Follow-up patch to fix valgrind warnings.

BY CACHING OR REDUCING CREATEEVENT CALLS".
 
5.5 versions of MySQL server performed worse than 5.1 versions 
under single-connection workload in autocommit mode on Windows XP.
 
Part of this slowdown can be attributed to overhead associated
with constant creation/destruction of MDL_lock objects in the MDL
subsystem. The problem is that creation/destruction of these
objects causes creation and destruction of associated
synchronization primitives, which are expensive on Windows XP.
 
This patch tries to alleviate this problem by introducing a cache
of unused MDL_object_lock objects. Instead of destroying such
objects we put them into the cache and then reuse with a new
key when creation of a new object is requested.

To limit the size of this cache, a new --metadata-locks-cache-size
start-up parameter was introduced.

mysql-test/r/mysqld--help-notwin.result:
  Updated test after adding --metadata-locks-cache-size
  parameter.
mysql-test/r/mysqld--help-win.result:
  Updated test after adding --metadata-locks-cache-size
  parameter.
mysql-test/suite/sys_vars/r/metadata_locks_cache_size_basic.result:
  Added test coverage for newly introduced --metadata_locks_cache_size
  start-up parameter and corresponding global read-only variable.
mysql-test/suite/sys_vars/t/metadata_locks_cache_size_basic-master.opt:
  Added test coverage for newly introduced --metadata_locks_cache_size
  start-up parameter and corresponding global read-only variable.
mysql-test/suite/sys_vars/t/metadata_locks_cache_size_basic.test:
  Added test coverage for newly introduced --metadata_locks_cache_size
  start-up parameter and corresponding global read-only variable.
sql/mdl.cc:
  Introduced caching of unused MDL_object_lock objects, in order to
  avoid costs associated with constant creation and destruction of
  such objects in single-connection workloads run in autocommit mode.
  Such costs can be pretty high on systems where creation and 
  destruction of synchronization primitives require a system call 
  (e.g. Windows XP).
   
  To implement this cache,a list of unused MDL_object_lock instances 
  was added to MDL_map object. Instead of being destroyed 
  MDL_object_lock instances are put into this list and re-used later 
  when creation of a new instance is required. Also added 
  MDL_lock::m_version counter to allow threads having outstanding 
  references to an MDL_object_lock instance to notice that it has 
  been moved to the unused objects list.
   
  Added a global variable for a start-up parameter that limits
  the size of the unused objects list.
   
  Note that we don't cache MDL_scoped_lock objects since they
  are supposed to be created only during execution of DDL 
  statements and therefore should not affect performance much.
sql/mdl.h:
  Added a global variable for start-up parameter that limits the
  size of the unused MDL_object_lock objects list and constant
  for its default value.
sql/sql_plist.h:
  Added I_P_List<>::pop_front() function.
sql/sys_vars.cc:
  Introduced --metadata-locks-cache-size start-up parameter
  for specifying size of the cache of unused MDL_object_lock
  objects.

Follow up to fix freebsd compile issue.

Automerged approved bzr bundle in latest mysql-5.5.

                    OPTION SKIP-WRITE-BINLOG

System tables were not getting upgraded when
mysql_upgrade was run with --skip-write-binlog
option. (Same for --write-binlog.) Also, with
this option, mysql_upgrade_info file was not
getting created after the upgrade.

mysql_upgrade makes use of mysql client tool in
order to run upgrade scripts, while doing so it
passes some of the command line options (used to
start mysql_upgrade) directly to mysql client.
The reason behind this bug being, some options
like skip-write-binlog and upgrade-system-tables
were being passed to mysql tool along with other
options, and hence mysql execution failed due
presence of these invalid options.

Fixed this issue by filtering out the above mentioned
options from the list of options that will be passed to
mysql and mysqlcheck tools. However, since --write-binlog
is supported by mysqlcheck, this option would be used
explicitly while running mysqlcheck. (not part of patch,
already there)

Checking the contents of general log after the upgrade
is not doable via an mtr test. So performed manual test.
Added a test to verify the creation of mysql_upgrade_info.


client/mysql_upgrade.c:
  Bug#11827359 60223: MYSQL_UPGRADE PROBLEM WITH
                      OPTION SKIP-WRITE-BINLOG
  
  With this patch, --upgrade-system-tables and
  --write-binlog options will not be added to the
  list of options, used to start mysql and mysqlcheck
  tools.
mysql-test/r/mysql_upgrade.result:
  Added a testcase for Bug#11827359.
mysql-test/t/mysql_upgrade.test:
  Added a testcase for Bug#11827359.

my_double_round(DBL_MAX, -12, ....)
should return 'inf' rather than DBL_MAX

The problem is that floor(value/tmp) * tmp
is inlined, and optimized away.

The solution seems to be to prevent inlining by pre-computing value/tmp and
storing it in a variable.

No new test case: main.type_float fails without this patch.

This patch corrects a defect whereby the --mysqld, --my-print-defaults, 
and --plugin-ini were required. These options are not required and the
code has been fixed accordingly.

              SCAN/CPU) => SLAVE FAILURE

When a statement containing a large amount of ROWs to be applied on
the slave, and the slave's table does not contain a PK, it can take a
considerable amount of time to find and change all the rows that are
to be changed.

The proper slave enhancement will be implemented in WL 5597. However,
in this bug we are making it clear to the user what the problem is, by
printing a message to the error log if the execution time, for a given
statement in RBR, takes more than LONG_FIND_ROW_THRESHOLD (set to 60
seconds). This shall help the DBA to diagnose what's happening when
facing a slave server that is quiet for no apparent reason...

The note is only printed to the error log if log_warnings is set to be
greater than 1.


sql/log_event.cc:
  Core of the patch. 
  
  In Rows_log_event::do_apply_event, sets STMT start 
  timestamp.
  
  In Rows_log_event::find_row, if a PK is not used, then the start 
  timestamp is checked to see if the time spent on this STMT is enough
  to justify the printing of a note (only if it was not printed before).
sql/log_event.h:
  Defining LONG_FIND_ROW_THRESHOLD.
sql/rpl_rli.cc:
  Resets long_find_row state in rli->context_cleanup().
sql/rpl_rli.h:
  Two new rli properties that are necessary to control when to
  emit a note in the error log: 1) timestamp that states when the
  ROW statement started; 2) flag indicating whether the note has
  been emitted for the current statement or not. Also deployed
  accessors.

A change has been made in the sql/sql_table.cc file to include debug_sync.

The bug was accidentally fixed by fixing
Bug#11759688 52020: InnoDB can still deadlock on just INSERT...ON DUPLICATE KEY
a.k.a. the reintroduction of
Bug#7975 deadlock without any locking, simple select and update

alter_treable-big.test was failing due to the use of RAND() function which is no more 
replication safe.
This has been modified using static values.

Also, 'sleep' has been replaced using 'debug_sync' and the execution time of the 
test has been reduced significantly.

This test is now taken out of the disabled.def file and is being enabled.

a.k.a. Bug#7975 deadlock without any locking, simple select and update

Bug#7975 was reintroduced when the storage engine API was made
pluggable in MySQL 5.1. Instead of looking at thd->lex directly, we
rely on handler::extra(). But, we were looking at the wrong extra()
flag, and we were ignoring the TRX_DUP_REPLACE flag in places where we
should obey it.

innodb_replace.test: Add tests for hopefully all affected statement
types, so that bug should never ever resurface. This kind of tests
should have been added when fixing Bug#7975 in MySQL 5.0.3 in the
first place.

rb:806 approved by Sunny Bains

No commit message

                      ALTER TABLE AND/OR PLUGIN/SEMISYNC

If a plugin was uninstalled, thread local values for plugin
variables of string type with PLUGIN_VAR_MEMALLOC flag were
not freed.

With this patch these variables are freed when thread is
done (like all other variables).

sql/sql_class.h:
  Added variable which stores memory hunks allocated
  for PLUGIN_VAR_MEMALLOC values.
sql/sql_plugin.cc:
  Normally all memory allocated for dynamic variables values must
  be freed by cleanup_variables().
  
  But if a plugin was uninstalled, descriptors of it's system
  variables are lost. Still some memory may be occupied for thread
  local values. It is ok for most kinds of variables, as they're
  stored on dynamic_variables_ptr and freed when thread is done.
  
  Values for PLUGIN_VAR_MEMALLOC variables are stored separately.
  These lost values are handled by plugin_var_memalloc_free().

      
      A patch for this bug has already been pushed. A minor change is made here.
      The database to be used after re-enabling the disabled code is 'TEST'.
      But instead, 'MYSQL' was being used. 
      This is the minor change that is being made here.

  Un-needed replace_result accidentally messed up a variable used
  *if* not running parallel.
  Removed the bogus --replace_result

    Don't do this for echo, instead:
    1) Enable replacements also for assignment from backquoted SQL
    2) Allow replace_regex to take a variable for the *entire* argument list
  
    With this, the test can be amended, but only in its version in trunk

btr_pcur_restore_position_func(): When the cursor was positioned at
the tree infimum or supremum, initialize pos_state and latch_mode. The
assertion failed, because pos_state was BTR_PCUR_WAS_POSITIONED.  In
the test failure of WL#5874, the purge thread attempted to restore the
cursor position on the infimum record (the clustered index was empty).

btr_pcur_detach(), btr_pcur_is_detached(): Unused functions, remove.

rb:804 approved by Inaam Rana

In all callers of row_sel_convert_mysql_key_to_innobase(), assert
that the converted key is empty or nonempty when it should be.

ibuf_insert_low(), the only caller of ibuf_set_entry_counter(), will
have latched an insert buffer bitmap page in bitmap_mtr before
invoking ibuf_set_entry_counter(). The latching order forbids any
further pages to be latched.

ibuf_set_entry_counter(): Renamed to ibuf_get_entry_counter(),
simplified the code and added comments.

Added the following symbols for predefined field numbers in change
buffer records:

#define IBUF_REC_FIELD_SPACE	0	/*!< in the pre-4.1 format,
					the page number. later, the space_id */
#define IBUF_REC_FIELD_MARKER	1	/*!< starting with 4.1, a marker
					consisting of 1 byte that is 0 */
#define IBUF_REC_FIELD_PAGE	2	/*!< starting with 4.1, the
					page number */
#define IBUF_REC_FIELD_METADATA	3	/* the metadata field */
#define IBUF_REC_FIELD_USER	4	/* first user field */

rb:802 approved by Sunny Bains

This patch corrects the test mysql_plugin so that it correctly masks
the library extension of the plugin daemon_example.

  Simplified fix avoiding changes to mysys:
  Use the MY_HOLD_ORIGINAL_MODES flag when calling my_copy(),
    this also stops it from attempting to chown() the file.
  Yes this behavior is a bit confusing....
  The only case this might change the behavior is if the destination file
    exists, but since we also use MY_DONT_OVERWRITE_FILE, it would fail
    in those cases anyway.

OF 16G BUFFER POOL TAKES HOURS

rb://787 approved by Sunny

In patch mysql-5.5:revno:3097.92.133, we made the gcc 4.6.1 compiler
to stop complaining about the fact that binlog_can_be_corrupted was
defined but not used. The fix consisted in checking the variable
and printing a warning message.

However, the fix caused a regression as a message was being printed
out when there was no corrupted binary log causing performance
problems and triggering users' suspicions when there was no need.

In BUG#13337202, we do not print any message and use the variable
in an "if" with an empty body to keep the compiler happy.

and query_cache don't play along nicely.

An alternative for RENAME DATABSE using RENAME TABLE has been used to implement this.

Parts of index_merge_innodb were disabled.These have been enabled with a few changes 
and the test is being made experimental to study it's behaviour.

Also fixed possibly uninitialized use of need_copy_table_res.