aboutsummaryrefslogtreecommitdiff
path: root/gdb/thread.c
blob: 7bc5271fedd1369c5efa4c10e7374f443f959b08 (plain)
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
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
/* Multi-process/thread control for GDB, the GNU debugger.

   Copyright (C) 1986-2014 Free Software Foundation, Inc.

   Contributed by Lynx Real-Time Systems, Inc.  Los Gatos, CA.

   This file is part of GDB.

   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 3 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, see <http://www.gnu.org/licenses/>.  */

#include "defs.h"
#include "symtab.h"
#include "frame.h"
#include "inferior.h"
#include "environ.h"
#include "value.h"
#include "target.h"
#include "gdbthread.h"
#include "exceptions.h"
#include "command.h"
#include "gdbcmd.h"
#include "regcache.h"
#include "gdb.h"
#include <string.h>
#include "btrace.h"

#include <ctype.h>
#include <sys/types.h>
#include <signal.h>
#include "ui-out.h"
#include "observer.h"
#include "annotate.h"
#include "cli/cli-decode.h"
#include "gdb_regex.h"
#include "cli/cli-utils.h"
#include "continuations.h"

/* Definition of struct thread_info exported to gdbthread.h.  */

/* Prototypes for exported functions.  */

void _initialize_thread (void);

/* Prototypes for local functions.  */

struct thread_info *thread_list = NULL;
static int highest_thread_num;

static void thread_command (char *tidstr, int from_tty);
static void thread_apply_all_command (char *, int);
static int thread_alive (struct thread_info *);
static void info_threads_command (char *, int);
static void thread_apply_command (char *, int);
static void restore_current_thread (ptid_t);
static void prune_threads (void);

/* Data to cleanup thread array.  */

struct thread_array_cleanup
{
  /* Array of thread pointers used to set
     reference count.  */
  struct thread_info **tp_array;

  /* Thread count in the array.  */
  int count;
};


struct thread_info*
inferior_thread (void)
{
  struct thread_info *tp = find_thread_ptid (inferior_ptid);
  gdb_assert (tp);
  return tp;
}

void
delete_step_resume_breakpoint (struct thread_info *tp)
{
  if (tp && tp->control.step_resume_breakpoint)
    {
      delete_breakpoint (tp->control.step_resume_breakpoint);
      tp->control.step_resume_breakpoint = NULL;
    }
}

void
delete_exception_resume_breakpoint (struct thread_info *tp)
{
  if (tp && tp->control.exception_resume_breakpoint)
    {
      delete_breakpoint (tp->control.exception_resume_breakpoint);
      tp->control.exception_resume_breakpoint = NULL;
    }
}

static void
clear_thread_inferior_resources (struct thread_info *tp)
{
  /* NOTE: this will take care of any left-over step_resume breakpoints,
     but not any user-specified thread-specific breakpoints.  We can not
     delete the breakpoint straight-off, because the inferior might not
     be stopped at the moment.  */
  if (tp->control.step_resume_breakpoint)
    {
      tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
      tp->control.step_resume_breakpoint = NULL;
    }

  if (tp->control.exception_resume_breakpoint)
    {
      tp->control.exception_resume_breakpoint->disposition
	= disp_del_at_next_stop;
      tp->control.exception_resume_breakpoint = NULL;
    }

  delete_longjmp_breakpoint_at_next_stop (tp->num);

  bpstat_clear (&tp->control.stop_bpstat);

  btrace_teardown (tp);

  do_all_intermediate_continuations_thread (tp, 1);
  do_all_continuations_thread (tp, 1);
}

static void
free_thread (struct thread_info *tp)
{
  if (tp->private)
    {
      if (tp->private_dtor)
	tp->private_dtor (tp->private);
      else
	xfree (tp->private);
    }

  xfree (tp->name);
  xfree (tp);
}

void
init_thread_list (void)
{
  struct thread_info *tp, *tpnext;

  highest_thread_num = 0;

  if (!thread_list)
    return;

  for (tp = thread_list; tp; tp = tpnext)
    {
      tpnext = tp->next;
      free_thread (tp);
    }

  thread_list = NULL;
}

/* Allocate a new thread with target id PTID and add it to the thread
   list.  */

static struct thread_info *
new_thread (ptid_t ptid)
{
  struct thread_info *tp;

  tp = xcalloc (1, sizeof (*tp));

  tp->ptid = ptid;
  tp->num = ++highest_thread_num;
  tp->next = thread_list;
  thread_list = tp;

  /* Nothing to follow yet.  */
  tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
  tp->state = THREAD_STOPPED;

  return tp;
}

struct thread_info *
add_thread_silent (ptid_t ptid)
{
  struct thread_info *tp;

  tp = find_thread_ptid (ptid);
  if (tp)
    /* Found an old thread with the same id.  It has to be dead,
       otherwise we wouldn't be adding a new thread with the same id.
       The OS is reusing this id --- delete it, and recreate a new
       one.  */
    {
      /* In addition to deleting the thread, if this is the current
	 thread, then we need to take care that delete_thread doesn't
	 really delete the thread if it is inferior_ptid.  Create a
	 new template thread in the list with an invalid ptid, switch
	 to it, delete the original thread, reset the new thread's
	 ptid, and switch to it.  */

      if (ptid_equal (inferior_ptid, ptid))
	{
	  tp = new_thread (null_ptid);

	  /* Make switch_to_thread not read from the thread.  */
	  tp->state = THREAD_EXITED;
	  switch_to_thread (null_ptid);

	  /* Now we can delete it.  */
	  delete_thread (ptid);

	  /* Now reset its ptid, and reswitch inferior_ptid to it.  */
	  tp->ptid = ptid;
	  tp->state = THREAD_STOPPED;
	  switch_to_thread (ptid);

	  observer_notify_new_thread (tp);

	  /* All done.  */
	  return tp;
	}
      else
	/* Just go ahead and delete it.  */
	delete_thread (ptid);
    }

  tp = new_thread (ptid);
  observer_notify_new_thread (tp);

  return tp;
}

struct thread_info *
add_thread_with_info (ptid_t ptid, struct private_thread_info *private)
{
  struct thread_info *result = add_thread_silent (ptid);

  result->private = private;

  if (print_thread_events)
    printf_unfiltered (_("[New %s]\n"), target_pid_to_str (ptid));

  annotate_new_thread ();
  return result;
}

struct thread_info *
add_thread (ptid_t ptid)
{
  return add_thread_with_info (ptid, NULL);
}

/* Delete thread PTID.  If SILENT, don't notify the observer of this
   exit.  */
static void
delete_thread_1 (ptid_t ptid, int silent)
{
  struct thread_info *tp, *tpprev;

  tpprev = NULL;

  for (tp = thread_list; tp; tpprev = tp, tp = tp->next)
    if (ptid_equal (tp->ptid, ptid))
      break;

  if (!tp)
    return;

  /* If this is the current thread, or there's code out there that
     relies on it existing (refcount > 0) we can't delete yet.  Mark
     it as exited, and notify it.  */
  if (tp->refcount > 0
      || ptid_equal (tp->ptid, inferior_ptid))
    {
      if (tp->state != THREAD_EXITED)
	{
	  observer_notify_thread_exit (tp, silent);

	  /* Tag it as exited.  */
	  tp->state = THREAD_EXITED;

	  /* Clear breakpoints, etc. associated with this thread.  */
	  clear_thread_inferior_resources (tp);
	}

       /* Will be really deleted some other time.  */
       return;
     }

  /* Notify thread exit, but only if we haven't already.  */
  if (tp->state != THREAD_EXITED)
    observer_notify_thread_exit (tp, silent);

  /* Tag it as exited.  */
  tp->state = THREAD_EXITED;
  clear_thread_inferior_resources (tp);

  if (tpprev)
    tpprev->next = tp->next;
  else
    thread_list = tp->next;

  free_thread (tp);
}

/* Delete thread PTID and notify of thread exit.  If this is
   inferior_ptid, don't actually delete it, but tag it as exited and
   do the notification.  If PTID is the user selected thread, clear
   it.  */
void
delete_thread (ptid_t ptid)
{
  delete_thread_1 (ptid, 0 /* not silent */);
}

void
delete_thread_silent (ptid_t ptid)
{
  delete_thread_1 (ptid, 1 /* silent */);
}

struct thread_info *
find_thread_id (int num)
{
  struct thread_info *tp;

  for (tp = thread_list; tp; tp = tp->next)
    if (tp->num == num)
      return tp;

  return NULL;
}

/* Find a thread_info by matching PTID.  */
struct thread_info *
find_thread_ptid (ptid_t ptid)
{
  struct thread_info *tp;

  for (tp = thread_list; tp; tp = tp->next)
    if (ptid_equal (tp->ptid, ptid))
      return tp;

  return NULL;
}

/*
 * Thread iterator function.
 *
 * Calls a callback function once for each thread, so long as
 * the callback function returns false.  If the callback function
 * returns true, the iteration will end and the current thread
 * will be returned.  This can be useful for implementing a 
 * search for a thread with arbitrary attributes, or for applying
 * some operation to every thread.
 *
 * FIXME: some of the existing functionality, such as 
 * "Thread apply all", might be rewritten using this functionality.
 */

struct thread_info *
iterate_over_threads (int (*callback) (struct thread_info *, void *),
		      void *data)
{
  struct thread_info *tp, *next;

  for (tp = thread_list; tp; tp = next)
    {
      next = tp->next;
      if ((*callback) (tp, data))
	return tp;
    }

  return NULL;
}

int
thread_count (void)
{
  int result = 0;
  struct thread_info *tp;

  for (tp = thread_list; tp; tp = tp->next)
    ++result;

  return result;  
}

int
valid_thread_id (int num)
{
  struct thread_info *tp;

  for (tp = thread_list; tp; tp = tp->next)
    if (tp->num == num)
      return 1;

  return 0;
}

int
pid_to_thread_id (ptid_t ptid)
{
  struct thread_info *tp;

  for (tp = thread_list; tp; tp = tp->next)
    if (ptid_equal (tp->ptid, ptid))
      return tp->num;

  return 0;
}

ptid_t
thread_id_to_pid (int num)
{
  struct thread_info *thread = find_thread_id (num);

  if (thread)
    return thread->ptid;
  else
    return pid_to_ptid (-1);
}

int
in_thread_list (ptid_t ptid)
{
  struct thread_info *tp;

  for (tp = thread_list; tp; tp = tp->next)
    if (ptid_equal (tp->ptid, ptid))
      return 1;

  return 0;			/* Never heard of 'im.  */
}

/* Finds the first thread of the inferior given by PID.  If PID is -1,
   return the first thread in the list.  */

struct thread_info *
first_thread_of_process (int pid)
{
  struct thread_info *tp, *ret = NULL;

  for (tp = thread_list; tp; tp = tp->next)
    if (pid == -1 || ptid_get_pid (tp->ptid) == pid)
      if (ret == NULL || tp->num < ret->num)
	ret = tp;

  return ret;
}

struct thread_info *
any_thread_of_process (int pid)
{
  struct thread_info *tp;

  for (tp = thread_list; tp; tp = tp->next)
    if (ptid_get_pid (tp->ptid) == pid)
      return tp;

  return NULL;
}

struct thread_info *
any_live_thread_of_process (int pid)
{
  struct thread_info *tp;
  struct thread_info *tp_executing = NULL;

  for (tp = thread_list; tp; tp = tp->next)
    if (tp->state != THREAD_EXITED && ptid_get_pid (tp->ptid) == pid)
      {
	if (tp->executing)
	  tp_executing = tp;
	else
	  return tp;
      }

  return tp_executing;
}

/* Print a list of thread ids currently known, and the total number of
   threads.  To be used from within catch_errors.  */
static int
do_captured_list_thread_ids (struct ui_out *uiout, void *arg)
{
  struct thread_info *tp;
  int num = 0;
  struct cleanup *cleanup_chain;
  int current_thread = -1;

  update_thread_list ();

  cleanup_chain = make_cleanup_ui_out_tuple_begin_end (uiout, "thread-ids");

  for (tp = thread_list; tp; tp = tp->next)
    {
      if (tp->state == THREAD_EXITED)
	continue;

      if (ptid_equal (tp->ptid, inferior_ptid))
	current_thread = tp->num;

      num++;
      ui_out_field_int (uiout, "thread-id", tp->num);
    }

  do_cleanups (cleanup_chain);

  if (current_thread != -1)
    ui_out_field_int (uiout, "current-thread-id", current_thread);
  ui_out_field_int (uiout, "number-of-threads", num);
  return GDB_RC_OK;
}

/* Official gdblib interface function to get a list of thread ids and
   the total number.  */
enum gdb_rc
gdb_list_thread_ids (struct ui_out *uiout, char **error_message)
{
  if (catch_exceptions_with_msg (uiout, do_captured_list_thread_ids, NULL,
				 error_message, RETURN_MASK_ALL) < 0)
    return GDB_RC_FAIL;
  return GDB_RC_OK;
}

/* Return true if TP is an active thread.  */
static int
thread_alive (struct thread_info *tp)
{
  if (tp->state == THREAD_EXITED)
    return 0;
  if (!target_thread_alive (tp->ptid))
    return 0;
  return 1;
}

static void
prune_threads (void)
{
  struct thread_info *tp, *next;

  for (tp = thread_list; tp; tp = next)
    {
      next = tp->next;
      if (!thread_alive (tp))
	delete_thread (tp->ptid);
    }
}

void
thread_change_ptid (ptid_t old_ptid, ptid_t new_ptid)
{
  struct inferior *inf;
  struct thread_info *tp;

  /* It can happen that what we knew as the target inferior id
     changes.  E.g, target remote may only discover the remote process
     pid after adding the inferior to GDB's list.  */
  inf = find_inferior_pid (ptid_get_pid (old_ptid));
  inf->pid = ptid_get_pid (new_ptid);

  tp = find_thread_ptid (old_ptid);
  tp->ptid = new_ptid;

  observer_notify_thread_ptid_changed (old_ptid, new_ptid);
}

void
set_running (ptid_t ptid, int running)
{
  struct thread_info *tp;
  int all = ptid_equal (ptid, minus_one_ptid);

  /* We try not to notify the observer if no thread has actually changed 
     the running state -- merely to reduce the number of messages to 
     frontend.  Frontend is supposed to handle multiple *running just fine.  */
  if (all || ptid_is_pid (ptid))
    {
      int any_started = 0;

      for (tp = thread_list; tp; tp = tp->next)
	if (all || ptid_get_pid (tp->ptid) == ptid_get_pid (ptid))
	  {
	    if (tp->state == THREAD_EXITED)
	      continue;
	    if (running && tp->state == THREAD_STOPPED)
	      any_started = 1;
	    tp->state = running ? THREAD_RUNNING : THREAD_STOPPED;
	  }
      if (any_started)
	observer_notify_target_resumed (ptid);
    }
  else
    {
      int started = 0;

      tp = find_thread_ptid (ptid);
      gdb_assert (tp);
      gdb_assert (tp->state != THREAD_EXITED);
      if (running && tp->state == THREAD_STOPPED)
 	started = 1;
      tp->state = running ? THREAD_RUNNING : THREAD_STOPPED;
      if (started)
  	observer_notify_target_resumed (ptid);
    }
}

static int
is_thread_state (ptid_t ptid, enum thread_state state)
{
  struct thread_info *tp;

  tp = find_thread_ptid (ptid);
  gdb_assert (tp);
  return tp->state == state;
}

int
is_stopped (ptid_t ptid)
{
  return is_thread_state (ptid, THREAD_STOPPED);
}

int
is_exited (ptid_t ptid)
{
  return is_thread_state (ptid, THREAD_EXITED);
}

int
is_running (ptid_t ptid)
{
  return is_thread_state (ptid, THREAD_RUNNING);
}

int
any_running (void)
{
  struct thread_info *tp;

  for (tp = thread_list; tp; tp = tp->next)
    if (tp->state == THREAD_RUNNING)
      return 1;

  return 0;
}

int
is_executing (ptid_t ptid)
{
  struct thread_info *tp;

  tp = find_thread_ptid (ptid);
  gdb_assert (tp);
  return tp->executing;
}

void
set_executing (ptid_t ptid, int executing)
{
  struct thread_info *tp;
  int all = ptid_equal (ptid, minus_one_ptid);

  if (all || ptid_is_pid (ptid))
    {
      for (tp = thread_list; tp; tp = tp->next)
	if (all || ptid_get_pid (tp->ptid) == ptid_get_pid (ptid))
	  tp->executing = executing;
    }
  else
    {
      tp = find_thread_ptid (ptid);
      gdb_assert (tp);
      tp->executing = executing;
    }
}

void
set_stop_requested (ptid_t ptid, int stop)
{
  struct thread_info *tp;
  int all = ptid_equal (ptid, minus_one_ptid);

  if (all || ptid_is_pid (ptid))
    {
      for (tp = thread_list; tp; tp = tp->next)
	if (all || ptid_get_pid (tp->ptid) == ptid_get_pid (ptid))
	  tp->stop_requested = stop;
    }
  else
    {
      tp = find_thread_ptid (ptid);
      gdb_assert (tp);
      tp->stop_requested = stop;
    }

  /* Call the stop requested observer so other components of GDB can
     react to this request.  */
  if (stop)
    observer_notify_thread_stop_requested (ptid);
}

void
finish_thread_state (ptid_t ptid)
{
  struct thread_info *tp;
  int all;
  int any_started = 0;

  all = ptid_equal (ptid, minus_one_ptid);

  if (all || ptid_is_pid (ptid))
    {
      for (tp = thread_list; tp; tp = tp->next)
	{
 	  if (tp->state == THREAD_EXITED)
  	    continue;
	  if (all || ptid_get_pid (ptid) == ptid_get_pid (tp->ptid))
	    {
	      if (tp->executing && tp->state == THREAD_STOPPED)
		any_started = 1;
	      tp->state = tp->executing ? THREAD_RUNNING : THREAD_STOPPED;
	    }
	}
    }
  else
    {
      tp = find_thread_ptid (ptid);
      gdb_assert (tp);
      if (tp->state != THREAD_EXITED)
	{
	  if (tp->executing && tp->state == THREAD_STOPPED)
	    any_started = 1;
	  tp->state = tp->executing ? THREAD_RUNNING : THREAD_STOPPED;
	}
    }

  if (any_started)
    observer_notify_target_resumed (ptid);
}

void
finish_thread_state_cleanup (void *arg)
{
  ptid_t *ptid_p = arg;

  gdb_assert (arg);

  finish_thread_state (*ptid_p);
}

int
pc_in_thread_step_range (CORE_ADDR pc, struct thread_info *thread)
{
  return (pc >= thread->control.step_range_start
	  && pc < thread->control.step_range_end);
}

/* Prints the list of threads and their details on UIOUT.
   This is a version of 'info_threads_command' suitable for
   use from MI.
   If REQUESTED_THREAD is not -1, it's the GDB id of the thread
   that should be printed.  Otherwise, all threads are
   printed.
   If PID is not -1, only print threads from the process PID.
   Otherwise, threads from all attached PIDs are printed.
   If both REQUESTED_THREAD and PID are not -1, then the thread
   is printed if it belongs to the specified process.  Otherwise,
   an error is raised.  */
void
print_thread_info (struct ui_out *uiout, char *requested_threads, int pid)
{
  struct thread_info *tp;
  ptid_t current_ptid;
  struct cleanup *old_chain;
  char *extra_info, *name, *target_id;
  int current_thread = -1;

  update_thread_list ();
  current_ptid = inferior_ptid;

  /* We'll be switching threads temporarily.  */
  old_chain = make_cleanup_restore_current_thread ();

  /* For backward compatibility, we make a list for MI.  A table is
     preferable for the CLI, though, because it shows table
     headers.  */
  if (ui_out_is_mi_like_p (uiout))
    make_cleanup_ui_out_list_begin_end (uiout, "threads");
  else
    {
      int n_threads = 0;

      for (tp = thread_list; tp; tp = tp->next)
	{
	  if (!number_is_in_list (requested_threads, tp->num))
	    continue;

	  if (pid != -1 && ptid_get_pid (tp->ptid) != pid)
	    continue;

	  if (tp->state == THREAD_EXITED)
	    continue;

	  ++n_threads;
	}

      if (n_threads == 0)
	{
	  if (requested_threads == NULL || *requested_threads == '\0')
	    ui_out_message (uiout, 0, _("No threads.\n"));
	  else
	    ui_out_message (uiout, 0, _("No threads match '%s'.\n"),
			    requested_threads);
	  do_cleanups (old_chain);
	  return;
	}

      make_cleanup_ui_out_table_begin_end (uiout, 4, n_threads, "threads");

      ui_out_table_header (uiout, 1, ui_left, "current", "");
      ui_out_table_header (uiout, 4, ui_left, "id", "Id");
      ui_out_table_header (uiout, 17, ui_left, "target-id", "Target Id");
      ui_out_table_header (uiout, 1, ui_left, "frame", "Frame");
      ui_out_table_body (uiout);
    }

  for (tp = thread_list; tp; tp = tp->next)
    {
      struct cleanup *chain2;
      int core;

      if (!number_is_in_list (requested_threads, tp->num))
	continue;

      if (pid != -1 && ptid_get_pid (tp->ptid) != pid)
	{
	  if (requested_threads != NULL && *requested_threads != '\0')
	    error (_("Requested thread not found in requested process"));
	  continue;
	}

      if (ptid_equal (tp->ptid, current_ptid))
	current_thread = tp->num;

      if (tp->state == THREAD_EXITED)
	continue;

      chain2 = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);

      if (ui_out_is_mi_like_p (uiout))
	{
	  /* Compatibility.  */
	  if (ptid_equal (tp->ptid, current_ptid))
	    ui_out_text (uiout, "* ");
	  else
	    ui_out_text (uiout, "  ");
	}
      else
	{
	  if (ptid_equal (tp->ptid, current_ptid))
	    ui_out_field_string (uiout, "current", "*");
	  else
	    ui_out_field_skip (uiout, "current");
	}

      ui_out_field_int (uiout, "id", tp->num);

      /* For the CLI, we stuff everything into the target-id field.
	 This is a gross hack to make the output come out looking
	 correct.  The underlying problem here is that ui-out has no
	 way to specify that a field's space allocation should be
	 shared by several fields.  For MI, we do the right thing
	 instead.  */

      target_id = target_pid_to_str (tp->ptid);
      extra_info = target_extra_thread_info (tp);
      name = tp->name ? tp->name : target_thread_name (tp);

      if (ui_out_is_mi_like_p (uiout))
	{
	  ui_out_field_string (uiout, "target-id", target_id);
	  if (extra_info)
	    ui_out_field_string (uiout, "details", extra_info);
	  if (name)
	    ui_out_field_string (uiout, "name", name);
	}
      else
	{
	  struct cleanup *str_cleanup;
	  char *contents;

	  if (extra_info && name)
	    contents = xstrprintf ("%s \"%s\" (%s)", target_id,
				   name, extra_info);
	  else if (extra_info)
	    contents = xstrprintf ("%s (%s)", target_id, extra_info);
	  else if (name)
	    contents = xstrprintf ("%s \"%s\"", target_id, name);
	  else
	    contents = xstrdup (target_id);
	  str_cleanup = make_cleanup (xfree, contents);

	  ui_out_field_string (uiout, "target-id", contents);
	  do_cleanups (str_cleanup);
	}

      if (tp->state == THREAD_RUNNING)
	ui_out_text (uiout, "(running)\n");
      else
	{
	  /* The switch below puts us at the top of the stack (leaf
	     frame).  */
	  switch_to_thread (tp->ptid);
	  print_stack_frame (get_selected_frame (NULL),
			     /* For MI output, print frame level.  */
			     ui_out_is_mi_like_p (uiout),
			     LOCATION, 0);
	}

      if (ui_out_is_mi_like_p (uiout))
	{
	  char *state = "stopped";

	  if (tp->state == THREAD_RUNNING)
	    state = "running";
	  ui_out_field_string (uiout, "state", state);
	}

      core = target_core_of_thread (tp->ptid);
      if (ui_out_is_mi_like_p (uiout) && core != -1)
	ui_out_field_int (uiout, "core", core);

      do_cleanups (chain2);
    }

  /* Restores the current thread and the frame selected before
     the "info threads" command.  */
  do_cleanups (old_chain);

  if (pid == -1 && requested_threads == NULL)
    {
      gdb_assert (current_thread != -1
		  || !thread_list
		  || ptid_equal (inferior_ptid, null_ptid));
      if (current_thread != -1 && ui_out_is_mi_like_p (uiout))
	ui_out_field_int (uiout, "current-thread-id", current_thread);

      if (current_thread != -1 && is_exited (current_ptid))
	ui_out_message (uiout, 0, "\n\
The current thread <Thread ID %d> has terminated.  See `help thread'.\n",
			current_thread);
      else if (thread_list
	       && current_thread == -1
	       && ptid_equal (current_ptid, null_ptid))
	ui_out_message (uiout, 0, "\n\
No selected thread.  See `help thread'.\n");
    }
}

/* Print information about currently known threads 

   Optional ARG is a thread id, or list of thread ids.

   Note: this has the drawback that it _really_ switches
         threads, which frees the frame cache.  A no-side
         effects info-threads command would be nicer.  */

static void
info_threads_command (char *arg, int from_tty)
{
  print_thread_info (current_uiout, arg, -1);
}

/* Switch from one thread to another.  */

void
switch_to_thread (ptid_t ptid)
{
  /* Switch the program space as well, if we can infer it from the now
     current thread.  Otherwise, it's up to the caller to select the
     space it wants.  */
  if (!ptid_equal (ptid, null_ptid))
    {
      struct inferior *inf;

      inf = find_inferior_pid (ptid_get_pid (ptid));
      gdb_assert (inf != NULL);
      set_current_program_space (inf->pspace);
      set_current_inferior (inf);
    }

  if (ptid_equal (ptid, inferior_ptid))
    return;

  inferior_ptid = ptid;
  reinit_frame_cache ();

  /* We don't check for is_stopped, because we're called at times
     while in the TARGET_RUNNING state, e.g., while handling an
     internal event.  */
  if (!ptid_equal (inferior_ptid, null_ptid)
      && !is_exited (ptid)
      && !is_executing (ptid))
    stop_pc = regcache_read_pc (get_thread_regcache (ptid));
  else
    stop_pc = ~(CORE_ADDR) 0;
}

static void
restore_current_thread (ptid_t ptid)
{
  switch_to_thread (ptid);
}

static void
restore_selected_frame (struct frame_id a_frame_id, int frame_level)
{
  struct frame_info *frame = NULL;
  int count;

  /* This means there was no selected frame.  */
  if (frame_level == -1)
    {
      select_frame (NULL);
      return;
    }

  gdb_assert (frame_level >= 0);

  /* Restore by level first, check if the frame id is the same as
     expected.  If that fails, try restoring by frame id.  If that
     fails, nothing to do, just warn the user.  */

  count = frame_level;
  frame = find_relative_frame (get_current_frame (), &count);
  if (count == 0
      && frame != NULL
      /* The frame ids must match - either both valid or both outer_frame_id.
	 The latter case is not failsafe, but since it's highly unlikely
	 the search by level finds the wrong frame, it's 99.9(9)% of
	 the time (for all practical purposes) safe.  */
      && frame_id_eq (get_frame_id (frame), a_frame_id))
    {
      /* Cool, all is fine.  */
      select_frame (frame);
      return;
    }

  frame = frame_find_by_id (a_frame_id);
  if (frame != NULL)
    {
      /* Cool, refound it.  */
      select_frame (frame);
      return;
    }

  /* Nothing else to do, the frame layout really changed.  Select the
     innermost stack frame.  */
  select_frame (get_current_frame ());

  /* Warn the user.  */
  if (frame_level > 0 && !ui_out_is_mi_like_p (current_uiout))
    {
      warning (_("Couldn't restore frame #%d in "
		 "current thread.  Bottom (innermost) frame selected:"),
	       frame_level);
      /* For MI, we should probably have a notification about
	 current frame change.  But this error is not very
	 likely, so don't bother for now.  */
      print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC, 1);
    }
}

struct current_thread_cleanup
{
  ptid_t inferior_ptid;
  struct frame_id selected_frame_id;
  int selected_frame_level;
  int was_stopped;
  int inf_id;
  int was_removable;
};

static void
do_restore_current_thread_cleanup (void *arg)
{
  struct thread_info *tp;
  struct current_thread_cleanup *old = arg;

  tp = find_thread_ptid (old->inferior_ptid);

  /* If the previously selected thread belonged to a process that has
     in the mean time been deleted (due to normal exit, detach, etc.),
     then don't revert back to it, but instead simply drop back to no
     thread selected.  */
  if (tp
      && find_inferior_pid (ptid_get_pid (tp->ptid)) != NULL)
    restore_current_thread (old->inferior_ptid);
  else
    {
      restore_current_thread (null_ptid);
      set_current_inferior (find_inferior_id (old->inf_id));
    }

  /* The running state of the originally selected thread may have
     changed, so we have to recheck it here.  */
  if (!ptid_equal (inferior_ptid, null_ptid)
      && old->was_stopped
      && is_stopped (inferior_ptid)
      && target_has_registers
      && target_has_stack
      && target_has_memory)
    restore_selected_frame (old->selected_frame_id,
			    old->selected_frame_level);
}

static void
restore_current_thread_cleanup_dtor (void *arg)
{
  struct current_thread_cleanup *old = arg;
  struct thread_info *tp;
  struct inferior *inf;

  tp = find_thread_ptid (old->inferior_ptid);
  if (tp)
    tp->refcount--;
  inf = find_inferior_id (old->inf_id);
  if (inf != NULL)
    inf->removable = old->was_removable;
  xfree (old);
}

/* Set the thread reference count.  */

static void
set_thread_refcount (void *data)
{
  int k;
  struct thread_array_cleanup *ta_cleanup = data;

  for (k = 0; k != ta_cleanup->count; k++)
    ta_cleanup->tp_array[k]->refcount--;
}

struct cleanup *
make_cleanup_restore_current_thread (void)
{
  struct thread_info *tp;
  struct frame_info *frame;
  struct current_thread_cleanup *old;

  old = xmalloc (sizeof (struct current_thread_cleanup));
  old->inferior_ptid = inferior_ptid;
  old->inf_id = current_inferior ()->num;
  old->was_removable = current_inferior ()->removable;

  if (!ptid_equal (inferior_ptid, null_ptid))
    {
      old->was_stopped = is_stopped (inferior_ptid);
      if (old->was_stopped
	  && target_has_registers
	  && target_has_stack
	  && target_has_memory)
	{
	  /* When processing internal events, there might not be a
	     selected frame.  If we naively call get_selected_frame
	     here, then we can end up reading debuginfo for the
	     current frame, but we don't generally need the debuginfo
	     at this point.  */
	  frame = get_selected_frame_if_set ();
	}
      else
	frame = NULL;

      old->selected_frame_id = get_frame_id (frame);
      old->selected_frame_level = frame_relative_level (frame);

      tp = find_thread_ptid (inferior_ptid);
      if (tp)
	tp->refcount++;
    }

  current_inferior ()->removable = 0;

  return make_cleanup_dtor (do_restore_current_thread_cleanup, old,
			    restore_current_thread_cleanup_dtor);
}

/* Apply a GDB command to a list of threads.  List syntax is a whitespace
   seperated list of numbers, or ranges, or the keyword `all'.  Ranges consist
   of two numbers seperated by a hyphen.  Examples:

   thread apply 1 2 7 4 backtrace       Apply backtrace cmd to threads 1,2,7,4
   thread apply 2-7 9 p foo(1)  Apply p foo(1) cmd to threads 2->7 & 9
   thread apply all p x/i $pc   Apply x/i $pc cmd to all threads.  */

static void
thread_apply_all_command (char *cmd, int from_tty)
{
  struct cleanup *old_chain;
  char *saved_cmd;
  int tc;
  struct thread_array_cleanup ta_cleanup;

  if (cmd == NULL || *cmd == '\000')
    error (_("Please specify a command following the thread ID list"));

  update_thread_list ();

  old_chain = make_cleanup_restore_current_thread ();

  /* Save a copy of the command in case it is clobbered by
     execute_command.  */
  saved_cmd = xstrdup (cmd);
  make_cleanup (xfree, saved_cmd);
  tc = thread_count ();

  if (tc)
    {
      struct thread_info **tp_array;
      struct thread_info *tp;
      int i = 0, k;

      /* Save a copy of the thread_list in case we execute detach
         command.  */
      tp_array = xmalloc (sizeof (struct thread_info *) * tc);
      make_cleanup (xfree, tp_array);
      ta_cleanup.tp_array = tp_array;
      ta_cleanup.count = tc;

      ALL_THREADS (tp)
        {
          tp_array[i] = tp;
          tp->refcount++;
          i++;
        }

      make_cleanup (set_thread_refcount, &ta_cleanup);

      for (k = 0; k != i; k++)
        if (thread_alive (tp_array[k]))
          {
            switch_to_thread (tp_array[k]->ptid);
            printf_filtered (_("\nThread %d (%s):\n"), 
			     tp_array[k]->num,
			     target_pid_to_str (inferior_ptid));
            execute_command (cmd, from_tty);

            /* Restore exact command used previously.  */
            strcpy (cmd, saved_cmd);
	  }
    }

  do_cleanups (old_chain);
}

static void
thread_apply_command (char *tidlist, int from_tty)
{
  char *cmd;
  struct cleanup *old_chain;
  char *saved_cmd;
  struct get_number_or_range_state state;

  if (tidlist == NULL || *tidlist == '\000')
    error (_("Please specify a thread ID list"));

  for (cmd = tidlist; *cmd != '\000' && !isalpha (*cmd); cmd++);

  if (*cmd == '\000')
    error (_("Please specify a command following the thread ID list"));

  /* Save a copy of the command in case it is clobbered by
     execute_command.  */
  saved_cmd = xstrdup (cmd);
  old_chain = make_cleanup (xfree, saved_cmd);

  init_number_or_range (&state, tidlist);
  while (!state.finished && state.string < cmd)
    {
      struct thread_info *tp;
      int start;

      start = get_number_or_range (&state);

      make_cleanup_restore_current_thread ();

      tp = find_thread_id (start);

      if (!tp)
	warning (_("Unknown thread %d."), start);
      else if (!thread_alive (tp))
	warning (_("Thread %d has terminated."), start);
      else
	{
	  switch_to_thread (tp->ptid);

	  printf_filtered (_("\nThread %d (%s):\n"), tp->num,
			   target_pid_to_str (inferior_ptid));
	  execute_command (cmd, from_tty);

	  /* Restore exact command used previously.  */
	  strcpy (cmd, saved_cmd);
	}
    }

  do_cleanups (old_chain);
}

/* Switch to the specified thread.  Will dispatch off to thread_apply_command
   if prefix of arg is `apply'.  */

static void
thread_command (char *tidstr, int from_tty)
{
  if (!tidstr)
    {
      if (ptid_equal (inferior_ptid, null_ptid))
	error (_("No thread selected"));

      if (target_has_stack)
	{
	  if (is_exited (inferior_ptid))
	    printf_filtered (_("[Current thread is %d (%s) (exited)]\n"),
			     pid_to_thread_id (inferior_ptid),
			     target_pid_to_str (inferior_ptid));
	  else
	    printf_filtered (_("[Current thread is %d (%s)]\n"),
			     pid_to_thread_id (inferior_ptid),
			     target_pid_to_str (inferior_ptid));
	}
      else
	error (_("No stack."));
      return;
    }

  gdb_thread_select (current_uiout, tidstr, NULL);
}

/* Implementation of `thread name'.  */

static void
thread_name_command (char *arg, int from_tty)
{
  struct thread_info *info;

  if (ptid_equal (inferior_ptid, null_ptid))
    error (_("No thread selected"));

  arg = skip_spaces (arg);

  info = inferior_thread ();
  xfree (info->name);
  info->name = arg ? xstrdup (arg) : NULL;
}

/* Find thread ids with a name, target pid, or extra info matching ARG.  */

static void
thread_find_command (char *arg, int from_tty)
{
  struct thread_info *tp;
  char *tmp;
  unsigned long match = 0;

  if (arg == NULL || *arg == '\0')
    error (_("Command requires an argument."));

  tmp = re_comp (arg);
  if (tmp != 0)
    error (_("Invalid regexp (%s): %s"), tmp, arg);

  update_thread_list ();
  for (tp = thread_list; tp; tp = tp->next)
    {
      if (tp->name != NULL && re_exec (tp->name))
	{
	  printf_filtered (_("Thread %d has name '%s'\n"),
			   tp->num, tp->name);
	  match++;
	}

      tmp = target_thread_name (tp);
      if (tmp != NULL && re_exec (tmp))
	{
	  printf_filtered (_("Thread %d has target name '%s'\n"),
			   tp->num, tmp);
	  match++;
	}

      tmp = target_pid_to_str (tp->ptid);
      if (tmp != NULL && re_exec (tmp))
	{
	  printf_filtered (_("Thread %d has target id '%s'\n"),
			   tp->num, tmp);
	  match++;
	}

      tmp = target_extra_thread_info (tp);
      if (tmp != NULL && re_exec (tmp))
	{
	  printf_filtered (_("Thread %d has extra info '%s'\n"),
			   tp->num, tmp);
	  match++;
	}
    }
  if (!match)
    printf_filtered (_("No threads match '%s'\n"), arg);
}

/* Print notices when new threads are attached and detached.  */
int print_thread_events = 1;
static void
show_print_thread_events (struct ui_file *file, int from_tty,
                          struct cmd_list_element *c, const char *value)
{
  fprintf_filtered (file,
		    _("Printing of thread events is %s.\n"),
                    value);
}

static int
do_captured_thread_select (struct ui_out *uiout, void *tidstr)
{
  int num;
  struct thread_info *tp;

  num = value_as_long (parse_and_eval (tidstr));

  tp = find_thread_id (num);

  if (!tp)
    error (_("Thread ID %d not known."), num);

  if (!thread_alive (tp))
    error (_("Thread ID %d has terminated."), num);

  switch_to_thread (tp->ptid);

  annotate_thread_changed ();

  ui_out_text (uiout, "[Switching to thread ");
  ui_out_field_int (uiout, "new-thread-id", pid_to_thread_id (inferior_ptid));
  ui_out_text (uiout, " (");
  ui_out_text (uiout, target_pid_to_str (inferior_ptid));
  ui_out_text (uiout, ")]");

  /* Note that we can't reach this with an exited thread, due to the
     thread_alive check above.  */
  if (tp->state == THREAD_RUNNING)
    ui_out_text (uiout, "(running)\n");
  else
    {
      ui_out_text (uiout, "\n");
      print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC, 1);
    }

  /* Since the current thread may have changed, see if there is any
     exited thread we can now delete.  */
  prune_threads ();

  return GDB_RC_OK;
}

enum gdb_rc
gdb_thread_select (struct ui_out *uiout, char *tidstr, char **error_message)
{
  if (catch_exceptions_with_msg (uiout, do_captured_thread_select, tidstr,
				 error_message, RETURN_MASK_ALL) < 0)
    return GDB_RC_FAIL;
  return GDB_RC_OK;
}

void
update_thread_list (void)
{
  prune_threads ();
  target_find_new_threads ();
}

/* Return a new value for the selected thread's id.  Return a value of 0 if
   no thread is selected, or no threads exist.  */

static struct value *
thread_id_make_value (struct gdbarch *gdbarch, struct internalvar *var,
		      void *ignore)
{
  struct thread_info *tp = find_thread_ptid (inferior_ptid);

  return value_from_longest (builtin_type (gdbarch)->builtin_int,
			     (tp ? tp->num : 0));
}

/* Commands with a prefix of `thread'.  */
struct cmd_list_element *thread_cmd_list = NULL;

/* Implementation of `thread' variable.  */

static const struct internalvar_funcs thread_funcs =
{
  thread_id_make_value,
  NULL,
  NULL
};

void
_initialize_thread (void)
{
  static struct cmd_list_element *thread_apply_list = NULL;

  add_info ("threads", info_threads_command, 
	    _("Display currently known threads.\n\
Usage: info threads [ID]...\n\
Optional arguments are thread IDs with spaces between.\n\
If no arguments, all threads are displayed."));

  add_prefix_cmd ("thread", class_run, thread_command, _("\
Use this command to switch between threads.\n\
The new thread ID must be currently known."),
		  &thread_cmd_list, "thread ", 1, &cmdlist);

  add_prefix_cmd ("apply", class_run, thread_apply_command,
		  _("Apply a command to a list of threads."),
		  &thread_apply_list, "thread apply ", 1, &thread_cmd_list);

  add_cmd ("all", class_run, thread_apply_all_command,
	   _("Apply a command to all threads."), &thread_apply_list);

  add_cmd ("name", class_run, thread_name_command,
	   _("Set the current thread's name.\n\
Usage: thread name [NAME]\n\
If NAME is not given, then any existing name is removed."), &thread_cmd_list);

  add_cmd ("find", class_run, thread_find_command, _("\
Find threads that match a regular expression.\n\
Usage: thread find REGEXP\n\
Will display thread ids whose name, target ID, or extra info matches REGEXP."),
	   &thread_cmd_list);

  if (!xdb_commands)
    add_com_alias ("t", "thread", class_run, 1);

  add_setshow_boolean_cmd ("thread-events", no_class,
         &print_thread_events, _("\
Set printing of thread events (such as thread start and exit)."), _("\
Show printing of thread events (such as thread start and exit)."), NULL,
         NULL,
         show_print_thread_events,
         &setprintlist, &showprintlist);

  create_internalvar_type_lazy ("_thread", &thread_funcs, NULL);
}