As documented in the bug report, the double checked locking
pattern has inherent issues, and cannot guarantee correct
initialization.
This patch replaces the logic in init_available_charsets()
with the use of pthread_once(3). A wrapper function,
my_pthread_once(), is introduced and is used in lieu of direct
calls to init_available_charsets(). Related defines
MY_PTHREAD_ONCE_* are also introduced.
For the Windows platform, the implementation in lp:sysbench is
ported. For single-thread use, a simple define calls the
function and sets the pthread_once control variable.
Charset initialization is modified to use my_pthread_once().
include/my_no_pthread.h:
Dummy my_pthread_once() for single thread use.
include/my_pthread.h:
Declaration for new function my_pthread_once().
mysys/charset.c:
Logic in init_available_charsets() is simplified.
Using my_pthread_once() for all calls to this func.
mysys/my_winthread.c:
Windows implementation of my_pthread_once().
Support for flushing individual logs, so that the user can
selectively flush a subset of the server logs.
Flush of individual logs is done according to the
following syntax:
FLUSH <log_category> LOGS;
The syntax is extended so that the user is able to flush a
subset of logs:
FLUSH [log_category LOGS,];
where log_category is one of:
SLOW
ERROR
BINARY
ENGINE
GENERAL
RELAY.
mysql-test/suite/rpl/r/rpl_flush_logs.result:
Test result for WL#5142.
mysql-test/suite/rpl/t/rpl_flush_logs.test:
Added the test file to verify if the 'flush individual log'
statement works fine.
sql/log.cc:
Added the two functions to flush slow and general log.
sql/sql_parse.cc:
Added code to flush specified logs against the option.
sql/sql_yacc.yy:
Added code to parse the 'flush * log' statement syntax and
set its option to Lex->type.
----------------------------------------------------------
revno: 2630.4.38
committer: Konstantin Osipov <konstantin@mysql.com>
branch nick: mysql-6.0-4144
timestamp: Wed 2008-06-25 22:07:06 +0400
message:
WL#4144 - Lock MERGE engine children.
Committing a version of the patch merged with WL#3726
on behalf of Ingo.
Step #1: Move locking from parent to children.
MERGE children are now left in the query list of tables
after inserted there in open_tables(). So they are locked
by lock_tables() as all other tables are.
The MERGE parent does not store locks any more. It appears
in a MYSQL_LOCK with zero lock data. This is kind of a "dummy"
lock.
All other lock handling is also done directly on the children.
To protect against parent or child modifications during LOCK
TABLES, the children are detached after every statement and
attached before every statement, even under LOCK TABLES.
The children table list is removed from the query list of tables
on every detach and on close of the parent.
Step #2: Move MERGE specific functionality from SQL layer
into table handler.
Functionality moved from SQL layer (mainly sql_base.cc)
to the table handler (ha_myisammrg.cc).
Unnecessary code is removed from the SQL layer.
Step #3: Moved all MERGE specific members from TABLE
to ha_myisammrg.
Moved members from TABLE to ha_myisammrg.
Renamed some mebers.
Fixed comments.
Step #4: Valgrind and coverage testing
Valgrind did not uncover new problems.
Added purecov comments.
Added a new test for DATA/INDEX DIRECTORY options.
Changed handling of ::reset() for non-attached children.
Fixed the merge-big test.
Step #5: Fixed crashes detected during review
Changed detection when to attach/detach.
Added new tests.
Backport also the fix for Bug#44040 "MySQL allows creating a
MERGE table upon VIEWs but crashes when using it"
include/my_base.h:
WL#4144 - Lock MERGE engine children
Added HA_EXTRA_ADD_CHILDREN_LIST and HA_EXTRA_IS_ATTACHED_CHILDREN
for MERGE table support
mysql-test/r/merge.result:
WL#4144 - Lock MERGE engine children
Fixed test result.
mysql-test/t/disabled.def:
Enable merge.test, which now is working again (WL#4144).
mysql-test/t/merge-big.test:
Fix the messages for wait_condition (merge with WL#3726).
mysql-test/t/merge.test:
WL#4144 - Lock MERGE engine children
Fixed one test to meet coding standards for tests
(upper case keywords, engine names as in SHOW ENGINES).
Fixed error codes.
Added a test for DATA/INDEX DIRECTORY.
mysys/thr_lock.c:
WL#4144 - Lock MERGE engine children
Added purecov comments.
sql/ha_partition.cc:
WL#4144 - Lock MERGE engine children
Added MERGE specific extra operations to ha_partition::extra().
Extended comments.
Changed function comment to doxygen style.
Fixed nomenclature: 'parameter' -> 'operation'.
sql/mysql_priv.h:
WL#4144 - Lock MERGE engine children
Removed declarations for removed functions.
sql/sql_base.cc:
WL#4144 - Lock MERGE engine children
Leave the children in the query list of tables after open_tables().
Set proper back links (prev_global).
Attach MERGE children before and detach them after every
statement. Even under LOCK TABLES.
Remove children from the query list when they are detached.
Remove lock forwarding from children to parent.
Moved MERGE specific functions to ha_myisammrg.cc.
Added purecov comments.
Backport the fix for Bug#44040 "MySQL allows creating a MERGE table upon VIEWs but crashes when using it"
sql/sql_table.cc:
WL#4144 - Lock MERGE engine children
Changed detection of MERGE tables.
sql/table.cc:
WL#4144 - Lock MERGE engine children
Moved is_children_attached() method from TABLE to ha_myisammrg.
sql/table.h:
WL#4144 - Lock MERGE engine children
Moved all MERGE specific members from TABLE to ha_myisammrg.
storage/myisammrg/ha_myisammrg.cc:
WL#4144 - Lock MERGE engine children
Set proper back links in the child list (prev_global).
Added a function for removal of the child list from the query list.
Remove children from the query list when the parent is closed.
Make parent lock handling a dummy (zero locks).
Moved MERGE specific functionality from SQL layer to here.
Moved all MERGE specific members from TABLE to ha_myisammrg.
Renamed children list pointers.
Added initialization and free for the children list mem_root.
Fixed comments.
Added purecov comments.
storage/myisammrg/ha_myisammrg.h:
WL#4144 - Lock MERGE engine children
Added method add_children_list().
Moved all MERGE specific members from TABLE to ha_myisammrg.
Renamed children list pointers.
Added a mem_root for the children list.
storage/myisammrg/myrg_extra.c:
WL#4144 - Lock MERGE engine children
Changed handling of ::reset() for non-attached children.
------------------------------------------------------------
revno: 2630.4.37
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-6.0-3726-w2
timestamp: Wed 2008-06-25 20:28:57 +0400
message:
Fix build failure of mysql-6.0-3726 tree on Windows.
The failure was caused by the fact that sql/mdl.cc was
using __func__ macro without including sql_profile.h
header which contained definition of this macro for
those platforms that miss it.
This patch solves this problem by moving this define to
include/my_global.h which makes it available in modules
which don't/can't include sql/mysql_priv.h.
This is a patch that is part of WL#3726.
include/my_global.h:
Moved definition of __func__ macro from sql/sql_profile.h to
include/my_global.h to make it accessible from those modules
of the server which don't include mysql_priv.h.
sql/sql_profile.cc:
Removed _unknown_func_ const variable since it is no longer used
by __func__ macro.
sql/sql_profile.h:
Moved definition of __func__ macro from sql/sql_profile.h to
include/my_global.h to make it accessible from those modules
of the server which don't include mysql_priv.h.
----------------------------------------------------------
revno: 2630.4.35
committer: Konstantin Osipov <konstantin@mysql.com>
branch nick: mysql-6.0-3726
timestamp: Wed 2008-06-25 16:44:00 +0400
message:
Fix a MyISAM-specific bug in the new implementation of
LOCK TABLES (WL#3726).
If more than one instance of a MyISAM table are open in the
same connection, all of them must share the same status_param.
Otherwise, unlock of a table may lead to lost records.
See also comments in thr_lock.c.
include/thr_lock.h:
Declare thr_lock_merge_status().
mysql-test/r/lock.result:
Update test results (WL#3726).
mysql-test/t/lock.test:
Add a test case for the situation when the same table is locked
twice by LOCK TABLES, and only one instance is updated.
mysys/thr_lock.c:
Move the code that makes sure all status_params of the same
table are shared into a separate function.
sql/lock.cc:
Make sure that status_param is shared when a table is reopened.
-------------------------------------------------------------
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.
configure.in:
Remove checks for functions that are not used anymore.
include/config-netware.h:
Remove unused define.
include/my_pthread.h:
Remove thread priority changing wrappers.
mysys/my_pthread.c:
Remove thread priority changing wrappers. They do not work properly
and their implementations were incorrectly protected by a check for
HAVE_PTHREAD_SETSCHEDPARAM.
mysys/thr_alarm.c:
Remove meaningless (100) increase of a thread priority.
sql/mysql_priv.h:
Remove meaningless thread priority values.
sql/mysqld.cc:
Don't change thread priorities.
sql/slave.cc:
Don't change thread priorities.
sql/slave.h:
Update function prototype.
sql/sql_parse.cc:
Don't change thread priorities.
sql/sql_prepare.cc:
Don't change thread priorities.
sql/unireg.h:
Mark flag as obsolete.
storage/innobase/handler/ha_innodb.cc:
Remove use of obsolete flag and associated behavior.
storage/innobase/include/srv0srv.h:
Remove use of obsolete flag and associated variables.
storage/innobase/os/os0thread.c:
Remove use of obsolete flag and associated behavior.
storage/innobase/srv/srv0srv.c:
Remove use of obsolete flag and associated variables.
