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Diffstat (limited to 'externals/mysql/thr_lock.h')
| -rw-r--r-- | externals/mysql/thr_lock.h | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/externals/mysql/thr_lock.h b/externals/mysql/thr_lock.h new file mode 100644 index 00000000000..38f0478f276 --- /dev/null +++ b/externals/mysql/thr_lock.h @@ -0,0 +1,181 @@ +/* Copyright 2000-2008 MySQL AB, 2008 Sun Microsystems, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; version 2 of the License. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ + +/* For use with thr_lock:s */ + +#ifndef _thr_lock_h +#define _thr_lock_h +#ifdef __cplusplus +extern "C" { +#endif + +#include <my_pthread.h> +#include <my_list.h> + +struct st_thr_lock; +extern ulong locks_immediate,locks_waited ; + +/** + Lock types are used to request a lock on a table. Changes in this enumeration + might affect transactional locks as well. + Important: if a new lock type is added, a matching lock description + must be added to sql_test.cc's lock_descriptions array. + @see set_handler_table_locks + @see read_lock_type_for_table +*/ +enum thr_lock_type { TL_IGNORE=-1, + TL_UNLOCK, /* UNLOCK ANY LOCK */ + /* + Parser only! At open_tables() becomes TL_READ or + TL_READ_NO_INSERT depending on the binary log format + (SBR/RBR) and on the table category (log table). + Used for tables that are read by statements which + modify tables. + */ + TL_READ_DEFAULT, + TL_READ, /* Read lock */ + TL_READ_WITH_SHARED_LOCKS, + /* High prior. than TL_WRITE. Allow concurrent insert */ + TL_READ_HIGH_PRIORITY, + /* READ, Don't allow concurrent insert */ + TL_READ_NO_INSERT, + /* + Write lock, but allow other threads to read / write. + Used by BDB tables in MySQL to mark that someone is + reading/writing to the table. + */ + TL_WRITE_ALLOW_WRITE, + /* + Write lock, but allow other threads to read. + Used by ALTER TABLE in MySQL to allow readers + to use the table until ALTER TABLE is finished. + */ + TL_WRITE_ALLOW_READ, + /* + WRITE lock used by concurrent insert. Will allow + READ, if one could use concurrent insert on table. + */ + TL_WRITE_CONCURRENT_INSERT, + /* Write used by INSERT DELAYED. Allows READ locks */ + TL_WRITE_DELAYED, + /* + parser only! Late bound low_priority flag. + At open_tables() becomes thd->update_lock_default. + */ + TL_WRITE_DEFAULT, + /* WRITE lock that has lower priority than TL_READ */ + TL_WRITE_LOW_PRIORITY, + /* Normal WRITE lock */ + TL_WRITE, + /* Abort new lock request with an error */ + TL_WRITE_ONLY}; + +enum enum_thr_lock_result { THR_LOCK_SUCCESS= 0, THR_LOCK_ABORTED= 1, + THR_LOCK_WAIT_TIMEOUT= 2, THR_LOCK_DEADLOCK= 3 }; + + +extern ulong max_write_lock_count; +extern ulong table_lock_wait_timeout; +extern my_bool thr_lock_inited; +extern enum thr_lock_type thr_upgraded_concurrent_insert_lock; + +/* + A description of the thread which owns the lock. The address + of an instance of this structure is used to uniquely identify the thread. +*/ + +typedef struct st_thr_lock_info +{ + pthread_t thread; + my_thread_id thread_id; + ulong n_cursors; +} THR_LOCK_INFO; + +/* + Lock owner identifier. Globally identifies the lock owner within the + thread and among all the threads. The address of an instance of this + structure is used as id. +*/ + +typedef struct st_thr_lock_owner +{ + THR_LOCK_INFO *info; +} THR_LOCK_OWNER; + + +typedef struct st_thr_lock_data { + THR_LOCK_OWNER *owner; + struct st_thr_lock_data *next,**prev; + struct st_thr_lock *lock; + pthread_cond_t *cond; + enum thr_lock_type type; + void *status_param; /* Param to status functions */ + void *debug_print_param; +} THR_LOCK_DATA; + +struct st_lock_list { + THR_LOCK_DATA *data,**last; +}; + +typedef struct st_thr_lock { + LIST list; + pthread_mutex_t mutex; + struct st_lock_list read_wait; + struct st_lock_list read; + struct st_lock_list write_wait; + struct st_lock_list write; + /* write_lock_count is incremented for write locks and reset on read locks */ + ulong write_lock_count; + uint read_no_write_count; + void (*get_status)(void*, my_bool); /* When one gets a lock */ + void (*copy_status)(void*,void*); + void (*update_status)(void*); /* Before release of write */ + void (*restore_status)(void*); /* Before release of read */ + my_bool (*check_status)(void *); + my_bool allow_multiple_concurrent_insert; +} THR_LOCK; + + +extern LIST *thr_lock_thread_list; +extern pthread_mutex_t THR_LOCK_lock; + +my_bool init_thr_lock(void); /* Must be called once/thread */ +#define thr_lock_owner_init(owner, info_arg) (owner)->info= (info_arg) +void thr_lock_info_init(THR_LOCK_INFO *info); +void thr_lock_init(THR_LOCK *lock); +void thr_lock_delete(THR_LOCK *lock); +void thr_lock_data_init(THR_LOCK *lock,THR_LOCK_DATA *data, + void *status_param); +enum enum_thr_lock_result thr_lock(THR_LOCK_DATA *data, + THR_LOCK_OWNER *owner, + enum thr_lock_type lock_type); +void thr_unlock(THR_LOCK_DATA *data); +enum enum_thr_lock_result thr_multi_lock(THR_LOCK_DATA **data, + uint count, THR_LOCK_OWNER *owner); +void thr_multi_unlock(THR_LOCK_DATA **data,uint count); +void +thr_lock_merge_status(THR_LOCK_DATA **data, uint count); +void thr_abort_locks(THR_LOCK *lock, my_bool upgrade_lock); +my_bool thr_abort_locks_for_thread(THR_LOCK *lock, my_thread_id thread); +void thr_print_locks(void); /* For debugging */ +my_bool thr_upgrade_write_delay_lock(THR_LOCK_DATA *data, + enum thr_lock_type new_lock_type); +void thr_downgrade_write_lock(THR_LOCK_DATA *data, + enum thr_lock_type new_lock_type); +my_bool thr_reschedule_write_lock(THR_LOCK_DATA *data); +#ifdef __cplusplus +} +#endif +#endif /* _thr_lock_h */ |