-------------------------------------------------------------
revno: 2877
committer: Davi Arnaut <Davi.Arnaut@Sun.COM>
branch nick: 35164-6.0
timestamp: Wed 2008-10-15 19:53:18 -0300
message:
Bug#35164: Large number of invalid pthread_attr_setschedparam calls
Bug#37536: Thread scheduling causes performance degradation at low thread count
Bug#12702: Long queries take 100% of CPU and freeze other applications under Windows

The problem is that although having threads with different priorities
yields marginal improvements [1] in some platforms [2], relying on some
statically defined priorities (QUERY_PRIOR and WAIT_PRIOR) to play well
(or to work at all) with different scheduling practices and disciplines
is, at best, a shot in the dark as the meaning of priority values may
change depending on the scheduling policy set for the process.

Another problem is that increasing priorities can hurt other concurrent
(running on the same hardware) applications (such as AMP) by causing
starvation problems as MySQL threads will successively preempt lower
priority processes. This can be evidenced by Bug#12702.

The solution is to not change the threads priorities and rely on the
system scheduler to perform its job. This also enables a system admin
to increase or decrease the scheduling priority of the MySQL process,
if intended.

Furthermore, the internal wrappers and code for changing the priority
of threads is being removed as they are now unused and ancient.

1. Due to unintentional side effects. On Solaris this could artificially
help benchmarks as calling the priority changing syscall millions of
times is more beneficial than the actual setting of the priority.

2. Where it actually works. It has never worked on Linux as the default
scheduling policy SCHED_OTHER only accepts the static priority 0.

------------------------------------------------------------
revno: 2630.13.2
committer: Davi Arnaut <davi@sun.com>
branch nick: WL4284-6.0
timestamp: Thu 2008-07-03 18:26:51 -0300
message:
Remove unused USING_TRANSACTIONS macro which unnecessarily
cumbers the code. This macro is a historical leftover and
has no practical use since its unconditionally defined.

------------------------------------------------------------
revno: 2642
committer: davi@mysql.com/endora.local
timestamp: Fri 2008-05-16 01:29:09 -0300
message:
Fix for a valgrind warning due to a jump on a uninitialized
variable. The problem was that the sql profile preparation
function wasn't being called for all possible code paths
of query execution. The solution is to move the preparation
to the dispatch_command function and to explicitly call the
profile preparation function on bootstrap.

------------------------------------------------------------
revno: 2627
committer: davi@mysql.com/endora.local
timestamp: Wed 2008-04-23 13:25:02 -0300
message:
Fix for a build failure on Windows due to ssize_t
not being declared.

Original changeset:
------------------------------------------------------------
revno: 2626
committer: davi@mysql.com/endora.local
timestamp: Wed 2008-04-23 09:33:25 -0300
message:
Fix for main.ssl and main.ssl_compress test case failures under pool-of-threads.

The problem is that the SSL layer has a read buffer and might read
more data than requested by the VIO layer. The SSL layer empties the
socket buffer which causes the socket to not be signaled for IO if
the client is waiting for a command which is sitting in the read
buffer.

The solution is to retrieve from the transport layer the number of
bytes waiting in the read buffer. The data in the read buffer needs
to be processed before waiting for more data.

 inside a stored routine" from 6.0-codebase.

------------------------------------------------------------
revno: 2597.42.4
committer: davi@mysql.com/endora.local
timestamp: Tue 2008-04-15 17:29:42 -0300
message:
Bug#36004 mysql_stmt_prepare resets the list of warnings

Although the manual says that "the list of messages is reset
for each new statement that uses a table", the list of messages
is being unconditionally reset for prepare commands.

The solution is to enforce that the prepare command will only
reset the message list if the statement being prepared uses
a table or a warning is pushed.

------------------------------------------------------------
revno: 2572.23.1
committer: davi@mysql.com/endora.local
timestamp: Wed 2008-03-19 09:03:08 -0300
message:
Bug#17954 Threads_connected > Threads_created

The problem is that insert delayed threads are counted as connected
but not as created, leading to a Threads_connected value greater then
the Threads_created value.

The solution is to enforce the documented behavior that the
Threads_connected value shall be the number of currently
open connections and that Threads_created shall be the
number of threads created to handle connections.

------------------------------------------------------------
revno: 2476.1116.1
committer: davi@mysql.com/endora.local
timestamp: Fri 2007-12-14 10:10:19 -0200
message:
DROP TABLE under LOCK TABLES simultaneous to a FLUSH TABLES
WITH READ LOCK (global read lock) can lead to a deadlock.

The solution is to not wait for the global read lock if the
thread is holding any locked tables.

Related to bugs 23713 and 32395. This issues is being fixed
only on 6.0 because it depends on the fix for bug 25858 --
which was fixed only on 6.0.

------------------------------------------------------------
revno: 2476.784.3
committer: davi@moksha.local
timestamp: Tue 2007-10-02 21:27:31 -0300
message:
Bug#25858 Some DROP TABLE under LOCK TABLES can cause deadlocks
        
When a client (connection) holds a lock on a table and attempts to
drop (obtain a exclusive lock) on a second table that is already
held by a second client and the second client then attempts to
drop the table that is held by the first client, leads to a
circular wait deadlock. This scenario is very similar to trying to
drop (or rename) a table while holding read locks and are
correctly forbidden.
        
The solution is to allow a drop table operation to continue only
if the table being dropped is write (exclusively) locked, or if
the table is temporary, or if the client is not holding any
locks. Using this scheme prevents the creation of a circular
chain in which each client is waiting for one table that the
next client in the chain is holding.
            
This is incompatible change, as can be seen by number of tests
cases that needed to be fixed, but is consistent with respect to
behavior of the different scenarios in which the circular wait
might happen.

revno: 2476.784.2
committer: davi@moksha.local
timestamp: Thu 2007-09-27 16:56:27 -0300 
message:
Bug#28870 check that table locks are released/reset
    
The problem is that some mysql_lock_tables error paths are not
resetting the tables lock type back to TL_UNLOCK. If the lock
types are not reset properly, a table might be returned to the
table cache with wrong lock_type.
      
The proposed fix is to ensure that the tables lock type is always
properly reset when mysql_lock_tables fails. This is a
incompatible change with respect to the process state information.

      
Just change mysql_foo to mysql_cv_foo for one cache-id variable name.  There
was only one bad variable name, present in 5.0 and 5.1, but not in the -pe
branch.


Backported to 5.6.0  (mysql-next-mr-runtime)

           STRING_RESULT argument

There is a "magic" number for precision : NOT_FIXED_DEC. 
This means that the precision is not a fixed number.
But this constant was re-defined in several files and 
was not available to the UDF developers.
 
Moved the NOT_FIXED_DEC definition to the correct header
and removed the redundant definitions.

Backported to 5.6.0  (mysql-next-mr-runtime)

Add result file format v2

Backport to 5.6.0   

Add support for being prompted for new passwords by mysqladmin instead of
specifying them on the command line. (Bug #5724, patch by Harrison Fisk)

(From: gkodinov)
Use and int * where possible to scan for trailing space in a
string instead of always iterating char-by-char.
Using the attached benchmark file on a 32 bit Intel Core 2 
Duo CPU I've got 43485 ms run with the fix compared to 44373 
without it.

Backported to 5.6.0 (next-mr-runtime)
6.0-codebase revid: 2476.1362.1

is invalid to preporcessor conditionals. Instead use
the autoconf generated macro to test the presence.

  In fact this crashes in normal (not embedded) run also.
  The problem is in the memory mapping. Handling the ha_myisammrg::extra(MMAP)
  the MERGE engine tries to mmap all the tables it unites.
  Though some can be empty and then in the mi_dynmap_file()
  we call the my_mmap(0). Normally this call returns MAP_FAILED,
  but not on FreeBSD. There it returns like a 'normal' value,
  and after the consequitive munmap systems gets unstable and
  crashes on some system call later.

per-file comments:
  storage/myisam/mi_dynrec.c
Bug #47139      Test "merge" crashes in "embedded" run
    don't try to mmap zero-length area, just return at once.

   The additional patch. That 'loadxml.test' failure was actually about our testing system,
   not the code.
   Firstly we need a new mysqltest command, wich i called 'send_eval'. So the expression
   can be evaluated, then started in a parallel thread. We only have separane 'send' and
   'eval' commands at the moment.
   Then we need to add the waiting code after the 'KILL' to our test, so the thread will be killed
   before the test goes further. The present 'reap' command doesn't handle the killed threads
   well.
      
per-file comments:
  client/mysqltest.cc
Bug#42520      killing load .. infile Assertion failed: ! is_set(), file .\sql_error.cc, line 8
    The 'send_eval' command implemented.

  mysql-test/r/loadxml.result
Bug#42520      killing load .. infile Assertion failed: ! is_set(), file .\sql_error.cc, line 8
   test result updated.

  mysql-test/t/loadxml.test
Bug#42520      killing load .. infile Assertion failed: ! is_set(), file .\sql_error.cc, line 8
   test case added.

------------------------------------------------------------
revno: 3405
revision-id: davi.arnaut@sun.com-20090626124624-m4wolyo5193j4cu7
parent: luis.soares@sun.com-20090626113019-1j4mn1jos480u9f3
committer: Davi Arnaut <Davi.Arnaut@Sun.COM>
branch nick: mysql-pe
timestamp: Fri 2009-06-26 09:46:24 -0300
message:
  Bug#45767: deprecate/remove Field::pack_key, Field::unpack_key, Field::pack_cmp
  
  Remove unused and dead code.
  
  Parts of the patch contributed by Zardosht Kasheff

------------------------------------------------------------
revno: 2476.784.4
revision-id: sp1r-davi@moksha.local-20071008114751-46069
parent: sp1r-davi@moksha.local-20071003002731-48537
committer: davi@moksha.local
timestamp: Mon 2007-10-08 08:47:51 -0300
message:
  Bug#27249 table_wild with alias: select t1.* as something

  Aliases to table wildcards are silently ignored, but they should
  not be allowed as it is non-standard and currently useless. There
  is not point in having a alias to a wildcard of column names.

  The solution is to rewrite the select_item rule so that aliases
  for table wildcards are not accepted.

  Contribution by Martin Friebe

------------------------------------------------------------
revno: 2597.4.17
revision-id: sp1r-davi@mysql.com/endora.local-20080328174753-24337
parent: sp1r-anozdrin/alik@quad.opbmk-20080328140038-16479
committer: davi@mysql.com/endora.local
timestamp: Fri 2008-03-28 14:47:53 -0300
message:
  Bug#15192 "fatal errors" are caught by handlers in stored procedures

  The problem is that fatal errors (e.g.: out of memory) were being
  caught by stored procedure exception handlers which could cause
  the execution to not be stopped due to a continue handler.

  The solution is to not call any exception handler if the error is
  fatal and send the fatal error to the client.

------------------------------------------------------------
revno: 3317
revision-id: davi.arnaut@sun.com-20090522170916-fzc5ca3tjs9roy1t
parent: patrick.crews@sun.com-20090522152933-ole8s3suy4zqyvku
committer: Davi Arnaut <Davi.Arnaut@Sun.COM>
branch nick: 41860-6.0
timestamp: Fri 2009-05-22 14:09:16 -0300
message:
  Bug#41860: Without Windows named pipe

  The problem was that the patch for Bug#10374 broke named pipe
  and shared memory transports on Windows due to a failure to
  implement a dummy poll method for transports other than BSD
  sockets. Another problem was that mysqltest lacked support
  for named pipe and shared memory connections, which lead to
  misleading test cases that were supposed run common queries
  over both transports.

  The solution is to properly implement, at the VIO layer, the
  poll and is_connected methods. The is_connected method is
  implemented for every suppported transport and the poll one
  only where it makes sense. Furthermore, support for named pipe
  and shared memory connections is added to mysqltest as to
  enable testing of both transports using the test suite.

------------------------------------------------------------
revno: 2597.37.3
revision-id: sp1r-davi@mysql.com/endora.local-20080328123626-16430
parent: sp1r-anozdrin/alik@quad.opbmk-20080327125300-11290
committer: davi@mysql.com/endora.local
timestamp: Fri 2008-03-28 09:36:26 -0300
message:
  Bug#10374 GET_LOCK does not let connection to close on the server side if it's aborted

  The problem is that the server doesn't detect aborted connections which
  are waiting on a lock or sleeping (user sleep), wasting system resources
  for a connection that is already dead.

  The solution is to peek at the connection every five seconds to verify if
  the connection is not aborted. A aborted connection is detect by polling
  the connection socket for available data to be read or end of file and in
  case of eof, the wait is aborted and the connection killed.