't occur since all lock conflicts
      in such situation are resolved within MDL subsystem.
      
      This patch also adds assert which should guarantee that
      such situations won't arise in future.
      
      mysql-test/r/lock_multi.result:
        Added main test for bug #50913 "Deadlock between
        open_and_lock_tables_derived and MDL".
      mysql-test/r/mdl_sync.result:
        Added additional coverage for bug #50913 "Deadlock
        between open_and_lock_tables_derived and MDL".
      mysql-test/t/lock_multi.test:
        Added main test for bug #50913 "Deadlock between
        open_and_lock_tables_derived and MDL".
      mysql-test/t/mdl_sync.test:
        Added additional coverage for bug #50913 "Deadlock
        between open_and_lock_tables_derived and MDL".
      sql/lock.cc:
        Added assert that enforces that when we are locking
        a non-temporary table we have an appropriate type of
        metadata lock on this table.
      sql/mysql_priv.h:
        Added separate flag for open_tables() to be able specify that
        SH metadata locks on table to be open should be acquired.
        We can no longer use MYSQL_LOCK_IGNORE_FLUSH flag for this
        as in addition to use in I_S implementation it is also used
        for opening system tables. Since in the latter case we also
        acquire thr_lock.c locks using SH metadata lock in it instead
        of SR or SW locks may lead to deadlock.
      sql/sql_base.cc:
        When opening tables don't interpret MYSQL_LOCK_IGNORE_FLUSH
        flag as request to acquire SH metadata locks. This flag is
        also used for opening system tables for which we also take
        thr_lock.c locks and thus proper metadata lock to take in
        this case is SR or SW lock (otherwise deadlocks can occur).
        In cases when SH lock is really required (e.g. when tables
        are open by I_S implementation) we rely on that newly
        introduced MYSQL_OPEN_FORCE_SHARED_HIGH_PRIO_MDL flag is
        used.
      sql/sql_delete.cc:
        mysql_truncate_by_delete():
          Adjust type of metadata lock to be requested after changing
          type of thr_lock.c lock for table list element from one
          which was set in parser to TL_WRITE.
          This removes discrepancy between types of these locks which
          allowed deadlocks to creep in.
      sql/sql_handler.cc:
        When closing table which was open by HANDLER statement clear
        TABLE::open_by_handler flag. This allows to use this flag as
        a reliable indication that TABLE instance was open by HANDLER
        statement in assert which was added to mysql_lock_tables().
      sql/sql_parse.cc:
        multi_delete_set_locks_and_link_aux_tables():
          Adjust type of metadata lock to be requested after changing
          type of thr_lock.c lock for table list element from one
          which was set in parser to TL_WRITE.
          This removes discrepancy between types of these locks which
          allowed deadlocks to creep in.
      sql/sql_show.cc:
        Use newly introduced MYSQL_OPEN_FORCE_SHARED_HIGH_PRIO_MDL
        flag in order to acquire SH metadata locks when opening tables
        in I_S implementation.
      sql/sql_update.cc:
        Added comment explaining why in multi-update after deciding
        that we need weaker thr_lock.c lock on a table we don't
        downgrade metadata lock on it.
      sql/sql_view.cc:
        When merging view into main statement adjust type of metadata
        lock to be requested after changing type of thr_lock.c lock
        for table. This removes discrepancy between types of these
        locks which allowed deadlocks to creep in.
      8018ec5a
    • Joerg Bruehe's avatar
      Bug#50950 Obsolete reference to www.mysql.com · 72da6b31
      Joerg Bruehe authored
                      in message printed at end of configure
      
      New text for the success message of "configure".
      
      configure.in:
        The message must be changed to drop the "www.mysql.com" URL.
      72da6b31
  6. 06 Feb, 2010 3 commits
    • Konstantin Osipov's avatar
      Merge next-4284 -> next-4284-merge · 4d4eed65
      Konstantin Osipov authored
      4d4eed65
    • Konstantin Osipov's avatar
      Merge next-mr -> next-4284. · a72f90bc
      Konstantin Osipov authored
      mysql-test/t/disabled.def:
        Restore disabled ssl tests: SSL certificates were updated.
        Disable sp_sync.test, the test case can't work in next-4284.
      mysql-test/t/partition_innodb.test:
        Disable parsing of the test case for Bug#47343, 
        the test can not work in next-4284.
      mysql-test/t/ps_ddl.test:
        Update results (CREATE TABLE IF NOT EXISTS takes
        into account existence of the temporary table).
      a72f90bc
    • Jon Olav Hauglid's avatar
      Bug #50912 Assertion `ticket->m_type >= mdl_request->type' · 95c23861
      Jon Olav Hauglid authored
                 failed on HANDLER + I_S
      
      This assert was triggered when an I_S query tried to acquire a
      metadata lock on a table which was already locked by a HANDLER
      statement in the same connection.
      
      First the HANDLER took a MDL_SHARED lock. Afterwards, the I_S query
      requested a MDL_SHARED_HIGH_PRIO lock. The existing MDL_SHARED ticket
      is found in find_ticket() since it satisfies 
      ticket->has_stronger_or_equal_type(mdl_request->type) as MDL_SHARED
      and MDL_SHARED_HIGH_PRIO have equal strengths, just different priority.
      
      However, two asserts later check lock type strengths using relational
      operators (>= and <=) rather than MDL_ticket::has_stronger_or_equal_type().
      These asserts are triggered since MDL_SHARED >= MDL_SHARED_HIGH_PRIORITY
      is false (mapped to 1 and 2 respectively).
      
      This patch updates the asserts to use MDL_ticket::has_stronger_or_equal_type()
      rather than relational operators to check lock type strength.
      
      Test case added to include/handler.inc.
      95c23861
  7. 05 Feb, 2010 12 commits
  8. 04 Feb, 2010 8 commits