1/* Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
2 Copyright (c) 2017, MariaDB Corporation.
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; version 2 of the License.
7
8 This program is distributed in the hope that it will be useful,
9 but WITHOUT ANY WARRANTY; without even the implied warranty of
10 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 GNU General Public License for more details.
12
13 You should have received a copy of the GNU General Public License
14 along with this program; if not, write to the Free Software
15 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
16
17/* For use with thr_lock:s */
18
19#ifndef _thr_lock_h
20#define _thr_lock_h
21#ifdef __cplusplus
22extern "C" {
23#endif
24#include <my_pthread.h>
25#include <my_list.h>
26
27struct st_thr_lock;
28extern ulong locks_immediate,locks_waited ;
29
30/*
31 Important: if a new lock type is added, a matching lock description
32 must be added to sql_test.cc's lock_descriptions array.
33*/
34enum thr_lock_type { TL_IGNORE=-1,
35 TL_UNLOCK, /* UNLOCK ANY LOCK */
36 /*
37 Parser only! At open_tables() becomes TL_READ or
38 TL_READ_NO_INSERT depending on the binary log format
39 (SBR/RBR) and on the table category (log table).
40 Used for tables that are read by statements which
41 modify tables.
42 */
43 TL_READ_DEFAULT,
44 TL_READ, /* Read lock */
45 TL_READ_WITH_SHARED_LOCKS,
46 /* High prior. than TL_WRITE. Allow concurrent insert */
47 TL_READ_HIGH_PRIORITY,
48 /* READ, Don't allow concurrent insert */
49 TL_READ_NO_INSERT,
50 /*
51 Write lock, but allow other threads to read / write.
52 Used by BDB tables in MySQL to mark that someone is
53 reading/writing to the table.
54 */
55 TL_WRITE_ALLOW_WRITE,
56 /*
57 WRITE lock used by concurrent insert. Will allow
58 READ, if one could use concurrent insert on table.
59 */
60 TL_WRITE_CONCURRENT_INSERT,
61 /* Write used by INSERT DELAYED. Allows READ locks */
62 TL_WRITE_DELAYED,
63 /*
64 parser only! Late bound low_priority flag.
65 At open_tables() becomes thd->update_lock_default.
66 */
67 TL_WRITE_DEFAULT,
68 /* WRITE lock that has lower priority than TL_READ */
69 TL_WRITE_LOW_PRIORITY,
70 /* Normal WRITE lock */
71 TL_WRITE,
72 /* Abort new lock request with an error */
73 TL_WRITE_ONLY};
74
75enum enum_thr_lock_result { THR_LOCK_SUCCESS= 0, THR_LOCK_ABORTED= 1,
76 THR_LOCK_WAIT_TIMEOUT= 2, THR_LOCK_DEADLOCK= 3 };
77
78
79/* Priority for locks */
80#define THR_LOCK_LATE_PRIV 1U /* For locks to be merged with org lock */
81#define THR_LOCK_MERGE_PRIV 2U /* For merge tables */
82
83#define THR_UNLOCK_UPDATE_STATUS 1U
84
85extern ulong max_write_lock_count;
86extern my_bool thr_lock_inited;
87extern enum thr_lock_type thr_upgraded_concurrent_insert_lock;
88
89/*
90 A description of the thread which owns the lock. The address
91 of an instance of this structure is used to uniquely identify the thread.
92*/
93
94typedef struct st_thr_lock_info
95{
96 pthread_t thread;
97 my_thread_id thread_id;
98 void *mysql_thd; // THD pointer
99} THR_LOCK_INFO;
100
101
102typedef struct st_thr_lock_data {
103 THR_LOCK_INFO *owner;
104 struct st_thr_lock_data *next,**prev;
105 struct st_thr_lock *lock;
106 mysql_cond_t *cond;
107 void *status_param; /* Param to status functions */
108 void *debug_print_param; /* For error messages */
109 struct PSI_table *m_psi;
110 enum thr_lock_type type;
111 enum thr_lock_type org_type; /* Cache for MariaDB */
112 uint priority;
113} THR_LOCK_DATA;
114
115struct st_lock_list {
116 THR_LOCK_DATA *data,**last;
117};
118
119typedef struct st_thr_lock {
120 LIST list;
121 mysql_mutex_t mutex;
122 struct st_lock_list read_wait;
123 struct st_lock_list read;
124 struct st_lock_list write_wait;
125 struct st_lock_list write;
126 /* write_lock_count is incremented for write locks and reset on read locks */
127 ulong write_lock_count;
128 uint read_no_write_count;
129 void (*get_status)(void*, my_bool); /* When one gets a lock */
130 void (*copy_status)(void*,void*);
131 void (*update_status)(void*); /* Before release of write */
132 void (*restore_status)(void*); /* Before release of read */
133 my_bool (*start_trans)(void*); /* When all locks are taken */
134 my_bool (*check_status)(void *);
135 void (*fix_status)(void *, void *);/* For thr_merge_locks() */
136 const char *name; /* Used for error reporting */
137 my_bool allow_multiple_concurrent_insert;
138} THR_LOCK;
139
140
141extern LIST *thr_lock_thread_list;
142extern mysql_mutex_t THR_LOCK_lock;
143struct st_my_thread_var;
144
145my_bool init_thr_lock(void); /* Must be called once/thread */
146void thr_lock_info_init(THR_LOCK_INFO *info, struct st_my_thread_var *tmp);
147void thr_lock_init(THR_LOCK *lock);
148void thr_lock_delete(THR_LOCK *lock);
149void thr_lock_data_init(THR_LOCK *lock,THR_LOCK_DATA *data,
150 void *status_param);
151void thr_unlock(THR_LOCK_DATA *data, uint unlock_flags);
152enum enum_thr_lock_result thr_multi_lock(THR_LOCK_DATA **data,
153 uint count, THR_LOCK_INFO *owner,
154 ulong lock_wait_timeout);
155void thr_multi_unlock(THR_LOCK_DATA **data,uint count, uint unlock_flags);
156void thr_merge_locks(THR_LOCK_DATA **data, uint org_count, uint new_count);
157void thr_abort_locks(THR_LOCK *lock, my_bool upgrade_lock);
158my_bool thr_abort_locks_for_thread(THR_LOCK *lock, my_thread_id thread);
159void thr_print_locks(void); /* For debugging */
160my_bool thr_upgrade_write_delay_lock(THR_LOCK_DATA *data,
161 enum thr_lock_type new_lock_type,
162 ulong lock_wait_timeout);
163void thr_downgrade_write_lock(THR_LOCK_DATA *data,
164 enum thr_lock_type new_lock_type);
165my_bool thr_reschedule_write_lock(THR_LOCK_DATA *data,
166 ulong lock_wait_timeout);
167void thr_set_lock_wait_callback(void (*before_wait)(void),
168 void (*after_wait)(void));
169
170#ifdef WITH_WSREP
171 typedef my_bool (* wsrep_thd_is_brute_force_fun)(void *, my_bool);
172 typedef int (* wsrep_abort_thd_fun)(void *, void *, my_bool);
173 typedef int (* wsrep_on_fun)(void *);
174 void wsrep_thr_lock_init(
175 wsrep_thd_is_brute_force_fun bf_fun, wsrep_abort_thd_fun abort_fun,
176 my_bool debug, my_bool convert_LOCK_to_trx, wsrep_on_fun on_fun);
177#endif
178
179#ifdef __cplusplus
180}
181#endif
182#endif /* _thr_lock_h */
183