gdb/thread.c

   1 /* Multi-process/thread control for GDB, the GNU debugger.
   2
   3    Copyright 1986, 1987, 1988, 1993, 1994, 1995, 1996, 1997, 1998,
   4    1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
   5
   6    Contributed by Lynx Real-Time Systems, Inc.  Los Gatos, CA.
   7
   8    This file is part of GDB.
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 2 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program; if not, write to the Free Software
  22    Foundation, Inc., 59 Temple Place - Suite 330,
  23    Boston, MA 02111-1307, USA.  */
  24
  25 #include "defs.h"
  26 #include "symtab.h"
  27 #include "frame.h"
  28 #include "inferior.h"
  29 #include "environ.h"
  30 #include "value.h"
  31 #include "target.h"
  32 #include "gdbthread.h"
  33 #include "command.h"
  34 #include "gdbcmd.h"
  35 #include "regcache.h"
  36 #include "gdb.h"
  37 #include "gdb_string.h"
  38
  39 #include <ctype.h>
  40 #include <sys/types.h>
  41 #include <signal.h>
  42 #include "ui-out.h"
  43
  44 /*#include "lynxos-core.h" */
  45
  46 /* Definition of struct thread_info exported to gdbthread.h */
  47
  48 /* Prototypes for exported functions. */
  49
  50 void _initialize_thread (void);
  51
  52 /* Prototypes for local functions. */
  53
  54 static struct thread_info *thread_list = NULL;
  55 static int highest_thread_num;
  56
  57 static struct thread_info *find_thread_id (int num);
  58
  59 static void thread_command (char *tidstr, int from_tty);
  60 static void thread_apply_all_command (char *, int);
  61 static int thread_alive (struct thread_info *);
  62 static void info_threads_command (char *, int);
  63 static void thread_apply_command (char *, int);
  64 static void restore_current_thread (ptid_t);
  65 static void switch_to_thread (ptid_t ptid);
  66 static void prune_threads (void);
  67
  68 void
  69 delete_step_resume_breakpoint (void *arg)
  70 {
  71   struct breakpoint **breakpointp = (struct breakpoint **) arg;
  72   struct thread_info *tp;
  73
  74   if (*breakpointp != NULL)
  75     {
  76       delete_breakpoint (*breakpointp);
  77       for (tp = thread_list; tp; tp = tp->next)
  78         if (tp->step_resume_breakpoint == *breakpointp)
  79           tp->step_resume_breakpoint = NULL;
  80
  81       *breakpointp = NULL;
  82     }
  83 }
  84
  85 static void
  86 free_thread (struct thread_info *tp)
  87 {
  88   /* NOTE: this will take care of any left-over step_resume breakpoints,
  89      but not any user-specified thread-specific breakpoints. */
  90   if (tp->step_resume_breakpoint)
  91     delete_breakpoint (tp->step_resume_breakpoint);
  92
  93   /* FIXME: do I ever need to call the back-end to give it a
  94      chance at this private data before deleting the thread?  */
  95   if (tp->private)
  96     xfree (tp->private);
  97
  98   xfree (tp);
  99 }
 100
 101 void
 102 init_thread_list (void)
 103 {
 104   struct thread_info *tp, *tpnext;
 105
 106   highest_thread_num = 0;
 107   if (!thread_list)
 108     return;
 109
 110   for (tp = thread_list; tp; tp = tpnext)
 111     {
 112       tpnext = tp->next;
 113       free_thread (tp);
 114     }
 115
 116   thread_list = NULL;
 117 }
 118
 119 /* add_thread now returns a pointer to the new thread_info,
 120    so that back_ends can initialize their private data.  */
 121
 122 struct thread_info *
 123 add_thread (ptid_t ptid)
 124 {
 125   struct thread_info *tp;
 126
 127   tp = (struct thread_info *) xmalloc (sizeof (*tp));
 128   memset (tp, 0, sizeof (*tp));
 129   tp->ptid = ptid;
 130   tp->num = ++highest_thread_num;
 131   tp->next = thread_list;
 132   thread_list = tp;
 133   return tp;
 134 }
 135
 136 void
 137 delete_thread (ptid_t ptid)
 138 {
 139   struct thread_info *tp, *tpprev;
 140
 141   tpprev = NULL;
 142
 143   for (tp = thread_list; tp; tpprev = tp, tp = tp->next)
 144     if (ptid_equal (tp->ptid, ptid))
 145       break;
 146
 147   if (!tp)
 148     return;
 149
 150   if (tpprev)
 151     tpprev->next = tp->next;
 152   else
 153     thread_list = tp->next;
 154
 155   free_thread (tp);
 156 }
 157
 158 static struct thread_info *
 159 find_thread_id (int num)
 160 {
 161   struct thread_info *tp;
 162
 163   for (tp = thread_list; tp; tp = tp->next)
 164     if (tp->num == num)
 165       return tp;
 166
 167   return NULL;
 168 }
 169
 170 /* Find a thread_info by matching PTID.  */
 171 struct thread_info *
 172 find_thread_pid (ptid_t ptid)
 173 {
 174   struct thread_info *tp;
 175
 176   for (tp = thread_list; tp; tp = tp->next)
 177     if (ptid_equal (tp->ptid, ptid))
 178       return tp;
 179
 180   return NULL;
 181 }
 182
 183 /*
 184  * Thread iterator function.
 185  *
 186  * Calls a callback function once for each thread, so long as
 187  * the callback function returns false.  If the callback function
 188  * returns true, the iteration will end and the current thread
 189  * will be returned.  This can be useful for implementing a
 190  * search for a thread with arbitrary attributes, or for applying
 191  * some operation to every thread.
 192  *
 193  * FIXME: some of the existing functionality, such as
 194  * "Thread apply all", might be rewritten using this functionality.
 195  */
 196
 197 struct thread_info *
 198 iterate_over_threads (int (*callback) (struct thread_info *, void *),
 199                       void *data)
 200 {
 201   struct thread_info *tp;
 202
 203   for (tp = thread_list; tp; tp = tp->next)
 204     if ((*callback) (tp, data))
 205       return tp;
 206
 207   return NULL;
 208 }
 209
 210 int
 211 valid_thread_id (int num)
 212 {
 213   struct thread_info *tp;
 214
 215   for (tp = thread_list; tp; tp = tp->next)
 216     if (tp->num == num)
 217       return 1;
 218
 219   return 0;
 220 }
 221
 222 int
 223 pid_to_thread_id (ptid_t ptid)
 224 {
 225   struct thread_info *tp;
 226
 227   for (tp = thread_list; tp; tp = tp->next)
 228     if (ptid_equal (tp->ptid, ptid))
 229       return tp->num;
 230
 231   return 0;
 232 }
 233
 234 ptid_t
 235 thread_id_to_pid (int num)
 236 {
 237   struct thread_info *thread = find_thread_id (num);
 238   if (thread)
 239     return thread->ptid;
 240   else
 241     return pid_to_ptid (-1);
 242 }
 243
 244 int
 245 in_thread_list (ptid_t ptid)
 246 {
 247   struct thread_info *tp;
 248
 249   for (tp = thread_list; tp; tp = tp->next)
 250     if (ptid_equal (tp->ptid, ptid))
 251       return 1;
 252
 253   return 0;                     /* Never heard of 'im */
 254 }
 255
 256 /* Print a list of thread ids currently known, and the total number of
 257    threads. To be used from within catch_errors. */
 258 static int
 259 do_captured_list_thread_ids (struct ui_out *uiout,
 260                              void *arg)
 261 {
 262   struct thread_info *tp;
 263   int num = 0;
 264   struct cleanup *cleanup_chain;
 265
 266   prune_threads ();
 267   target_find_new_threads ();
 268
 269   cleanup_chain = make_cleanup_ui_out_tuple_begin_end (uiout, "thread-ids");
 270
 271   for (tp = thread_list; tp; tp = tp->next)
 272     {
 273       num++;
 274       ui_out_field_int (uiout, "thread-id", tp->num);
 275     }
 276
 277   do_cleanups (cleanup_chain);
 278   ui_out_field_int (uiout, "number-of-threads", num);
 279   return GDB_RC_OK;
 280 }
 281
 282 /* Official gdblib interface function to get a list of thread ids and
 283    the total number. */
 284 enum gdb_rc
 285 gdb_list_thread_ids (struct ui_out *uiout)
 286 {
 287   return catch_exceptions (uiout, do_captured_list_thread_ids, NULL,
 288                            NULL, RETURN_MASK_ALL);
 289 }
 290
 291 /* Load infrun state for the thread PID.  */
 292
 293 void
 294 load_infrun_state (ptid_t ptid,
 295                    CORE_ADDR *prev_pc,
 296                    CORE_ADDR *prev_func_start,
 297                    char **prev_func_name,
 298                    int *trap_expected,
 299                    struct breakpoint **step_resume_breakpoint,
 300                    struct breakpoint **through_sigtramp_breakpoint,
 301                    CORE_ADDR *step_range_start,
 302                    CORE_ADDR *step_range_end,
 303                    struct frame_id *step_frame_id,
 304                    int *handling_longjmp,
 305                    int *another_trap,
 306                    int *stepping_through_solib_after_catch,
 307                    bpstat *stepping_through_solib_catchpoints,
 308                    int *stepping_through_sigtramp,
 309                    int *current_line,
 310                    struct symtab **current_symtab,
 311                    CORE_ADDR *step_sp)
 312 {
 313   struct thread_info *tp;
 314
 315   /* If we can't find the thread, then we're debugging a single threaded
 316      process.  No need to do anything in that case.  */
 317   tp = find_thread_id (pid_to_thread_id (ptid));
 318   if (tp == NULL)
 319     return;
 320
 321   *prev_pc = tp->prev_pc;
 322   *prev_func_start = tp->prev_func_start;
 323   *prev_func_name = tp->prev_func_name;
 324   *trap_expected = tp->trap_expected;
 325   *step_resume_breakpoint = tp->step_resume_breakpoint;
 326   *through_sigtramp_breakpoint = tp->through_sigtramp_breakpoint;
 327   *step_range_start = tp->step_range_start;
 328   *step_range_end = tp->step_range_end;
 329   *step_frame_id = tp->step_frame_id;
 330   *handling_longjmp = tp->handling_longjmp;
 331   *another_trap = tp->another_trap;
 332   *stepping_through_solib_after_catch = tp->stepping_through_solib_after_catch;
 333   *stepping_through_solib_catchpoints = tp->stepping_through_solib_catchpoints;
 334   *stepping_through_sigtramp = tp->stepping_through_sigtramp;
 335   *current_line = tp->current_line;
 336   *current_symtab = tp->current_symtab;
 337   *step_sp = tp->step_sp;
 338 }
 339
 340 /* Save infrun state for the thread PID.  */
 341
 342 void
 343 save_infrun_state (ptid_t ptid,
 344                    CORE_ADDR prev_pc,
 345                    CORE_ADDR prev_func_start,
 346                    char *prev_func_name,
 347                    int trap_expected,
 348                    struct breakpoint *step_resume_breakpoint,
 349                    struct breakpoint *through_sigtramp_breakpoint,
 350                    CORE_ADDR step_range_start,
 351                    CORE_ADDR step_range_end,
 352                    const struct frame_id *step_frame_id,
 353                    int handling_longjmp,
 354                    int another_trap,
 355                    int stepping_through_solib_after_catch,
 356                    bpstat stepping_through_solib_catchpoints,
 357                    int stepping_through_sigtramp,
 358                    int current_line,
 359                    struct symtab *current_symtab,
 360                    CORE_ADDR step_sp)
 361 {
 362   struct thread_info *tp;
 363
 364   /* If we can't find the thread, then we're debugging a single-threaded
 365      process.  Nothing to do in that case.  */
 366   tp = find_thread_id (pid_to_thread_id (ptid));
 367   if (tp == NULL)
 368     return;
 369
 370   tp->prev_pc = prev_pc;
 371   tp->prev_func_start = prev_func_start;
 372   tp->prev_func_name = prev_func_name;
 373   tp->trap_expected = trap_expected;
 374   tp->step_resume_breakpoint = step_resume_breakpoint;
 375   tp->through_sigtramp_breakpoint = through_sigtramp_breakpoint;
 376   tp->step_range_start = step_range_start;
 377   tp->step_range_end = step_range_end;
 378   tp->step_frame_id = (*step_frame_id);
 379   tp->handling_longjmp = handling_longjmp;
 380   tp->another_trap = another_trap;
 381   tp->stepping_through_solib_after_catch = stepping_through_solib_after_catch;
 382   tp->stepping_through_solib_catchpoints = stepping_through_solib_catchpoints;
 383   tp->stepping_through_sigtramp = stepping_through_sigtramp;
 384   tp->current_line = current_line;
 385   tp->current_symtab = current_symtab;
 386   tp->step_sp = step_sp;
 387 }
 388
 389 /* Return true if TP is an active thread. */
 390 static int
 391 thread_alive (struct thread_info *tp)
 392 {
 393   if (PIDGET (tp->ptid) == -1)
 394     return 0;
 395   if (!target_thread_alive (tp->ptid))
 396     {
 397       tp->ptid = pid_to_ptid (-1);      /* Mark it as dead */
 398       return 0;
 399     }
 400   return 1;
 401 }
 402
 403 static void
 404 prune_threads (void)
 405 {
 406   struct thread_info *tp, *next;
 407
 408   for (tp = thread_list; tp; tp = next)
 409     {
 410       next = tp->next;
 411       if (!thread_alive (tp))
 412         delete_thread (tp->ptid);
 413     }
 414 }
 415
 416 /* Print information about currently known threads
 417
 418  * Note: this has the drawback that it _really_ switches
 419  *       threads, which frees the frame cache.  A no-side
 420  *       effects info-threads command would be nicer.
 421  */
 422
 423 static void
 424 info_threads_command (char *arg, int from_tty)
 425 {
 426   struct thread_info *tp;
 427   ptid_t current_ptid;
 428   struct frame_info *cur_frame;
 429   int saved_frame_level = frame_relative_level (deprecated_selected_frame);
 430   int counter;
 431   char *extra_info;
 432
 433   /* Avoid coredumps which would happen if we tried to access a NULL
 434      deprecated_selected_frame.  */
 435   if (!target_has_stack)
 436     error ("No stack.");
 437
 438   prune_threads ();
 439   target_find_new_threads ();
 440   current_ptid = inferior_ptid;
 441   for (tp = thread_list; tp; tp = tp->next)
 442     {
 443       if (ptid_equal (tp->ptid, current_ptid))
 444         printf_filtered ("* ");
 445       else
 446         printf_filtered ("  ");
 447
 448 #ifdef HPUXHPPA
 449       printf_filtered ("%d %s", tp->num, target_tid_to_str (tp->ptid));
 450 #else
 451       printf_filtered ("%d %s", tp->num, target_pid_to_str (tp->ptid));
 452 #endif
 453
 454       extra_info = target_extra_thread_info (tp);
 455       if (extra_info)
 456         printf_filtered (" (%s)", extra_info);
 457       puts_filtered ("  ");
 458
 459       switch_to_thread (tp->ptid);
 460       if (deprecated_selected_frame)
 461         print_stack_frame (deprecated_selected_frame, -1, 0);
 462       else
 463         printf_filtered ("[No stack.]\n");
 464     }
 465
 466   switch_to_thread (current_ptid);
 467
 468   /* Code below copied from "up_silently_base" in "stack.c".
 469    * It restores the frame set by the user before the "info threads"
 470    * command.  We have finished the info-threads display by switching
 471    * back to the current thread.  That switch has put us at the top
 472    * of the stack (leaf frame).
 473    */
 474   counter = saved_frame_level;
 475   cur_frame = find_relative_frame (deprecated_selected_frame, &counter);
 476   if (counter != 0)
 477     {
 478       /* Ooops, can't restore, tell user where we are. */
 479       warning ("Couldn't restore frame in current thread, at frame 0");
 480       print_stack_frame (deprecated_selected_frame, -1, 0);
 481     }
 482   else
 483     {
 484       select_frame (cur_frame);
 485     }
 486
 487   /* re-show current frame. */
 488   show_stack_frame (cur_frame);
 489 }
 490
 491 /* Switch from one thread to another. */
 492
 493 static void
 494 switch_to_thread (ptid_t ptid)
 495 {
 496   if (ptid_equal (ptid, inferior_ptid))
 497     return;
 498
 499   inferior_ptid = ptid;
 500   flush_cached_frames ();
 501   registers_changed ();
 502   stop_pc = read_pc ();
 503   select_frame (get_current_frame ());
 504 }
 505
 506 static void
 507 restore_current_thread (ptid_t ptid)
 508 {
 509   if (! ptid_equal (ptid, inferior_ptid))
 510     {
 511       switch_to_thread (ptid);
 512       print_stack_frame (get_current_frame (), 0, -1);
 513     }
 514 }
 515
 516 struct current_thread_cleanup
 517 {
 518   ptid_t inferior_ptid;
 519 };
 520
 521 static void
 522 do_restore_current_thread_cleanup (void *arg)
 523 {
 524   struct current_thread_cleanup *old = arg;
 525   restore_current_thread (old->inferior_ptid);
 526   xfree (old);
 527 }
 528
 529 static struct cleanup *
 530 make_cleanup_restore_current_thread (ptid_t inferior_ptid)
 531 {
 532   struct current_thread_cleanup *old
 533     = xmalloc (sizeof (struct current_thread_cleanup));
 534   old->inferior_ptid = inferior_ptid;
 535   return make_cleanup (do_restore_current_thread_cleanup, old);
 536 }
 537
 538 /* Apply a GDB command to a list of threads.  List syntax is a whitespace
 539    seperated list of numbers, or ranges, or the keyword `all'.  Ranges consist
 540    of two numbers seperated by a hyphen.  Examples:
 541
 542    thread apply 1 2 7 4 backtrace       Apply backtrace cmd to threads 1,2,7,4
 543    thread apply 2-7 9 p foo(1)  Apply p foo(1) cmd to threads 2->7 & 9
 544    thread apply all p x/i $pc   Apply x/i $pc cmd to all threads
 545  */
 546
 547 static void
 548 thread_apply_all_command (char *cmd, int from_tty)
 549 {
 550   struct thread_info *tp;
 551   struct cleanup *old_chain;
 552   struct cleanup *saved_cmd_cleanup_chain;
 553   char *saved_cmd;
 554
 555   if (cmd == NULL || *cmd == '\000')
 556     error ("Please specify a command following the thread ID list");
 557
 558   old_chain = make_cleanup_restore_current_thread (inferior_ptid);
 559
 560   /* It is safe to update the thread list now, before
 561      traversing it for "thread apply all".  MVS */
 562   target_find_new_threads ();
 563
 564   /* Save a copy of the command in case it is clobbered by
 565      execute_command */
 566   saved_cmd = xstrdup (cmd);
 567   saved_cmd_cleanup_chain = make_cleanup (xfree, (void *) saved_cmd);
 568   for (tp = thread_list; tp; tp = tp->next)
 569     if (thread_alive (tp))
 570       {
 571         switch_to_thread (tp->ptid);
 572 #ifdef HPUXHPPA
 573         printf_filtered ("\nThread %d (%s):\n",
 574                          tp->num,
 575                          target_tid_to_str (inferior_ptid));
 576 #else
 577         printf_filtered ("\nThread %d (%s):\n", tp->num,
 578                          target_pid_to_str (inferior_ptid));
 579 #endif
 580         execute_command (cmd, from_tty);
 581         strcpy (cmd, saved_cmd); /* Restore exact command used previously */
 582       }
 583
 584   do_cleanups (saved_cmd_cleanup_chain);
 585   do_cleanups (old_chain);
 586 }
 587
 588 static void
 589 thread_apply_command (char *tidlist, int from_tty)
 590 {
 591   char *cmd;
 592   char *p;
 593   struct cleanup *old_chain;
 594   struct cleanup *saved_cmd_cleanup_chain;
 595   char *saved_cmd;
 596
 597   if (tidlist == NULL || *tidlist == '\000')
 598     error ("Please specify a thread ID list");
 599
 600   for (cmd = tidlist; *cmd != '\000' && !isalpha (*cmd); cmd++);
 601
 602   if (*cmd == '\000')
 603     error ("Please specify a command following the thread ID list");
 604
 605   old_chain = make_cleanup_restore_current_thread (inferior_ptid);
 606
 607   /* Save a copy of the command in case it is clobbered by
 608      execute_command */
 609   saved_cmd = xstrdup (cmd);
 610   saved_cmd_cleanup_chain = make_cleanup (xfree, (void *) saved_cmd);
 611   while (tidlist < cmd)
 612     {
 613       struct thread_info *tp;
 614       int start, end;
 615
 616       start = strtol (tidlist, &p, 10);
 617       if (p == tidlist)
 618         error ("Error parsing %s", tidlist);
 619       tidlist = p;
 620
 621       while (*tidlist == ' ' || *tidlist == '\t')
 622         tidlist++;
 623
 624       if (*tidlist == '-')      /* Got a range of IDs? */
 625         {
 626           tidlist++;            /* Skip the - */
 627           end = strtol (tidlist, &p, 10);
 628           if (p == tidlist)
 629             error ("Error parsing %s", tidlist);
 630           tidlist = p;
 631
 632           while (*tidlist == ' ' || *tidlist == '\t')
 633             tidlist++;
 634         }
 635       else
 636         end = start;
 637
 638       for (; start <= end; start++)
 639         {
 640           tp = find_thread_id (start);
 641
 642           if (!tp)
 643             warning ("Unknown thread %d.", start);
 644           else if (!thread_alive (tp))
 645             warning ("Thread %d has terminated.", start);
 646           else
 647             {
 648               switch_to_thread (tp->ptid);
 649 #ifdef HPUXHPPA
 650               printf_filtered ("\nThread %d (%s):\n", tp->num,
 651                                target_tid_to_str (inferior_ptid));
 652 #else
 653               printf_filtered ("\nThread %d (%s):\n", tp->num,
 654                                target_pid_to_str (inferior_ptid));
 655 #endif
 656               execute_command (cmd, from_tty);
 657               strcpy (cmd, saved_cmd);  /* Restore exact command used previously */
 658             }
 659         }
 660     }
 661
 662   do_cleanups (saved_cmd_cleanup_chain);
 663   do_cleanups (old_chain);
 664 }
 665
 666 /* Switch to the specified thread.  Will dispatch off to thread_apply_command
 667    if prefix of arg is `apply'.  */
 668
 669 static void
 670 thread_command (char *tidstr, int from_tty)
 671 {
 672   if (!tidstr)
 673     {
 674       /* Don't generate an error, just say which thread is current. */
 675       if (target_has_stack)
 676         printf_filtered ("[Current thread is %d (%s)]\n",
 677                          pid_to_thread_id (inferior_ptid),
 678 #if defined(HPUXHPPA)
 679                          target_tid_to_str (inferior_ptid)
 680 #else
 681                          target_pid_to_str (inferior_ptid)
 682 #endif
 683           );
 684       else
 685         error ("No stack.");
 686       return;
 687     }
 688
 689   gdb_thread_select (uiout, tidstr);
 690 }
 691
 692 static int
 693 do_captured_thread_select (struct ui_out *uiout,
 694                            void *tidstr)
 695 {
 696   int num;
 697   struct thread_info *tp;
 698
 699   num = value_as_long (parse_and_eval (tidstr));
 700
 701   tp = find_thread_id (num);
 702
 703   if (!tp)
 704     error ("Thread ID %d not known.", num);
 705
 706   if (!thread_alive (tp))
 707     error ("Thread ID %d has terminated.\n", num);
 708
 709   switch_to_thread (tp->ptid);
 710
 711   ui_out_text (uiout, "[Switching to thread ");
 712   ui_out_field_int (uiout, "new-thread-id", pid_to_thread_id (inferior_ptid));
 713   ui_out_text (uiout, " (");
 714 #if defined(HPUXHPPA)
 715   ui_out_text (uiout, target_tid_to_str (inferior_ptid));
 716 #else
 717   ui_out_text (uiout, target_pid_to_str (inferior_ptid));
 718 #endif
 719   ui_out_text (uiout, ")]");
 720
 721   print_stack_frame (deprecated_selected_frame,
 722                      frame_relative_level (deprecated_selected_frame), 1);
 723   return GDB_RC_OK;
 724 }
 725
 726 enum gdb_rc
 727 gdb_thread_select (struct ui_out *uiout,
 728                    char *tidstr)
 729 {
 730   return catch_exceptions (uiout, do_captured_thread_select, tidstr,
 731                            NULL, RETURN_MASK_ALL);
 732 }
 733
 734 /* Commands with a prefix of `thread'.  */
 735 struct cmd_list_element *thread_cmd_list = NULL;
 736
 737 void
 738 _initialize_thread (void)
 739 {
 740   static struct cmd_list_element *thread_apply_list = NULL;
 741
 742   add_info ("threads", info_threads_command,
 743             "IDs of currently known threads.");
 744
 745   add_prefix_cmd ("thread", class_run, thread_command,
 746                   "Use this command to switch between threads.\n\
 747 The new thread ID must be currently known.", &thread_cmd_list, "thread ", 1,
 748                   &cmdlist);
 749
 750   add_prefix_cmd ("apply", class_run, thread_apply_command,
 751                   "Apply a command to a list of threads.",
 752                   &thread_apply_list, "apply ", 1, &thread_cmd_list);
 753
 754   add_cmd ("all", class_run, thread_apply_all_command,
 755            "Apply a command to all threads.",
 756            &thread_apply_list);
 757
 758   if (!xdb_commands)
 759     add_com_alias ("t", "thread", class_run, 1);
 760 }