to string conversions and vice versa"
Initial import of the dtoa.c code and custom wrappers around it
to allow its usage from the server code.
Conversion of FLOAT/DOUBLE values to DECIMAL ones or strings
and vice versa has been significantly reworked. As the new
algoritms are more precise than the older ones, results of such
conversions may not always match those obtained from older
server versions. This in turn may break compatibility for some
applications.
This patch also fixes the following bugs:
- bug #12860 "Difference in zero padding of exponent between
Unix and Windows"
- bug #21497 "DOUBLE truncated to unusable value"
- bug #26788 "mysqld (debug) aborts when inserting specific
numbers into char fields"
- bug #24541 "Data truncated..." on decimal type columns
without any good reason"
to string conversions and vice versa"
Initial import of the dtoa.c code and custom wrappers around it
to allow its usage from the server code.
Conversion of FLOAT/DOUBLE values to DECIMAL ones or strings
and vice versa has been significantly reworked. As the new
algoritms are more precise than the older ones, results of such
conversions may not always match those obtained from older
server versions. This in turn may break compatibility for some
applications.
This patch also fixes the following bugs:
- bug #12860 "Difference in zero padding of exponent between
Unix and Windows"
- bug #21497 "DOUBLE truncated to unusable value"
- bug #26788 "mysqld (debug) aborts when inserting specific
numbers into char fields"
- bug #24541 "Data truncated..." on decimal type columns
without any good reason"
Bug#16565 mysqld --help --verbose does not order variablesBug#20413 sql_slave_skip_counter is not shown in show variables
Bug#20415 Output of mysqld --help --verbose is incomplete
Bug#25430 variable not found in SELECT @@global.ft_max_word_len;
Bug#32902 plugin variables don't know their names
Bug#34599 MySQLD Option and Variable Reference need to be consistent in formatting!
Bug#34829 No default value for variable and setting default does not raise error
Bug#34834 ? Is accepted as a valid sql mode
Bug#34878 Few variables have default value according to documentation but error occurs
Bug#34883 ft_boolean_syntax cant be assigned from user variable to global var.
Bug#37187 `INFORMATION_SCHEMA`.`GLOBAL_VARIABLES`: inconsistent status
Bug#40988 log_output_basic.test succeeded though syntactically false.
Bug#41010 enum-style command-line options are not honoured (maria.maria-recover fails)
Bug#42103 Setting key_buffer_size to a negative value may lead to very large allocations
Bug#44691 Some plugins configured as MYSQL_PLUGIN_MANDATORY in can be disabled
Bug#44797 plugins w/o command-line options have no disabling option in --help
Bug#46314 string system variables don't support expressions
Bug#46470 sys_vars.max_binlog_cache_size_basic_32 is broken
Bug#46586 When using the plugin interface the type "set" for options caused a crash.
Bug#47212 Crash in DBUG_PRINT in mysqltest.cc when trying to print octal number
Bug#48758 mysqltest crashes on sys_vars.collation_server_basic in gcov builds
Bug#49417 some complaints about mysqld --help --verbose output
Bug#49540 DEFAULT value of binlog_format isn't the default value
Bug#49640 ambiguous option '--skip-skip-myisam' (double skip prefix)
Bug#49644 init_connect and \0
Bug#49645 init_slave and multi-byte characters
Bug#49646 mysql --show-warnings crashes when server dies
CMakeLists.txt:
Bug#44691 Some plugins configured as MYSQL_PLUGIN_MANDATORY in can be disabled
client/mysql.cc:
don't crash with --show-warnings when mysqld dies
config/ac-macros/plugins.m4:
Bug#44691 Some plugins configured as MYSQL_PLUGIN_MANDATORY in can be disabled
include/my_getopt.h:
comments
include/my_pthread.h:
fix double #define
mysql-test/mysql-test-run.pl:
run sys_vars suite by default
properly recognize envirinment variables (e.g. MTR_MAX_SAVE_CORE) set to 0
escape gdb command line arguments
mysql-test/suite/sys_vars/r/rpl_init_slave_func.result:
init_slave+utf8 bug
mysql-test/suite/sys_vars/t/rpl_init_slave_func.test:
init_slave+utf8 bug
mysys/my_getopt.c:
Bug#34599 MySQLD Option and Variable Reference need to be consistent in formatting!
Bug#46586 When using the plugin interface the type "set" for options caused a crash.
Bug#49640 ambiguous option '--skip-skip-myisam' (double skip prefix)
mysys/typelib.c:
support for flagset
sql/ha_ndbcluster.cc:
backport from telco tree
sql/item_func.cc:
Bug#49644 init_connect and \0
Bug#49645 init_slave and multi-byte characters
sql/sql_builtin.cc.in:
Bug#44691 Some plugins configured as MYSQL_PLUGIN_MANDATORY in can be disabled
sql/sql_plugin.cc:
Bug#44691 Some plugins configured as MYSQL_PLUGIN_MANDATORY in can be disabled
Bug#32902 plugin variables don't know their names
Bug#44797 plugins w/o command-line options have no disabling option in --help
sql/sys_vars.cc:
all server variables are defined here
storage/myisam/ft_parser.c:
remove unnecessary updates of param->quot
storage/myisam/ha_myisam.cc:
myisam_* variables belong here
strings/my_vsnprintf.c:
%o and %llx
unittest/mysys/my_vsnprintf-t.c:
%o and %llx tests
vio/viosocket.c:
bugfix: fix @@wait_timeout to work with socket timeouts (vs. alarm thread)
Bug#16565 mysqld --help --verbose does not order variablesBug#20413 sql_slave_skip_counter is not shown in show variables
Bug#20415 Output of mysqld --help --verbose is incomplete
Bug#25430 variable not found in SELECT @@global.ft_max_word_len;
Bug#32902 plugin variables don't know their names
Bug#34599 MySQLD Option and Variable Reference need to be consistent in formatting!
Bug#34829 No default value for variable and setting default does not raise error
Bug#34834 ? Is accepted as a valid sql mode
Bug#34878 Few variables have default value according to documentation but error occurs
Bug#34883 ft_boolean_syntax cant be assigned from user variable to global var.
Bug#37187 `INFORMATION_SCHEMA`.`GLOBAL_VARIABLES`: inconsistent status
Bug#40988 log_output_basic.test succeeded though syntactically false.
Bug#41010 enum-style command-line options are not honoured (maria.maria-recover fails)
Bug#42103 Setting key_buffer_size to a negative value may lead to very large allocations
Bug#44691 Some plugins configured as MYSQL_PLUGIN_MANDATORY in can be disabled
Bug#44797 plugins w/o command-line options have no disabling option in --help
Bug#46314 string system variables don't support expressions
Bug#46470 sys_vars.max_binlog_cache_size_basic_32 is broken
Bug#46586 When using the plugin interface the type "set" for options caused a crash.
Bug#47212 Crash in DBUG_PRINT in mysqltest.cc when trying to print octal number
Bug#48758 mysqltest crashes on sys_vars.collation_server_basic in gcov builds
Bug#49417 some complaints about mysqld --help --verbose output
Bug#49540 DEFAULT value of binlog_format isn't the default value
Bug#49640 ambiguous option '--skip-skip-myisam' (double skip prefix)
Bug#49644 init_connect and \0
Bug#49645 init_slave and multi-byte characters
Bug#49646 mysql --show-warnings crashes when server dies
------------------------------------------------------------
revno: 2617.68.25
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-next-bg-pre2-2
timestamp: Wed 2009-09-16 18:26:50 +0400
message:
Follow-up for one of pre-requisite patches for fixing bug #30977
"Concurrent statement using stored function and DROP FUNCTION
breaks SBR".
Made enum_mdl_namespace enum part of MDL_key class and removed MDL_
prefix from the names of enum members. In order to do the latter
changed name of PROCEDURE symbol to PROCEDURE_SYM (otherwise macro
which was automatically generated for this symbol conflicted with
MDL_key::PROCEDURE enum member).
------------------------------------------------------------
revno: 2617.68.25
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-next-bg-pre2-2
timestamp: Wed 2009-09-16 18:26:50 +0400
message:
Follow-up for one of pre-requisite patches for fixing bug #30977
"Concurrent statement using stored function and DROP FUNCTION
breaks SBR".
Made enum_mdl_namespace enum part of MDL_key class and removed MDL_
prefix from the names of enum members. In order to do the latter
changed name of PROCEDURE symbol to PROCEDURE_SYM (otherwise macro
which was automatically generated for this symbol conflicted with
MDL_key::PROCEDURE enum member).
------------------------------------------------------------
revno: 2617.68.7
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-next-bg46044
timestamp: Thu 2009-08-27 10:22:17 +0400
message:
Fix for bug #46044 "MDL deadlock on LOCK TABLE + CREATE TABLE HIGH_PRIORITY
FOR UPDATE".
Deadlock occured when during execution of query to I_S we tried to open
a table or its .FRM in order to get information about it and had to wait
because we have encountered exclusive metadata lock on this table held by
a DDL operation from another connection which in its turn waited for some
resource currently owned by connection executing this I_S query.
For example, this might have happened if one under LOCK TABLES executed I_S
query targeted to particular table (which was not among locked) and also
concurrently tried to create this table using CREATE TABLE SELECT which
had to wait for one of tables locked by the first connection.
Another situation in which deadlock might have occured is when I_S query,
which was executed as part of transaction, tried to get information about
table which just has been dropped by concurrent DROP TABLES executed under
LOCK TABLES and this DROP TABLES for its completion also had to wait
transaction from the first connection.
This problem stemmed from the fact that opening of tables/.FRMs for I_S
filling is happening outside of connection's main MDL_context so code
which tries to detect deadlocks due to conflicting metadata locks doesn't
work in this case. Indeed, this led to deadlocks when during I_S filling
we tried to wait for conflicting metadata lock to go away, while its owner
was waiting for some resource held by connection executing I_S query.
This patch solves this problem by avoiding waiting in such situation.
Instead we skip this table and produce warning that information about
it was omitted from I_S due to concurrent DDL operation. We still wait
for conflicting metadata lock to go away when it is known that deadlock
is not possible (i.e. when connection executing I_S query does not hold
any metadata or table-level locks).
Basically, we apply our standard deadlock avoidance technique for metadata
locks to the process of filling of I_S tables but replace ER_LOCK_DEADLOCK
error with a warning.
Note that this change is supposed to be safe for 'mysqldump' since the
only its mode which is affected by this change is --single-transaction mode
is not safe in the presence of concurrent DDL anyway (and this fact is
documented). Other modes are unaffected because they either use
SHOW TABLES/SELECT * FROM I_S.TABLE_NAMES which do not take any metadata
locks in the process of I_S table filling and thus cannot skip tables or
execute I_S queries for tables which were previously locked by LOCK TABLES
(or in the presence of global read lock) which excludes possibility of
encountering conflicting metadata lock.
mysql-test/r/mdl_sync.result:
Added test for bug #46044 "MDL deadlock on LOCK TABLE + CREATE TABLE
HIGH_PRIORITY FOR UPDATE".
mysql-test/t/mdl_sync.test:
Added test for bug #46044 "MDL deadlock on LOCK TABLE + CREATE TABLE
HIGH_PRIORITY FOR UPDATE".
sql/mysql_priv.h:
Added a new flag for open_table() call which allows it to fail
with an error in cases when conflicting metadata lock is discovered
instead of waiting until this lock goes away.
sql/share/errmsg-utf8.txt:
Added error/warning message to be generated in cases when information
about table is omitted from I_S since there is conflicting metadata lock
on the table.
sql/share/errmsg.txt:
Added error/warning message to be generated in cases when information
about table is omitted from I_S since there is conflicting metadata lock
on the table.
sql/sql_base.cc:
Added a new flag for open_table() call which allows it to fail
with an error in cases when conflicting metadata lock is discovered
instead of waiting until this lock goes away.
sql/sql_show.cc:
When we are opening a table (or just .FRM) in order to fill I_S with
information about this table and encounter conflicting metadata lock
waiting for this lock to go away can lead to a deadlock in some
situations (under LOCK TABLES, within transaction, etc.). To avoid
these deadlocks we detect such situations and don't do waiting.
Instead, we skip table for which we have conflicting metadata lock,
thus omitting information about it from I_S table, and produce an
appropriate warning.
------------------------------------------------------------
revno: 2617.68.7
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-next-bg46044
timestamp: Thu 2009-08-27 10:22:17 +0400
message:
Fix for bug #46044 "MDL deadlock on LOCK TABLE + CREATE TABLE HIGH_PRIORITY
FOR UPDATE".
Deadlock occured when during execution of query to I_S we tried to open
a table or its .FRM in order to get information about it and had to wait
because we have encountered exclusive metadata lock on this table held by
a DDL operation from another connection which in its turn waited for some
resource currently owned by connection executing this I_S query.
For example, this might have happened if one under LOCK TABLES executed I_S
query targeted to particular table (which was not among locked) and also
concurrently tried to create this table using CREATE TABLE SELECT which
had to wait for one of tables locked by the first connection.
Another situation in which deadlock might have occured is when I_S query,
which was executed as part of transaction, tried to get information about
table which just has been dropped by concurrent DROP TABLES executed under
LOCK TABLES and this DROP TABLES for its completion also had to wait
transaction from the first connection.
This problem stemmed from the fact that opening of tables/.FRMs for I_S
filling is happening outside of connection's main MDL_context so code
which tries to detect deadlocks due to conflicting metadata locks doesn't
work in this case. Indeed, this led to deadlocks when during I_S filling
we tried to wait for conflicting metadata lock to go away, while its owner
was waiting for some resource held by connection executing I_S query.
This patch solves this problem by avoiding waiting in such situation.
Instead we skip this table and produce warning that information about
it was omitted from I_S due to concurrent DDL operation. We still wait
for conflicting metadata lock to go away when it is known that deadlock
is not possible (i.e. when connection executing I_S query does not hold
any metadata or table-level locks).
Basically, we apply our standard deadlock avoidance technique for metadata
locks to the process of filling of I_S tables but replace ER_LOCK_DEADLOCK
error with a warning.
Note that this change is supposed to be safe for 'mysqldump' since the
only its mode which is affected by this change is --single-transaction mode
is not safe in the presence of concurrent DDL anyway (and this fact is
documented). Other modes are unaffected because they either use
SHOW TABLES/SELECT * FROM I_S.TABLE_NAMES which do not take any metadata
locks in the process of I_S table filling and thus cannot skip tables or
execute I_S queries for tables which were previously locked by LOCK TABLES
(or in the presence of global read lock) which excludes possibility of
encountering conflicting metadata lock.
A pre-requisite patch for Bug#30977 "Concurrent statement using
stored function and DROP FUNCTION breaks SBR".
This patch changes the MDL API by introducing a namespace for
lock keys: MDL_TABLE for tables and views and MDL_PROCEDURE
for stored procedures and functions. The latter is needed for
the fix for Bug#30977.
A pre-requisite patch for Bug#30977 "Concurrent statement using
stored function and DROP FUNCTION breaks SBR".
This patch changes the MDL API by introducing a namespace for
lock keys: MDL_TABLE for tables and views and MDL_PROCEDURE
for stored procedures and functions. The latter is needed for
the fix for Bug#30977.
----------------------------------------------------------
revno: 2617.69.20
committer: Konstantin Osipov <kostja@sun.com>
branch nick: 5.4-4284-1-assert
timestamp: Thu 2009-08-13 18:29:55 +0400
message:
WL#4284 "Transactional DDL locking"
A review fix.
Since WL#4284 implementation separated MDL_request and MDL_ticket,
MDL_request becamse a utility object necessary only to get a ticket.
Store it by-value in TABLE_LIST with the intent to merge
MDL_request::key with table_list->table_name and table_list->db
in future.
Change the MDL subsystem to not require MDL_requests to
stay around till close_thread_tables().
Remove the list of requests from the MDL context.
Requests for shared metadata locks acquired in open_tables()
are only used as a list in recover_from_failed_open_table_attempt(),
which calls mdl_context.wait_for_locks() for this list.
To keep such list for recover_from_failed_open_table_attempt(),
introduce a context class (Open_table_context), that collects
all requests.
A lot of minor cleanups and simplications that became possible
with this change.
sql/event_db_repository.cc:
Remove alloc_mdl_requests(). Now MDL_request instance is a member
of TABLE_LIST, and init_one_table() initializes it.
sql/ha_ndbcluster_binlog.cc:
Remove now unnecessary declaration and initialization
of binlog_mdl_request.
sql/lock.cc:
No need to allocate MDL requests in lock_table_names() now.
sql/log.cc:
Use init_one_table() method, remove alloc_mdl_requests(),
which is now unnecessary.
sql/log_event.cc:
No need to allocate mdl_request separately now.
Use init_one_table() method.
sql/log_event_old.cc:
Update to the new signature of close_tables_for_reopen().
sql/mdl.cc:
Update try_acquire_exclusive_lock() to be more easy to use.
Function lock_table_name_if_not_cached() has been removed.
Make acquire_shared_lock() signature consistent with
try_acquire_exclusive_lock() signature.
Remove methods that are no longer used.
Update comments.
sql/mdl.h:
Implement an assignment operator that doesn't
copy MDL_key (MDL_key::operator= is private and
should remain private).
This is a hack to work-around assignment of TABLE_LIST
by value in several places. Such assignments violate
encapsulation, since only perform a shallow copy.
In most cases these assignments are a hack on their own.
sql/mysql_priv.h:
Update signatures of close_thread_tables() and close_tables_for_reopen().
sql/sp.cc:
Allocate TABLE_LIST in thd->mem_root.
Use init_one_table().
sql/sp_head.cc:
Use init_one_table().
Remove thd->locked_tables_root, it's no longer needed.
sql/sql_acl.cc:
Use init_mdl_requests() and init_one_table().
sql/sql_base.cc:
Update to new signatures of try_acquire_shared_lock() and
try_acquire_exclusive_lock().
Remove lock_table_name_if_not_cached().
Fix a bug in open_ltable() that would not return ER_LOCK_DEADLOCK
in case of a failed lock_tables() and a multi-statement
transaction.
Fix a bug in open_and_lock_tables_derived() that would
not return ER_LOCK_DEADLOCK in case of a multi-statement
transaction and a failure of lock_tables().
Move assignment of enum_open_table_action to a method of Open_table_context, a new class that maintains information
for backoff actions.
Minor rearrangements of the code.
Remove alloc_mdl_requests() in functions that work with system
tables: instead the patch ensures that callers always initialize
TABLE_LIST argument.
sql/sql_class.cc:
THD::locked_tables_root is no more.
sql/sql_class.h:
THD::locked_tables_root is no more.
Add a declaration for Open_table_context class.
sql/sql_delete.cc:
Update to use the simplified MDL API.
sql/sql_handler.cc:
TABLE_LIST::mdl_request is stored by-value now.
Ensure that mdl_request.ticket is NULL for every request
that is passed into MDL, to satisfy MDL asserts.
@ sql/sql_help.cc
Function open_system_tables_for_read() no longer initializes
mdl_requests.
Move TABLE_LIST::mdl_request initialization closer to
TABLE_LIST initialization.
sql/sql_help.cc:
Function open_system_tables_for_read() no longer initializes
mdl_requests.
Move TABLE_LIST::mdl_request initialization closer to
TABLE_LIST initialization.
sql/sql_insert.cc:
Remove assignment by-value of TABLE_LIST in
TABLEOP_HOOKS. We can't carry over a granted
MDL ticket from one table list to another.
sql/sql_parse.cc:
Change alloc_mdl_requests() -> init_mdl_requests().
@todo We can remove init_mdl_requests() altogether
in some places: all places that call add_table_to_list()
already have mdl requests initialized.
sql/sql_plugin.cc:
Use init_one_table().
THD::locked_tables_root is no more.
sql/sql_servers.cc:
Use init_one_table().
sql/sql_show.cc:
Update acquire_high_priority_shared_lock() to use
TABLE_LIST::mdl_request rather than allocate an own.
Fix get_trigger_table_impl() to use init_one_table(),
check for out of memory, follow the coding style.
sql/sql_table.cc:
Update to work with TABLE_LIST::mdl_request by-value.
Remove lock_table_name_if_not_cached().
The code that used to delegate to it is quite simple and
concise without it now.
sql/sql_udf.cc:
Use init_one_table().
sql/sql_update.cc:
Update to use the new signature of close_tables_for_reopen().
sql/table.cc:
Move re-setting of mdl_requests for prepared statements
and stored procedures from close_thread_tables() to
reinit_stmt_before_use().
Change alloc_mdl_requests() to init_mdl_requests().
init_mdl_requests() is a hack that can't be deleted
until we don't have a list-aware TABLE_LIST constructor.
Hopefully its use will be minimal
sql/table.h:
Change alloc_mdl_requests() to init_mdl_requests()
TABLE_LIST::mdl_request is stored by value.
sql/tztime.cc:
We no longer initialize mdl requests in open_system_tables_for*()
functions. Move this initialization closer to initialization
of the rest of TABLE_LIST members.
storage/myisammrg/ha_myisammrg.cc:
Simplify mdl_request initialization.
----------------------------------------------------------
revno: 2617.69.20
committer: Konstantin Osipov <kostja@sun.com>
branch nick: 5.4-4284-1-assert
timestamp: Thu 2009-08-13 18:29:55 +0400
message:
WL#4284 "Transactional DDL locking"
A review fix.
Since WL#4284 implementation separated MDL_request and MDL_ticket,
MDL_request becamse a utility object necessary only to get a ticket.
Store it by-value in TABLE_LIST with the intent to merge
MDL_request::key with table_list->table_name and table_list->db
in future.
Change the MDL subsystem to not require MDL_requests to
stay around till close_thread_tables().
Remove the list of requests from the MDL context.
Requests for shared metadata locks acquired in open_tables()
are only used as a list in recover_from_failed_open_table_attempt(),
which calls mdl_context.wait_for_locks() for this list.
To keep such list for recover_from_failed_open_table_attempt(),
introduce a context class (Open_table_context), that collects
all requests.
A lot of minor cleanups and simplications that became possible
with this change.
Implemented a new INFORMATION_SCHEMA table, which is intended to
provide information about tablespaces.
mysql-test/r/information_schema.result:
Updated test result according to WL#2511. With this WL
I_S has new TABLESPACES schema.
mysql-test/r/information_schema_db.result:
Updated test result according to WL#2511. With this WL
I_S has new TABLESPACES schema.
mysql-test/r/mysqlshow.result:
Updated test result according to WL#2511. With this WL
I_S has new TABLESPACES schema.
mysql-test/suite/funcs_1/r/is_columns_is.result:
Updated test result according to WL#2511. With this WL
I_S has new TABLESPACES schema.
mysql-test/suite/funcs_1/r/is_tables_is.result:
Updated test result according to WL#2511. With this WL
I_S has new TABLESPACES schema.
sql/handler.h:
Added SCH_TABLESPACES to enum_schema_tables.
sql/mysql_priv.h:
Added human readable definitions for I_S.TABLESPACES field
identifiers.
sql/sql_show.cc:
Added I_S.TABLESPACES schema. The code which handles I_S.FILES
is capable to handle I_S.TABLESPACES as well. Thus we reuse
this code and let functions/variables have more generic names.
----------------------------------------------------------
revno: 2617.23.20
committer: Konstantin Osipov <kostja@sun.com>
branch nick: mysql-6.0-runtime
timestamp: Wed 2009-03-04 16:31:31 +0300
message:
WL#4284 "Transactional DDL locking"
Review comments: "Objectify" the MDL API.
MDL_request and MDL_context still need manual construction and
destruction, since they are used in environment that is averse
to constructors/destructors.
sql/mdl.cc:
Improve comments.
Add asserts to backup()/restore_from_backup()/merge() methods.
Fix an order bug in the error path of mdl_acquire_exclusive_locks():
we used to first free a ticket object, and only then exclude
it from the list of tickets.
----------------------------------------------------------
revno: 2617.23.20
committer: Konstantin Osipov <kostja@sun.com>
branch nick: mysql-6.0-runtime
timestamp: Wed 2009-03-04 16:31:31 +0300
message:
WL#4284 "Transactional DDL locking"
Review comments: "Objectify" the MDL API.
MDL_request and MDL_context still need manual construction and
destruction, since they are used in environment that is averse
to constructors/destructors.
------------------------------------------------------------
revno: 2617.23.18
committer: Davi Arnaut <Davi.Arnaut@Sun.COM>
branch nick: 4284-6.0
timestamp: Mon 2009-03-02 18:18:26 -0300
message:
Bug#989: If DROP TABLE while there's an active transaction, wrong binlog order
WL#4284: Transactional DDL locking
This is a prerequisite patch:
These changes are intended to split lock requests from granted
locks and to allow the memory and lifetime of granted locks to
be managed within the MDL subsystem. Furthermore, tickets can
now be shared and therefore are used to satisfy multiple lock
requests, but only shared locks can be recursive.
The problem is that the MDL subsystem morphs lock requests into
granted locks locks but does not manage the memory and lifetime
of lock requests, and hence, does not manage the memory of
granted locks either. This can be problematic because it puts the
burden of tracking references on the users of the subsystem and
it can't be easily done in transactional contexts where the locks
have to be kept around for the duration of a transaction.
Another issue is that recursive locks (when the context trying to
acquire a lock already holds a lock on the same object) requires
that each time the lock is granted, a unique lock request/granted
lock structure structure must be kept around until the lock is
released. This can lead to memory leaks in transactional contexts
as locks taken during the transaction should only be released at
the end of the transaction. This also leads to unnecessary wake
ups (broadcasts) in the MDL subsystem if the context still holds
a equivalent of the lock being released.
These issues are exacerbated due to the fact that WL#4284 low-level
design says that the implementation should "2) Store metadata locks
in transaction memory root, rather than statement memory root" but
this is not possible because a memory root, as implemented in mysys,
requires all objects allocated from it to be freed all at once.
This patch combines review input and significant code contributions
from Konstantin Osipov (kostja) and Dmitri Lenev (dlenev).
mysql-test/r/mdl_sync.result:
Add test case result.
mysql-test/t/mdl_sync.test:
Add test case for shared lock upgrade case.
sql/event_db_repository.cc:
Rename mdl_alloc_lock to mdl_request_alloc.
sql/ha_ndbcluster_binlog.cc:
Use new function names to initialize MDL lock requests.
sql/lock.cc:
Rename MDL functions.
sql/log_event.cc:
The MDL request now holds the table and database name data (MDL_KEY).
sql/mdl.cc:
Move the MDL key to the MDL_LOCK structure in order to make the
object suitable for allocation from a fixed-size allocator. This
allows the simplification of the lists in the MDL_LOCK object,
which now are just two, one for granted tickets and other for
waiting (upgraders) tickets.
Recursive requests for a shared lock on the same object can now
be granted using the same lock ticket. This schema is only used
for shared locks because that the only case that matters. This
is used to avoid waste of resources in case a context (connection)
already holds a shared lock on a object.
sql/mdl.h:
Introduce a metadata lock object key which is used to uniquely
identify lock objects.
Separate the structure used to represent pending lock requests
from the structure used to represent granted metadata locks.
Rename functions used to manipulate locks requests in order to
have a more consistent function naming schema.
sql/sp_head.cc:
Rename mdl_alloc_lock to mdl_request_alloc.
sql/sql_acl.cc:
Rename alloc_mdl_locks to alloc_mdl_requests.
sql/sql_base.cc:
Various changes to accommodate that lock requests are separated
from lock tickets (granted locks).
sql/sql_class.h:
Last acquired lock before the savepoint was set.
sql/sql_delete.cc:
Various changes to accommodate that lock requests are separated
from lock tickets (granted locks).
sql/sql_handler.cc:
Various changes to accommodate that lock requests are separated
from lock tickets (granted locks).
sql/sql_insert.cc:
Rename alloc_mdl_locks to alloc_mdl_requests.
sql/sql_parse.cc:
Rename alloc_mdl_locks to alloc_mdl_requests.
sql/sql_plist.h:
Typedef for iterator type.
sql/sql_plugin.cc:
Rename alloc_mdl_locks to alloc_mdl_requests.
sql/sql_servers.cc:
Rename alloc_mdl_locks to alloc_mdl_requests.
sql/sql_show.cc:
Various changes to accommodate that lock requests are separated
from lock tickets (granted locks).
sql/sql_table.cc:
Various changes to accommodate that lock requests are separated
from lock tickets (granted locks).
sql/sql_trigger.cc:
Save reference to the lock ticket so it can be downgraded later.
sql/sql_udf.cc:
Rename alloc_mdl_locks to alloc_mdl_requests.
sql/table.cc:
Rename mdl_alloc_lock to mdl_request_alloc.
sql/table.h:
Separate MDL lock requests from lock tickets (granted locks).
storage/myisammrg/ha_myisammrg.cc:
Rename alloc_mdl_locks to alloc_mdl_requests.
------------------------------------------------------------
revno: 2617.23.18
committer: Davi Arnaut <Davi.Arnaut@Sun.COM>
branch nick: 4284-6.0
timestamp: Mon 2009-03-02 18:18:26 -0300
message:
Bug#989: If DROP TABLE while there's an active transaction, wrong binlog order
WL#4284: Transactional DDL locking
This is a prerequisite patch:
These changes are intended to split lock requests from granted
locks and to allow the memory and lifetime of granted locks to
be managed within the MDL subsystem. Furthermore, tickets can
now be shared and therefore are used to satisfy multiple lock
requests, but only shared locks can be recursive.
The problem is that the MDL subsystem morphs lock requests into
granted locks locks but does not manage the memory and lifetime
of lock requests, and hence, does not manage the memory of
granted locks either. This can be problematic because it puts the
burden of tracking references on the users of the subsystem and
it can't be easily done in transactional contexts where the locks
have to be kept around for the duration of a transaction.
Another issue is that recursive locks (when the context trying to
acquire a lock already holds a lock on the same object) requires
that each time the lock is granted, a unique lock request/granted
lock structure structure must be kept around until the lock is
released. This can lead to memory leaks in transactional contexts
as locks taken during the transaction should only be released at
the end of the transaction. This also leads to unnecessary wake
ups (broadcasts) in the MDL subsystem if the context still holds
a equivalent of the lock being released.
These issues are exacerbated due to the fact that WL#4284 low-level
design says that the implementation should "2) Store metadata locks
in transaction memory root, rather than statement memory root" but
this is not possible because a memory root, as implemented in mysys,
requires all objects allocated from it to be freed all at once.
This patch combines review input and significant code contributions
from Konstantin Osipov (kostja) and Dmitri Lenev (dlenev).
When checking for an error after removing the special view error handler the code
was not taking into account that open_tables() may fail because of the current
statement being killed.
Added a check for thd->killed.
Added a client program to test it.
When checking for an error after removing the special view error handler the code
was not taking into account that open_tables() may fail because of the current
statement being killed.
Added a check for thd->killed.
Added a client program to test it.
The attached patch adds a method
handlerton::fill_is_table that can be used
instead of having to create specific
handlerton::fill_*_table methods.
sql/ha_ndbcluster.cc:
WL#4448 Generalize the handlerton::fill_files_table call with handlerton::fill_is_table
Implemented the method ndbcluster_fill_is_table
that uses the supplied table id to switch to the
appropriate fill_*_table method.
sql/handler.h:
WL#4448 Generalize the handlerton::fill_files_table call with handlerton::fill_is_table
Moved the enum_schema_table enumeration
from table.h to here.
contains the declaration for the new method
fill_is_tables.
sql/sql_show.cc:
WL#4448 Generalize the handlerton::fill_files_table call with handlerton::fill_is_table
calls the fill_is_table method instead of the
fill_files_table method.
sql/table.h:
WL#4448 Generalize the handlerton::fill_files_table call with handlerton::fill_is_table
removed the earlier definition of enum_schema_tables.
------------------------------------------------------------
revno: 2630.4.33
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-6.0-3726-w2
timestamp: Fri 2008-06-20 17:11:20 +0400
message:
WL#3726 "DDL locking for all metadata objects".
After-review fixes in progress.
Minimized dependency of mdl.cc on other modules (particularly
made it independant of mysql_priv.h) in order to be able
write unit tests for metadata locking subsystem.
sql/ha_ndbcluster_binlog.cc:
Use newly introduced MAX_MDLKEY_LENGTH constant for allocating
buffer for object key for metadata locking subsystem.
sql/log_event.cc:
Use newly introduced MAX_MDLKEY_LENGTH constant for allocating
buffer for object key for metadata locking subsystem.
sql/mdl.cc:
Removed dependency on THD class (and thus on mysql_priv.h)
by using direct access to members of st_my_thread_var instead
of accessing THD::killed/enter_cond()/exit_cond().
sql/mdl.h:
Added MAX_MDLKEY_LENGTH constant to be used for allocating
buffers for key for metadata locking subsystem.
Added declarations of server kernel functions used by metadata
locking subsystem to mdl.h in order to decrease dependency of
mdl.cc on other files.
sql/mysql_priv.h:
Moved declaration of notify_thread_having_shared_lock() to the
mdl.h (also renamed it to make clear in metadata locking code
that it is a callback to SQL-layer).
sql/sql_base.cc:
Renamed notify_thread_having_shared_lock() to make it clear
in metadata locking subsystem code that it is a callback
to SQL layer.
sql/sql_handler.cc:
Use newly introduced MAX_MDLKEY_LENGTH constant for allocating
buffer for object key for metadata locking subsystem.
sql/sql_show.cc:
Use newly introduced MAX_MDLKEY_LENGTH constant for allocating
buffer for object key for metadata locking subsystem.
