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Author SHA1 Message Date
Sergei Golubchik
d3935adf7a mysql-5.5.29 merge 2013-01-15 19:13:32 +01:00
Annamalai Gurusami
378a7d1ef5 Bug #14036214 MYSQLD CRASHES WHEN EXECUTING UPDATE IN TRX WITH 
CONSISTENT SNAPSHOT OPTION

A transaction is started with a consistent snapshot.  After 
the transaction is started new indexes are added to the 
table.  Now when we issue an update statement, the optimizer
chooses an index.  When the index scan is being initialized
via ha_innobase::change_active_index(), InnoDB reports 
the error code HA_ERR_TABLE_DEF_CHANGED, with message 
stating that "insufficient history for index".

This error message is propagated up to the SQL layer.  But
the my_error() api is never called.  The statement level
diagnostics area is not updated with the correct error 
status (it remains in Diagnostics_area::DA_EMPTY).  

Hence the following check in the Protocol::end_statement()
fails.

 516   case Diagnostics_area::DA_EMPTY:
 517   default:
 518     DBUG_ASSERT(0);
 519     error= send_ok(thd->server_status, 0, 0, 0, NULL);
 520     break;

The fix is to backport the fix of bugs 14365043, 11761652 
and 11746399. 

14365043 PROTOCOL::END_STATEMENT(): ASSERTION `0' FAILED
11761652 HA_RND_INIT() RESULT CODE NOT CHECKED
11746399 RETURN VALUES OF HA_INDEX_INIT() AND INDEX_INIT() IGNORED

rb://1227 approved by guilhem and mattiasj.
 2012-10-08 19:40:30 +05:30
unknown
335de5db18 Merge mariadb 5.3->mariadb 5.5 2012-03-24 18:21:22 +01:00
Michael Widenius
c36bdf1c88 Speedup: 
- Don't call update_virtual_fields() if table->vfield is not set
- Don't prealloc memory for in open_tables() as this is very seldom used.


sql/records.cc:
  Don't call update_virtual_fields() if table->vfield is not set
sql/sql_base.cc:
  Don't prealloc memory for in open_tables() as this is very seldom used.
  Don't call update_virtual_fields() if table->vfield is not set
sql/sql_delete.cc:
  Don't call update_virtual_fields() if table->vfield is not set
sql/sql_handler.cc:
  Don't call update_virtual_fields() if table->vfield is not set
sql/sql_join_cache.cc:
  Don't call update_virtual_fields() if table->vfield is not set
  Move some frequent values to local variables
sql/sql_table.cc:
  Don't call update_virtual_fields() if table->vfield is not set
sql/sql_update.cc:
  Don't call update_virtual_fields() if table->vfield is not set
sql/table.cc:
  Assert if update_virtual_fields is called with wrong parameters
 2012-03-23 18:22:39 +02:00
Michael Widenius
2b625ac3e0 Fixed lp:933719, "Assertion open_tables == 0 ... " in THD::restore_backup_open_tables_state. 
This also fixes a (not likely) crashing bug when forcing a thread that was doing a table lock to re-open it's files, for example by creating a trigger.


mysys/thr_lock.c:
  Added more checking to find wrong locks.
  Removed one, not needed, parameter to thr_lock
sql/lock.cc:
  Fixed mysql_lock_tables() to retry with new sql_lock if lock fails. This was needed as table may be closed and reopened between retry's and then the old sql_lock will point to stale data.
sql/mysql_priv.h:
  Updated prototype
sql/sql_base.cc:
  Ensure that all tables are closed if opening of system table failes; This fixes the assert in THD::restore_backup_open_tables_state
sql/sql_handler.cc:
  Updated variable type
 2012-02-23 16:43:35 +02:00
Sergei Golubchik
3f28115e0e 5.3 merge 2012-02-24 14:37:00 +01:00
Michael Widenius
6d4224a31c Merge with 5.2. 
no_error handling for select (used by INSERT ... SELECT) still needs to be fixed, but I will do that in a separate commit
 2011-12-11 11:34:44 +02:00
Michael Widenius
6920457142 Merge with MariaDB 5.1 2011-11-24 18:48:58 +02:00
Michael Widenius
a8d03ab235 Initail merge with MySQL 5.1 (XtraDB still needs to be merged) 
Fixed up copyright messages.
 2011-11-21 19:13:14 +02:00
Sergei Golubchik
0e007344ea mysql-5.5.18 merge 2011-11-03 19:17:05 +01:00
Sergei Golubchik
76f0b94bb0 merge with 5.3 
sql/sql_insert.cc:
  CREATE ... IF NOT EXISTS may do nothing, but
  it is still not a failure. don't forget to my_ok it.
  ******
  CREATE ... IF NOT EXISTS may do nothing, but
  it is still not a failure. don't forget to my_ok it.
sql/sql_table.cc:
  small cleanup
  ******
  small cleanup
 2011-10-19 21:45:18 +02:00
Sergei Golubchik
9809f05199 5.5-merge 2011-07-02 22:08:51 +02:00
Kent Boortz
68f00a5686 Updated/added copyright headers 2011-06-30 17:37:13 +02:00
Kent Boortz
44135d4725 Updated/added copyright headers 2011-06-30 17:31:31 +02:00
Kent Boortz
02e07e3b51 Updated/added copyright headers 2011-06-30 17:46:53 +02:00
Vladislav Vaintroub
9e97c1eb06 Fix formatting error message (invalid table name) in handler tests. 2011-03-29 20:37:30 +02:00
Guilhem Bichot
1756d087cd Fix for BUG#59894 
"set optimizer_switch to e or d causes invalid memory writes/valgrind warnings":
due to prefix support, the argument "e" was overwritten with its full value
"engine_condition_pushdown", which caused a buffer overrun.
This was wrong usage of find_type(); other wrong usages are fixed here too.
Please start reading with the comment of typelib.c.

client/mysqldump.c:
  A bug: find_type() expects a bitmap as 3rd argument
  (each bit is a flag controlling a behaviour of the function);
  here it was instead passed the length of the string to search!
  That could give random behaviour of find_type()
  depending on the string.
  We rather need to pass a correct flag to find_type().
  The correct flag is FIND_TYPE_BASIC (0).
  Flag 8 is not needed as buff cannot have a comma (see how buff is filled).
  Flag 1 looks like a superfluous restriction.
  Flag 4 is not user-friendly (why use
  --compatible=2 rather than --compatible=mysql40 ?, and
  we probably not commit to "2" always meaning "mysql40"
  until the end of times).
include/mysql.h.pp:
  This isn't a problematic API change as we go from char* to const char*:
  existing code will run unchanged.
include/typelib.h:
  named constants. Not an enum to not significantly change
  the declaration of find_type() which would be an API change
  (typelib.h is included in mysql.h).
mysql-test/r/mysqldump.result:
  correct result (see the two requested modes in SQL_MODE)
mysql-test/suite/sys_vars/t/optimizer_switch_basic.test:
  test for BUG#59894. The second SET used to crash.
mysql-test/t/mysqldump.test:
  we had no test for multiple modes in --compatible, which is
  supported according to --help
mysys/typelib.c:
  Fix for BUG#59894. parse_name() is asked to match "e" with a row
  of the TYPELIB (the TYPELIB lists permitted flags of optimizer_switch;
  and comes from optimizer_switch_names[] of sys_vars.cc).
  find_type() is capable of supporting prefixes, but if it is not
  passed flag 2 in third argument, it will overwrite its first
  argument (the string to search for) with the complete name,
  here overwriting "e" with "engine_condition_pushdown". But
  as this "e" was a buffer allocated in an Item, it was not big
  enough to host the longer name, thus the crash.
  We don't need to know the complete flag's name; the output used
  from find_type() is just the flag's number (== function's return
  code). So we can pass flag 2 to find_type() in parse_name().
  After doing this fix and the other fixes in this patch, all usages
  of find_type() were using flag 2; in most usages the string to search for,
  is not guaranteed to be long enough to host the complete name
  (it is either directly from argv, or from alloc_root/my_malloc
  done in an earlier call).
  Thus, flag 2 is here made implicit: callers need not pass it anymore,
  it is always automatically turned on.
  This allows to eliminate an oddity: parse_name() took a const char**,
  and then removed "const" before calling find_type(), which could
  theoretically modify the pointed data, thus lying on constness.
  Last, constants for find_type() are now named.
sql-common/client.c:
  Two bugs:
  1) The enum was not in sync with the array (due to a bad porting of WL 1054;
  the extra OPT_ values are about options present in 5.1 and deleted in 5.5);
  added a compile_time_assert() to make sure this doesn't happen again
  2) find_type() was writing past the end of opt_arg; as opt_arg was allocated
  with alloc_root() with no extra space, this was an overrun; it could be seen
  when
  ** building with -DWITH_VALGRIND -DHAVE_purify -DEXTRA_DEBUG
  ** making execution go through the faulty code; this faulty
  code is executed only if the client asks to read a configuration
  file like this:
    mysql_options(mysql, MYSQL_READ_DEFAULT_FILE, "/tmp/cnf.cnf");
  so by adding such line to the start of mysql_client_test.c::client_connect(),
  we could see the valgrind warning:
  ==30548== Invalid write of size 1
  ==30548==    at 0x4C2624C: strcpy (mc_replace_strmem.c:303)
  ==30548==    by 0x48DC29: find_type (typelib.c:120)
  ==30548==    by 0x465686: mysql_read_default_options (client.c:1344)
  ==30548==    by 0x46830F: mysql_real_connect (client.c:2971)
  ==30548==    by 0x409339: client_connect (mysql_client_test.c:331)
  ==30548==    by 0x463A7F: main (mysql_client_test.c:19902)
  ==30548==  Address 0x61875ad is 0 bytes after a block of size 29 alloc'd
  ==30548==    at 0x4C25153: malloc (vg_replace_malloc.c:195)
  ==30548==    by 0x49BFF1: my_malloc (my_malloc.c:38)
  ==30548==    by 0x49C65C: alloc_root (my_alloc.c:166)
  ==30548==    by 0x48EF97: handle_default_option (default.c:381)
  ==30548==    by 0x49068C: search_default_file_with_ext (default.c:992)
  ==30548==    by 0x48F929: search_default_file (default.c:670)
  ==30548==    by 0x48EDC4: my_search_option_files (default.c:312)
  ==30548==    by 0x48F4B1: my_load_defaults (default.c:576)
  ==30548==    by 0x46517A: mysql_read_default_options (client.c:1207)
  ==30548==    by 0x46830F: mysql_real_connect (client.c:2971)
  ==30548==    by 0x409339: client_connect (mysql_client_test.c:331)
  ==30548==    by 0x463A7F: main (mysql_client_test.c:19902)
  This is fixed by having find_type() not overwrite anymore.
sql/sql_help.cc:
  cast not needed anymore.
sql/table.cc:
  cast not needed anymore.
 2011-02-11 15:00:09 +01:00
Michael Widenius
26aa83bfc0 Fix for LP#702786 "Two handler read f1 next gives different errors" 
mysql-test/suite/handler/heap.result:
  New test case
mysql-test/suite/handler/heap.test:
  New test case
sql/sql_handler.cc:
  If we get a fatal error in handler read, end table/index scan as it's likely it was wrongly used (for example not supported feature for index)
 2011-01-14 12:32:23 +02:00
Michael Widenius
0d01dd200f Added HANDLER support for MEMORY tables 
Added key and file version numbers to MEMORY tables so that we can detect if someone has changed them between HANDLER calls.


mysql-test/suite/handler/aria.result:
  Fixed result after test changes
mysql-test/suite/handler/handler.inc:
  Changed test to use combined key to ensure rows are returned in a pre-determinated order.
mysql-test/suite/handler/heap.result:
  New result
mysql-test/suite/handler/heap.test:
  Added test for HANDLER + HEAP
mysql-test/suite/handler/innodb.result:
  Fixed result after test changes
mysql-test/suite/handler/myisam.result:
  Fixed result after test changes
sql/sql_handler.cc:
  Fixed wrong parameter to ha_index_next_same()
storage/heap/ha_heap.cc:
  Abort key scan if table has changed.
  Abort table scan if table has been recreated.
storage/heap/ha_heap.h:
  Added support for HANDLER
storage/heap/hp_clear.c:
  Increase version number so that we can notice changes if using HANDLER
storage/heap/hp_delete.c:
  Increase key data version number on key changes.
storage/heap/hp_rfirst.c:
  Remember version of key data
  Give error if using read-first on hash key.
storage/heap/hp_rkey.c:
  Remember version of key data
storage/heap/hp_rlast.c:
  Remember version of key data
  Give error if using read-last on hash key.
storage/heap/hp_rnext.c:
  Fixed that we get next key from last search.
storage/heap/hp_rprev.c:
  Fixed that we get previous key from last search.
storage/heap/hp_scan.c:
  Remember version of key and file data
storage/heap/hp_update.c:
  Increase key data version number on key changes.
storage/heap/hp_write.c:
  Increase key data version number on key changes.
 2011-01-11 18:51:59 +02:00
Michael Widenius
050c004f5e Merge with 5.1 
Fixes to get Aria handler tests to work.
Fixes LP#697597 "HANDLER + Aria asserts in maria-5.3-handler"
 2011-01-11 15:36:41 +02:00
Michael Widenius
2eaa76b844 Automatic merge with 5.1 2011-01-10 23:42:47 +02:00
Michael Widenius
505c663a1e - Fixed that Aria works with HANDLER commands 
- Added test case for Aria
- Tested HANDLER with HEAP (changes to HEAP code will be pushed in 5.3)
- Moved all HANDLER test to suite/handler.


mysql-test/Makefile.am:
  Added suite/handler
mysql-test/mysql-test-run.pl:
  Added suite/handler
mysql-test/r/lock_multi.result:
  Remove test that is already in handler test suite
mysql-test/suite/handler/aria.result:
  Test for HANDLER with Aria storage engine
mysql-test/suite/handler/aria.test:
  Test for HANDLER with Aria storage engine
mysql-test/suite/handler/handler.inc:
  Extended the general handler test
  Moved interface testing to 'interface.test'
mysql-test/suite/handler/init.inc:
  Common init for handler tests.
mysql-test/suite/handler/innodb.result:
  New results
mysql-test/suite/handler/innodb.test:
  Update to use new include files
mysql-test/suite/handler/interface.result:
  Test of HANDLER interface (not storage engine dependent parts)
mysql-test/suite/handler/interface.test:
  Test of HANDLER interface (not storage engine dependent parts)
mysql-test/suite/handler/myisam.result:
  New results
mysql-test/suite/handler/myisam.test:
  Update to use new include files
mysql-test/t/lock_multi.test:
  Remove test that is already in handler test suite
mysys/tree.c:
  Added missing handling of read previous (showed up in HEAP testing)
sql/handler.cc:
  Don't marka 'HA_ERR_RECORD_CHANGED' as fatal (can be used with HANDLER READ, especially with MEMORY ENGINE)
sql/handler.h:
  Added prototype for can_continue_handler_scan()
sql/sql_handler.cc:
  Re-initialize search if we switch from key to table search.
  Check if handler can continue searching between calls (via can_continue_handler_scan())
  Don't write common not fatal errors to log
storage/maria/ma_extra.c:
  Don't set index 0 as default. This forces call to ma_check_index() to set up index variables.
storage/maria/ma_ft_boolean_search.c:
  Ensure that info->last_key.keyinfo is set
storage/maria/ma_open.c:
  Don't set index 0 as default. This forces call to ma_check_index() to set up index variables.
storage/maria/ma_rkey.c:
  Trivial optimization
storage/maria/ma_rnext.c:
  Added missing code from mi_rnext.c to ensure that handler next/prev works.
storage/maria/ma_rsame.c:
  Simple optimizations
storage/maria/ma_search.c:
  Initialize info->last_key once and for all when we change keys.
storage/maria/ma_unique.c:
  Ensure that info->last_key.keyinfo is up to date.
 2011-01-10 23:22:40 +02:00
Michael Widenius
e63b5546c5 Implementation of MWL#172: Add support for prepared statements to HANDLER READ 
It includes speed optimizations for HANDLER READ by caching as much as possible in HANDLER OPEN
Other things:
- Added mysqld option --disable-thr-alarm to be able to benchmark things without thr_alarm
- Changed 'Locked' state to 'System lock' and 'Table lock' (these where used in the code but never shown to end user)
- Better error message if mysql_install_db.sh fails
- Moved handler function prototypes to sql_handler.h
- Remove not anymore used 'thd->locked' member


include/thr_alarm.h:
  Added my_disable_thr_alarm
include/thr_lock.h:
  Add new member to THR_LOCK_DATA to remember original lock type state. This is needed as thr_unlock() resets type to TL_UNLOCK.
mysql-test/include/check_no_concurrent_insert.inc:
  Locked -> Table lock
mysql-test/include/handler.inc:
  Locked -> Table lock
mysql-test/r/handler_innodb.result:
  Updated results for new tests
mysql-test/r/handler_myisam.result:
  Updated results for new tests
mysql-test/r/sp-threads.result:
  Locked -> Table lock
mysql-test/suite/binlog/t/binlog_stm_row.test:
  Locked -> Table lock
mysql-test/suite/funcs_1/datadict/processlist_val.inc:
  Locked -> Table lock
mysql-test/suite/pbxt/t/lock_multi.test:
  Locked -> Table lock
mysql-test/suite/sys_vars/r/concurrent_insert_func.result:
  Locked -> Table lock
mysql-test/suite/sys_vars/t/concurrent_insert_func.test:
  Locked -> Table lock
mysql-test/suite/sys_vars/t/delayed_insert_limit_func.test:
  Locked -> Table lock
mysql-test/suite/sys_vars/t/query_cache_wlock_invalidate_func.test:
  Locked -> Table lock
mysql-test/suite/sys_vars/t/sql_low_priority_updates_func.test:
  Locked -> Table lock
mysql-test/t/insert_notembedded.test:
  Locked -> Table lock
mysql-test/t/lock_multi.test:
  Locked -> Table lock
mysql-test/t/merge-big.test:
  Locked -> Table lock
mysql-test/t/multi_update.test:
  Locked -> Table lock
mysql-test/t/query_cache_28249.test:
  Locked -> Table lock
mysql-test/t/sp_notembedded.test:
  Locked -> Table lock
mysql-test/t/sp_sync.test:
  Locked -> Table lock
mysql-test/t/status.test:
  Locked -> Table lock
mysql-test/t/trigger_notembedded.test:
  Locked -> Table lock
mysys/thr_alarm.c:
  Added option to disable thr_alarm
mysys/thr_lock.c:
  Detect loops
scripts/mysql_install_db.sh:
  Give better error message if something goes wrong
sql/Makefile.am:
  Added sql_handler.h
sql/lock.cc:
  Split functions to allow one to cache value if store_lock() (for HANDLER functions).
  - Split mysql_lock_tables() into two functions, where first one allocates MYSQL_LOCK and other other one uses it.
  - Made get_lock_data() an external function.
  - Added argument to mysql_unlock_tables() to not free sql_lock.
  - Added argument to reset_lock_data() to reset lock structure to initial state (as after get_lock_data())
sql/mysql_priv.h:
  Moved handler function prototypes to sql_handler.h
  Added new lock functions.
sql/mysqld.cc:
  Added --thread-alarm startup option
sql/net_serv.cc:
  Don't call vio_blocking() if not needed
sql/sql_base.cc:
  include sql_handler.h
sql/sql_class.cc:
  include sql_handler.h
  Remove not anymore used 'thd->locked' member
sql/sql_class.h:
  Remove not anymore used 'thd->locked' member
sql/sql_db.cc:
  include sql_handler.h
sql/sql_delete.cc:
  include sql_handler.h
sql/sql_handler.cc:
  Rewrote all code to use SQL_HANDLER instead of TABLE_LIST (original interface)
  Rewrote mysql_ha_open() to cache all things from TABLE_LIST and items for field list, where etc.
  In mysql_ha_open() also cache MYSQL_LOCK structure from get_lock_data().
  Split functions into smaller sub functions (needed to be able to implement mysql_ha_read_prepare())
  Added mysql_ha_read_prepare() to allow one to prepare HANDLER READ.
sql/sql_handler.h:
  Interface to sql_handler.cc
sql/sql_parse.cc:
  include sql_handler.h
sql/sql_prepare.cc:
  Added mysql_test_handler_read(), prepare for HANDLER READ
sql/sql_rename.cc:
  include sql_handler.h
sql/sql_show.cc:
  Removed usage of thd->locked
sql/sql_table.cc:
  include sql_handler.h
sql/sql_trigger.cc:
  include sql_handler.h
 2011-01-04 00:55:41 +02:00
Sergei Golubchik
65ca700def merge. 
checkpoint.
does not compile.
 2010-11-25 18:17:28 +01:00
Dmitry Lenev
6bf6272fda Patch that refactors global read lock implementation and fixes 
bug #57006 "Deadlock between HANDLER and FLUSH TABLES WITH READ
LOCK" and bug #54673 "It takes too long to get readlock for
'FLUSH TABLES WITH READ LOCK'".

The first bug manifested itself as a deadlock which occurred
when a connection, which had some table open through HANDLER
statement, tried to update some data through DML statement
while another connection tried to execute FLUSH TABLES WITH
READ LOCK concurrently.

What happened was that FTWRL in the second connection managed
to perform first step of GRL acquisition and thus blocked all
upcoming DML. After that it started to wait for table open
through HANDLER statement to be flushed. When the first connection
tried to execute DML it has started to wait for GRL/the second
connection creating deadlock.

The second bug manifested itself as starvation of FLUSH TABLES
WITH READ LOCK statements in cases when there was a constant
stream of concurrent DML statements (in two or more
connections).

This has happened because requests for protection against GRL
which were acquired by DML statements were ignoring presence of
pending GRL and thus the latter was starved.

This patch solves both these problems by re-implementing GRL
using metadata locks.

Similar to the old implementation acquisition of GRL in new
implementation is two-step. During the first step we block
all concurrent DML and DDL statements by acquiring global S
metadata lock (each DML and DDL statement acquires global IX
lock for its duration). During the second step we block commits
by acquiring global S lock in COMMIT namespace (commit code
acquires global IX lock in this namespace).

Note that unlike in old implementation acquisition of
protection against GRL in DML and DDL is semi-automatic.
We assume that any statement which should be blocked by GRL
will either open and acquires write-lock on tables or acquires
metadata locks on objects it is going to modify. For any such
statement global IX metadata lock is automatically acquired
for its duration.

The first problem is solved because waits for GRL become
visible to deadlock detector in metadata locking subsystem
and thus deadlocks like one in the first bug become impossible.

The second problem is solved because global S locks which
are used for GRL implementation are given preference over
IX locks which are acquired by concurrent DML (and we can
switch to fair scheduling in future if needed).

Important change:
FTWRL/GRL no longer blocks DML and DDL on temporary tables.
Before this patch behavior was not consistent in this respect:
in some cases DML/DDL statements on temporary tables were
blocked while in others they were not. Since the main use cases
for FTWRL are various forms of backups and temporary tables are
not preserved during backups we have opted for consistently
allowing DML/DDL on temporary tables during FTWRL/GRL.

Important change:
This patch changes thread state names which are used when
DML/DDL of FTWRL is waiting for global read lock. It is now
either "Waiting for global read lock" or "Waiting for commit
lock" depending on the stage on which FTWRL is.

Incompatible change:
To solve deadlock in events code which was exposed by this
patch we have to replace LOCK_event_metadata mutex with
metadata locks on events. As result we have to prohibit
DDL on events under LOCK TABLES.

This patch also adds extensive test coverage for interaction
of DML/DDL and FTWRL.

Performance of new and old global read lock implementations
in sysbench tests were compared. There were no significant
difference between new and old implementations.

mysql-test/include/check_ftwrl_compatible.inc:
  Added helper script which allows to check that a statement is
  compatible with FLUSH TABLES WITH READ LOCK.
mysql-test/include/check_ftwrl_incompatible.inc:
  Added helper script which allows to check that a statement is
  incompatible with FLUSH TABLES WITH READ LOCK.
mysql-test/include/handler.inc:
  Adjusted test case to the fact that now DROP TABLE closes
  open HANDLERs for the table to be dropped before checking
  if there active FTWRL in this connection.
mysql-test/include/wait_show_condition.inc:
  Fixed small error in the timeout message. The correct name
  of variable used as parameter for this script is "$condition"
  and not "$wait_condition".
mysql-test/r/delayed.result:
  Added test coverage for scenario which triggered assert in
  metadata locking subsystem.
mysql-test/r/events_2.result:
  Updated test results after prohibiting event DDL operations
  under LOCK TABLES.
mysql-test/r/flush.result:
  Added test coverage for bug #57006 "Deadlock between HANDLER
  and FLUSH TABLES WITH READ LOCK".
mysql-test/r/flush_read_lock.result:
  Added test coverage for various aspects of FLUSH TABLES WITH
  READ LOCK functionality.
mysql-test/r/flush_read_lock_kill.result:
  Adjusted test case after replacing custom global read lock
  implementation with one based on metadata locks. Use new
  debug_sync point. Do not disable concurrent inserts as now
  InnoDB we always use InnoDB table.
mysql-test/r/handler_innodb.result:
  Adjusted test case to the fact that now DROP TABLE closes
  open HANDLERs for the table to be dropped before checking
  if there active FTWRL in this connection.
mysql-test/r/handler_myisam.result:
  Adjusted test case to the fact that now DROP TABLE closes
  open HANDLERs for the table to be dropped before checking
  if there active FTWRL in this connection.
mysql-test/r/mdl_sync.result:
  Adjusted test case after replacing custom global read lock
  implementation with one based on metadata locks. Replaced
  usage of GRL-specific debug_sync's with appropriate sync
  points in MDL subsystem.
mysql-test/suite/perfschema/r/dml_setup_instruments.result:
  Updated test results after removing global
  COND_global_read_lock condition variable.
mysql-test/suite/perfschema/r/func_file_io.result:
  Ensure that this test doesn't affect subsequent tests.
  At the end of its execution enable back P_S instrumentation
  which this test disables at some point.
mysql-test/suite/perfschema/r/func_mutex.result:
  Ensure that this test doesn't affect subsequent tests.
  At the end of its execution enable back P_S instrumentation
  which this test disables at some point.
mysql-test/suite/perfschema/r/global_read_lock.result:
  Adjusted test case to take into account that new GRL
  implementation is based on MDL.
mysql-test/suite/perfschema/r/server_init.result:
  Adjusted test case after replacing custom global read
  lock implementation with one based on MDL and replacing
  LOCK_event_metadata mutex with metadata lock.
mysql-test/suite/perfschema/t/func_file_io.test:
  Ensure that this test doesn't affect subsequent tests.
  At the end of its execution enable back P_S instrumentation
  which this test disables at some point.
mysql-test/suite/perfschema/t/func_mutex.test:
  Ensure that this test doesn't affect subsequent tests.
  At the end of its execution enable back P_S instrumentation
  which this test disables at some point.
mysql-test/suite/perfschema/t/global_read_lock.test:
  Adjusted test case to take into account that new GRL
  implementation is based on MDL.
mysql-test/suite/perfschema/t/server_init.test:
  Adjusted test case after replacing custom global read
  lock implementation with one based on MDL and replacing
  LOCK_event_metadata mutex with metadata lock.
mysql-test/suite/rpl/r/rpl_tmp_table_and_DDL.result:
  Updated test results after prohibiting event DDL under
  LOCK TABLES.
mysql-test/t/delayed.test:
  Added test coverage for scenario which triggered assert in
  metadata locking subsystem.
mysql-test/t/events_2.test:
  Updated test case after prohibiting event DDL operations
  under LOCK TABLES.
mysql-test/t/flush.test:
  Added test coverage for bug #57006 "Deadlock between HANDLER
  and FLUSH TABLES WITH READ LOCK".
mysql-test/t/flush_block_commit.test:
  Adjusted test case after changing thread state name which
  is used when COMMIT waits for FLUSH TABLES WITH READ LOCK
  from "Waiting for release of readlock" to "Waiting for commit
  lock".
mysql-test/t/flush_block_commit_notembedded.test:
  Adjusted test case after changing thread state name which is
  used when DML waits for FLUSH TABLES WITH READ LOCK. Now we
  use "Waiting for global read lock" in this case.
mysql-test/t/flush_read_lock.test:
  Added test coverage for various aspects of FLUSH TABLES WITH
  READ LOCK functionality.
mysql-test/t/flush_read_lock_kill-master.opt:
  We no longer need to use make_global_read_lock_block_commit_loop
  debug tag in this test. Instead we rely on an appropriate
  debug_sync point in MDL code.
mysql-test/t/flush_read_lock_kill.test:
  Adjusted test case after replacing custom global read lock
  implementation with one based on metadata locks. Use new
  debug_sync point. Do not disable concurrent inserts as now
  InnoDB we always use InnoDB table.
mysql-test/t/lock_multi.test:
  Adjusted test case after changing thread state names which
  are used when DML or DDL waits for FLUSH TABLES WITH READ
  LOCK to "Waiting for global read lock".
mysql-test/t/mdl_sync.test:
  Adjusted test case after replacing custom global read lock
  implementation with one based on metadata locks. Replaced
  usage of GRL-specific debug_sync's with appropriate sync
  points in MDL subsystem. Updated thread state names which
  are used when DDL waits for FTWRL.
mysql-test/t/trigger_notembedded.test:
  Adjusted test case after changing thread state names which
  are used when DML or DDL waits for FLUSH TABLES WITH READ
  LOCK to "Waiting for global read lock".
sql/event_data_objects.cc:
  Removed Event_queue_element::status/last_executed_changed
  members and Event_queue_element::update_timing_fields()
  method. We no longer use this class for updating mysql.events
  once event is chosen for execution. Accesses to instances of
  this class in scheduler thread require protection by
  Event_queue::LOCK_event_queue mutex and we try to avoid
  updating table while holding this lock.
sql/event_data_objects.h:
  Removed Event_queue_element::status/last_executed_changed
  members and Event_queue_element::update_timing_fields()
  method. We no longer use this class for updating mysql.events
  once event is chosen for execution. Accesses to instances of
  this class in scheduler thread require protection by
  Event_queue::LOCK_event_queue mutex and we try to avoid
  updating table while holding this lock.
sql/event_db_repository.cc:
  - Changed Event_db_repository methods to not release all
    metadata locks once they are done updating mysql.events
    table. This allows to keep metadata lock protecting
    against GRL and lock protecting particular event around
    until corresponding DDL statement is written to the binary
    log.
  - Removed logic for conditional update of "status" and
    "last_executed" fields from update_timing_fields_for_event()
    method. In the only case when this method is called now
    "last_executed" is always modified and tracking change
    of "status" is too much hassle.
sql/event_db_repository.h:
  Removed logic for conditional update of "status" and
  "last_executed" fields from Event_db_repository::
  update_timing_fields_for_event() method.
  In the only case when this method is called now "last_executed"
  is always modified and tracking change of "status" field is
  too much hassle.
sql/event_queue.cc:
  Changed event scheduler code not to update mysql.events
  table while holding Event_queue::LOCK_event_queue mutex.
  Doing so led to a deadlock with a new GRL implementation.
  This deadlock didn't occur with old implementation due to
  fact that code acquiring protection against GRL ignored
  pending GRL requests (which lead to GRL starvation).
  One of goals of new implementation is to disallow GRL
  starvation and so we have to solve problem with this
  deadlock in a different way.
sql/events.cc:
  Changed methods of Events class to acquire protection
  against GRL while perfoming DDL statement and keep it
  until statement is written to the binary log.
  Unfortunately this step together with new GRL implementation
  exposed deadlock involving Events::LOCK_event_metadata
  and GRL. To solve it Events::LOCK_event_metadata mutex was
  replaced with a metadata lock on event. As a side-effect
  events DDL has to be prohibited under LOCK TABLES even in
  cases when mysql.events table was explicitly locked for
  write.
sql/events.h:
  Replaced Events::LOCK_event_metadata mutex with a metadata
  lock on event.
sql/ha_ndbcluster.cc:
  Updated code after replacing custom global read lock
  implementation with one based on MDL. Since MDL subsystem
  should now be able to detect deadlocks involving metadata
  locks and GRL there is no need for special handling of
  active GRL.
sql/handler.cc:
  Replaced custom implementation of global read lock with
  one based on metadata locks. Consequently when doing
  commit instead of calling method of Global_read_lock
  class to acquire protection against GRL we simply acquire
  IX in COMMIT namespace.
sql/lock.cc:
  Replaced custom implementation of global read lock with
  one based on metadata locks. This step allows to expose
  wait for GRL to deadlock detector of MDL subsystem and
  thus succesfully resolve deadlocks similar to one behind
  bug #57006 "Deadlock between HANDLER and FLUSH TABLES
  WITH READ LOCK". It also solves problem with GRL starvation
  described in bug #54673 "It takes too long to get readlock
  for 'FLUSH TABLES WITH READ LOCK'" since metadata locks used
  by GRL give preference to FTWRL statement instead of DML
  statements (if needed in future this can be changed to
  fair scheduling).
  
  Similar to old implementation of acquisition of GRL is
  two-step. During the first step we block all concurrent
  DML and DDL statements by acquiring global S metadata lock
  (each DML and DDL statement acquires global IX lock for
  its duration). During the second step we block commits by
  acquiring global S lock in COMMIT namespace (commit code
  acquires global IX lock in this namespace).
  
  Note that unlike in old implementation acquisition of
  protection against GRL in DML and DDL is semi-automatic.
  We assume that any statement which should be blocked by GRL
  will either open and acquires write-lock on tables or acquires
  metadata locks on objects it is going to modify. For any such
  statement global IX metadata lock is automatically acquired
  for its duration.
  
  To support this change:
  - Global_read_lock::lock/unlock_global_read_lock and
    make_global_read_lock_block_commit methods were changed
    accordingly.
  - Global_read_lock::wait_if_global_read_lock() and
    start_waiting_global_read_lock() methods were dropped.
    It is now responsibility of code acquiring metadata locks
    opening tables to acquire protection against GRL by
    explicitly taking global IX lock with statement duration.
  - Global variables, mutex and condition variable used by
    old implementation was removed.
  - lock_routine_name() was changed to use statement duration for
    its global IX lock. It was also renamed to lock_object_name()
    as it now also used to take metadata locks on events.
  - Global_read_lock::set_explicit_lock_duration() was added which
    allows not to release locks used for GRL when leaving prelocked
    mode.
sql/lock.h:
  - Renamed lock_routine_name() to lock_object_name() and changed
    its signature to allow its usage for events.
  - Removed broadcast_refresh() function. It is no longer needed
    with new GRL implementation.
sql/log_event.cc:
  Release metadata locks with statement duration at the end
  of processing legacy event for LOAD DATA. This ensures that
  replication thread processing such event properly releases
  its protection against global read lock.
sql/mdl.cc:
  Changed MDL subsystem to support new MDL-based implementation
  of global read lock.
  
  Added COMMIT and EVENTS namespaces for metadata locks. Changed
  thread state name for GLOBAL namespace to "Waiting for global
  read lock".
  
  Optimized MDL_map::find_or_insert() method to avoid taking
  m_mutex mutex when looking up MDL_lock objects for GLOBAL
  or COMMIT namespaces. We keep pre-created MDL_lock objects
  for these namespaces around and simply return pointers to
  these global objects when needed.
  
  Changed MDL_lock/MDL_scoped_lock to properly handle
  notification of insert delayed handler threads when FTWRL
  takes global S lock.
  
  Introduced concept of lock duration. In addition to locks with
  transaction duration which work in the way which is similar to
  how locks worked before (i.e. they are released at the end of
  transaction), locks with statement and explicit duration were
  introduced.
  Locks with statement duration are automatically released at the
  end of statement. Locks with explicit duration require explicit
  release and obsolete concept of transactional sentinel.
  
  * Changed MDL_request and MDL_ticket classes to support notion
    of duration.
  * Changed MDL_context to keep locks with different duration in
    different lists. Changed code handling ticket list to take
    this into account.
  * Changed methods responsible for releasing locks to take into
    account duration of tickets. Particularly public
    MDL_context::release_lock() method now only can release
    tickets with explicit duration (there is still internal
    method which allows to specify duration). To release locks
    with statement or transaction duration one have to use
    release_statement/transactional_locks() methods.
  * Concept of savepoint for MDL subsystem now has to take into
    account locks with statement duration. Consequently
    MDL_savepoint class was introduced and methods working with
    savepoints were updated accordingly.
  * Added methods which allow to set duration for one or all
    locks in the context.
sql/mdl.h:
  Changed MDL subsystem to support new MDL-based implementation
  of global read lock.
  
  Added COMMIT and EVENTS namespaces for metadata locks.
  
  Introduced concept of lock duration. In addition to locks with
  transaction duration which work in the way which is similar to
  how locks worked before (i.e. they are released at the end of
  transaction), locks with statement and explicit duration were
  introduced.
  Locks with statement duration are automatically released at the
  end of statement. Locks with explicit duration require explicit
  release and obsolete concept of transactional sentinel.
  
  * Changed MDL_request and MDL_ticket classes to support notion
    of duration.
  * Changed MDL_context to keep locks with different duration in
    different lists. Changed code handling ticket list to take
    this into account.
  * Changed methods responsible for releasing locks to take into
    account duration of tickets. Particularly public
    MDL_context::release_lock() method now only can release
    tickets with explicit duration (there is still internal
    method which allows to specify duration). To release locks
    with statement or transaction duration one have to use
    release_statement/transactional_locks() methods.
  * Concept of savepoint for MDL subsystem now has to take into
    account locks with statement duration. Consequently
    MDL_savepoint class was introduced and methods working with
    savepoints were updated accordingly.
  * Added methods which allow to set duration for one or all
    locks in the context.
sql/mysqld.cc:
  Removed global mutex and condition variables which were used
  by old implementation of GRL.
  Also we no longer need to initialize Events::LOCK_event_metadata
  mutex as it was replaced with metadata locks on events.
sql/mysqld.h:
  Removed global variable, mutex and condition variables which
  were used by old implementation of GRL.
sql/rpl_rli.cc:
  When slave thread closes tables which were open for handling
  of RBR events ensure that it releases global IX lock which
  was acquired as protection against GRL.
sql/sp.cc:
  Adjusted code to the new signature of lock_object/routine_name(),
  to the fact that one now needs specify duration of lock when
  initializing MDL_request and to the fact that savepoints for MDL
  subsystem are now represented by MDL_savepoint class.
sql/sp_head.cc:
  Ensure that statements in stored procedures release statement
  metadata locks and thus release their protectiong against GRL
  in proper moment in time.
  Adjusted code to the fact that one now needs specify duration
  of lock when initializing MDL_request.
sql/sql_admin.cc:
  Adjusted code to the fact that one now needs specify duration
  of lock when initializing MDL_request.
sql/sql_base.cc:
  - Implemented support for new approach to acquiring protection
    against global read lock. We no longer acquire such protection
    explicitly on the basis of statement flags. Instead we always
    rely on code which is responsible for acquiring metadata locks
    on object to be changed acquiring this protection. This is
    achieved by acquiring global IX metadata lock with statement
    duration. Code doing this also responsible for checking that
    current connection has no active GRL by calling an
    Global_read_lock::can_acquire_protection() method.
    Changed code in open_table() and lock_table_names()
    accordingly.
    Note that as result of this change DDL and DML on temporary
    tables is always compatible with GRL (before it was
    incompatible in some cases and compatible in other cases).
  - To speed-up code acquiring protection against GRL introduced
    m_has_protection_against_grl member in Open_table_context
    class. It indicates that protection was already acquired
    sometime during open_tables() execution and new attempts
    can be skipped.
  - Thanks to new GRL implementation calls to broadcast_refresh()
    became unnecessary and were removed.
  - Adjusted code to the fact that one now needs specify duration
    of lock when initializing MDL_request and to the fact that
    savepoints for MDL subsystem are now represented by
    MDL_savepoint class.
sql/sql_base.h:
  Adjusted code to the fact that savepoints for MDL subsystem are
  now represented by MDL_savepoint class.
  Also introduced Open_table_context::m_has_protection_against_grl
  member which allows to avoid acquiring protection against GRL
  while opening tables if such protection was already acquired.
sql/sql_class.cc:
  Changed THD::leave_locked_tables_mode() after transactional
  sentinel for metadata locks was obsoleted by introduction of
  locks with explicit duration.
sql/sql_class.h:
  - Adjusted code to the fact that savepoints for MDL subsystem
    are now represented by MDL_savepoint class.
  - Changed Global_read_lock class according to changes in
    global read lock implementation:
    * wait_if_global_read_lock and start_waiting_global_read_lock
      are now gone. Instead code needing protection against GRL
      has to acquire global IX metadata lock with statement
      duration itself. To help it new can_acquire_protection()
      was introduced. Also as result of the above change
      m_protection_count member is gone too.
    * Added m_mdl_blocks_commits_lock member to store metadata
      lock blocking commits.
    * Adjusted code to the fact that concept of transactional
      sentinel was obsoleted by concept of lock duration.
  - Removed CF_PROTECT_AGAINST_GRL flag as it is no longer
    necessary. New GRL implementation acquires protection
    against global read lock automagically when statement
    acquires metadata locks on tables or other objects it
    is going to change.
sql/sql_db.cc:
  Adjusted code to the fact that one now needs specify duration
  of lock when initializing MDL_request.
sql/sql_handler.cc:
  Removed call to broadcast_refresh() function. It is no longer
  needed with new GRL implementation.
  Adjusted code after introducing duration concept for metadata
  locks. Particularly to the fact transactional sentinel was
  replaced with explicit duration.
sql/sql_handler.h:
  Renamed mysql_ha_move_tickets_after_trans_sentinel() to
  mysql_ha_set_explicit_lock_duration() after transactional
  sentinel was obsoleted by locks with explicit duration.
sql/sql_insert.cc:
  Adjusted code handling delaying inserts after switching to
  new GRL implementation. Now connection thread initiating
  delayed insert has to acquire global IX lock in addition
  to metadata lock on table being inserted into. This IX lock
  protects against GRL and similarly to SW lock on table being
  inserted into has to be passed to handler thread in order to
  avoid deadlocks.
sql/sql_lex.cc:
  LEX::protect_against_global_read_lock member is no longer
  necessary since protection against GRL is automatically
  taken by code acquiring metadata locks/opening tables.
sql/sql_lex.h:
  LEX::protect_against_global_read_lock member is no longer
  necessary since protection against GRL is automatically
  taken by code acquiring metadata locks/opening tables.
sql/sql_parse.cc:
  - Implemented support for new approach to acquiring protection
    against global read lock. We no longer acquire such protection
    explicitly on the basis of statement flags. Instead we always
    rely on code which is responsible for acquiring metadata locks
    on object to be changed acquiring this protection. This is
    achieved by acquiring global IX metadata lock with statement
    duration. This lock is automatically released at the end of
    statement execution.
  - Changed implementation of CREATE/DROP PROCEDURE/FUNCTION not
    to release metadata locks and thus protection against of GRL
    in the middle of statement execution.
  - Adjusted code to the fact that one now needs specify duration
    of lock when initializing MDL_request and to the fact that
    savepoints for MDL subsystem are now represented by
    MDL_savepoint class.
sql/sql_prepare.cc:
  Adjusted code to the to the fact that savepoints for MDL
  subsystem are now represented by MDL_savepoint class.
sql/sql_rename.cc:
  With new GRL implementation there is no need to explicitly
  acquire protection against GRL before renaming tables.
  This happens automatically in code which acquires metadata
  locks on tables being renamed.
sql/sql_show.cc:
  Adjusted code to the fact that one now needs specify duration
  of lock when initializing MDL_request and to the fact that
  savepoints for MDL subsystem are now represented by
  MDL_savepoint class.
sql/sql_table.cc:
  - With new GRL implementation there is no need to explicitly
    acquire protection against GRL before dropping tables.
    This happens automatically in code which acquires metadata
    locks on tables being dropped.
  - Changed mysql_alter_table() not to release lock on new table
    name explicitly and to rely on automatic release of locks
    at the end of statement instead. This was necessary since
    now MDL_context::release_lock() is supported only for locks
    for explicit duration.
sql/sql_trigger.cc:
  With new GRL implementation there is no need to explicitly
  acquire protection against GRL before changing table triggers.
  This happens automatically in code which acquires metadata
  locks on tables which triggers are to be changed.
sql/sql_update.cc:
  Fix bug exposed by GRL testing. During prepare phase acquire
  only S metadata locks instead of SW locks to keep prepare of
  multi-UPDATE compatible with concurrent LOCK TABLES WRITE
  and global read lock.
sql/sql_view.cc:
  With new GRL implementation there is no need to explicitly
  acquire protection against GRL before creating view.
  This happens automatically in code which acquires metadata
  lock on view to be created.
sql/sql_yacc.yy:
  LEX::protect_against_global_read_lock member is no longer
  necessary since protection against GRL is automatically
  taken by code acquiring metadata locks/opening tables.
sql/table.cc:
  Adjusted code to the fact that one now needs specify duration
  of lock when initializing MDL_request.
sql/table.h:
  Adjusted code to the fact that one now needs specify duration
  of lock when initializing MDL_request.
sql/transaction.cc:
  Replaced custom implementation of global read lock with
  one based on metadata locks. Consequently when doing
  commit instead of calling method of Global_read_lock
  class to acquire protection against GRL we simply acquire
  IX in COMMIT namespace.
  Also adjusted code to the fact that MDL savepoint is now
  represented by MDL_savepoint class.
 2010-11-11 20:11:05 +03:00
Konstantin Osipov
29c4873ad5 Commit on behalf of Dmitry Lenev. 
Merge his patch for Bug#52044 into 5.5, and apply 
review comments.
 2010-08-12 17:50:23 +04:00
Michael Widenius
d042146e5b Merge with MariaDB 5.1.49 
Removed references to HA_END_SPACE_KEY (which has been 0 for a long time)
 2010-08-05 22:56:11 +03:00
Konstantin Osipov
36290c0923 A pre-requisite patch for the fix for Bug#52044. 
This patch also fixes Bug#55452 "SET PASSWORD is
replicated twice in RBR mode".

The goal of this patch is to remove the release of 
metadata locks from close_thread_tables().
This is necessary to not mistakenly release
the locks in the course of a multi-step
operation that involves multiple close_thread_tables()
or close_tables_for_reopen().

On the same token, move statement commit outside 
close_thread_tables().

Other cleanups:
Cleanup COM_FIELD_LIST.
Don't call close_thread_tables() in COM_SHUTDOWN -- there
are no open tables there that can be closed (we leave
the locked tables mode in THD destructor, and this
close_thread_tables() won't leave it anyway).

Make open_and_lock_tables() and open_and_lock_tables_derived()
call close_thread_tables() upon failure.
Remove the calls to close_thread_tables() that are now
unnecessary.

Simplify the back off condition in Open_table_context.

Streamline metadata lock handling in LOCK TABLES 
implementation.

Add asserts to ensure correct life cycle of 
statement transaction in a session.

Remove a piece of dead code that has also become redundant
after the fix for Bug 37521.

mysql-test/r/variables.result:
  Update results: set @@autocommit and statement transaction/
  prelocked mode.
mysql-test/r/view.result:
  A harmless change in CHECK TABLE <view> status for a broken view.
  If previously a failure to prelock all functions used in a view 
  would leave the connection in LTM_PRELOCKED mode, now we call
  close_thread_tables() from open_and_lock_tables()
  and leave prelocked mode, thus some check in mysql_admin_table() that
  works only in prelocked/locked tables mode is no longer activated.
mysql-test/suite/rpl/r/rpl_row_implicit_commit_binlog.result:
  Fixed Bug#55452 "SET PASSWORD is replicated twice in
  RBR mode": extra binlog events are gone from the
  binary log.
mysql-test/t/variables.test:
  Add a test case: set autocommit and statement transaction/prelocked
  mode.
sql/event_data_objects.cc:
  Simplify code in Event_job_data::execute().
  Move sp_head memory management to lex_end().
sql/event_db_repository.cc:
  Move the release of metadata locks outside
  close_thread_tables().
  Make sure we call close_thread_tables() when
  open_and_lock_tables() fails and remove extra
  code from the events data dictionary.
  Use close_mysql_tables(), a new internal
  function to properly close mysql.* tables
  in the data dictionary.
  Contract Event_db_repository::drop_events_by_field,
  drop_schema_events into one function.
  When dropping all events in a schema,
  make sure we don't mistakenly release all
  locks acquired by DROP DATABASE. These
  include locks on the database name
  and the global intention exclusive
  metadata lock.
sql/event_db_repository.h:
  Function open_event_table() does not require an instance 
  of Event_db_repository.
sql/events.cc:
  Use close_mysql_tables() instead of close_thread_tables()
  to bootstrap events, since the latter no longer
  releases metadata locks.
sql/ha_ndbcluster.cc:
  - mysql_rm_table_part2 no longer releases
  acquired metadata locks. Do it in the caller.
sql/ha_ndbcluster_binlog.cc:
  Deploy the new protocol for closing thread
  tables in run_query() and ndb_binlog_index
  code.
sql/handler.cc:
  Assert that we never call ha_commit_trans/
  ha_rollback_trans in sub-statement, which
  is now the case.
sql/handler.h:
  Add an accessor to check whether THD_TRANS object
  is empty (has no transaction started).
sql/log.cc:
  Update a comment.
sql/log_event.cc:
  Since now we commit/rollback statement transaction in 
  mysql_execute_command(), we need a mechanism to communicate
  from Query_log_event::do_apply_event() to mysql_execute_command()
  that the statement transaction should be rolled back, not committed.
  Ideally it would be a virtual method of THD. I hesitate
  to make THD a virtual base class in this already large patch.
  Use a thd->variables.option_bits for now.
  
  Remove a call to close_thread_tables() from the slave IO
  thread. It doesn't open any tables, and the protocol
  for closing thread tables is more complicated now.
  
  Make sure we properly close thread tables, however, 
  in Load_data_log_event, which doesn't
  follow the standard server execution procedure
  with mysql_execute_command().
  @todo: this piece should use Server_runnable
  framework instead.
  Remove an unnecessary call to mysql_unlock_tables().
sql/rpl_rli.cc:
  Update Relay_log_info::slave_close_thread_tables()
  to follow the new close protocol.
sql/set_var.cc:
  Remove an unused header.
sql/slave.cc:
  Remove an unnecessary call to
  close_thread_tables().
sql/sp.cc:
  Remove unnecessary calls to close_thread_tables()
  from SP DDL implementation. The tables will
  be closed by the caller, in mysql_execute_command().
  When dropping all routines in a database, make sure
  to not mistakenly drop all metadata locks acquired
  so far, they include the scoped lock on the schema.
sql/sp_head.cc:
  Correct the protocol that closes thread tables
  in an SP instruction.
  Clear lex->sphead before cleaning up lex
  with lex_end to make sure that we don't
  delete the sphead twice. It's considered
  to be "cleaner" and more in line with
  future changes than calling delete lex->sphead
  in other places that cleanup the lex.
sql/sp_head.h:
  When destroying m_lex_keeper of an instruction,
  don't delete the sphead that all lex objects
  share. 
  @todo: don't store a reference to routine's sp_head
  instance in instruction's lex.
sql/sql_acl.cc:
  Don't call close_thread_tables() where the caller will
  do that for us.
  Fix Bug#55452 "SET PASSWORD is replicated twice in RBR 
  mode" by disabling RBR replication in change_password()
  function.
  Use close_mysql_tables() in bootstrap and ACL reload
  code to make sure we release all metadata locks.
sql/sql_base.cc:
  This is the main part of the patch:
  - remove manipulation with thd->transaction
  and thd->mdl_context from close_thread_tables().
  Now this function is only responsible for closing
  tables, nothing else.
  This is necessary to be able to easily use
  close_thread_tables() in procedures, that
  involve multiple open/close tables, which all
  need to be protected continuously by metadata
  locks.
  Add asserts ensuring that TABLE object
  is only used when is protected by a metadata lock.
  Simplify the back off condition of Open_table_context,
  we no longer need to look at the autocommit mode.
  Make open_and_lock_tables() and open_normal_and_derived_tables()
  close thread tables and release metadata locks acquired so-far 
  upon failure. This simplifies their usage.
  Implement close_mysql_tables().
sql/sql_base.h:
  Add declaration for close_mysql_tables().
sql/sql_class.cc:
  Remove a piece of dead code that has also become redundant
  after the fix for Bug 37521.
  The code became dead when my_eof() was made a non-protocol method,
  but a method that merely modifies the diagnostics area.
  The code became redundant with the fix for Bug#37521, when 
  we started to cal close_thread_tables() before
  Protocol::end_statement().
sql/sql_do.cc:
  Do nothing in DO if inside a substatement
  (the assert moved out of trans_rollback_stmt).
sql/sql_handler.cc:
  Add comments.
sql/sql_insert.cc:
  Remove dead code. 
  Release metadata locks explicitly at the
  end of the delayed insert thread.
sql/sql_lex.cc:
  Add destruction of lex->sphead to lex_end(),
  lex "reset" method called at the end of each statement.
sql/sql_parse.cc:
  Move close_thread_tables() and other related
  cleanups to mysql_execute_command()
  from dispatch_command(). This has become
  possible after the fix for Bug#37521.
  Mark federated SERVER statements as DDL.
  
  Next step: make sure that we don't store
  eof packet in the query cache, and move
  the query cache code outside mysql_parse.
  
  Brush up the code of COM_FIELD_LIST.
  Remove unnecessary calls to close_thread_tables().
  
  When killing a query, don't report "OK"
  if it was a suicide.
sql/sql_parse.h:
  Remove declaration of a function that is now static.
sql/sql_partition.cc:
  Remove an unnecessary call to close_thread_tables().
sql/sql_plugin.cc:
  open_and_lock_tables() will clean up
  after itself after a failure.
  Move close_thread_tables() above
  end: label, and replace with close_mysql_tables(),
  which will also release the metadata lock
  on mysql.plugin.
sql/sql_prepare.cc:
  Now that we no longer release locks in close_thread_tables()
  statement prepare code has become more straightforward.
  Remove the now redundant check for thd->killed() (used
  only by the backup project) from Execute_server_runnable.
  Reorder code to take into account that now mysql_execute_command()
  performs lex->unit.cleanup() and close_thread_tables().
sql/sql_priv.h:
  Add a new option to server options to interact
  between the slave SQL thread and execution
  framework (hack). @todo: use a virtual
  method of class THD instead.
sql/sql_servers.cc:
  Due to Bug 25705 replication of 
  DROP/CREATE/ALTER SERVER is broken.
  Make sure at least we do not attempt to 
  replicate these statements using RBR,
  as this violates the assert in close_mysql_tables().
sql/sql_table.cc:
  Do not release metadata locks in mysql_rm_table_part2,
  this is done by the caller.
  Do not call close_thread_tables() in mysql_create_table(),
  this is done by the caller. 
  Fix a bug in DROP TABLE under LOCK TABLES when,
  upon error in wait_while_table_is_used() we would mistakenly
  release the metadata lock on a non-dropped table.
  Explicitly release metadata locks when doing an implicit
  commit.
sql/sql_trigger.cc:
  Now that we delete lex->sphead in lex_end(),
  zero the trigger's sphead in lex after loading
  the trigger, to avoid double deletion.
sql/sql_udf.cc:
  Use close_mysql_tables() instead of close_thread_tables().
sql/sys_vars.cc:
  Remove code added in scope of WL#4284 which would
  break when we perform set @@session.autocommit along
  with setting other variables and using tables or functions.
  A test case added to variables.test.
sql/transaction.cc:
  Add asserts.
sql/tztime.cc:
  Use close_mysql_tables() rather than close_thread_tables().
 2010-07-27 14:25:53 +04:00
Igor Babaev
452860dfde Fixed bug #604503. 
If the expression for a virtual column of table contained datetime
comparison then the execution of the second query that used this
virtual column caused a crash. It happened because the execution
of the first query that used this virtual column inserted a cached
item into the expression tree. The cached tree was allocated in
the statement memory while the expression tree was allocated in
the table memory.
Now the cached items that are inserted into expressions for virtual
columns with datetime comparisons are always allocated in the same
mem_root as the expressions for virtual columns. So now the inserted
cached items are valid for any queries that use these virtual columns.
 2010-07-17 11:16:16 -07:00
Jon Olav Hauglid
f45523188e merge from mysql-trunk-bugfixing 2010-07-13 10:39:24 +02:00
Davi Arnaut
f56dd32bf7 Bug#34043: Server loops excessively in _checkchunk() when safemalloc is enabled 
Essentially, the problem is that safemalloc is excruciatingly
slow as it checks all allocated blocks for overrun at each
memory management primitive, yielding a almost exponential
slowdown for the memory management functions (malloc, realloc,
free). The overrun check basically consists of verifying some
bytes of a block for certain magic keys, which catches some
simple forms of overrun. Another minor problem is violation
of aliasing rules and that its own internal list of blocks
is prone to corruption.

Another issue with safemalloc is rather the maintenance cost
as the tool has a significant impact on the server code.
Given the magnitude of memory debuggers available nowadays,
especially those that are provided with the platform malloc
implementation, maintenance of a in-house and largely obsolete
memory debugger becomes a burden that is not worth the effort
due to its slowness and lack of support for detecting more
common forms of heap corruption.

Since there are third-party tools that can provide the same
functionality at a lower or comparable performance cost, the
solution is to simply remove safemalloc. Third-party tools
can provide the same functionality at a lower or comparable
performance cost. 

The removal of safemalloc also allows a simplification of the
malloc wrappers, removing quite a bit of kludge: redefinition
of my_malloc, my_free and the removal of the unused second
argument of my_free. Since free() always check whether the
supplied pointer is null, redudant checks are also removed.

Also, this patch adds unit testing for my_malloc and moves
my_realloc implementation into the same file as the other
memory allocation primitives.

client/mysqldump.c:
  Pass my_free directly as its signature is compatible with the
  callback type -- which wasn't the case for free_table_ent.
 2010-07-08 18:20:08 -03:00
Jon Olav Hauglid
132ccf93d8 Bug #54401 assert in Diagnostics_area::set_eof_status , HANDLER 
This assert checks that the server does not try to send EOF to the
client if there has been some error during processing. This to make
sure that the error is in fact sent to the client.

The problem was that any errors during processing of WHERE conditions
in HANDLER ... READ statements where not detected by the handler code.
The handler code therefore still tried to send EOF to the client,
triggering the assert. The bug was only noticeable in debug builds.

This patch fixes the problem by making sure that the handler code
checks for errors during condition processing and acts accordingly.
 2010-07-05 13:59:34 +02:00
Konstantin Osipov
cc6dabba37 Merge trunk-bugfixing -> trunk-runtime 2010-06-17 17:31:51 +04:00
Ramil Kalimullin
3844367f2b Automerge. 2010-06-11 19:36:57 +04:00
Ramil Kalimullin
f4b7c50d6e Fix for bug #54007: assert in ha_myisam::index_next, HANDLER 
Problem: the server missed the fact that one can read from 
2 indexes alternately using HANDLER interface.

Fix: check if the same (initialized) index is involved
reading next/prev values from the index.


mysql-test/r/handler_myisam.result:
  Fix for bug #54007: assert in ha_myisam::index_next, HANDLER
    - test result.
mysql-test/t/handler_myisam.test:
  Fix for bug #54007: assert in ha_myisam::index_next, HANDLER
    - test case.
sql/sql_handler.cc:
  Fix for bug #54007: assert in ha_myisam::index_next, HANDLER
    - check if we use the same (initialized) index 
  to read next/prev values from the index.
 2010-06-09 14:45:04 +04:00
Konstantin Osipov
8d42534182 A review comment for WL#4441 " LOCK_open: Remove requirement of 
mutex protecting thd->open_tables".

We should not manipulate with table->s->version outside the 
table definition cache code, but use the TDC API
to achieve the desired result.

Fix one violation: close_all_tables_for_name().

sql/sql_base.cc:
  Use tdc_remove_table(TDC_RT_REMOVE_ALL) to expel the
  table share in close_all_tables_for_name, rather
  than manipulate with the table cache explicitly.
  
  Make sure that close_cached_tables() calls 
  close_all_tables_for_name() after closing all the involved
  handlers. The rest of the code was inspected to
  make sure that mysql_ha_rm_tables() is called.
sql/sql_handler.cc:
  Add a method to close all HANDLER cursors for a list
  of tables.
sql/sql_handler.h:
  Add declaration for mysql_ha_flush_tables().
 2010-06-09 12:39:09 +04:00
Konstantin Osipov
d4f1abaad2 WL#4441 "LOCK_open: Remove requirement of mutex protecting 
thd->open_tables"

thd->open_tables list is not normally accessed concurrently
except for one case: when the connection has open SQL
HANDLER tables, and we want to perform a DDL on the table,
we want to abort waits on MyISAM thr_lock of those connections
that prevent the DDL from proceeding, and iterate
over thd->open_tables list to find out the tables on which
the thread is waiting.

In 5.5 we mostly use deadlock detection and soft deadlock 
prevention, as opposed to "hard" deadlock prevention
of 5.1, which would abort any transaction that
may cause a deadlock. The only remaining case when
neither deadlock detection nor deadlock prevention
is implemented in 5.5 is HANDLER SQL, where we use
old good thr_lock_abort() technique form 5.1. 

Thus, replace use of LOCK_open to protect thd->open_tables
with thd->LOCK_ha_data (a lock protecting various session
private data).

This is a port of the work done for 5.5.4 for review
and inclusion into 5.5.5.

sql/sql_base.cc:
  Use thd->LOCK_ha_data (systematically) to set
  thd->open_tables.
sql/sql_class.h:
  Implement THD::set_open_tables().
sql/sql_cursor.cc:
  Use thd->LOCK_ha_data (systematically) to set
  thd->open_tables.
sql/sql_handler.cc:
  Use thd->LOCK_ha_data (systematically) to set
  thd->open_tables.
  Acquisition of LOCK_open is moved inside close_thread_table().
sql/sql_table.cc:
  Acquisition of LOCK_open is moved inside close_thread_tables().
 2010-06-08 12:08:46 +04:00
Mats Kindahl
23d8586dbf WL#5030: Split and remove mysql_priv.h 
This patch:

- Moves all definitions from the mysql_priv.h file into
  header files for the component where the variable is
  defined
- Creates header files if the component lacks one
- Eliminates all include directives from mysql_priv.h
- Eliminates all circular include cycles
- Rename time.cc to sql_time.cc
- Rename mysql_priv.h to sql_priv.h
 2010-03-31 16:05:33 +02:00
Konstantin Osipov
09b7a0d115 A post-review fix for type-aware metadata locks. 
DDL no longer aborts mysql_lock_tables(), and hence
we no longer need to support need_reopen flag of this
call. 
Remove the flag, and all the code in the server
that was responsible for handling the case when
it was set. This allowed to simplify: 
open_and_lock_tables_derived(), the delayed thread,
multi-update.

Rename MYSQL_LOCK_IGNORE_FLUSH to MYSQL_OPEN_IGNORE_FLUSH,
since we now only support this flag in open_table().

Rename MYSQL_LOCK_PERF_SCHEMA to MYSQL_LOCK_LOG_TABLE,
to avoid confusion.

Move the wait for the global read lock for cases
when we do updates in SELECT f1() or DO (UPDATE) to 
open_table() from mysql_lock_tables(). When waiting
for the read lock, we could raise need_reopen flag,
which is no longer present in mysql_lock_tables().
Since the block responsible for waiting for GRL
was moved, MYSQL_LOCK_IGNORE_GLOBAL_READ_LOCK
was renamed to MYSQL_OPEN_IGNORE_GLOBAL_READ_LOCK.


mysql-test/r/mdl_sync.result:
  Update test results (see comments for mdl_sync.test).
mysql-test/t/mdl_sync.test:
  Update tests: an abort mysql_lock_tables() called for an
  INSERT no longer auto-closes SQL HANDLERS, since it
  no longer leads to back-off and retry.
sql/ha_ndbcluster_binlog.cc:
  Remove unused variables.
sql/lock.cc:
  Remove support for need_reopen parameter of mysql_lock_tables().
  Update comments.
sql/log_event_old.cc:
  Remove the loop responsible for handling need_reopen
  out parameter of mysql_lock_tables().
sql/mysql_priv.h:
  Update open and lock tables flag names.
sql/share/errmsg-utf8.txt:
  Add a new error message to report when
  thr_multi_lock() is aborted.
sql/sql_base.cc:
  Update comments. Rename MYSQL_LOCK_IGNORE_FLUSH
  to MYSQL_OPEN_IGNORE_FLUSH.
sql/sql_class.h:
  Remove unused code.
sql/sql_db.cc:
  Remove an unused bit of code.
sql/sql_handler.cc:
  For backward compatibility, we still want to back off and
  retry when a call to mysql_lock_tables() is aborted
  from within an SQL HANDLER. Write an internal error
  handler to support the case.
sql/sql_insert.cc:
  Call mysql_lock_tables() no longer has need_reopen
  out parameter. Simplify the code by removing 
  the crud that took care of it.
  MYSQL_LOCK_IGNORE_FLUSH is now only supported by
  open_tables().
sql/sql_show.cc:
  Rename MYSQL_LOCK_IGNORE_FLUSH to MYSQL_OPEN_IGNORE_FLUSH
sql/sql_table.cc:
  Remove an unused parameter.
sql/sql_update.cc:
  Remove the need_reopen loop from multi-update.
  We no also longer need to cleanup the parse tree in case
  when mysql_lock_tables() is aborted and thus an infinite
  source of multi-update bugs is gone.
sql/tztime.cc:
  Rename MYSQL_LOCK_IGNORE_FLUSH to MYSQL_OPEN_IGNORE_FLUSH,
  since from now on this flag is only supported by open_table().
 2010-03-16 00:20:20 +03:00
Konstantin Osipov
7116431a8a A review comment for the fix for Bug#46672. 
Remove unnecessary need_reopen loops.
 2010-03-13 13:58:27 +03:00
Jon Olav Hauglid
3f1a9baf0b Bug #51355 handler stmt cause assertion in 
bool MDL_context::try_acquire_lock(MDL_request*)

This assert was triggered in the following way:
1) HANDLER OPEN t1 from connection 1
2) DROP TABLE t1 from connection 2. This will block due to the metadata lock
held by the open handler in connection 1.
3) DML statement (e.g. INSERT) from connection 1. This will close the table
opened by the HANDLER in 1) and release its metadata lock. This is done due
to the pending exclusive metadata lock from 2). 
4) DROP TABLE t1 from connection 2 now completes and removes table t1.
5) HANDLER READ from connection 1. Since the handler table was closed in 3),
the handler code will try to reopen the table. First a new metadata lock on
t1 will be granted before the command fails since the table was removed in 4).
6) HANDLER READ from connection 1. This caused the assert.

The reason for the assert was that the MDL_request's pointer to the lock
ticket was not reset when the statement failed. HANDLER READ then tried to
acquire a lock using the same MDL_request object, triggering the assert.
This bug was only noticeable on debug builds and did not cause any problems
on release builds.

This patch fixes the problem by assuring that the pointer to the metadata 
lock ticket is reset when reopening of handler tables fails.

Test case added to handler.inc
 2010-02-25 18:08:12 +01:00
Dmitry Lenev
d5a498abc6 Fix for bug #50908 "Assertion `handler_tables_hash.records == 0' 
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.
 2010-02-12 10:05:43 +03:00
Dmitry Lenev
8018ec5adb Fix for bug #50913 "Deadlock between open_and_lock_tables_derived 
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.
 2010-02-08 23:19:55 +03:00
Jon Olav Hauglid
82f4494125 Bug #50907 Assertion `hash_tables->table->next == __null' on 
HANDLER OPEN

The problem was a too restrictive assert in the code for 
HANDLER ... OPEN and HANDLER ... READ that checked table->next
to verify that we didn't open views or merge tables.

This pointer is also used to link temporary tables together
(see thd->temporary_tables). In this case TABLE::next can be
set even if we're trying to open a single table.

This patch adjust the two asserts to also check for the presence
of temporary tables.

Test case added to handler_myisam.test.
 2010-02-05 15:52:17 +01:00
Konstantin Osipov
665100b69d Merge next-mr -> next-4284. 2010-02-02 02:22:16 +03:00
Dmitry Lenev
eba5d30e67 Implement new type-of-operation-aware metadata locks. 
Add a wait-for graph based deadlock detector to the
MDL subsystem.

Fixes bug #46272 "MySQL 5.4.4, new MDL: unnecessary deadlock" and
bug #37346 "innodb does not detect deadlock between update and
alter table".

The first bug manifested itself as an unwarranted abort of a
transaction with ER_LOCK_DEADLOCK error by a concurrent ALTER
statement, when this transaction tried to repeat use of a
table, which it has already used in a similar fashion before
ALTER started.

The second bug showed up as a deadlock between table-level
locks and InnoDB row locks, which was "detected" only after
innodb_lock_wait_timeout timeout.

A transaction would start using the table and modify a few
rows.
Then ALTER TABLE would come in, and start copying rows
into a temporary table. Eventually it would stumble on
the modified records and get blocked on a row lock.
The first transaction would try to do more updates, and get
blocked on thr_lock.c lock.
This situation of circular wait would only get resolved
by a timeout.

Both these bugs stemmed from inadequate solutions to the
problem of deadlocks occurring between different
locking subsystems.

In the first case we tried to avoid deadlocks between metadata
locking and table-level locking subsystems, when upgrading shared
metadata lock to exclusive one.
Transactions holding the shared lock on the table and waiting for
some table-level lock used to be aborted too aggressively.

We also allowed ALTER TABLE to start in presence of transactions
that modify the subject table. ALTER TABLE acquires
TL_WRITE_ALLOW_READ lock at start, and that block all writes
against the table (naturally, we don't want any writes to be lost
when switching the old and the new table). TL_WRITE_ALLOW_READ
lock, in turn, would block the started transaction on thr_lock.c
lock, should they do more updates. This, again, lead to the need
to abort such transactions.

The second bug occurred simply because we didn't have any
mechanism to detect deadlocks between the table-level locks
in thr_lock.c and row-level locks in InnoDB, other than
innodb_lock_wait_timeout.

This patch solves both these problems by moving lock conflicts
which are causing these deadlocks into the metadata locking
subsystem, thus making it possible to avoid or detect such
deadlocks inside MDL.

To do this we introduce new type-of-operation-aware metadata
locks, which allow MDL subsystem to know not only the fact that
transaction has used or is going to use some object but also what
kind of operation it has carried out or going to carry out on the
object.

This, along with the addition of a special kind of upgradable
metadata lock, allows ALTER TABLE to wait until all
transactions which has updated the table to go away.
This solves the second issue.
Another special type of upgradable metadata lock is acquired
by LOCK TABLE WRITE. This second lock type allows to solve the
first issue, since abortion of table-level locks in event of
DDL under LOCK TABLES becomes also unnecessary.

Below follows the list of incompatible changes introduced by
this patch:

- From now on, ALTER TABLE and CREATE/DROP TRIGGER SQL (i.e. those
  statements that acquire TL_WRITE_ALLOW_READ lock)
  wait for all transactions which has *updated* the table to
  complete.

- From now on, LOCK TABLES ... WRITE, REPAIR/OPTIMIZE TABLE
  (i.e. all statements which acquire TL_WRITE table-level lock) wait
  for all transaction which *updated or read* from the table
  to complete.
  As a consequence, innodb_table_locks=0 option no longer applies
  to LOCK TABLES ... WRITE.

- DROP DATABASE, DROP TABLE, RENAME TABLE no longer abort
  statements or transactions which use tables being dropped or
  renamed, and instead wait for these transactions to complete.

- Since LOCK TABLES WRITE now takes a special metadata lock,
  not compatible with with reads or writes against the subject table
  and transaction-wide, thr_lock.c deadlock avoidance algorithm
  that used to ensure absence of deadlocks between LOCK TABLES
  WRITE and other statements is no longer sufficient, even for
  MyISAM. The wait-for graph based deadlock detector of MDL
  subsystem may sometimes be necessary and is involved. This may
  lead to ER_LOCK_DEADLOCK error produced for multi-statement
  transactions even if these only use MyISAM:

  session 1:         session 2:
  begin;

  update t1 ...      lock table t2 write, t1 write;
                     -- gets a lock on t2, blocks on t1

  update t2 ...
  (ER_LOCK_DEADLOCK)

- Finally,  support of LOW_PRIORITY option for LOCK TABLES ... WRITE
  was abandoned.
  LOCK TABLE ... LOW_PRIORITY WRITE from now on has the same
  priority as the usual LOCK TABLE ... WRITE.
  SELECT HIGH PRIORITY no longer trumps LOCK TABLE ... WRITE  in
  the wait queue.

- We do not take upgradable metadata locks on implicitly
  locked tables. So if one has, say, a view v1 that uses
  table t1, and issues:
  LOCK TABLE v1 WRITE;
  FLUSH TABLE t1; -- (or just 'FLUSH TABLES'),
  an error is produced.
  In order to be able to perform DDL on a table under LOCK TABLES,
  the table must be locked explicitly in the LOCK TABLES list.

mysql-test/include/handler.inc:
  Adjusted test case to trigger an execution path on which bug 41110
  "crash with handler command when used concurrently with alter
  table" and bug 41112 "crash in mysql_ha_close_table/get_lock_data
  with alter table" were originally discovered. Left old test case
  which no longer triggers this execution path for the sake of
  coverage.
  Added test coverage for HANDLER SQL statements and type-aware
  metadata locks.
  Added a test for the global shared lock and HANDLER SQL.
  Updated tests to take into account that the old simple deadlock
  detection heuristics was replaced with a graph-based deadlock
  detector.
mysql-test/r/debug_sync.result:
  Updated results (see debug_sync.test).
mysql-test/r/handler_innodb.result:
  Updated results (see handler.inc test).
mysql-test/r/handler_myisam.result:
  Updated results (see handler.inc test).
mysql-test/r/innodb-lock.result:
  Updated results (see innodb-lock.test).
mysql-test/r/innodb_mysql_lock.result:
  Updated results (see innodb_mysql_lock.test).
mysql-test/r/lock.result:
  Updated results (see lock.test).
mysql-test/r/lock_multi.result:
  Updated results (see lock_multi.test).
mysql-test/r/lock_sync.result:
  Updated results (see lock_sync.test).
mysql-test/r/mdl_sync.result:
  Updated results (see mdl_sync.test).
mysql-test/r/sp-threads.result:
  SHOW PROCESSLIST output has changed due to the fact that waiting
  for LOCK TABLES WRITE now happens within metadata locking
  subsystem.
mysql-test/r/truncate_coverage.result:
  Updated results (see truncate_coverage.test).
mysql-test/suite/funcs_1/datadict/processlist_val.inc:
  SELECT FROM I_S.PROCESSLIST output has changed due to fact that
  waiting for LOCK TABLES WRITE now happens within metadata locking
  subsystem.
mysql-test/suite/funcs_1/r/processlist_val_no_prot.result:
  SELECT FROM I_S.PROCESSLIST output has changed due to fact that
  waiting for LOCK TABLES WRITE now happens within metadata locking
  subsystem.
mysql-test/suite/rpl/t/rpl_sp.test:
  Updated to a new SHOW PROCESSLIST state name.
mysql-test/t/debug_sync.test:
  Use LOCK TABLES READ instead of LOCK TABLES WRITE as the latter
  no longer allows to trigger execution path involving waiting on
  thr_lock.c lock and therefore reaching debug sync-point covered
  by this test.
mysql-test/t/innodb-lock.test:
  Adjusted test case to the fact that innodb_table_locks=0 option is
  no longer supported, since LOCK TABLES WRITE handles all its
  conflicts within MDL subsystem.
mysql-test/t/innodb_mysql_lock.test:
  Added test for bug #37346 "innodb does not detect deadlock between
  update and alter table".
mysql-test/t/lock.test:
  Added test coverage which checks the fact that we no longer support
  DDL under LOCK TABLES on tables which were locked implicitly.
  Adjusted existing test cases accordingly.
mysql-test/t/lock_multi.test:
  Added test for bug #46272 "MySQL 5.4.4, new MDL: unnecessary
  deadlock".  Adjusted other test cases to take into account the
  fact that waiting for LOCK TABLES ... WRITE now happens within MDL
  subsystem.
mysql-test/t/lock_sync.test:
  Since LOCK TABLES ... WRITE now takes SNRW metadata lock for
  tables locked explicitly we have to implicitly lock InnoDB tables
  (through view) to trigger the table-level lock conflict between
  TL_WRITE and TL_WRITE_ALLOW_WRITE.
mysql-test/t/mdl_sync.test:
  Added basic test coverage for type-of-operation-aware metadata
  locks. Also covered with tests some use cases involving HANDLER
  statements in which a deadlock could arise.
  Adjusted existing tests to take type-of-operation-aware MDL into
  account.
mysql-test/t/multi_update.test:
  Update to a new SHOW PROCESSLIST state name.
mysql-test/t/truncate_coverage.test:
  Adjusted test case after making LOCK TABLES WRITE to wait until
  transactions that use the table to be locked are completed.
  Updated to the changed name of DEBUG_SYNC point.
sql/handler.cc:
  Global read lock functionality has been
  moved into a class.
sql/lock.cc:
  Global read lock functionality has been
  moved into a class.
  Updated code to use the new MDL API.
sql/mdl.cc:
  Introduced new type-of-operation aware metadata locks.
  To do this:
  - Changed MDL_lock to use one list for waiting requests and one
    list for granted requests. For each list, added a bitmap
    that holds information what lock types a list contains.
    Added a helper class MDL_lock::List to manipulate with granted
    and waited lists while keeping the bitmaps in sync
    with list contents.
  - Changed lock-compatibility functions to use bitmaps that
    define compatibility.
  - Introduced a graph based deadlock detector inspired by
    waiting_threads.c from Maria implementation.
  - Now that we have a deadlock detector, and no longer have
    a global lock to protect individual lock objects, but rather
    use an rw lock per object, removed redundant code for upgrade,
    and the global read lock. Changed the MDL API to
    no longer require the caller to acquire the global
    intention exclusive lock by means of a separate method.
    Removed a few more methods that became redundant.
  - Removed deadlock detection heuristic, it has been made
    obsolete by the deadlock detector.
  - With operation-type-aware metadata locks, MDL subsystem has
    become aware of potential conflicts between DDL and open
    transactions. This made it possible to remove calls to
    mysql_abort_transactions_with_shared_lock() from acquisition
    paths for exclusive lock and lock upgrade. Now we can simply
    wait for these transactions to complete without fear of
    deadlock. Function mysql_lock_abort() has also become
    unnecessary for all conflicting cases except when a DDL
    conflicts with a connection that has an open HANDLER.
sql/mdl.h:
  Introduced new type-of-operation aware metadata locks.
  Introduced a graph based deadlock detector and supporting
  methods.
  Added comments.
  God rid of redundant API calls.
  Renamed m_lt_or_ha_sentinel to m_trans_sentinel,
  since now it guards the global read lock as well as
  LOCK TABLES and HANDLER locks.
sql/mysql_priv.h:
  Moved the global read lock functionality into a
  class.
  Added MYSQL_OPEN_FORCE_SHARED_MDL flag which forces
  open_tables() to take MDL_SHARED on tables instead of
  metadata locks specified in the parser. We use this to
  allow PREPARE run concurrently in presence of
  LOCK TABLES ... WRITE.
  Added signature for find_table_for_mdl_ugprade().
sql/set_var.cc:
  Global read lock functionality has been
  moved into a class.
sql/sp_head.cc:
  When creating TABLE_LIST elements for prelocking or
  system tables set the type of request for metadata
  lock according to the operation that will be performed
  on the table.
sql/sql_base.cc:
  - Updated code to use the new MDL API.
  - In order to avoid locks starvation we take upgradable
    locks all at once. As result implicitly locked tables no
    longer get an upgradable lock. Consequently DDL and FLUSH
    TABLES for such tables is prohibited.
    find_write_locked_table() was replaced by
    find_table_for_mdl_upgrade() function.
    open_table() was adjusted to return TABLE instance with
    upgradable ticket when necessary.
  - We no longer wait for all locks on OT_WAIT back off
    action -- only on the lock that caused the wait
    conflict. Moreover, now we distinguish cases when we
    have to wait due to conflict in MDL and old version
    of table in TDC.
  - Upate mysql_notify_threads_having_share_locks()
    to only abort thr_lock.c waits of threads that
    have open HANDLERs, since lock conflicts with only
    these threads now can lead to deadlocks not detectable
    by the MDL deadlock detector.
  - Remove mysql_abort_transactions_with_shared_locks()
    which is no longer needed.
sql/sql_class.cc:
  Global read lock functionality has been moved into a class.
  Re-arranged code in THD::cleanup() to simplify assert.
sql/sql_class.h:
  Introduced class to incapsulate global read lock
  functionality.
  Now sentinel in MDL subsystem guards the global read lock
  as well as LOCK TABLES and HANDLER locks. Adjusted code
  accordingly.
sql/sql_db.cc:
  Global read lock functionality has been moved into a class.
sql/sql_delete.cc:
  We no longer acquire upgradable metadata locks on tables
  which are locked by LOCK TABLES implicitly. As result
  TRUNCATE TABLE is no longer allowed for such tables.
  Updated code to use the new MDL API.
sql/sql_handler.cc:
  Inform MDL_context about presence of open HANDLERs.
  Since HANLDERs break MDL protocol by acquiring table-level
  lock while holding only S metadata lock on a table MDL
  subsystem should take special care about such contexts (Now
  this is the only case when mysql_lock_abort() is used).
sql/sql_parse.cc:
  Global read lock functionality has been moved into a class.
  Do not take upgradable metadata locks when opening tables
  for CREATE TABLE SELECT as it is not necessary and limits
  concurrency.
  When initializing TABLE_LIST objects before adding them
  to the table list set the type of request for metadata lock
  according to the operation that will be performed on the
  table.
  We no longer acquire upgradable metadata locks on tables
  which are locked by LOCK TABLES implicitly. As result FLUSH
  TABLES is no longer allowed for such tables.
sql/sql_prepare.cc:
  Use MYSQL_OPEN_FORCE_SHARED_MDL flag when opening
  tables during PREPARE. This allows PREPARE to run
  concurrently in presence of LOCK TABLES ... WRITE.
sql/sql_rename.cc:
  Global read lock functionality has been moved into a class.
sql/sql_show.cc:
  Updated code to use the new MDL API.
sql/sql_table.cc:
  Global read lock functionality has been moved into a class.
  We no longer acquire upgradable metadata locks on tables
  which are locked by LOCK TABLES implicitly. As result DROP
  TABLE is no longer allowed for such tables.
  Updated code to use the new MDL API.
sql/sql_trigger.cc:
  Global read lock functionality has been moved into a class.
  We no longer acquire upgradable metadata locks on tables
  which are locked by LOCK TABLES implicitly. As result
  CREATE/DROP TRIGGER is no longer allowed for such tables.
  Updated code to use the new MDL API.
sql/sql_view.cc:
  Global read lock functionality has been moved into a class.
  Fixed results of wrong merge that led to misuse of GLR API.
  CREATE VIEW statement is not a commit statement.
sql/table.cc:
  When resetting TABLE_LIST objects for PS or SP re-execution
  set the type of request for metadata lock according to the
  operation that will be performed on the table. Do the same
  in auxiliary function initializing metadata lock requests
  in a table list.
sql/table.h:
  When initializing TABLE_LIST objects set the type of request
  for metadata lock according to the operation that will be
  performed on the table.
sql/transaction.cc:
  Global read lock functionality has been moved into a class.
 2010-02-01 14:43:06 +03:00
Konstantin Osipov
dfdbc84585 A prerequisite patch for the fix for Bug#46224 
"HANDLER statements within a transaction might lead to deadlocks".
Introduce a notion of a sentinel to MDL_context. A sentinel
is a ticket that separates all tickets in the context into two
groups: before and after it. Currently we can have (and need) only
one designated sentinel -- it separates all locks taken by LOCK
TABLE or HANDLER statement, which must survive COMMIT and ROLLBACK
and all other locks, which must be released at COMMIT or ROLLBACK.
The tricky part is maintaining the sentinel up to date when
someone release its corresponding ticket. This can happen, e.g.
if someone issues DROP TABLE under LOCK TABLES (generally,
see all calls to release_all_locks_for_name()).
MDL_context::release_ticket() is modified to take care of it.

******
A fix and a test case for Bug#46224 "HANDLER statements within a
transaction might lead to deadlocks".

An attempt to mix HANDLER SQL statements, which are transaction-
agnostic, an open multi-statement transaction,
and DDL against the involved tables (in a concurrent connection) 
could lead to a deadlock. The deadlock would occur when
HANDLER OPEN or HANDLER READ would have to wait on a conflicting
metadata lock. If the connection that issued HANDLER statement
also had other metadata locks (say, acquired in scope of a 
transaction), a classical deadlock situation of mutual wait
could occur.

Incompatible change: entering LOCK TABLES mode automatically
closes all open HANDLERs in the current connection.

Incompatible change: previously an attempt to wait on a lock
in a connection that has an open HANDLER statement could wait
indefinitely/deadlock. After this patch, an error ER_LOCK_DEADLOCK
is produced.

The idea of the fix is to merge thd->handler_mdl_context
with the main mdl_context of the connection, used for transactional
locks. This makes deadlock detection possible, since all waits
with locks are "visible" and available to analysis in a single
MDL context of the connection.

Since HANDLER locks and transactional locks have a different life
cycle -- HANDLERs are explicitly open and closed, and so
are HANDLER locks, explicitly acquired and released, whereas
transactional locks "accumulate" till the end of a transaction
and are released only with COMMIT, ROLLBACK and ROLLBACK TO SAVEPOINT,
a concept of "sentinel" was introduced to MDL_context.
All locks, HANDLER and others, reside in the same linked list.
However, a selected element of the list separates locks with
different life cycle. HANDLER locks always reside at the
end of the list, after the sentinel. Transactional locks are
prepended to the beginning of the list, before the sentinel.
Thus, ROLLBACK, COMMIT or ROLLBACK TO SAVEPOINT, only
release those locks that reside before the sentinel. HANDLER locks
must be released explicitly as part of HANDLER CLOSE statement,
or an implicit close. 
The same approach with sentinel
is also employed for LOCK TABLES locks. Since HANDLER and LOCK TABLES
statement has never worked together, the implementation is
made simple and only maintains one sentinel, which is used either
for HANDLER locks, or for LOCK TABLES locks.


mysql-test/include/handler.inc:
  Add test coverage for Bug#46224 "HANDLER statements within a
  transaction might lead to deadlocks".
  Extended HANDLER coverage to cover a mix of HANDLER, transactions
  and DDL statements.
mysql-test/r/handler_innodb.result:
  Update results (Bug#46224).
mysql-test/r/handler_myisam.result:
  Update results (Bug#46224).
sql/lock.cc:
  Remove thd->some_tables_deleted, it's never used.
sql/log_event.cc:
  No need to check for thd->locked_tables_mode, 
  it's done inside release_transactional_locks().
sql/mdl.cc:
  Implement the concept of HANDLER and LOCK TABLES "sentinel".
  Implement a method to clone an acquired ticket.
  Do not return tickets beyond the sentinel when acquiring
  locks, create a copy.
  Remove methods to merge and backup MDL_context, they are now
  not used (Hurra!). This opens a path to a proper constructor
  and destructor of class MDL_context (to be done in a separate
  patch).
  Modify find_ticket() to provide information about where
  the ticket position is with regard to the sentinel.
sql/mdl.h:
  Add declarations necessary for the implementation of the concept
  of "sentinel", a dedicated ticket separating transactional and
  non-transactional locks.
sql/mysql_priv.h:
  Add mark_tmp_table_for_reuse() declaration, 
  a function to "close" a single session (temporary) table.
sql/sql_base.cc:
  Remove thd->some_tables_deleted.
  Modify deadlock-prevention asserts and deadlock detection
  heuristics to take into account that from now on HANDLER locks
  reside in the same locking context.
  Add broadcast_refresh() to mysql_notify_thread_having_shared_lock():
  this is necessary for the case when a thread having a shared lock
  is asleep in tdc_wait_for_old_versions(). This situation is only
  possible with HANDLER t1 OPEN; FLUSH TABLE (since all over code paths
  that lead to tdc_wait_for_old_versions() always have an
  empty MDL_context). Previously the server would simply deadlock
  in this situation.
sql/sql_class.cc:
  Remove now unused member "THD::some_tables_deleted". 
  Move mysql_ha_cleanup() a few lines above in THD::cleanup() 
  to make sure that all handlers are closed when it's time to 
  destroy the MDL_context of this connection.
  Remove handler_mdl_context and handler_tables.
sql/sql_class.h:
  Remove THD::handler_tables, THD::handler_mdl_context,
  THD::some_tables_deleted.
sql/sql_handler.cc:
  Remove thd->handler_tables.
  Remove thd->handler_mdl_context.
  Rewrite mysql_ha_open() to have no special provision for MERGE
  tables, now that we don't have to manipulate with thd->handler_tables
  it's easy to do.
  Remove dead code.
  Fix a bug in mysql_ha_flush() when we would always flush
  a temporary HANDLER when mysql_ha_flush() is called (actually
  mysql_ha_flush() never needs to flush temporary tables).
sql/sql_insert.cc:
  Update a comment, no more thd->some_tables_deleted.
sql/sql_parse.cc:
  Implement an incompatible change: entering LOCK TABLES closes
  active HANDLERs, if any.
  Now that we have a sentinel, we don't need to check
  for thd->locked_tables_mode when releasing metadata locks in
  COMMIT/ROLLBACK.
sql/sql_plist.h:
  Add new (now necessary) methods to the list class.
sql/sql_prepare.cc:
  Make sure we don't release HANDLER locks when rollback to a
  savepoint, set to not keep locks taken at PREPARE.
sql/sql_servers.cc:
  Update to a new signature of MDL_context::release_all_locks().
sql/sql_table.cc:
  Remove thd->some_tables_deleted.
sql/transaction.cc:
  Add comments. 
  Make sure rollback to (MDL) savepoint works under LOCK TABLES and
  with HANDLER tables.
 2009-12-22 19:09:15 +03:00
Marc Alff
0531f85e16 Merge cleanup 2009-12-11 12:45:44 -07:00
Jon Olav Hauglid
fb6b5ee462 Backport of revno: 2617.68.37 
Bug #46654 False deadlock on concurrent DML/DDL with partitions, 
           inconsistent behavior

The problem was that if one connection is running a multi-statement 
transaction which involves a single partitioned table, and another 
connection attempts to alter the table, the first connection gets 
ER_LOCK_DEADLOCK and cannot proceed anymore, even when the ALTER TABLE 
statement in another connection has timed out or failed.

The reason for this was that the prepare phase for ALTER TABLE for 
partitioned tables removed all instances of the table from the table 
definition cache before it started waiting on the lock. The transaction 
running in the first connection would notice this and report ER_LOCK_DEADLOCK. 

This patch changes the prep_alter_part_table() ALTER TABLE code so that 
tdc_remove_table() is no longer called. Instead, only the TABLE instance
changed by prep_alter_part_table() is marked as needing reopen.

The patch also removes an unnecessary call to tdc_remove_table() from 
mysql_unpack_partition() as the changed TABLE object is destroyed by the 
caller at a later point.

Test case added in partition_sync.test.
 2009-12-10 14:26:00 +01:00
Konstantin Osipov
f129367288 Merge with next-4284. 2009-12-10 11:41:03 +03:00