← Back to branch summary

~drizzle-trunk/drizzle/development

« back to all changes in this revision

Viewing changes to include/thr_lock.h

  • Committer: brian
  • Date: 2008-06-25 05:29:13 UTC
  • Revision ID: brian@localhost.localdomain-20080625052913-6upwo0jsrl4lnapl
clean slate

Show diffs side-by-side

added added

removed removed

Lines of Context:
include/thr_lock.h
 
1
/* Copyright (C) 2000 MySQL AB
 
2
 
 
3
   This program is free software; you can redistribute it and/or modify
 
4
   it under the terms of the GNU General Public License as published by
 
5
   the Free Software Foundation; version 2 of the License.
 
6
 
 
7
   This program is distributed in the hope that it will be useful,
 
8
   but WITHOUT ANY WARRANTY; without even the implied warranty of
 
9
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 
10
   GNU General Public License for more details.
 
11
 
 
12
   You should have received a copy of the GNU General Public License
 
13
   along with this program; if not, write to the Free Software
 
14
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
 
15
 
 
16
/* For use with thr_lock:s */
 
17
 
 
18
#ifndef _thr_lock_h
 
19
#define _thr_lock_h
 
20
#ifdef  __cplusplus
 
21
extern "C" {
 
22
#endif
 
23
 
 
24
#include <my_pthread.h>
 
25
#include <my_list.h>
 
26
 
 
27
struct st_thr_lock;
 
28
extern ulong locks_immediate,locks_waited ;
 
29
 
 
30
enum thr_lock_type { TL_IGNORE=-1,
 
31
                     TL_UNLOCK,                 /* UNLOCK ANY LOCK */
 
32
                     TL_READ,                   /* Read lock */
 
33
                     TL_READ_WITH_SHARED_LOCKS,
 
34
                     /* High prior. than TL_WRITE. Allow concurrent insert */
 
35
                     TL_READ_HIGH_PRIORITY,
 
36
                     /* READ, Don't allow concurrent insert */
 
37
                     TL_READ_NO_INSERT,
 
38
                     /* 
 
39
                        Write lock, but allow other threads to read / write.
 
40
                        Used by BDB tables in MySQL to mark that someone is
 
41
                        reading/writing to the table.
 
42
                      */
 
43
                     TL_WRITE_ALLOW_WRITE,
 
44
                     /*
 
45
                        Write lock, but allow other threads to read.
 
46
                        Used by ALTER TABLE in MySQL to allow readers
 
47
                        to use the table until ALTER TABLE is finished.
 
48
                     */
 
49
                     TL_WRITE_ALLOW_READ,
 
50
                     /*
 
51
                       WRITE lock used by concurrent insert. Will allow
 
52
                       READ, if one could use concurrent insert on table.
 
53
                     */
 
54
                     TL_WRITE_CONCURRENT_INSERT,
 
55
                     /* Write used by INSERT DELAYED.  Allows READ locks */
 
56
                     TL_WRITE_DELAYED,
 
57
                     /* 
 
58
                       parser only! Late bound low_priority flag. 
 
59
                       At open_tables() becomes thd->update_lock_default.
 
60
                     */
 
61
                     TL_WRITE_DEFAULT,
 
62
                     /* WRITE lock that has lower priority than TL_READ */
 
63
                     TL_WRITE_LOW_PRIORITY,
 
64
                     /* Normal WRITE lock */
 
65
                     TL_WRITE,
 
66
                     /* Abort new lock request with an error */
 
67
                     TL_WRITE_ONLY};
 
68
 
 
69
enum enum_thr_lock_result { THR_LOCK_SUCCESS= 0, THR_LOCK_ABORTED= 1,
 
70
                            THR_LOCK_WAIT_TIMEOUT= 2, THR_LOCK_DEADLOCK= 3 };
 
71
 
 
72
 
 
73
extern ulong max_write_lock_count;
 
74
extern ulong table_lock_wait_timeout;
 
75
extern my_bool thr_lock_inited;
 
76
extern enum thr_lock_type thr_upgraded_concurrent_insert_lock;
 
77
 
 
78
/*
 
79
  A description of the thread which owns the lock. The address
 
80
  of an instance of this structure is used to uniquely identify the thread.
 
81
*/
 
82
 
 
83
typedef struct st_thr_lock_info
 
84
{
 
85
  pthread_t thread;
 
86
  my_thread_id thread_id;
 
87
  ulong n_cursors;
 
88
} THR_LOCK_INFO;
 
89
 
 
90
/*
 
91
  Lock owner identifier. Globally identifies the lock owner within the
 
92
  thread and among all the threads. The address of an instance of this
 
93
  structure is used as id.
 
94
*/
 
95
 
 
96
typedef struct st_thr_lock_owner
 
97
{
 
98
  THR_LOCK_INFO *info;
 
99
} THR_LOCK_OWNER;
 
100
 
 
101
 
 
102
typedef struct st_thr_lock_data {
 
103
  THR_LOCK_OWNER *owner;
 
104
  struct st_thr_lock_data *next,**prev;
 
105
  struct st_thr_lock *lock;
 
106
  pthread_cond_t *cond;
 
107
  enum thr_lock_type type;
 
108
  void *status_param;                   /* Param to status functions */
 
109
  void *debug_print_param;
 
110
} THR_LOCK_DATA;
 
111
 
 
112
struct st_lock_list {
 
113
  THR_LOCK_DATA *data,**last;
 
114
};
 
115
 
 
116
typedef struct st_thr_lock {
 
117
  LIST list;
 
118
  pthread_mutex_t mutex;
 
119
  struct st_lock_list read_wait;
 
120
  struct st_lock_list read;
 
121
  struct st_lock_list write_wait;
 
122
  struct st_lock_list write;
 
123
  /* write_lock_count is incremented for write locks and reset on read locks */
 
124
  ulong write_lock_count;
 
125
  uint read_no_write_count;
 
126
  void (*get_status)(void*, int);       /* When one gets a lock */
 
127
  void (*copy_status)(void*,void*);
 
128
  void (*update_status)(void*);         /* Before release of write */
 
129
  void (*restore_status)(void*);         /* Before release of read */
 
130
  my_bool (*check_status)(void *);
 
131
} THR_LOCK;
 
132
 
 
133
 
 
134
extern LIST *thr_lock_thread_list;
 
135
extern pthread_mutex_t THR_LOCK_lock;
 
136
 
 
137
my_bool init_thr_lock(void);            /* Must be called once/thread */
 
138
#define thr_lock_owner_init(owner, info_arg) (owner)->info= (info_arg)
 
139
void thr_lock_info_init(THR_LOCK_INFO *info);
 
140
void thr_lock_init(THR_LOCK *lock);
 
141
void thr_lock_delete(THR_LOCK *lock);
 
142
void thr_lock_data_init(THR_LOCK *lock,THR_LOCK_DATA *data,
 
143
                        void *status_param);
 
144
enum enum_thr_lock_result thr_lock(THR_LOCK_DATA *data,
 
145
                                   THR_LOCK_OWNER *owner,
 
146
                                   enum thr_lock_type lock_type);
 
147
void thr_unlock(THR_LOCK_DATA *data);
 
148
enum enum_thr_lock_result thr_multi_lock(THR_LOCK_DATA **data,
 
149
                                         uint count, THR_LOCK_OWNER *owner);
 
150
void thr_multi_unlock(THR_LOCK_DATA **data,uint count);
 
151
void thr_abort_locks(THR_LOCK *lock, my_bool upgrade_lock);
 
152
my_bool thr_abort_locks_for_thread(THR_LOCK *lock, my_thread_id thread);
 
153
void thr_print_locks(void);             /* For debugging */
 
154
my_bool thr_upgrade_write_delay_lock(THR_LOCK_DATA *data);
 
155
void    thr_downgrade_write_lock(THR_LOCK_DATA *data,
 
156
                                 enum thr_lock_type new_lock_type);
 
157
my_bool thr_reschedule_write_lock(THR_LOCK_DATA *data);
 
158
#ifdef  __cplusplus
 
159
}
 
160
#endif
 
161
#endif /* _thr_lock_h */