1. 22 Aug, 2006 2 commits
    • kroki/tomash@moonlight.intranet's avatar
      Merge moonlight.intranet:/home/tomash/src/mysql_ab/mysql-5.0 · 9c1b3f57
      kroki/tomash@moonlight.intranet authored
      into  moonlight.intranet:/home/tomash/src/mysql_ab/mysql-5.0-bug21051-2
      9c1b3f57
    • kroki/tomash@moonlight.intranet's avatar
      BUG#21051: RESET QUERY CACHE very slow when query_cache_type=0 · 0f0ddc39
      kroki/tomash@moonlight.intranet authored
      There were two problems: RESET QUERY CACHE took a long time to complete
      and other threads were blocked during this time.
      
      The patch does three things:
        1 fixes a bug with improper use of test-lock-test_again technique.
            AKA Double-Checked Locking is applicable here only in few places.
        2 Somewhat improves performance of RESET QUERY CACHE.
            Do my_hash_reset() instead of deleting elements one by one.  Note
            however that the slowdown also happens when inserting into sorted
            list of free blocks, should be rewritten using balanced tree.
        3 Makes RESET QUERY CACHE non-blocking.
            The patch adjusts the locking protocol of the query cache in the
            following way: it introduces a flag flush_in_progress, which is
            set when Query_cache::flush_cache() is in progress.  This call
            sets the flag on enter, and then releases the lock.  Every other
            call is able to acquire the lock, but does nothing if
            flush_in_progress is set (as if the query cache is disabled).
            The only exception is the concurrent calls to
            Query_cache::flush_cache(), that are blocked until the flush is
            over.  When leaving Query_cache::flush_cache(), the lock is
            acquired and the flag is reset, and one thread waiting on
            Query_cache::flush_cache() (if any) is notified that it may
            proceed.
      0f0ddc39
  2. 21 Aug, 2006 2 commits
    • dlenev@mockturtle.local's avatar
      Merge bk-internal.mysql.com:/home/bk/mysql-5.0-runtime · 320f8ccc
      dlenev@mockturtle.local authored
      into  mockturtle.local:/home/dlenev/src/mysql-5.0-bg21216-2
      320f8ccc
    • dlenev@mockturtle.local's avatar
      Fix for bug#21216 "Simultaneous DROP TABLE and SHOW OPEN TABLES causes · 186fa6c2
      dlenev@mockturtle.local authored
      server to crash".
      
      Crash caused by assertion failure happened when one ran SHOW OPEN TABLES
      while concurrently doing DROP TABLE (or RENAME TABLE, CREATE TABLE LIKE
      or any other command that takes name-lock) in other connection.
      For non-debug version of server problem exposed itself as wrong output
      of SHOW OPEN TABLES statement (it was missing name-locked tables).
      Finally in 5.1 both debug and non-debug versions simply crashed in
      this situation due to NULL-pointer dereference.
      
      This problem was caused by the fact that table placeholders which were
      added to table cache in order to obtain name-lock had TABLE_SHARE::table_name
      set to 0. Therefore they broke assumption that this member is non-0 for
      all tables in table cache which was checked by assert in list_open_tables()
      (in 5.1 this function simply relies on it).
      The fix simply sets this member for such placeholders to appropriate value
      making this assumption true again.
      
      This patch also includes test for similar bug 12212 "Crash that happens
      during removing of database name from cache" reappeared in 5.1 as bug 19403.
      186fa6c2
  3. 19 Aug, 2006 1 commit
  4. 17 Aug, 2006 1 commit
  5. 15 Aug, 2006 1 commit
  6. 02 Aug, 2006 15 commits
  7. 01 Aug, 2006 9 commits
  8. 31 Jul, 2006 9 commits