aboutsummaryrefslogtreecommitdiff
path: root/gdb/thread.c
blob: 249f096b057bf40c6b3d0dc606ce05f5776dd293 (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
/* Multi-process/thread control for GDB, the GNU debugger.

   Copyright 1986, 1987, 1988, 1993, 1994, 1995, 1996, 1997, 1998,
   1999, 2000, 2001, 2002, 2003, 2004 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 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#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 "gdb_string.h"

#include <ctype.h>
#include <sys/types.h>
#include <signal.h>
#include "ui-out.h"

/*#include "lynxos-core.h" */

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

/* Prototypes for exported functions. */

void _initialize_thread (void);

/* Prototypes for local functions. */

static struct thread_info *thread_list = NULL;
static int highest_thread_num;

static struct thread_info *find_thread_id (int 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 switch_to_thread (ptid_t ptid);
static void prune_threads (void);

void
delete_step_resume_breakpoint (void *arg)
{
  struct breakpoint **breakpointp = (struct breakpoint **) arg;
  struct thread_info *tp;

  if (*breakpointp != NULL)
    {
      delete_breakpoint (*breakpointp);
      for (tp = thread_list; tp; tp = tp->next)
	if (tp->step_resume_breakpoint == *breakpointp)
	  tp->step_resume_breakpoint = NULL;

      *breakpointp = NULL;
    }
}

static void
free_thread (struct thread_info *tp)
{
  /* NOTE: this will take care of any left-over step_resume breakpoints,
     but not any user-specified thread-specific breakpoints. */
  if (tp->step_resume_breakpoint)
    delete_breakpoint (tp->step_resume_breakpoint);

  /* FIXME: do I ever need to call the back-end to give it a
     chance at this private data before deleting the thread?  */
  if (tp->private)
    xfree (tp->private);

  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;
}

/* add_thread now returns a pointer to the new thread_info, 
   so that back_ends can initialize their private data.  */

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

  tp = (struct thread_info *) xmalloc (sizeof (*tp));
  memset (tp, 0, sizeof (*tp));
  tp->ptid = ptid;
  tp->num = ++highest_thread_num;
  tp->next = thread_list;
  thread_list = tp;
  return tp;
}

void
delete_thread (ptid_t ptid)
{
  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 (tpprev)
    tpprev->next = tp->next;
  else
    thread_list = tp->next;

  free_thread (tp);
}

static 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_pid (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;

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

  return NULL;
}

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 */
}

/* 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;

  prune_threads ();
  target_find_new_threads ();

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

  for (tp = thread_list; tp; tp = tp->next)
    {
      num++;
      ui_out_field_int (uiout, "thread-id", tp->num);
    }

  do_cleanups (cleanup_chain);
  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)
{
  return catch_exceptions_with_msg (uiout, do_captured_list_thread_ids, NULL,
				    error_message, RETURN_MASK_ALL);
}

/* Load infrun state for the thread PID.  */

void
load_infrun_state (ptid_t ptid,
		   CORE_ADDR *prev_pc,
		   int *trap_expected,
		   struct breakpoint **step_resume_breakpoint,
		   CORE_ADDR *step_range_start,
		   CORE_ADDR *step_range_end,
		   struct frame_id *step_frame_id,
		   int *handling_longjmp,
		   int *another_trap,
		   int *stepping_through_solib_after_catch,
		   bpstat *stepping_through_solib_catchpoints,
		   int *current_line,
		   struct symtab **current_symtab)
{
  struct thread_info *tp;

  /* If we can't find the thread, then we're debugging a single threaded
     process.  No need to do anything in that case.  */
  tp = find_thread_id (pid_to_thread_id (ptid));
  if (tp == NULL)
    return;

  *prev_pc = tp->prev_pc;
  *trap_expected = tp->trap_expected;
  *step_resume_breakpoint = tp->step_resume_breakpoint;
  *step_range_start = tp->step_range_start;
  *step_range_end = tp->step_range_end;
  *step_frame_id = tp->step_frame_id;
  *handling_longjmp = tp->handling_longjmp;
  *another_trap = tp->another_trap;
  *stepping_through_solib_after_catch =
    tp->stepping_through_solib_after_catch;
  *stepping_through_solib_catchpoints =
    tp->stepping_through_solib_catchpoints;
  *current_line = tp->current_line;
  *current_symtab = tp->current_symtab;
}

/* Save infrun state for the thread PID.  */

void
save_infrun_state (ptid_t ptid,
		   CORE_ADDR prev_pc,
		   int trap_expected,
		   struct breakpoint *step_resume_breakpoint,
		   CORE_ADDR step_range_start,
		   CORE_ADDR step_range_end,
		   const struct frame_id *step_frame_id,
		   int handling_longjmp,
		   int another_trap,
		   int stepping_through_solib_after_catch,
		   bpstat stepping_through_solib_catchpoints,
		   int current_line,
		   struct symtab *current_symtab)
{
  struct thread_info *tp;

  /* If we can't find the thread, then we're debugging a single-threaded
     process.  Nothing to do in that case.  */
  tp = find_thread_id (pid_to_thread_id (ptid));
  if (tp == NULL)
    return;

  tp->prev_pc = prev_pc;
  tp->trap_expected = trap_expected;
  tp->step_resume_breakpoint = step_resume_breakpoint;
  tp->step_range_start = step_range_start;
  tp->step_range_end = step_range_end;
  tp->step_frame_id = (*step_frame_id);
  tp->handling_longjmp = handling_longjmp;
  tp->another_trap = another_trap;
  tp->stepping_through_solib_after_catch = stepping_through_solib_after_catch;
  tp->stepping_through_solib_catchpoints = stepping_through_solib_catchpoints;
  tp->current_line = current_line;
  tp->current_symtab = current_symtab;
}

/* Return true if TP is an active thread. */
static int
thread_alive (struct thread_info *tp)
{
  if (PIDGET (tp->ptid) == -1)
    return 0;
  if (!target_thread_alive (tp->ptid))
    {
      tp->ptid = pid_to_ptid (-1);	/* Mark it as dead */
      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);
    }
}

/* Print information about currently known threads 

 * 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)
{
  struct thread_info *tp;
  ptid_t current_ptid;
  struct frame_info *cur_frame;
  struct frame_id saved_frame_id = get_frame_id (get_selected_frame (NULL));
  char *extra_info;

  prune_threads ();
  target_find_new_threads ();
  current_ptid = inferior_ptid;
  for (tp = thread_list; tp; tp = tp->next)
    {
      if (ptid_equal (tp->ptid, current_ptid))
	printf_filtered ("* ");
      else
	printf_filtered ("  ");

      printf_filtered ("%d %s", tp->num, target_tid_to_str (tp->ptid));

      extra_info = target_extra_thread_info (tp);
      if (extra_info)
	printf_filtered (" (%s)", extra_info);
      puts_filtered ("  ");

      switch_to_thread (tp->ptid);
      print_stack_frame (get_selected_frame (NULL), 0, LOCATION);
    }

  switch_to_thread (current_ptid);

  /* Restores the frame set by the user before the "info threads"
     command.  We have finished the info-threads display by switching
     back to the current thread.  That switch has put us at the top of
     the stack (leaf frame).  */
  cur_frame = frame_find_by_id (saved_frame_id);
  if (cur_frame == NULL)
    {
      /* Ooops, can't restore, tell user where we are.  */
      warning (_("Couldn't restore frame in current thread, at frame 0"));
      print_stack_frame (get_selected_frame (NULL), 0, LOCATION);
    }
  else
    {
      select_frame (cur_frame);
      /* re-show current frame. */
      show_stack_frame (cur_frame);
    }
}

/* Switch from one thread to another. */

static void
switch_to_thread (ptid_t ptid)
{
  if (ptid_equal (ptid, inferior_ptid))
    return;

  inferior_ptid = ptid;
  flush_cached_frames ();
  registers_changed ();
  stop_pc = read_pc ();
  select_frame (get_current_frame ());
}

static void
restore_current_thread (ptid_t ptid)
{
  if (!ptid_equal (ptid, inferior_ptid))
    {
      switch_to_thread (ptid);
      print_stack_frame (get_current_frame (), 1, SRC_LINE);
    }
}

struct current_thread_cleanup
{
  ptid_t inferior_ptid;
};

static void
do_restore_current_thread_cleanup (void *arg)
{
  struct current_thread_cleanup *old = arg;
  restore_current_thread (old->inferior_ptid);
  xfree (old);
}

static struct cleanup *
make_cleanup_restore_current_thread (ptid_t inferior_ptid)
{
  struct current_thread_cleanup *old
    = xmalloc (sizeof (struct current_thread_cleanup));
  old->inferior_ptid = inferior_ptid;
  return make_cleanup (do_restore_current_thread_cleanup, old);
}

/* 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 thread_info *tp;
  struct cleanup *old_chain;
  struct cleanup *saved_cmd_cleanup_chain;
  char *saved_cmd;

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

  old_chain = make_cleanup_restore_current_thread (inferior_ptid);

  /* It is safe to update the thread list now, before
     traversing it for "thread apply all".  MVS */
  target_find_new_threads ();

  /* Save a copy of the command in case it is clobbered by
     execute_command */
  saved_cmd = xstrdup (cmd);
  saved_cmd_cleanup_chain = make_cleanup (xfree, (void *) saved_cmd);
  for (tp = thread_list; tp; tp = tp->next)
    if (thread_alive (tp))
      {
	switch_to_thread (tp->ptid);
	printf_filtered (_("\nThread %d (%s):\n"),
			 tp->num, target_tid_to_str (inferior_ptid));
	execute_command (cmd, from_tty);
	strcpy (cmd, saved_cmd);	/* Restore exact command used previously */
      }

  do_cleanups (saved_cmd_cleanup_chain);
  do_cleanups (old_chain);
}

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

  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"));

  old_chain = make_cleanup_restore_current_thread (inferior_ptid);

  /* Save a copy of the command in case it is clobbered by
     execute_command */
  saved_cmd = xstrdup (cmd);
  saved_cmd_cleanup_chain = make_cleanup (xfree, (void *) saved_cmd);
  while (tidlist < cmd)
    {
      struct thread_info *tp;
      int start, end;

      start = strtol (tidlist, &p, 10);
      if (p == tidlist)
	error (_("Error parsing %s"), tidlist);
      tidlist = p;

      while (*tidlist == ' ' || *tidlist == '\t')
	tidlist++;

      if (*tidlist == '-')	/* Got a range of IDs? */
	{
	  tidlist++;		/* Skip the - */
	  end = strtol (tidlist, &p, 10);
	  if (p == tidlist)
	    error (_("Error parsing %s"), tidlist);
	  tidlist = p;

	  while (*tidlist == ' ' || *tidlist == '\t')
	    tidlist++;
	}
      else
	end = start;

      for (; start <= end; start++)
	{
	  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_tid_to_str (inferior_ptid));
	      execute_command (cmd, from_tty);
	      strcpy (cmd, saved_cmd);	/* Restore exact command used previously */
	    }
	}
    }

  do_cleanups (saved_cmd_cleanup_chain);
  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)
    {
      /* Don't generate an error, just say which thread is current. */
      if (target_has_stack)
	printf_filtered (_("[Current thread is %d (%s)]\n"),
			 pid_to_thread_id (inferior_ptid),
			 target_tid_to_str (inferior_ptid));
      else
	error (_("No stack."));
      return;
    }

  gdb_thread_select (uiout, tidstr, NULL);
}

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);

  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_tid_to_str (inferior_ptid));
  ui_out_text (uiout, ")]");

  print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC);
  return GDB_RC_OK;
}

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

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

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

  add_info ("threads", info_threads_command,
	    "IDs of currently known threads.");

  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, "apply ", 1, &thread_cmd_list);

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

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