/* 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 #include 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 */