thr_lock.h
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上传日期:2022-05-23
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- /* Copyright (C) 2000 MySQL AB
- 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; either version 2 of the License, or
- (at your option) any later version.
- 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 ;
- enum thr_lock_type { TL_IGNORE=-1,
- TL_UNLOCK, /* UNLOCK ANY LOCK */
- 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,
- /* 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};
- extern ulong max_write_lock_count;
- extern my_bool thr_lock_inited;
- extern enum thr_lock_type thr_upgraded_concurrent_insert_lock;
- typedef struct st_thr_lock_data {
- pthread_t thread;
- struct st_thr_lock_data *next,**prev;
- struct st_thr_lock *lock;
- pthread_cond_t *cond;
- enum thr_lock_type type;
- ulong thread_id;
- 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*); /* When one gets a lock */
- void (*copy_status)(void*,void*);
- void (*update_status)(void*); /* Before release of write */
- my_bool (*check_status)(void *);
- } 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 */
- 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);
- int thr_lock(THR_LOCK_DATA *data,enum thr_lock_type lock_type);
- void thr_unlock(THR_LOCK_DATA *data);
- int thr_multi_lock(THR_LOCK_DATA **data,uint count);
- void thr_multi_unlock(THR_LOCK_DATA **data,uint count);
- void thr_abort_locks(THR_LOCK *lock);
- my_bool thr_abort_locks_for_thread(THR_LOCK *lock, pthread_t thread);
- void thr_print_locks(void); /* For debugging */
- my_bool thr_upgrade_write_delay_lock(THR_LOCK_DATA *data);
- my_bool thr_reschedule_write_lock(THR_LOCK_DATA *data);
- #ifdef __cplusplus
- }
- #endif
- #endif /* _thr_lock_h */