1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
|
/*****************************************************************************
Copyright (c) 1996, 2011, Oracle and/or its affiliates. All Rights Reserved.
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.,
51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA
*****************************************************************************/
/**************************************************//**
@file include/lock0lock.h
The transaction lock system
Created 5/7/1996 Heikki Tuuri
*******************************************************/
#ifndef lock0lock_h
#define lock0lock_h
#include "univ.i"
#include "buf0types.h"
#include "trx0types.h"
#include "mtr0types.h"
#include "rem0types.h"
#include "dict0types.h"
#include "que0types.h"
#include "lock0types.h"
#include "read0types.h"
#include "hash0hash.h"
#include "srv0srv.h"
#include "ut0vec.h"
#ifdef UNIV_DEBUG
extern ibool lock_print_waits;
#endif /* UNIV_DEBUG */
/*********************************************************************//**
Gets the size of a lock struct.
@return size in bytes */
UNIV_INTERN
ulint
lock_get_size(void);
/*===============*/
/*********************************************************************//**
Creates the lock system at database start. */
UNIV_INTERN
void
lock_sys_create(
/*============*/
ulint n_cells); /*!< in: number of slots in lock hash table */
/*********************************************************************//**
Closes the lock system at database shutdown. */
UNIV_INTERN
void
lock_sys_close(void);
/*================*/
/*********************************************************************//**
Gets the heap_no of the smallest user record on a page.
@return heap_no of smallest user record, or PAGE_HEAP_NO_SUPREMUM */
UNIV_INLINE
ulint
lock_get_min_heap_no(
/*=================*/
const buf_block_t* block); /*!< in: buffer block */
/*************************************************************//**
Updates the lock table when we have reorganized a page. NOTE: we copy
also the locks set on the infimum of the page; the infimum may carry
locks if an update of a record is occurring on the page, and its locks
were temporarily stored on the infimum. */
UNIV_INTERN
void
lock_move_reorganize_page(
/*======================*/
const buf_block_t* block, /*!< in: old index page, now
reorganized */
const buf_block_t* oblock);/*!< in: copy of the old, not
reorganized page */
/*************************************************************//**
Moves the explicit locks on user records to another page if a record
list end is moved to another page. */
UNIV_INTERN
void
lock_move_rec_list_end(
/*===================*/
const buf_block_t* new_block, /*!< in: index page to move to */
const buf_block_t* block, /*!< in: index page */
const rec_t* rec); /*!< in: record on page: this
is the first record moved */
/*************************************************************//**
Moves the explicit locks on user records to another page if a record
list start is moved to another page. */
UNIV_INTERN
void
lock_move_rec_list_start(
/*=====================*/
const buf_block_t* new_block, /*!< in: index page to move to */
const buf_block_t* block, /*!< in: index page */
const rec_t* rec, /*!< in: record on page:
this is the first
record NOT copied */
const rec_t* old_end); /*!< in: old
previous-to-last
record on new_page
before the records
were copied */
/*************************************************************//**
Updates the lock table when a page is split to the right. */
UNIV_INTERN
void
lock_update_split_right(
/*====================*/
const buf_block_t* right_block, /*!< in: right page */
const buf_block_t* left_block); /*!< in: left page */
/*************************************************************//**
Updates the lock table when a page is merged to the right. */
UNIV_INTERN
void
lock_update_merge_right(
/*====================*/
const buf_block_t* right_block, /*!< in: right page to
which merged */
const rec_t* orig_succ, /*!< in: original
successor of infimum
on the right page
before merge */
const buf_block_t* left_block); /*!< in: merged index
page which will be
discarded */
/*************************************************************//**
Updates the lock table when the root page is copied to another in
btr_root_raise_and_insert. Note that we leave lock structs on the
root page, even though they do not make sense on other than leaf
pages: the reason is that in a pessimistic update the infimum record
of the root page will act as a dummy carrier of the locks of the record
to be updated. */
UNIV_INTERN
void
lock_update_root_raise(
/*===================*/
const buf_block_t* block, /*!< in: index page to which copied */
const buf_block_t* root); /*!< in: root page */
/*************************************************************//**
Updates the lock table when a page is copied to another and the original page
is removed from the chain of leaf pages, except if page is the root! */
UNIV_INTERN
void
lock_update_copy_and_discard(
/*=========================*/
const buf_block_t* new_block, /*!< in: index page to
which copied */
const buf_block_t* block); /*!< in: index page;
NOT the root! */
/*************************************************************//**
Updates the lock table when a page is split to the left. */
UNIV_INTERN
void
lock_update_split_left(
/*===================*/
const buf_block_t* right_block, /*!< in: right page */
const buf_block_t* left_block); /*!< in: left page */
/*************************************************************//**
Updates the lock table when a page is merged to the left. */
UNIV_INTERN
void
lock_update_merge_left(
/*===================*/
const buf_block_t* left_block, /*!< in: left page to
which merged */
const rec_t* orig_pred, /*!< in: original predecessor
of supremum on the left page
before merge */
const buf_block_t* right_block); /*!< in: merged index page
which will be discarded */
/*************************************************************//**
Resets the original locks on heir and replaces them with gap type locks
inherited from rec. */
UNIV_INTERN
void
lock_rec_reset_and_inherit_gap_locks(
/*=================================*/
const buf_block_t* heir_block, /*!< in: block containing the
record which inherits */
const buf_block_t* block, /*!< in: block containing the
record from which inherited;
does NOT reset the locks on
this record */
ulint heir_heap_no, /*!< in: heap_no of the
inheriting record */
ulint heap_no); /*!< in: heap_no of the
donating record */
/*************************************************************//**
Updates the lock table when a page is discarded. */
UNIV_INTERN
void
lock_update_discard(
/*================*/
const buf_block_t* heir_block, /*!< in: index page
which will inherit the locks */
ulint heir_heap_no, /*!< in: heap_no of the record
which will inherit the locks */
const buf_block_t* block); /*!< in: index page
which will be discarded */
/*************************************************************//**
Updates the lock table when a new user record is inserted. */
UNIV_INTERN
void
lock_update_insert(
/*===============*/
const buf_block_t* block, /*!< in: buffer block containing rec */
const rec_t* rec); /*!< in: the inserted record */
/*************************************************************//**
Updates the lock table when a record is removed. */
UNIV_INTERN
void
lock_update_delete(
/*===============*/
const buf_block_t* block, /*!< in: buffer block containing rec */
const rec_t* rec); /*!< in: the record to be removed */
/*********************************************************************//**
Stores on the page infimum record the explicit locks of another record.
This function is used to store the lock state of a record when it is
updated and the size of the record changes in the update. The record
is in such an update moved, perhaps to another page. The infimum record
acts as a dummy carrier record, taking care of lock releases while the
actual record is being moved. */
UNIV_INTERN
void
lock_rec_store_on_page_infimum(
/*===========================*/
const buf_block_t* block, /*!< in: buffer block containing rec */
const rec_t* rec); /*!< in: record whose lock state
is stored on the infimum
record of the same page; lock
bits are reset on the
record */
/*********************************************************************//**
Restores the state of explicit lock requests on a single record, where the
state was stored on the infimum of the page. */
UNIV_INTERN
void
lock_rec_restore_from_page_infimum(
/*===============================*/
const buf_block_t* block, /*!< in: buffer block containing rec */
const rec_t* rec, /*!< in: record whose lock state
is restored */
const buf_block_t* donator);/*!< in: page (rec is not
necessarily on this page)
whose infimum stored the lock
state; lock bits are reset on
the infimum */
/*********************************************************************//**
Determines if there are explicit record locks on a page.
@return an explicit record lock on the page, or NULL if there are none */
UNIV_INTERN
lock_t*
lock_rec_expl_exist_on_page(
/*========================*/
ulint space, /*!< in: space id */
ulint page_no)/*!< in: page number */
__attribute__((warn_unused_result));
/*********************************************************************//**
Checks if locks of other transactions prevent an immediate insert of
a record. If they do, first tests if the query thread should anyway
be suspended for some reason; if not, then puts the transaction and
the query thread to the lock wait state and inserts a waiting request
for a gap x-lock to the lock queue.
@return DB_SUCCESS, DB_LOCK_WAIT, DB_DEADLOCK, or DB_QUE_THR_SUSPENDED */
UNIV_INTERN
ulint
lock_rec_insert_check_and_lock(
/*===========================*/
ulint flags, /*!< in: if BTR_NO_LOCKING_FLAG bit is
set, does nothing */
const rec_t* rec, /*!< in: record after which to insert */
buf_block_t* block, /*!< in/out: buffer block of rec */
dict_index_t* index, /*!< in: index */
que_thr_t* thr, /*!< in: query thread */
mtr_t* mtr, /*!< in/out: mini-transaction */
ibool* inherit);/*!< out: set to TRUE if the new
inserted record maybe should inherit
LOCK_GAP type locks from the successor
record */
/*********************************************************************//**
Checks if locks of other transactions prevent an immediate modify (update,
delete mark, or delete unmark) of a clustered index record. If they do,
first tests if the query thread should anyway be suspended for some
reason; if not, then puts the transaction and the query thread to the
lock wait state and inserts a waiting request for a record x-lock to the
lock queue.
@return DB_SUCCESS, DB_LOCK_WAIT, DB_DEADLOCK, or DB_QUE_THR_SUSPENDED */
UNIV_INTERN
ulint
lock_clust_rec_modify_check_and_lock(
/*=================================*/
ulint flags, /*!< in: if BTR_NO_LOCKING_FLAG
bit is set, does nothing */
const buf_block_t* block, /*!< in: buffer block of rec */
const rec_t* rec, /*!< in: record which should be
modified */
dict_index_t* index, /*!< in: clustered index */
const ulint* offsets,/*!< in: rec_get_offsets(rec, index) */
que_thr_t* thr); /*!< in: query thread */
/*********************************************************************//**
Checks if locks of other transactions prevent an immediate modify
(delete mark or delete unmark) of a secondary index record.
@return DB_SUCCESS, DB_LOCK_WAIT, DB_DEADLOCK, or DB_QUE_THR_SUSPENDED */
UNIV_INTERN
ulint
lock_sec_rec_modify_check_and_lock(
/*===============================*/
ulint flags, /*!< in: if BTR_NO_LOCKING_FLAG
bit is set, does nothing */
buf_block_t* block, /*!< in/out: buffer block of rec */
const rec_t* rec, /*!< in: record which should be
modified; NOTE: as this is a secondary
index, we always have to modify the
clustered index record first: see the
comment below */
dict_index_t* index, /*!< in: secondary index */
que_thr_t* thr, /*!< in: query thread */
mtr_t* mtr); /*!< in/out: mini-transaction */
/*********************************************************************//**
Like lock_clust_rec_read_check_and_lock(), but reads a
secondary index record.
@return DB_SUCCESS, DB_SUCCESS_LOCKED_REC, DB_LOCK_WAIT, DB_DEADLOCK,
or DB_QUE_THR_SUSPENDED */
UNIV_INTERN
enum db_err
lock_sec_rec_read_check_and_lock(
/*=============================*/
ulint flags, /*!< in: if BTR_NO_LOCKING_FLAG
bit is set, does nothing */
const buf_block_t* block, /*!< in: buffer block of rec */
const rec_t* rec, /*!< in: user record or page
supremum record which should
be read or passed over by a
read cursor */
dict_index_t* index, /*!< in: secondary index */
const ulint* offsets,/*!< in: rec_get_offsets(rec, index) */
enum lock_mode mode, /*!< in: mode of the lock which
the read cursor should set on
records: LOCK_S or LOCK_X; the
latter is possible in
SELECT FOR UPDATE */
ulint gap_mode,/*!< in: LOCK_ORDINARY, LOCK_GAP, or
LOCK_REC_NOT_GAP */
que_thr_t* thr); /*!< in: query thread */
/*********************************************************************//**
Checks if locks of other transactions prevent an immediate read, or passing
over by a read cursor, of a clustered index record. If they do, first tests
if the query thread should anyway be suspended for some reason; if not, then
puts the transaction and the query thread to the lock wait state and inserts a
waiting request for a record lock to the lock queue. Sets the requested mode
lock on the record.
@return DB_SUCCESS, DB_SUCCESS_LOCKED_REC, DB_LOCK_WAIT, DB_DEADLOCK,
or DB_QUE_THR_SUSPENDED */
UNIV_INTERN
enum db_err
lock_clust_rec_read_check_and_lock(
/*===============================*/
ulint flags, /*!< in: if BTR_NO_LOCKING_FLAG
bit is set, does nothing */
const buf_block_t* block, /*!< in: buffer block of rec */
const rec_t* rec, /*!< in: user record or page
supremum record which should
be read or passed over by a
read cursor */
dict_index_t* index, /*!< in: clustered index */
const ulint* offsets,/*!< in: rec_get_offsets(rec, index) */
enum lock_mode mode, /*!< in: mode of the lock which
the read cursor should set on
records: LOCK_S or LOCK_X; the
latter is possible in
SELECT FOR UPDATE */
ulint gap_mode,/*!< in: LOCK_ORDINARY, LOCK_GAP, or
LOCK_REC_NOT_GAP */
que_thr_t* thr); /*!< in: query thread */
/*********************************************************************//**
Checks if locks of other transactions prevent an immediate read, or passing
over by a read cursor, of a clustered index record. If they do, first tests
if the query thread should anyway be suspended for some reason; if not, then
puts the transaction and the query thread to the lock wait state and inserts a
waiting request for a record lock to the lock queue. Sets the requested mode
lock on the record. This is an alternative version of
lock_clust_rec_read_check_and_lock() that does not require the parameter
"offsets".
@return DB_SUCCESS, DB_LOCK_WAIT, DB_DEADLOCK, or DB_QUE_THR_SUSPENDED */
UNIV_INTERN
ulint
lock_clust_rec_read_check_and_lock_alt(
/*===================================*/
ulint flags, /*!< in: if BTR_NO_LOCKING_FLAG
bit is set, does nothing */
const buf_block_t* block, /*!< in: buffer block of rec */
const rec_t* rec, /*!< in: user record or page
supremum record which should
be read or passed over by a
read cursor */
dict_index_t* index, /*!< in: clustered index */
enum lock_mode mode, /*!< in: mode of the lock which
the read cursor should set on
records: LOCK_S or LOCK_X; the
latter is possible in
SELECT FOR UPDATE */
ulint gap_mode,/*!< in: LOCK_ORDINARY, LOCK_GAP, or
LOCK_REC_NOT_GAP */
que_thr_t* thr); /*!< in: query thread */
/*********************************************************************//**
Checks that a record is seen in a consistent read.
@return TRUE if sees, or FALSE if an earlier version of the record
should be retrieved */
UNIV_INTERN
ibool
lock_clust_rec_cons_read_sees(
/*==========================*/
const rec_t* rec, /*!< in: user record which should be read or
passed over by a read cursor */
dict_index_t* index, /*!< in: clustered index */
const ulint* offsets,/*!< in: rec_get_offsets(rec, index) */
read_view_t* view); /*!< in: consistent read view */
/*********************************************************************//**
Checks that a non-clustered index record is seen in a consistent read.
NOTE that a non-clustered index page contains so little information on
its modifications that also in the case FALSE, the present version of
rec may be the right, but we must check this from the clustered index
record.
@return TRUE if certainly sees, or FALSE if an earlier version of the
clustered index record might be needed */
UNIV_INTERN
ulint
lock_sec_rec_cons_read_sees(
/*========================*/
const rec_t* rec, /*!< in: user record which
should be read or passed over
by a read cursor */
const read_view_t* view); /*!< in: consistent read view */
/*********************************************************************//**
Locks the specified database table in the mode given. If the lock cannot
be granted immediately, the query thread is put to wait.
@return DB_SUCCESS, DB_LOCK_WAIT, DB_DEADLOCK, or DB_QUE_THR_SUSPENDED */
UNIV_INTERN
ulint
lock_table(
/*=======*/
ulint flags, /*!< in: if BTR_NO_LOCKING_FLAG bit is set,
does nothing */
dict_table_t* table, /*!< in/out: database table
in dictionary cache */
enum lock_mode mode, /*!< in: lock mode */
que_thr_t* thr); /*!< in: query thread */
/*************************************************************//**
Removes a granted record lock of a transaction from the queue and grants
locks to other transactions waiting in the queue if they now are entitled
to a lock. */
UNIV_INTERN
void
lock_rec_unlock(
/*============*/
trx_t* trx, /*!< in/out: transaction that has
set a record lock */
const buf_block_t* block, /*!< in: buffer block containing rec */
const rec_t* rec, /*!< in: record */
enum lock_mode lock_mode);/*!< in: LOCK_S or LOCK_X */
/*********************************************************************//**
Releases a transaction's locks, and releases possible other transactions
waiting because of these locks. Change the state of the transaction to
TRX_STATE_COMMITTED_IN_MEMORY. */
UNIV_INTERN
void
lock_trx_release_locks(
/*===================*/
trx_t* trx); /*!< in/out: transaction */
/*********************************************************************//**
Removes locks on a table to be dropped or truncated.
If remove_also_table_sx_locks is TRUE then table-level S and X locks are
also removed in addition to other table-level and record-level locks.
No lock, that is going to be removed, is allowed to be a wait lock. */
UNIV_INTERN
void
lock_remove_all_on_table(
/*=====================*/
dict_table_t* table, /*!< in: table to be dropped
or truncated */
ibool remove_also_table_sx_locks);/*!< in: also removes
table S and X locks */
/*********************************************************************//**
Calculates the fold value of a page file address: used in inserting or
searching for a lock in the hash table.
@return folded value */
UNIV_INLINE
ulint
lock_rec_fold(
/*==========*/
ulint space, /*!< in: space */
ulint page_no)/*!< in: page number */
__attribute__((const));
/*********************************************************************//**
Calculates the hash value of a page file address: used in inserting or
searching for a lock in the hash table.
@return hashed value */
UNIV_INLINE
ulint
lock_rec_hash(
/*==========*/
ulint space, /*!< in: space */
ulint page_no);/*!< in: page number */
/**********************************************************************//**
Looks for a set bit in a record lock bitmap. Returns ULINT_UNDEFINED,
if none found.
@return bit index == heap number of the record, or ULINT_UNDEFINED if
none found */
UNIV_INTERN
ulint
lock_rec_find_set_bit(
/*==================*/
const lock_t* lock); /*!< in: record lock with at least one
bit set */
/*********************************************************************//**
Gets the source table of an ALTER TABLE transaction. The table must be
covered by an IX or IS table lock.
@return the source table of transaction, if it is covered by an IX or
IS table lock; dest if there is no source table, and NULL if the
transaction is locking more than two tables or an inconsistency is
found */
UNIV_INTERN
dict_table_t*
lock_get_src_table(
/*===============*/
trx_t* trx, /*!< in: transaction */
dict_table_t* dest, /*!< in: destination of ALTER TABLE */
enum lock_mode* mode); /*!< out: lock mode of the source table */
/*********************************************************************//**
Determine if the given table is exclusively "owned" by the given
transaction, i.e., transaction holds LOCK_IX and possibly LOCK_AUTO_INC
on the table.
@return TRUE if table is only locked by trx, with LOCK_IX, and
possibly LOCK_AUTO_INC */
UNIV_INTERN
ibool
lock_is_table_exclusive(
/*====================*/
const dict_table_t* table, /*!< in: table */
const trx_t* trx) /*!< in: transaction */
__attribute__((nonnull));
/*********************************************************************//**
Checks if a lock request lock1 has to wait for request lock2.
@return TRUE if lock1 has to wait for lock2 to be removed */
UNIV_INTERN
ibool
lock_has_to_wait(
/*=============*/
const lock_t* lock1, /*!< in: waiting lock */
const lock_t* lock2); /*!< in: another lock; NOTE that it is
assumed that this has a lock bit set
on the same record as in lock1 if the
locks are record locks */
/*********************************************************************//**
Reports that a transaction id is insensible, i.e., in the future. */
UNIV_INTERN
void
lock_report_trx_id_insanity(
/*========================*/
trx_id_t trx_id, /*!< in: trx id */
const rec_t* rec, /*!< in: user record */
dict_index_t* index, /*!< in: index */
const ulint* offsets, /*!< in: rec_get_offsets(rec, index) */
trx_id_t max_trx_id) /*!< in: trx_sys_get_max_trx_id() */
__attribute__((nonnull));
/*********************************************************************//**
Prints info of a table lock. */
UNIV_INTERN
void
lock_table_print(
/*=============*/
FILE* file, /*!< in: file where to print */
const lock_t* lock); /*!< in: table type lock */
/*********************************************************************//**
Prints info of a record lock. */
UNIV_INTERN
void
lock_rec_print(
/*===========*/
FILE* file, /*!< in: file where to print */
const lock_t* lock); /*!< in: record type lock */
/*********************************************************************//**
Prints info of locks for all transactions.
@return FALSE if not able to obtain lock mutex and exits without
printing info */
UNIV_INTERN
ibool
lock_print_info_summary(
/*====================*/
FILE* file, /*!< in: file where to print */
ibool nowait) /*!< in: whether to wait for the lock mutex */
__attribute__((nonnull, warn_unused_result));
/*********************************************************************//**
Prints info of locks for each transaction. This function assumes that the
caller holds the lock mutex and more importantly it will release the lock
mutex on behalf of the caller. (This should be fixed in the future). */
UNIV_INTERN
void
lock_print_info_all_transactions(
/*=============================*/
FILE* file); /*!< in: file where to print */
/*********************************************************************//**
Return approximate number or record locks (bits set in the bitmap) for
this transaction. Since delete-marked records may be removed, the
record count will not be precise.
The caller must be holding lock_sys->mutex. */
UNIV_INTERN
ulint
lock_number_of_rows_locked(
/*=======================*/
const trx_lock_t* trx_lock) /*!< in: transaction locks */
__attribute__((nonnull, warn_unused_result));
/*******************************************************************//**
Gets the type of a lock. Non-inline version for using outside of the
lock module.
@return LOCK_TABLE or LOCK_REC */
UNIV_INTERN
ulint
lock_get_type(
/*==========*/
const lock_t* lock); /*!< in: lock */
/*******************************************************************//**
Gets the id of the transaction owning a lock.
@return transaction id */
UNIV_INTERN
trx_id_t
lock_get_trx_id(
/*============*/
const lock_t* lock); /*!< in: lock */
/*******************************************************************//**
Gets the mode of a lock in a human readable string.
The string should not be free()'d or modified.
@return lock mode */
UNIV_INTERN
const char*
lock_get_mode_str(
/*==============*/
const lock_t* lock); /*!< in: lock */
/*******************************************************************//**
Gets the type of a lock in a human readable string.
The string should not be free()'d or modified.
@return lock type */
UNIV_INTERN
const char*
lock_get_type_str(
/*==============*/
const lock_t* lock); /*!< in: lock */
/*******************************************************************//**
Gets the id of the table on which the lock is.
@return id of the table */
UNIV_INTERN
table_id_t
lock_get_table_id(
/*==============*/
const lock_t* lock); /*!< in: lock */
/*******************************************************************//**
Gets the name of the table on which the lock is.
The string should not be free()'d or modified.
@return name of the table */
UNIV_INTERN
const char*
lock_get_table_name(
/*================*/
const lock_t* lock); /*!< in: lock */
/*******************************************************************//**
For a record lock, gets the index on which the lock is.
@return index */
UNIV_INTERN
const dict_index_t*
lock_rec_get_index(
/*===============*/
const lock_t* lock); /*!< in: lock */
/*******************************************************************//**
For a record lock, gets the name of the index on which the lock is.
The string should not be free()'d or modified.
@return name of the index */
UNIV_INTERN
const char*
lock_rec_get_index_name(
/*====================*/
const lock_t* lock); /*!< in: lock */
/*******************************************************************//**
For a record lock, gets the tablespace number on which the lock is.
@return tablespace number */
UNIV_INTERN
ulint
lock_rec_get_space_id(
/*==================*/
const lock_t* lock); /*!< in: lock */
/*******************************************************************//**
For a record lock, gets the page number on which the lock is.
@return page number */
UNIV_INTERN
ulint
lock_rec_get_page_no(
/*=================*/
const lock_t* lock); /*!< in: lock */
/*******************************************************************//**
Check if there are any locks (table or rec) against table.
@return TRUE if locks exist */
UNIV_INTERN
ibool
lock_table_has_locks(
/*=================*/
const dict_table_t* table); /*!< in: check if there are any locks
held on records in this table or on the
table itself */
/*********************************************************************//**
A thread which wakes up threads whose lock wait may have lasted too long.
@return a dummy parameter */
extern "C" UNIV_INTERN
os_thread_ret_t
DECLARE_THREAD(lock_wait_timeout_thread)(
/*=====================================*/
void* arg); /*!< in: a dummy parameter required by
os_thread_create */
/********************************************************************//**
Releases a user OS thread waiting for a lock to be released, if the
thread is already suspended. */
UNIV_INTERN
void
lock_wait_release_thread_if_suspended(
/*==================================*/
que_thr_t* thr); /*!< in: query thread associated with the
user OS thread */
/***************************************************************//**
Puts a user OS thread to wait for a lock to be released. If an error
occurs during the wait trx->error_state associated with thr is
!= DB_SUCCESS when we return. DB_LOCK_WAIT_TIMEOUT and DB_DEADLOCK
are possible errors. DB_DEADLOCK is returned if selective deadlock
resolution chose this transaction as a victim. */
UNIV_INTERN
void
lock_wait_suspend_thread(
/*=====================*/
que_thr_t* thr); /*!< in: query thread associated with the
user OS thread */
/*********************************************************************//**
Unlocks AUTO_INC type locks that were possibly reserved by a trx. This
function should be called at the the end of an SQL statement, by the
connection thread that owns the transaction (trx->mysql_thd). */
UNIV_INTERN
void
lock_unlock_table_autoinc(
/*======================*/
trx_t* trx); /*!< in/out: transaction */
/*********************************************************************//**
Check whether the transaction has already been rolled back because it
was selected as a deadlock victim, or if it has to wait then cancel
the wait lock.
@return DB_DEADLOCK, DB_LOCK_WAIT or DB_SUCCESS */
UNIV_INTERN
enum db_err
lock_trx_handle_wait(
/*=================*/
trx_t* trx) /*!< in/out: trx lock state */
__attribute__((nonnull));
/*********************************************************************//**
Get the number of locks on a table.
@return number of locks */
UNIV_INTERN
ulint
lock_table_get_n_locks(
/*===================*/
const dict_table_t* table) /*!< in: table */
__attribute__((nonnull));
#ifdef UNIV_DEBUG
/*********************************************************************//**
Checks that a transaction id is sensible, i.e., not in the future.
@return true if ok */
UNIV_INTERN
bool
lock_check_trx_id_sanity(
/*=====================*/
trx_id_t trx_id, /*!< in: trx id */
const rec_t* rec, /*!< in: user record */
dict_index_t* index, /*!< in: index */
const ulint* offsets) /*!< in: rec_get_offsets(rec, index) */
__attribute__((nonnull, warn_unused_result));
/*******************************************************************//**
Check if the transaction holds any locks on the sys tables
or its records.
@return the strongest lock found on any sys table or 0 for none */
UNIV_INTERN
const lock_t*
lock_trx_has_sys_table_locks(
/*=========================*/
const trx_t* trx) /*!< in: transaction to check */
__attribute__((warn_unused_result));
#endif /* UNIV_DEBUG */
/** Lock modes and types */
/* @{ */
#define LOCK_MODE_MASK 0xFUL /*!< mask used to extract mode from the
type_mode field in a lock */
/** Lock types */
/* @{ */
#define LOCK_TABLE 16 /*!< table lock */
#define LOCK_REC 32 /*!< record lock */
#define LOCK_TYPE_MASK 0xF0UL /*!< mask used to extract lock type from the
type_mode field in a lock */
#if LOCK_MODE_MASK & LOCK_TYPE_MASK
# error "LOCK_MODE_MASK & LOCK_TYPE_MASK"
#endif
#define LOCK_WAIT 256 /*!< Waiting lock flag; when set, it
means that the lock has not yet been
granted, it is just waiting for its
turn in the wait queue */
/* Precise modes */
#define LOCK_ORDINARY 0 /*!< this flag denotes an ordinary
next-key lock in contrast to LOCK_GAP
or LOCK_REC_NOT_GAP */
#define LOCK_GAP 512 /*!< when this bit is set, it means that the
lock holds only on the gap before the record;
for instance, an x-lock on the gap does not
give permission to modify the record on which
the bit is set; locks of this type are created
when records are removed from the index chain
of records */
#define LOCK_REC_NOT_GAP 1024 /*!< this bit means that the lock is only on
the index record and does NOT block inserts
to the gap before the index record; this is
used in the case when we retrieve a record
with a unique key, and is also used in
locking plain SELECTs (not part of UPDATE
or DELETE) when the user has set the READ
COMMITTED isolation level */
#define LOCK_INSERT_INTENTION 2048 /*!< this bit is set when we place a waiting
gap type record lock request in order to let
an insert of an index record to wait until
there are no conflicting locks by other
transactions on the gap; note that this flag
remains set when the waiting lock is granted,
or if the lock is inherited to a neighboring
record */
#define LOCK_CONV_BY_OTHER 4096 /*!< this bit is set when the lock is created
by other transaction */
#if (LOCK_WAIT|LOCK_GAP|LOCK_REC_NOT_GAP|LOCK_INSERT_INTENTION|LOCK_CONV_BY_OTHER)&LOCK_MODE_MASK
# error
#endif
#if (LOCK_WAIT|LOCK_GAP|LOCK_REC_NOT_GAP|LOCK_INSERT_INTENTION|LOCK_CONV_BY_OTHER)&LOCK_TYPE_MASK
# error
#endif
/* @} */
/** Checks if this is a waiting lock created by lock->trx itself.
@param type_mode lock->type_mode
@return whether it is a waiting lock belonging to lock->trx */
#define lock_is_wait_not_by_other(type_mode) \
((type_mode & (LOCK_CONV_BY_OTHER | LOCK_WAIT)) == LOCK_WAIT)
/** Lock operation struct */
typedef struct lock_op_struct lock_op_t;
/** Lock operation struct */
struct lock_op_struct{
dict_table_t* table; /*!< table to be locked */
enum lock_mode mode; /*!< lock mode */
};
/** The lock system struct */
struct lock_sys_struct{
mutex_t mutex; /*!< Mutex protecting the
locks */
hash_table_t* rec_hash; /*!< hash table of the record
locks */
mutex_t wait_mutex; /*!< Mutex protecting the
next two fields */
srv_slot_t* waiting_threads; /*!< Array of user threads
suspended while waiting for
locks within InnoDB, protected
by the lock_sys->wait_mutex */
srv_slot_t* last_slot; /*!< highest slot ever used
in the waiting_threads array,
protected by
lock_sys->wait_mutex */
ibool rollback_complete;
/*!< TRUE if rollback of all
recovered transactions is
complete. Protected by
lock_sys->mutex */
};
/** The lock system */
extern lock_sys_t* lock_sys;
/** Test if lock_sys->mutex can be acquired without waiting. */
#define lock_mutex_enter_nowait() mutex_enter_nowait(&lock_sys->mutex)
/** Test if lock_sys->mutex is owned. */
#define lock_mutex_own() mutex_own(&lock_sys->mutex)
/** Acquire the lock_sys->mutex. */
#define lock_mutex_enter() do { \
mutex_enter(&lock_sys->mutex); \
} while (0)
/** Release the lock_sys->mutex. */
#define lock_mutex_exit() do { \
mutex_exit(&lock_sys->mutex); \
} while (0)
/** Test if lock_sys->wait_mutex is owned. */
#define lock_wait_mutex_own() mutex_own(&lock_sys->wait_mutex)
/** Acquire the lock_sys->wait_mutex. */
#define lock_wait_mutex_enter() do { \
mutex_enter(&lock_sys->wait_mutex); \
} while (0)
/** Release the lock_sys->wait_mutex. */
#define lock_wait_mutex_exit() do { \
mutex_exit(&lock_sys->wait_mutex); \
} while (0)
// FIXME: Move these to lock_sys_t
extern ibool srv_lock_timeout_active;
extern ulint srv_n_lock_wait_count;
extern ulint srv_n_lock_wait_current_count;
extern ib_int64_t srv_n_lock_wait_time;
extern ulint srv_n_lock_max_wait_time;
extern os_event_t srv_lock_timeout_thread_event;
#ifndef UNIV_NONINL
#include "lock0lock.ic"
#endif
#endif
|