The problem here is that embedded server starts handle_thread manager
thread on mysql_library_init() does not stop it on mysql_library_end().
At shutdown, my_thread_global_end() waits for thread count to become 0,
but since we did not stop the thread it will give up after 5 seconds.
Solution is to move shutdown for handle_manager thread from kill_server()
(mysqld specific) to clean_up() that is used by both embedded and mysqld.
This patch also contains some refactorings - to avoid duplicate code,
start_handle_manager() and stop_handle_manager() functions are introduced.
Unused variables are eliminated. handle_manager does not rely on global
variable abort_loop anymore to stop (abort_loop is not set for embedded).
Note: Specifically on Windows and when using DBUG version of libmysqld,
the complete solution requires removing obsolete code my_thread_init()
from my_thread_var(). This has a side effect that a DBUG statement
after my_thread_end() can cause thread counter to be incremented, and
embedded will hang for some seconds. Or worse, my_thread_init() will
crash if critical sections have been deleted by the global cleanup
routine that runs in a different thread.
This patch also fixes and revert prior changes for Bug#38293
"Libmysqld crash in mysql_library_init if language file missing".
Root cause of the crash observed in Bug#38293 was bug in my_thread_init()
described above
client/mysql.cc:
sql_protocol_typelib is not exported from libmysqld
(does not make sense either)
thus excluded from embedded client
dbug/dbug.c:
revert changes for Bug#38293
include/my_dbug.h:
revert changes for Bug#38293
libmysql/libmysql.c:
Removed DBUG_POP call, because when called after my_end(), will access
THR_key_mysys that is already deleted. The result of pthread_get_specific
is not predictable in this case and hence DBUG_POP can crash.
libmysqld/examples/CMakeLists.txt:
Revert changes for Bug#38293.
libmysqld/lib_sql.cc:
code to start handle manager is factored out into
start_handle_manager() function
libmysqld/libmysqld.def:
Revert changes for Bug #38293
Remove excessive exports from libmysqld, export what API documents.
mysys/my_thr_init.c:
Remove windows-DLL-specific workaround for something (old code, no documentation for
what specifically). The problem is that even after my_thread_end() is finished,
DBUG statement can initiate my_thread_init(). This does not happen anywhere else and
should not happen on Windows either.
sql/mysql_priv.h:
- new functions start_handle_manager() and stop_handle_manager()
- move manager_thread_in_use variable to sql_manager.cc and made
it static
- remove manager_status, as it is unused
sql/mysqld.cc:
Code to start/stop handle_manager thread is factored out into start_handle_manager()
The problem here is that embedded server starts handle_thread manager
thread on mysql_library_init() does not stop it on mysql_library_end().
At shutdown, my_thread_global_end() waits for thread count to become 0,
but since we did not stop the thread it will give up after 5 seconds.
Solution is to move shutdown for handle_manager thread from kill_server()
(mysqld specific) to clean_up() that is used by both embedded and mysqld.
This patch also contains some refactorings - to avoid duplicate code,
start_handle_manager() and stop_handle_manager() functions are introduced.
Unused variables are eliminated. handle_manager does not rely on global
variable abort_loop anymore to stop (abort_loop is not set for embedded).
Note: Specifically on Windows and when using DBUG version of libmysqld,
the complete solution requires removing obsolete code my_thread_init()
from my_thread_var(). This has a side effect that a DBUG statement
after my_thread_end() can cause thread counter to be incremented, and
embedded will hang for some seconds. Or worse, my_thread_init() will
crash if critical sections have been deleted by the global cleanup
routine that runs in a different thread.
This patch also fixes and revert prior changes for Bug#38293
"Libmysqld crash in mysql_library_init if language file missing".
Root cause of the crash observed in Bug#38293 was bug in my_thread_init()
described above
This writes a warning on stderr if one uses mutex in different order,
like if one in one case would lock mutex in the order A,B and in another case
would lock mutex in the order B,A
This is inspired by and loosely based on the LOCKDEP patch by Jonas
Wrong mutex order is either fixed or mutex are marked with MYF_NO_DEADLOCK_DETECTION
if used inconsistently (need to be fixed by server team)
KNOWN_BUGS.txt:
Added information that one need to dump and restore Maria tables
include/hash.h:
Added prototype function for walking over all elements in a hash
include/my_pthread.h:
Added my_pthread_mutex_init() and my_pthread_mutex_lock(); These should be used if one wants to disable mutex order checking.
Changed names of the nonposix mutex_init functions to not conflict with my_phread_mutex_init()
Added and extended structures for mutex deadlock detection.
New arguments to sage_mutex_init() and safe_mutex_lock() to allow one to disable mutex order checking.
Added variable 'safe_mutex_deadlock_detector' to enable/disable deadlock detection for all pthread_mutex_init()
mysys/Makefile.am:
Added cleaning of test files
Added test_thr_mutex
mysys/hash.c:
Added hash_iterate() to iterate over all elements in a hash
More comments
mysys/my_init.c:
Added calls to destory all mutex uses by mysys()
Added waiting for threads to end before calling TERMINATE() to list not freed memory
mysys/my_pthread.c:
Changed names to free my_pthread_mutex_init() for mutex-lock-order-checking
mysys/my_sleep.c:
Fixed too long wait if using 1000000L as argument
mysys/my_thr_init.c:
Mark THR_LOCK_threads and THR_LOCK_malloc to not have mutex deadlock detection.
(We can't have it enabled for this as these are internal mutex used by the detector
Call my_thread_init() early as we need thread specific variables enabled for the following pthread_mutex_init()
Move code to wait for threads to end to my_wait_for_other_threads_to_die()
Don't destroy mutex and conditions unless all threads have died
Added my_thread_destroy_mutex() to destroy all mutex used by the mysys thread system
Name the thread specific mutex as "mysys_var->mutex"
Added my_thread_var_mutex_in_use() to return pointer to mutex in use or 0 if thread variables are not initialized
mysys/mysys_priv.h:
Added prototypes for functions used internally with mutex-wrong-usage detection
mysys/thr_mutex.c:
Added runtime detection of mutex used in conflicting order
See WL#3262 or test_thr_mutex.c for examples
The base idea is for each mutex have two hashes:
- mutex->locked_mutex points to all mutex used after this one
- mutex->used_mutex points to all mutex which has this mutex in it's mutex->locked_mutex
There is a wrong mutex order if any mutex currently locked before this mutex is in the mutex->locked_mutex hash
sql/event_queue.cc:
Mark mutex used inconsistently (need to be fixed by server team)
sql/event_scheduler.cc:
Declare the right order to take the mutex
sql/events.cc:
Mark mutex used inconsistently (need to be fixed by server team)
sql/ha_ndbcluster_binlog.cc:
Mark mutex used inconsistently (need to be fixed by server team)
sql/log.cc:
Mark mutex used inconsistently (need to be fixed by server team)
sql/mysqld.cc:
Use pthread_mutex_trylock instead of pthread_mutex_unlock() when sending kill signal to thread
This is needed to avoid wrong mutex order as normally one takes 'current_mutex' before mysys_var->mutex.
Added call to free sp cache.
Add destruction of LOCK_server_started and COND_server_started.
Added register_mutex_order() function to register in which order mutex should be taken
(to initiailize mutex_deadlock_detector).
Added option to turn off safe_mutex_deadlock_detector
sql/protocol.cc:
Fixed wrong argument to DBUG_PRINT (found by valgrind)
sql/rpl_mi.cc:
Mark mutex used inconsistently (need to be fixed by server team)
sql/set_var.cc:
Remove wrong locking of LOCK_global_system_variables when reading and setting log variables
(would cause inconsistent mutex order).
Update global variables outside of logger.unlock() as LOCK_global_system_variables has to be taken before logger locks
Reviewed by gluh
sql/sp_cache.cc:
Added function to destroy mutex used by sp cache
sql/sp_cache.h:
Added function to destroy mutex used by sp cache
sql/sql_class.cc:
Use pthread_mutex_trylock instead of pthread_mutex_unlock() when sending kill signal to thread
This is needed to avoid wrong mutex order as normally one takes 'current_mutex' before mysys_var->mutex.
Register order in which LOCK_delete and mysys_var->mutex is taken
sql/sql_insert.cc:
Give a name for Delayed_insert::mutex
Mark mutex used inconsistently (need to be fixed by server team)
Move closing of tables outside of di->mutex (to avoid wrong mutex order)
sql/sql_show.cc:
Don't keep LOCK_global_system_variables locked over value->show_type() as this leads to wrong mutex order
storage/innobase/handler/ha_innodb.cc:
Disable safe_muted_deadlock_detector for innobase intern mutex (to speed up page cache initialization)
storage/maria/ha_maria.cc:
Added flag to ha_maria::info() to signal if we need to lock table share or not.
This is needed to avoid locking mutex in wrong order
storage/maria/ha_maria.h:
Added flag to ha_maria::info() to signal if we need to lock table share or not.
storage/maria/ma_close.c:
Destroy key_del_lock
Simplify freeing ftparser_param
storage/maria/ma_key.c:
Better comment
storage/maria/ma_loghandler.c:
Mark mutex used inconsistently (need to be fixed by sanja)
storage/maria/ma_state.c:
More comments
storage/maria/ma_test1.c:
Ensure that safe_mutex_deadlock_detector is always on (should be, this is just for safety)
storage/maria/ma_test2.c:
Ensure that safe_mutex_deadlock_detector is always on (should be, this is just for safety)
Ensure that if we send 'sigint' to mysqld started with --gdb it's taken down nicely
Clear THR_THD when thread ends to get a valid stack trace if we die late
Bug #37869 mysqld stopped reacting to SIGINT when run with --gdb
The SHOW VARIABLES LIKE .../SELECT @@/SELECT ... FROM INFORMATION_SCHEMA.VARIABLES
were assuming that all the system variables are in system charset (UTF-8).
However the variables that are settable through command line will have a different
character set (character_set_filesystem).
Fixed the server to remember the correct character set of basedir, datadir, tmpdir,
ssl, plugin_dir, slave_load_tmpdir, innodb variables; init_connect and init_slave
variables and use it when processing data.
mysql-test/r/ctype_filesystem.result:
Bug #37339: test case (should be in utf-8)
mysql-test/t/ctype_filesystem-master.opt:
Bug #37339: test case (should be in ISO-8859-1)
mysql-test/t/ctype_filesystem.test:
Bug #37339: test case
sql/mysqld.cc:
Bug #37339: remember the correct character set for init_slave and init_connect
sql/set_var.cc:
Bug #37339:
- remember the character set of the relevant variables
- implement storing and using the correct
character set
sql/set_var.h:
Bug #37339: implement storing and using the correct
character set
sql/sql_show.cc:
Bug #37339: implement storing and using the correct
character set
The SHOW VARIABLES LIKE .../SELECT @@/SELECT ... FROM INFORMATION_SCHEMA.VARIABLES
were assuming that all the system variables are in system charset (UTF-8).
However the variables that are settable through command line will have a different
character set (character_set_filesystem).
Fixed the server to remember the correct character set of basedir, datadir, tmpdir,
ssl, plugin_dir, slave_load_tmpdir, innodb variables; init_connect and init_slave
variables and use it when processing data.
That's a Win-specific error.
When we create libmysqld.dll we have many libraries like mysys, dbug,
strings, etc linked into that dll, so the application built upon
this library shouldn't link these libraries to itself, rather use
those inside the dll.
Fixed by redirecting calls into the libmysqld.dll
per-file comments:
dbug/dbug.c
Bug#38293 Libmysqld crash in mysql_library_init if language file missing
fake _db_something definitions added
include/my_dbug.h
Bug#38293 Libmysqld crash in mysql_library_init if language file missing
fake _db_something declarations added
libmysqld/examples/CMakeLists.txt
Bug#38293 Libmysqld crash in mysql_library_init if language file missing
superfluous libraries removed from linking
libmysqld/libmysqld.def
Bug#38293 Libmysqld crash in mysql_library_init if language file missing
set of mysys functions added to the export section
That's a Win-specific error.
When we create libmysqld.dll we have many libraries like mysys, dbug,
strings, etc linked into that dll, so the application built upon
this library shouldn't link these libraries to itself, rather use
those inside the dll.
Fixed by redirecting calls into the libmysqld.dll
per-file comments:
dbug/dbug.c
Bug#38293 Libmysqld crash in mysql_library_init if language file missing
fake _db_something definitions added
include/my_dbug.h
Bug#38293 Libmysqld crash in mysql_library_init if language file missing
fake _db_something declarations added
libmysqld/examples/CMakeLists.txt
Bug#38293 Libmysqld crash in mysql_library_init if language file missing
superfluous libraries removed from linking
libmysqld/libmysqld.def
Bug#38293 Libmysqld crash in mysql_library_init if language file missing
set of mysys functions added to the export section
status
The problem appears to be a race condition, when service is being
stopped right after startup. We set the service status to SERVICE_RUNNING
way too early it cannot yet handle stop requests - initialization has
not finished and hEventShutdown that signals server to stop is not yet
created. If somebody issues "net stop MySQL" at this time, MySQL is not
informed about the stop and continues to run as usual, while
NTService::ServiceMain() stucks forever waiting for mysql's "main" thread
to finish.
Solution is to remain in SERVICE_START_PENDING status until after server
initialization is fully complete and only then change the status to
SERVICE_RUNNING. In SERVICE_START_PENDING we do not accept service control
requests, i.e it is not possible to stop service in that time.
sql/mysqld.cc:
Set service status to running after all initialization is complete
sql/nt_servc.cc:
New method SetRunning() to be called by application
to set service status to SERVICE_RUNNING when apllication
has finished initialization.
sql/nt_servc.h:
New method SetRunning() to be called by application
when initialization completes
status
The problem appears to be a race condition, when service is being
stopped right after startup. We set the service status to SERVICE_RUNNING
way too early it cannot yet handle stop requests - initialization has
not finished and hEventShutdown that signals server to stop is not yet
created. If somebody issues "net stop MySQL" at this time, MySQL is not
informed about the stop and continues to run as usual, while
NTService::ServiceMain() stucks forever waiting for mysql's "main" thread
to finish.
Solution is to remain in SERVICE_START_PENDING status until after server
initialization is fully complete and only then change the status to
SERVICE_RUNNING. In SERVICE_START_PENDING we do not accept service control
requests, i.e it is not possible to stop service in that time.
Several functions (mostly in mysqld.cc) directly call
exit() function in case of errors, which is not a desired
behaviour expecially in the embedded-server library.
Fixed by making these functions return error sign instead
of exiting.
per-file comments:
include/my_getopt.h
Bug#39289 libmysqld.a calls exit() upon error
added 'error' retvalue for my_getopt_register_get_addr
libmysqld/lib_sql.cc
Bug#39289 libmysqld.a calls exit() upon error
unireg_clear() function implemented
mysys/default.c
Bug#39289 libmysqld.a calls exit() upon error
error returned instead of exit() call
mysys/mf_tempdir.c
Bug#39289 libmysqld.a calls exit() upon error
free_tmpdir() - fixed so it's not produce crash on uninitialized
tmpdir structure
mysys/my_getopt.c
Bug#39289 libmysqld.a calls exit() upon error
error returned instead of exit() call
sql/mysql_priv.h
Bug#39289 libmysqld.a calls exit() upon error
unireg_abort definition fixed for the embedded server
sql/mysqld.cc
Bug#39289 libmysqld.a calls exit() upon error
various functions fixed
error returned instead of exit() call
Several functions (mostly in mysqld.cc) directly call
exit() function in case of errors, which is not a desired
behaviour expecially in the embedded-server library.
Fixed by making these functions return error sign instead
of exiting.
per-file comments:
include/my_getopt.h
Bug#39289 libmysqld.a calls exit() upon error
added 'error' retvalue for my_getopt_register_get_addr
libmysqld/lib_sql.cc
Bug#39289 libmysqld.a calls exit() upon error
unireg_clear() function implemented
mysys/default.c
Bug#39289 libmysqld.a calls exit() upon error
error returned instead of exit() call
mysys/mf_tempdir.c
Bug#39289 libmysqld.a calls exit() upon error
free_tmpdir() - fixed so it's not produce crash on uninitialized
tmpdir structure
mysys/my_getopt.c
Bug#39289 libmysqld.a calls exit() upon error
error returned instead of exit() call
sql/mysql_priv.h
Bug#39289 libmysqld.a calls exit() upon error
unireg_abort definition fixed for the embedded server
sql/mysqld.cc
Bug#39289 libmysqld.a calls exit() upon error
various functions fixed
error returned instead of exit() call
- The problem was that we didn't inform the handler that we are going to close tables that are locked and may have (at least in Maria) be part of an active transaction.
Fix for Bug#39227 Maria: crash with ALTER TABLE PARTITION
Fix for Bug #39987 main.partition_not_windows fails under debug build
Fixed some compiler errors & warnings found by pushbuild
include/my_base.h:
Added HA_EXTRA_PREPARE_FOR_FORCED_CLOSE for signaling the handler that the file will be forced closed
include/my_global.h:
Removed 'register' from 'swap_variables' as this gives a warnings when the variables are structs. Compilers should also now be smart enough to figure out this themselves
mysql-test/r/subselect_debug.result:
Reset value of the debug variable; Without setting this the subselect_innodb test will fail when run after this one
mysql-test/suite/maria/r/maria.result:
Merged test with myisam.test
Added tests for new fixed bugs
mysql-test/suite/maria/t/maria.test:
Merged test with myisam.test
Added tests for new fixed bugs
mysql-test/t/subselect_debug.test:
Reset value of the debug variable; Without setting this the subselect_innodb test will fail when run after this one
mysys/my_uuid.c:
Fixed compiler error on windows
sql/ha_partition.cc:
Added support for the new extra flag: HA_EXTRA_PREPARE_FOR_FORCED_CLOSE (Bug #39226)
Ensure that we call extra() for HA_EXTRA_PREPARE_FOR_DROP (Bug#39227)
sql/mysqld.cc:
Fix for Bug #39987 main.partition_not_windows fails under debug build
The problem was that when compiling for purify/valgrind realpath() is not used, which causes test_if_data_home_dir to fail when it shouldn't
sql/sql_base.cc:
Call HA_EXTRA_PREPARE_FOR_FORCED_CLOSE for tables that are locked but we are going to force close without doing a commit
sql/sql_parse.cc:
More DBUG_PRINT. Fixed comments
storage/maria/ma_extra.c:
If HA_EXTRA_PREPARE_FOR_FORCED_CLOSE is called and the table is part of a transaction, remove the table from beeing part of a transaction.
This is safe as this is only used as part of flush tables or when the table is not part of a transaction
storage/myisam/mi_open.c:
Indentation fix
unittest/mysys/waiting_threads-t.c:
Remove not needed 'volatile' to get rid of compiler warnings on windows
When running Stored Routines the Status Variable "Questions" was wrongly
incremented. According to the manual it should contain the "number of
statements that clients have sent to the server"
Introduced a new status variable 'questions' to replace the query_id
variable which currently corresponds badly with the number of statements
sent by the client.
The new behavior is ment to be backward compatible with 4.0 and at the
same time work with new features in a similar way.
This is a backport from 6.0
mysql-test/r/status2.result:
Added test case
mysql-test/t/status2.test:
Added test case
sql/mysqld.cc:
Introduced a new status variable 'questions' to replace the query_id
variable which currently corresponds badly with the number of statements
sent by the client.
sql/sql_class.h:
Introduced a new status variable 'questions' to replace the query_id
variable which currently corresponds badly with the number of statements
sent by the client.
sql/sql_parse.cc:
To be backward compatible with 4.0 and at the same time extend the
interpretation of the Question variable, it should be increased on
all COM-commands but COM_STATISTICS, COM_PING, COM_STMT_PREPARE,
COM_STMT_CLOSE and COM_STMT_RESET.
Since COM_QUERY can process multiple statements, there has to be an
extra increase there as well.
sql/sql_show.cc:
Removed deprecated SHOW_QUESTION status code.
sql/structs.h:
Removed deprecated SHOW_QUESTION status code.
When running Stored Routines the Status Variable "Questions" was wrongly
incremented. According to the manual it should contain the "number of
statements that clients have sent to the server"
Introduced a new status variable 'questions' to replace the query_id
variable which currently corresponds badly with the number of statements
sent by the client.
The new behavior is ment to be backward compatible with 4.0 and at the
same time work with new features in a similar way.
This is a backport from 6.0
