gdb/thread.c

   1 /* Multi-process/thread control for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986-2014 Free Software Foundation, Inc.
   4
   5    Contributed by Lynx Real-Time Systems, Inc.  Los Gatos, CA.
   6
   7    This file is part of GDB.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22 #include "defs.h"
  23 #include "symtab.h"
  24 #include "frame.h"
  25 #include "inferior.h"
  26 #include "environ.h"
  27 #include "value.h"
  28 #include "target.h"
  29 #include "gdbthread.h"
  30 #include "exceptions.h"
  31 #include "command.h"
  32 #include "gdbcmd.h"
  33 #include "regcache.h"
  34 #include "gdb.h"
  35 #include "btrace.h"
  36
  37 #include <ctype.h>
  38 #include <sys/types.h>
  39 #include <signal.h>
  40 #include "ui-out.h"
  41 #include "observer.h"
  42 #include "annotate.h"
  43 #include "cli/cli-decode.h"
  44 #include "gdb_regex.h"
  45 #include "cli/cli-utils.h"
  46 #include "continuations.h"
  47
  48 /* Definition of struct thread_info exported to gdbthread.h.  */
  49
  50 /* Prototypes for exported functions.  */
  51
  52 void _initialize_thread (void);
  53
  54 /* Prototypes for local functions.  */
  55
  56 struct thread_info *thread_list = NULL;
  57 static int highest_thread_num;
  58
  59 /* True if any thread is, or may be executing.  We need to track this
  60    separately because until we fully sync the thread list, we won't
  61    know whether the target is fully stopped, even if we see stop
  62    events for all known threads, because any of those threads may have
  63    spawned new threads we haven't heard of yet.  */
  64 static int threads_executing;
  65
  66 static void thread_command (char *tidstr, int from_tty);
  67 static void thread_apply_all_command (char *, int);
  68 static int thread_alive (struct thread_info *);
  69 static void info_threads_command (char *, int);
  70 static void thread_apply_command (char *, int);
  71 static void restore_current_thread (ptid_t);
  72 static void prune_threads (void);
  73
  74 /* Data to cleanup thread array.  */
  75
  76 struct thread_array_cleanup
  77 {
  78   /* Array of thread pointers used to set
  79      reference count.  */
  80   struct thread_info **tp_array;
  81
  82   /* Thread count in the array.  */
  83   int count;
  84 };
  85
  86
  87 struct thread_info*
  88 inferior_thread (void)
  89 {
  90   struct thread_info *tp = find_thread_ptid (inferior_ptid);
  91   gdb_assert (tp);
  92   return tp;
  93 }
  94
  95 void
  96 delete_step_resume_breakpoint (struct thread_info *tp)
  97 {
  98   if (tp && tp->control.step_resume_breakpoint)
  99     {
 100       delete_breakpoint (tp->control.step_resume_breakpoint);
 101       tp->control.step_resume_breakpoint = NULL;
 102     }
 103 }
 104
 105 void
 106 delete_exception_resume_breakpoint (struct thread_info *tp)
 107 {
 108   if (tp && tp->control.exception_resume_breakpoint)
 109     {
 110       delete_breakpoint (tp->control.exception_resume_breakpoint);
 111       tp->control.exception_resume_breakpoint = NULL;
 112     }
 113 }
 114
 115 static void
 116 clear_thread_inferior_resources (struct thread_info *tp)
 117 {
 118   /* NOTE: this will take care of any left-over step_resume breakpoints,
 119      but not any user-specified thread-specific breakpoints.  We can not
 120      delete the breakpoint straight-off, because the inferior might not
 121      be stopped at the moment.  */
 122   if (tp->control.step_resume_breakpoint)
 123     {
 124       tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
 125       tp->control.step_resume_breakpoint = NULL;
 126     }
 127
 128   if (tp->control.exception_resume_breakpoint)
 129     {
 130       tp->control.exception_resume_breakpoint->disposition
 131         = disp_del_at_next_stop;
 132       tp->control.exception_resume_breakpoint = NULL;
 133     }
 134
 135   delete_longjmp_breakpoint_at_next_stop (tp->num);
 136
 137   bpstat_clear (&tp->control.stop_bpstat);
 138
 139   btrace_teardown (tp);
 140
 141   do_all_intermediate_continuations_thread (tp, 1);
 142   do_all_continuations_thread (tp, 1);
 143 }
 144
 145 static void
 146 free_thread (struct thread_info *tp)
 147 {
 148   if (tp->private)
 149     {
 150       if (tp->private_dtor)
 151         tp->private_dtor (tp->private);
 152       else
 153         xfree (tp->private);
 154     }
 155
 156   xfree (tp->name);
 157   xfree (tp);
 158 }
 159
 160 void
 161 init_thread_list (void)
 162 {
 163   struct thread_info *tp, *tpnext;
 164
 165   highest_thread_num = 0;
 166
 167   if (!thread_list)
 168     return;
 169
 170   for (tp = thread_list; tp; tp = tpnext)
 171     {
 172       tpnext = tp->next;
 173       free_thread (tp);
 174     }
 175
 176   thread_list = NULL;
 177   threads_executing = 0;
 178 }
 179
 180 /* Allocate a new thread with target id PTID and add it to the thread
 181    list.  */
 182
 183 static struct thread_info *
 184 new_thread (ptid_t ptid)
 185 {
 186   struct thread_info *tp;
 187
 188   tp = xcalloc (1, sizeof (*tp));
 189
 190   tp->ptid = ptid;
 191   tp->num = ++highest_thread_num;
 192   tp->next = thread_list;
 193   thread_list = tp;
 194
 195   /* Nothing to follow yet.  */
 196   tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
 197   tp->state = THREAD_STOPPED;
 198
 199   return tp;
 200 }
 201
 202 struct thread_info *
 203 add_thread_silent (ptid_t ptid)
 204 {
 205   struct thread_info *tp;
 206
 207   tp = find_thread_ptid (ptid);
 208   if (tp)
 209     /* Found an old thread with the same id.  It has to be dead,
 210        otherwise we wouldn't be adding a new thread with the same id.
 211        The OS is reusing this id --- delete it, and recreate a new
 212        one.  */
 213     {
 214       /* In addition to deleting the thread, if this is the current
 215          thread, then we need to take care that delete_thread doesn't
 216          really delete the thread if it is inferior_ptid.  Create a
 217          new template thread in the list with an invalid ptid, switch
 218          to it, delete the original thread, reset the new thread's
 219          ptid, and switch to it.  */
 220
 221       if (ptid_equal (inferior_ptid, ptid))
 222         {
 223           tp = new_thread (null_ptid);
 224
 225           /* Make switch_to_thread not read from the thread.  */
 226           tp->state = THREAD_EXITED;
 227           switch_to_thread (null_ptid);
 228
 229           /* Now we can delete it.  */
 230           delete_thread (ptid);
 231
 232           /* Now reset its ptid, and reswitch inferior_ptid to it.  */
 233           tp->ptid = ptid;
 234           tp->state = THREAD_STOPPED;
 235           switch_to_thread (ptid);
 236
 237           observer_notify_new_thread (tp);
 238
 239           /* All done.  */
 240           return tp;
 241         }
 242       else
 243         /* Just go ahead and delete it.  */
 244         delete_thread (ptid);
 245     }
 246
 247   tp = new_thread (ptid);
 248   observer_notify_new_thread (tp);
 249
 250   return tp;
 251 }
 252
 253 struct thread_info *
 254 add_thread_with_info (ptid_t ptid, struct private_thread_info *private)
 255 {
 256   struct thread_info *result = add_thread_silent (ptid);
 257
 258   result->private = private;
 259
 260   if (print_thread_events)
 261     printf_unfiltered (_("[New %s]\n"), target_pid_to_str (ptid));
 262
 263   annotate_new_thread ();
 264   return result;
 265 }
 266
 267 struct thread_info *
 268 add_thread (ptid_t ptid)
 269 {
 270   return add_thread_with_info (ptid, NULL);
 271 }
 272
 273 /* Delete thread PTID.  If SILENT, don't notify the observer of this
 274    exit.  */
 275 static void
 276 delete_thread_1 (ptid_t ptid, int silent)
 277 {
 278   struct thread_info *tp, *tpprev;
 279
 280   tpprev = NULL;
 281
 282   for (tp = thread_list; tp; tpprev = tp, tp = tp->next)
 283     if (ptid_equal (tp->ptid, ptid))
 284       break;
 285
 286   if (!tp)
 287     return;
 288
 289   /* If this is the current thread, or there's code out there that
 290      relies on it existing (refcount > 0) we can't delete yet.  Mark
 291      it as exited, and notify it.  */
 292   if (tp->refcount > 0
 293       || ptid_equal (tp->ptid, inferior_ptid))
 294     {
 295       if (tp->state != THREAD_EXITED)
 296         {
 297           observer_notify_thread_exit (tp, silent);
 298
 299           /* Tag it as exited.  */
 300           tp->state = THREAD_EXITED;
 301
 302           /* Clear breakpoints, etc. associated with this thread.  */
 303           clear_thread_inferior_resources (tp);
 304         }
 305
 306        /* Will be really deleted some other time.  */
 307        return;
 308      }
 309
 310   /* Notify thread exit, but only if we haven't already.  */
 311   if (tp->state != THREAD_EXITED)
 312     observer_notify_thread_exit (tp, silent);
 313
 314   /* Tag it as exited.  */
 315   tp->state = THREAD_EXITED;
 316   clear_thread_inferior_resources (tp);
 317
 318   if (tpprev)
 319     tpprev->next = tp->next;
 320   else
 321     thread_list = tp->next;
 322
 323   free_thread (tp);
 324 }
 325
 326 /* Delete thread PTID and notify of thread exit.  If this is
 327    inferior_ptid, don't actually delete it, but tag it as exited and
 328    do the notification.  If PTID is the user selected thread, clear
 329    it.  */
 330 void
 331 delete_thread (ptid_t ptid)
 332 {
 333   delete_thread_1 (ptid, 0 /* not silent */);
 334 }
 335
 336 void
 337 delete_thread_silent (ptid_t ptid)
 338 {
 339   delete_thread_1 (ptid, 1 /* silent */);
 340 }
 341
 342 struct thread_info *
 343 find_thread_id (int num)
 344 {
 345   struct thread_info *tp;
 346
 347   for (tp = thread_list; tp; tp = tp->next)
 348     if (tp->num == num)
 349       return tp;
 350
 351   return NULL;
 352 }
 353
 354 /* Find a thread_info by matching PTID.  */
 355 struct thread_info *
 356 find_thread_ptid (ptid_t ptid)
 357 {
 358   struct thread_info *tp;
 359
 360   for (tp = thread_list; tp; tp = tp->next)
 361     if (ptid_equal (tp->ptid, ptid))
 362       return tp;
 363
 364   return NULL;
 365 }
 366
 367 /*
 368  * Thread iterator function.
 369  *
 370  * Calls a callback function once for each thread, so long as
 371  * the callback function returns false.  If the callback function
 372  * returns true, the iteration will end and the current thread
 373  * will be returned.  This can be useful for implementing a
 374  * search for a thread with arbitrary attributes, or for applying
 375  * some operation to every thread.
 376  *
 377  * FIXME: some of the existing functionality, such as
 378  * "Thread apply all", might be rewritten using this functionality.
 379  */
 380
 381 struct thread_info *
 382 iterate_over_threads (int (*callback) (struct thread_info *, void *),
 383                       void *data)
 384 {
 385   struct thread_info *tp, *next;
 386
 387   for (tp = thread_list; tp; tp = next)
 388     {
 389       next = tp->next;
 390       if ((*callback) (tp, data))
 391         return tp;
 392     }
 393
 394   return NULL;
 395 }
 396
 397 int
 398 thread_count (void)
 399 {
 400   int result = 0;
 401   struct thread_info *tp;
 402
 403   for (tp = thread_list; tp; tp = tp->next)
 404     ++result;
 405
 406   return result;
 407 }
 408
 409 int
 410 valid_thread_id (int num)
 411 {
 412   struct thread_info *tp;
 413
 414   for (tp = thread_list; tp; tp = tp->next)
 415     if (tp->num == num)
 416       return 1;
 417
 418   return 0;
 419 }
 420
 421 int
 422 pid_to_thread_id (ptid_t ptid)
 423 {
 424   struct thread_info *tp;
 425
 426   for (tp = thread_list; tp; tp = tp->next)
 427     if (ptid_equal (tp->ptid, ptid))
 428       return tp->num;
 429
 430   return 0;
 431 }
 432
 433 ptid_t
 434 thread_id_to_pid (int num)
 435 {
 436   struct thread_info *thread = find_thread_id (num);
 437
 438   if (thread)
 439     return thread->ptid;
 440   else
 441     return pid_to_ptid (-1);
 442 }
 443
 444 int
 445 in_thread_list (ptid_t ptid)
 446 {
 447   struct thread_info *tp;
 448
 449   for (tp = thread_list; tp; tp = tp->next)
 450     if (ptid_equal (tp->ptid, ptid))
 451       return 1;
 452
 453   return 0;                     /* Never heard of 'im.  */
 454 }
 455
 456 /* Finds the first thread of the inferior given by PID.  If PID is -1,
 457    return the first thread in the list.  */
 458
 459 struct thread_info *
 460 first_thread_of_process (int pid)
 461 {
 462   struct thread_info *tp, *ret = NULL;
 463
 464   for (tp = thread_list; tp; tp = tp->next)
 465     if (pid == -1 || ptid_get_pid (tp->ptid) == pid)
 466       if (ret == NULL || tp->num < ret->num)
 467         ret = tp;
 468
 469   return ret;
 470 }
 471
 472 struct thread_info *
 473 any_thread_of_process (int pid)
 474 {
 475   struct thread_info *tp;
 476
 477   gdb_assert (pid != 0);
 478
 479   /* Prefer the current thread.  */
 480   if (ptid_get_pid (inferior_ptid) == pid)
 481     return inferior_thread ();
 482
 483   ALL_NON_EXITED_THREADS (tp)
 484     if (ptid_get_pid (tp->ptid) == pid)
 485       return tp;
 486
 487   return NULL;
 488 }
 489
 490 struct thread_info *
 491 any_live_thread_of_process (int pid)
 492 {
 493   struct thread_info *curr_tp = NULL;
 494   struct thread_info *tp;
 495   struct thread_info *tp_executing = NULL;
 496
 497   gdb_assert (pid != 0);
 498
 499   /* Prefer the current thread if it's not executing.  */
 500   if (ptid_get_pid (inferior_ptid) == pid)
 501     {
 502       /* If the current thread is dead, forget it.  If it's not
 503          executing, use it.  Otherwise, still choose it (below), but
 504          only if no other non-executing thread is found.  */
 505       curr_tp = inferior_thread ();
 506       if (curr_tp->state == THREAD_EXITED)
 507         curr_tp = NULL;
 508       else if (!curr_tp->executing)
 509         return curr_tp;
 510     }
 511
 512   ALL_NON_EXITED_THREADS (tp)
 513     if (ptid_get_pid (tp->ptid) == pid)
 514       {
 515         if (!tp->executing)
 516           return tp;
 517
 518         tp_executing = tp;
 519       }
 520
 521   /* If both the current thread and all live threads are executing,
 522      prefer the current thread.  */
 523   if (curr_tp != NULL)
 524     return curr_tp;
 525
 526   /* Otherwise, just return an executing thread, if any.  */
 527   return tp_executing;
 528 }
 529
 530 /* Print a list of thread ids currently known, and the total number of
 531    threads.  To be used from within catch_errors.  */
 532 static int
 533 do_captured_list_thread_ids (struct ui_out *uiout, void *arg)
 534 {
 535   struct thread_info *tp;
 536   int num = 0;
 537   struct cleanup *cleanup_chain;
 538   int current_thread = -1;
 539
 540   update_thread_list ();
 541
 542   cleanup_chain = make_cleanup_ui_out_tuple_begin_end (uiout, "thread-ids");
 543
 544   for (tp = thread_list; tp; tp = tp->next)
 545     {
 546       if (tp->state == THREAD_EXITED)
 547         continue;
 548
 549       if (ptid_equal (tp->ptid, inferior_ptid))
 550         current_thread = tp->num;
 551
 552       num++;
 553       ui_out_field_int (uiout, "thread-id", tp->num);
 554     }
 555
 556   do_cleanups (cleanup_chain);
 557
 558   if (current_thread != -1)
 559     ui_out_field_int (uiout, "current-thread-id", current_thread);
 560   ui_out_field_int (uiout, "number-of-threads", num);
 561   return GDB_RC_OK;
 562 }
 563
 564 /* Official gdblib interface function to get a list of thread ids and
 565    the total number.  */
 566 enum gdb_rc
 567 gdb_list_thread_ids (struct ui_out *uiout, char **error_message)
 568 {
 569   if (catch_exceptions_with_msg (uiout, do_captured_list_thread_ids, NULL,
 570                                  error_message, RETURN_MASK_ALL) < 0)
 571     return GDB_RC_FAIL;
 572   return GDB_RC_OK;
 573 }
 574
 575 /* Return true if TP is an active thread.  */
 576 static int
 577 thread_alive (struct thread_info *tp)
 578 {
 579   if (tp->state == THREAD_EXITED)
 580     return 0;
 581   if (!target_thread_alive (tp->ptid))
 582     return 0;
 583   return 1;
 584 }
 585
 586 static void
 587 prune_threads (void)
 588 {
 589   struct thread_info *tp, *next;
 590
 591   for (tp = thread_list; tp; tp = next)
 592     {
 593       next = tp->next;
 594       if (!thread_alive (tp))
 595         delete_thread (tp->ptid);
 596     }
 597 }
 598
 599 void
 600 thread_change_ptid (ptid_t old_ptid, ptid_t new_ptid)
 601 {
 602   struct inferior *inf;
 603   struct thread_info *tp;
 604
 605   /* It can happen that what we knew as the target inferior id
 606      changes.  E.g, target remote may only discover the remote process
 607      pid after adding the inferior to GDB's list.  */
 608   inf = find_inferior_pid (ptid_get_pid (old_ptid));
 609   inf->pid = ptid_get_pid (new_ptid);
 610
 611   tp = find_thread_ptid (old_ptid);
 612   tp->ptid = new_ptid;
 613
 614   observer_notify_thread_ptid_changed (old_ptid, new_ptid);
 615 }
 616
 617 void
 618 set_running (ptid_t ptid, int running)
 619 {
 620   struct thread_info *tp;
 621   int all = ptid_equal (ptid, minus_one_ptid);
 622
 623   /* We try not to notify the observer if no thread has actually changed
 624      the running state -- merely to reduce the number of messages to
 625      frontend.  Frontend is supposed to handle multiple *running just fine.  */
 626   if (all || ptid_is_pid (ptid))
 627     {
 628       int any_started = 0;
 629
 630       for (tp = thread_list; tp; tp = tp->next)
 631         if (all || ptid_get_pid (tp->ptid) == ptid_get_pid (ptid))
 632           {
 633             if (tp->state == THREAD_EXITED)
 634               continue;
 635             if (running && tp->state == THREAD_STOPPED)
 636               any_started = 1;
 637             tp->state = running ? THREAD_RUNNING : THREAD_STOPPED;
 638           }
 639       if (any_started)
 640         observer_notify_target_resumed (ptid);
 641     }
 642   else
 643     {
 644       int started = 0;
 645
 646       tp = find_thread_ptid (ptid);
 647       gdb_assert (tp);
 648       gdb_assert (tp->state != THREAD_EXITED);
 649       if (running && tp->state == THREAD_STOPPED)
 650         started = 1;
 651       tp->state = running ? THREAD_RUNNING : THREAD_STOPPED;
 652       if (started)
 653         observer_notify_target_resumed (ptid);
 654     }
 655 }
 656
 657 static int
 658 is_thread_state (ptid_t ptid, enum thread_state state)
 659 {
 660   struct thread_info *tp;
 661
 662   tp = find_thread_ptid (ptid);
 663   gdb_assert (tp);
 664   return tp->state == state;
 665 }
 666
 667 int
 668 is_stopped (ptid_t ptid)
 669 {
 670   return is_thread_state (ptid, THREAD_STOPPED);
 671 }
 672
 673 int
 674 is_exited (ptid_t ptid)
 675 {
 676   return is_thread_state (ptid, THREAD_EXITED);
 677 }
 678
 679 int
 680 is_running (ptid_t ptid)
 681 {
 682   return is_thread_state (ptid, THREAD_RUNNING);
 683 }
 684
 685 int
 686 is_executing (ptid_t ptid)
 687 {
 688   struct thread_info *tp;
 689
 690   tp = find_thread_ptid (ptid);
 691   gdb_assert (tp);
 692   return tp->executing;
 693 }
 694
 695 void
 696 set_executing (ptid_t ptid, int executing)
 697 {
 698   struct thread_info *tp;
 699   int all = ptid_equal (ptid, minus_one_ptid);
 700
 701   if (all || ptid_is_pid (ptid))
 702     {
 703       for (tp = thread_list; tp; tp = tp->next)
 704         if (all || ptid_get_pid (tp->ptid) == ptid_get_pid (ptid))
 705           tp->executing = executing;
 706     }
 707   else
 708     {
 709       tp = find_thread_ptid (ptid);
 710       gdb_assert (tp);
 711       tp->executing = executing;
 712     }
 713
 714   /* It only takes one running thread to spawn more threads.*/
 715   if (executing)
 716     threads_executing = 1;
 717   /* Only clear the flag if the caller is telling us everything is
 718      stopped.  */
 719   else if (ptid_equal (minus_one_ptid, ptid))
 720     threads_executing = 0;
 721 }
 722
 723 /* See gdbthread.h.  */
 724
 725 int
 726 threads_are_executing (void)
 727 {
 728   return threads_executing;
 729 }
 730
 731 void
 732 set_stop_requested (ptid_t ptid, int stop)
 733 {
 734   struct thread_info *tp;
 735   int all = ptid_equal (ptid, minus_one_ptid);
 736
 737   if (all || ptid_is_pid (ptid))
 738     {
 739       for (tp = thread_list; tp; tp = tp->next)
 740         if (all || ptid_get_pid (tp->ptid) == ptid_get_pid (ptid))
 741           tp->stop_requested = stop;
 742     }
 743   else
 744     {
 745       tp = find_thread_ptid (ptid);
 746       gdb_assert (tp);
 747       tp->stop_requested = stop;
 748     }
 749
 750   /* Call the stop requested observer so other components of GDB can
 751      react to this request.  */
 752   if (stop)
 753     observer_notify_thread_stop_requested (ptid);
 754 }
 755
 756 void
 757 finish_thread_state (ptid_t ptid)
 758 {
 759   struct thread_info *tp;
 760   int all;
 761   int any_started = 0;
 762
 763   all = ptid_equal (ptid, minus_one_ptid);
 764
 765   if (all || ptid_is_pid (ptid))
 766     {
 767       for (tp = thread_list; tp; tp = tp->next)
 768         {
 769           if (tp->state == THREAD_EXITED)
 770             continue;
 771           if (all || ptid_get_pid (ptid) == ptid_get_pid (tp->ptid))
 772             {
 773               if (tp->executing && tp->state == THREAD_STOPPED)
 774                 any_started = 1;
 775               tp->state = tp->executing ? THREAD_RUNNING : THREAD_STOPPED;
 776             }
 777         }
 778     }
 779   else
 780     {
 781       tp = find_thread_ptid (ptid);
 782       gdb_assert (tp);
 783       if (tp->state != THREAD_EXITED)
 784         {
 785           if (tp->executing && tp->state == THREAD_STOPPED)
 786             any_started = 1;
 787           tp->state = tp->executing ? THREAD_RUNNING : THREAD_STOPPED;
 788         }
 789     }
 790
 791   if (any_started)
 792     observer_notify_target_resumed (ptid);
 793 }
 794
 795 void
 796 finish_thread_state_cleanup (void *arg)
 797 {
 798   ptid_t *ptid_p = arg;
 799
 800   gdb_assert (arg);
 801
 802   finish_thread_state (*ptid_p);
 803 }
 804
 805 int
 806 pc_in_thread_step_range (CORE_ADDR pc, struct thread_info *thread)
 807 {
 808   return (pc >= thread->control.step_range_start
 809           && pc < thread->control.step_range_end);
 810 }
 811
 812 /* Prints the list of threads and their details on UIOUT.
 813    This is a version of 'info_threads_command' suitable for
 814    use from MI.
 815    If REQUESTED_THREAD is not -1, it's the GDB id of the thread
 816    that should be printed.  Otherwise, all threads are
 817    printed.
 818    If PID is not -1, only print threads from the process PID.
 819    Otherwise, threads from all attached PIDs are printed.
 820    If both REQUESTED_THREAD and PID are not -1, then the thread
 821    is printed if it belongs to the specified process.  Otherwise,
 822    an error is raised.  */
 823 void
 824 print_thread_info (struct ui_out *uiout, char *requested_threads, int pid)
 825 {
 826   struct thread_info *tp;
 827   ptid_t current_ptid;
 828   struct cleanup *old_chain;
 829   char *extra_info, *name, *target_id;
 830   int current_thread = -1;
 831
 832   update_thread_list ();
 833   current_ptid = inferior_ptid;
 834
 835   /* We'll be switching threads temporarily.  */
 836   old_chain = make_cleanup_restore_current_thread ();
 837
 838   /* For backward compatibility, we make a list for MI.  A table is
 839      preferable for the CLI, though, because it shows table
 840      headers.  */
 841   if (ui_out_is_mi_like_p (uiout))
 842     make_cleanup_ui_out_list_begin_end (uiout, "threads");
 843   else
 844     {
 845       int n_threads = 0;
 846
 847       for (tp = thread_list; tp; tp = tp->next)
 848         {
 849           if (!number_is_in_list (requested_threads, tp->num))
 850             continue;
 851
 852           if (pid != -1 && ptid_get_pid (tp->ptid) != pid)
 853             continue;
 854
 855           if (tp->state == THREAD_EXITED)
 856             continue;
 857
 858           ++n_threads;
 859         }
 860
 861       if (n_threads == 0)
 862         {
 863           if (requested_threads == NULL || *requested_threads == '\0')
 864             ui_out_message (uiout, 0, _("No threads.\n"));
 865           else
 866             ui_out_message (uiout, 0, _("No threads match '%s'.\n"),
 867                             requested_threads);
 868           do_cleanups (old_chain);
 869           return;
 870         }
 871
 872       make_cleanup_ui_out_table_begin_end (uiout, 4, n_threads, "threads");
 873
 874       ui_out_table_header (uiout, 1, ui_left, "current", "");
 875       ui_out_table_header (uiout, 4, ui_left, "id", "Id");
 876       ui_out_table_header (uiout, 17, ui_left, "target-id", "Target Id");
 877       ui_out_table_header (uiout, 1, ui_left, "frame", "Frame");
 878       ui_out_table_body (uiout);
 879     }
 880
 881   for (tp = thread_list; tp; tp = tp->next)
 882     {
 883       struct cleanup *chain2;
 884       int core;
 885
 886       if (!number_is_in_list (requested_threads, tp->num))
 887         continue;
 888
 889       if (pid != -1 && ptid_get_pid (tp->ptid) != pid)
 890         {
 891           if (requested_threads != NULL && *requested_threads != '\0')
 892             error (_("Requested thread not found in requested process"));
 893           continue;
 894         }
 895
 896       if (ptid_equal (tp->ptid, current_ptid))
 897         current_thread = tp->num;
 898
 899       if (tp->state == THREAD_EXITED)
 900         continue;
 901
 902       chain2 = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
 903
 904       if (ui_out_is_mi_like_p (uiout))
 905         {
 906           /* Compatibility.  */
 907           if (ptid_equal (tp->ptid, current_ptid))
 908             ui_out_text (uiout, "* ");
 909           else
 910             ui_out_text (uiout, "  ");
 911         }
 912       else
 913         {
 914           if (ptid_equal (tp->ptid, current_ptid))
 915             ui_out_field_string (uiout, "current", "*");
 916           else
 917             ui_out_field_skip (uiout, "current");
 918         }
 919
 920       ui_out_field_int (uiout, "id", tp->num);
 921
 922       /* For the CLI, we stuff everything into the target-id field.
 923          This is a gross hack to make the output come out looking
 924          correct.  The underlying problem here is that ui-out has no
 925          way to specify that a field's space allocation should be
 926          shared by several fields.  For MI, we do the right thing
 927          instead.  */
 928
 929       target_id = target_pid_to_str (tp->ptid);
 930       extra_info = target_extra_thread_info (tp);
 931       name = tp->name ? tp->name : target_thread_name (tp);
 932
 933       if (ui_out_is_mi_like_p (uiout))
 934         {
 935           ui_out_field_string (uiout, "target-id", target_id);
 936           if (extra_info)
 937             ui_out_field_string (uiout, "details", extra_info);
 938           if (name)
 939             ui_out_field_string (uiout, "name", name);
 940         }
 941       else
 942         {
 943           struct cleanup *str_cleanup;
 944           char *contents;
 945
 946           if (extra_info && name)
 947             contents = xstrprintf ("%s \"%s\" (%s)", target_id,
 948                                    name, extra_info);
 949           else if (extra_info)
 950             contents = xstrprintf ("%s (%s)", target_id, extra_info);
 951           else if (name)
 952             contents = xstrprintf ("%s \"%s\"", target_id, name);
 953           else
 954             contents = xstrdup (target_id);
 955           str_cleanup = make_cleanup (xfree, contents);
 956
 957           ui_out_field_string (uiout, "target-id", contents);
 958           do_cleanups (str_cleanup);
 959         }
 960
 961       if (tp->state == THREAD_RUNNING)
 962         ui_out_text (uiout, "(running)\n");
 963       else
 964         {
 965           /* The switch below puts us at the top of the stack (leaf
 966              frame).  */
 967           switch_to_thread (tp->ptid);
 968           print_stack_frame (get_selected_frame (NULL),
 969                              /* For MI output, print frame level.  */
 970                              ui_out_is_mi_like_p (uiout),
 971                              LOCATION, 0);
 972         }
 973
 974       if (ui_out_is_mi_like_p (uiout))
 975         {
 976           char *state = "stopped";
 977
 978           if (tp->state == THREAD_RUNNING)
 979             state = "running";
 980           ui_out_field_string (uiout, "state", state);
 981         }
 982
 983       core = target_core_of_thread (tp->ptid);
 984       if (ui_out_is_mi_like_p (uiout) && core != -1)
 985         ui_out_field_int (uiout, "core", core);
 986
 987       do_cleanups (chain2);
 988     }
 989
 990   /* Restores the current thread and the frame selected before
 991      the "info threads" command.  */
 992   do_cleanups (old_chain);
 993
 994   if (pid == -1 && requested_threads == NULL)
 995     {
 996       gdb_assert (current_thread != -1
 997                   || !thread_list
 998                   || ptid_equal (inferior_ptid, null_ptid));
 999       if (current_thread != -1 && ui_out_is_mi_like_p (uiout))
1000         ui_out_field_int (uiout, "current-thread-id", current_thread);
1001
1002       if (current_thread != -1 && is_exited (current_ptid))
1003         ui_out_message (uiout, 0, "\n\
1004 The current thread <Thread ID %d> has terminated.  See `help thread'.\n",
1005                         current_thread);
1006       else if (thread_list
1007                && current_thread == -1
1008                && ptid_equal (current_ptid, null_ptid))
1009         ui_out_message (uiout, 0, "\n\
1010 No selected thread.  See `help thread'.\n");
1011     }
1012 }
1013
1014 /* Print information about currently known threads
1015
1016    Optional ARG is a thread id, or list of thread ids.
1017
1018    Note: this has the drawback that it _really_ switches
1019          threads, which frees the frame cache.  A no-side
1020          effects info-threads command would be nicer.  */
1021
1022 static void
1023 info_threads_command (char *arg, int from_tty)
1024 {
1025   print_thread_info (current_uiout, arg, -1);
1026 }
1027
1028 /* Switch from one thread to another.  */
1029
1030 void
1031 switch_to_thread (ptid_t ptid)
1032 {
1033   /* Switch the program space as well, if we can infer it from the now
1034      current thread.  Otherwise, it's up to the caller to select the
1035      space it wants.  */
1036   if (!ptid_equal (ptid, null_ptid))
1037     {
1038       struct inferior *inf;
1039
1040       inf = find_inferior_pid (ptid_get_pid (ptid));
1041       gdb_assert (inf != NULL);
1042       set_current_program_space (inf->pspace);
1043       set_current_inferior (inf);
1044     }
1045
1046   if (ptid_equal (ptid, inferior_ptid))
1047     return;
1048
1049   inferior_ptid = ptid;
1050   reinit_frame_cache ();
1051
1052   /* We don't check for is_stopped, because we're called at times
1053      while in the TARGET_RUNNING state, e.g., while handling an
1054      internal event.  */
1055   if (!ptid_equal (inferior_ptid, null_ptid)
1056       && !is_exited (ptid)
1057       && !is_executing (ptid))
1058     stop_pc = regcache_read_pc (get_thread_regcache (ptid));
1059   else
1060     stop_pc = ~(CORE_ADDR) 0;
1061 }
1062
1063 static void
1064 restore_current_thread (ptid_t ptid)
1065 {
1066   switch_to_thread (ptid);
1067 }
1068
1069 static void
1070 restore_selected_frame (struct frame_id a_frame_id, int frame_level)
1071 {
1072   struct frame_info *frame = NULL;
1073   int count;
1074
1075   /* This means there was no selected frame.  */
1076   if (frame_level == -1)
1077     {
1078       select_frame (NULL);
1079       return;
1080     }
1081
1082   gdb_assert (frame_level >= 0);
1083
1084   /* Restore by level first, check if the frame id is the same as
1085      expected.  If that fails, try restoring by frame id.  If that
1086      fails, nothing to do, just warn the user.  */
1087
1088   count = frame_level;
1089   frame = find_relative_frame (get_current_frame (), &count);
1090   if (count == 0
1091       && frame != NULL
1092       /* The frame ids must match - either both valid or both outer_frame_id.
1093          The latter case is not failsafe, but since it's highly unlikely
1094          the search by level finds the wrong frame, it's 99.9(9)% of
1095          the time (for all practical purposes) safe.  */
1096       && frame_id_eq (get_frame_id (frame), a_frame_id))
1097     {
1098       /* Cool, all is fine.  */
1099       select_frame (frame);
1100       return;
1101     }
1102
1103   frame = frame_find_by_id (a_frame_id);
1104   if (frame != NULL)
1105     {
1106       /* Cool, refound it.  */
1107       select_frame (frame);
1108       return;
1109     }
1110
1111   /* Nothing else to do, the frame layout really changed.  Select the
1112      innermost stack frame.  */
1113   select_frame (get_current_frame ());
1114
1115   /* Warn the user.  */
1116   if (frame_level > 0 && !ui_out_is_mi_like_p (current_uiout))
1117     {
1118       warning (_("Couldn't restore frame #%d in "
1119                  "current thread.  Bottom (innermost) frame selected:"),
1120                frame_level);
1121       /* For MI, we should probably have a notification about
1122          current frame change.  But this error is not very
1123          likely, so don't bother for now.  */
1124       print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC, 1);
1125     }
1126 }
1127
1128 struct current_thread_cleanup
1129 {
1130   ptid_t inferior_ptid;
1131   struct frame_id selected_frame_id;
1132   int selected_frame_level;
1133   int was_stopped;
1134   int inf_id;
1135   int was_removable;
1136 };
1137
1138 static void
1139 do_restore_current_thread_cleanup (void *arg)
1140 {
1141   struct thread_info *tp;
1142   struct current_thread_cleanup *old = arg;
1143
1144   tp = find_thread_ptid (old->inferior_ptid);
1145
1146   /* If the previously selected thread belonged to a process that has
1147      in the mean time been deleted (due to normal exit, detach, etc.),
1148      then don't revert back to it, but instead simply drop back to no
1149      thread selected.  */
1150   if (tp
1151       && find_inferior_pid (ptid_get_pid (tp->ptid)) != NULL)
1152     restore_current_thread (old->inferior_ptid);
1153   else
1154     {
1155       restore_current_thread (null_ptid);
1156       set_current_inferior (find_inferior_id (old->inf_id));
1157     }
1158
1159   /* The running state of the originally selected thread may have
1160      changed, so we have to recheck it here.  */
1161   if (!ptid_equal (inferior_ptid, null_ptid)
1162       && old->was_stopped
1163       && is_stopped (inferior_ptid)
1164       && target_has_registers
1165       && target_has_stack
1166       && target_has_memory)
1167     restore_selected_frame (old->selected_frame_id,
1168                             old->selected_frame_level);
1169 }
1170
1171 static void
1172 restore_current_thread_cleanup_dtor (void *arg)
1173 {
1174   struct current_thread_cleanup *old = arg;
1175   struct thread_info *tp;
1176   struct inferior *inf;
1177
1178   tp = find_thread_ptid (old->inferior_ptid);
1179   if (tp)
1180     tp->refcount--;
1181   inf = find_inferior_id (old->inf_id);
1182   if (inf != NULL)
1183     inf->removable = old->was_removable;
1184   xfree (old);
1185 }
1186
1187 /* Set the thread reference count.  */
1188
1189 static void
1190 set_thread_refcount (void *data)
1191 {
1192   int k;
1193   struct thread_array_cleanup *ta_cleanup = data;
1194
1195   for (k = 0; k != ta_cleanup->count; k++)
1196     ta_cleanup->tp_array[k]->refcount--;
1197 }
1198
1199 struct cleanup *
1200 make_cleanup_restore_current_thread (void)
1201 {
1202   struct thread_info *tp;
1203   struct frame_info *frame;
1204   struct current_thread_cleanup *old;
1205
1206   old = xmalloc (sizeof (struct current_thread_cleanup));
1207   old->inferior_ptid = inferior_ptid;
1208   old->inf_id = current_inferior ()->num;
1209   old->was_removable = current_inferior ()->removable;
1210
1211   if (!ptid_equal (inferior_ptid, null_ptid))
1212     {
1213       old->was_stopped = is_stopped (inferior_ptid);
1214       if (old->was_stopped
1215           && target_has_registers
1216           && target_has_stack
1217           && target_has_memory)
1218         {
1219           /* When processing internal events, there might not be a
1220              selected frame.  If we naively call get_selected_frame
1221              here, then we can end up reading debuginfo for the
1222              current frame, but we don't generally need the debuginfo
1223              at this point.  */
1224           frame = get_selected_frame_if_set ();
1225         }
1226       else
1227         frame = NULL;
1228
1229       old->selected_frame_id = get_frame_id (frame);
1230       old->selected_frame_level = frame_relative_level (frame);
1231
1232       tp = find_thread_ptid (inferior_ptid);
1233       if (tp)
1234         tp->refcount++;
1235     }
1236
1237   current_inferior ()->removable = 0;
1238
1239   return make_cleanup_dtor (do_restore_current_thread_cleanup, old,
1240                             restore_current_thread_cleanup_dtor);
1241 }
1242
1243 /* Apply a GDB command to a list of threads.  List syntax is a whitespace
1244    seperated list of numbers, or ranges, or the keyword `all'.  Ranges consist
1245    of two numbers seperated by a hyphen.  Examples:
1246
1247    thread apply 1 2 7 4 backtrace       Apply backtrace cmd to threads 1,2,7,4
1248    thread apply 2-7 9 p foo(1)  Apply p foo(1) cmd to threads 2->7 & 9
1249    thread apply all p x/i $pc   Apply x/i $pc cmd to all threads.  */
1250
1251 static void
1252 thread_apply_all_command (char *cmd, int from_tty)
1253 {
1254   struct cleanup *old_chain;
1255   char *saved_cmd;
1256   int tc;
1257   struct thread_array_cleanup ta_cleanup;
1258
1259   if (cmd == NULL || *cmd == '\000')
1260     error (_("Please specify a command following the thread ID list"));
1261
1262   update_thread_list ();
1263
1264   old_chain = make_cleanup_restore_current_thread ();
1265
1266   /* Save a copy of the command in case it is clobbered by
1267      execute_command.  */
1268   saved_cmd = xstrdup (cmd);
1269   make_cleanup (xfree, saved_cmd);
1270   tc = thread_count ();
1271
1272   if (tc)
1273     {
1274       struct thread_info **tp_array;
1275       struct thread_info *tp;
1276       int i = 0, k;
1277
1278       /* Save a copy of the thread_list in case we execute detach
1279          command.  */
1280       tp_array = xmalloc (sizeof (struct thread_info *) * tc);
1281       make_cleanup (xfree, tp_array);
1282       ta_cleanup.tp_array = tp_array;
1283       ta_cleanup.count = tc;
1284
1285       ALL_NON_EXITED_THREADS (tp)
1286         {
1287           tp_array[i] = tp;
1288           tp->refcount++;
1289           i++;
1290         }
1291
1292       make_cleanup (set_thread_refcount, &ta_cleanup);
1293
1294       for (k = 0; k != i; k++)
1295         if (thread_alive (tp_array[k]))
1296           {
1297             switch_to_thread (tp_array[k]->ptid);
1298             printf_filtered (_("\nThread %d (%s):\n"),
1299                              tp_array[k]->num,
1300                              target_pid_to_str (inferior_ptid));
1301             execute_command (cmd, from_tty);
1302
1303             /* Restore exact command used previously.  */
1304             strcpy (cmd, saved_cmd);
1305           }
1306     }
1307
1308   do_cleanups (old_chain);
1309 }
1310
1311 static void
1312 thread_apply_command (char *tidlist, int from_tty)
1313 {
1314   char *cmd;
1315   struct cleanup *old_chain;
1316   char *saved_cmd;
1317   struct get_number_or_range_state state;
1318
1319   if (tidlist == NULL || *tidlist == '\000')
1320     error (_("Please specify a thread ID list"));
1321
1322   for (cmd = tidlist; *cmd != '\000' && !isalpha (*cmd); cmd++);
1323
1324   if (*cmd == '\000')
1325     error (_("Please specify a command following the thread ID list"));
1326
1327   /* Save a copy of the command in case it is clobbered by
1328      execute_command.  */
1329   saved_cmd = xstrdup (cmd);
1330   old_chain = make_cleanup (xfree, saved_cmd);
1331
1332   init_number_or_range (&state, tidlist);
1333   while (!state.finished && state.string < cmd)
1334     {
1335       struct thread_info *tp;
1336       int start;
1337
1338       start = get_number_or_range (&state);
1339
1340       make_cleanup_restore_current_thread ();
1341
1342       tp = find_thread_id (start);
1343
1344       if (!tp)
1345         warning (_("Unknown thread %d."), start);
1346       else if (!thread_alive (tp))
1347         warning (_("Thread %d has terminated."), start);
1348       else
1349         {
1350           switch_to_thread (tp->ptid);
1351
1352           printf_filtered (_("\nThread %d (%s):\n"), tp->num,
1353                            target_pid_to_str (inferior_ptid));
1354           execute_command (cmd, from_tty);
1355
1356           /* Restore exact command used previously.  */
1357           strcpy (cmd, saved_cmd);
1358         }
1359     }
1360
1361   do_cleanups (old_chain);
1362 }
1363
1364 /* Switch to the specified thread.  Will dispatch off to thread_apply_command
1365    if prefix of arg is `apply'.  */
1366
1367 static void
1368 thread_command (char *tidstr, int from_tty)
1369 {
1370   if (!tidstr)
1371     {
1372       if (ptid_equal (inferior_ptid, null_ptid))
1373         error (_("No thread selected"));
1374
1375       if (target_has_stack)
1376         {
1377           if (is_exited (inferior_ptid))
1378             printf_filtered (_("[Current thread is %d (%s) (exited)]\n"),
1379                              pid_to_thread_id (inferior_ptid),
1380                              target_pid_to_str (inferior_ptid));
1381           else
1382             printf_filtered (_("[Current thread is %d (%s)]\n"),
1383                              pid_to_thread_id (inferior_ptid),
1384                              target_pid_to_str (inferior_ptid));
1385         }
1386       else
1387         error (_("No stack."));
1388       return;
1389     }
1390
1391   gdb_thread_select (current_uiout, tidstr, NULL);
1392 }
1393
1394 /* Implementation of `thread name'.  */
1395
1396 static void
1397 thread_name_command (char *arg, int from_tty)
1398 {
1399   struct thread_info *info;
1400
1401   if (ptid_equal (inferior_ptid, null_ptid))
1402     error (_("No thread selected"));
1403
1404   arg = skip_spaces (arg);
1405
1406   info = inferior_thread ();
1407   xfree (info->name);
1408   info->name = arg ? xstrdup (arg) : NULL;
1409 }
1410
1411 /* Find thread ids with a name, target pid, or extra info matching ARG.  */
1412
1413 static void
1414 thread_find_command (char *arg, int from_tty)
1415 {
1416   struct thread_info *tp;
1417   char *tmp;
1418   unsigned long match = 0;
1419
1420   if (arg == NULL || *arg == '\0')
1421     error (_("Command requires an argument."));
1422
1423   tmp = re_comp (arg);
1424   if (tmp != 0)
1425     error (_("Invalid regexp (%s): %s"), tmp, arg);
1426
1427   update_thread_list ();
1428   for (tp = thread_list; tp; tp = tp->next)
1429     {
1430       if (tp->name != NULL && re_exec (tp->name))
1431         {
1432           printf_filtered (_("Thread %d has name '%s'\n"),
1433                            tp->num, tp->name);
1434           match++;
1435         }
1436
1437       tmp = target_thread_name (tp);
1438       if (tmp != NULL && re_exec (tmp))
1439         {
1440           printf_filtered (_("Thread %d has target name '%s'\n"),
1441                            tp->num, tmp);
1442           match++;
1443         }
1444
1445       tmp = target_pid_to_str (tp->ptid);
1446       if (tmp != NULL && re_exec (tmp))
1447         {
1448           printf_filtered (_("Thread %d has target id '%s'\n"),
1449                            tp->num, tmp);
1450           match++;
1451         }
1452
1453       tmp = target_extra_thread_info (tp);
1454       if (tmp != NULL && re_exec (tmp))
1455         {
1456           printf_filtered (_("Thread %d has extra info '%s'\n"),
1457                            tp->num, tmp);
1458           match++;
1459         }
1460     }
1461   if (!match)
1462     printf_filtered (_("No threads match '%s'\n"), arg);
1463 }
1464
1465 /* Print notices when new threads are attached and detached.  */
1466 int print_thread_events = 1;
1467 static void
1468 show_print_thread_events (struct ui_file *file, int from_tty,
1469                           struct cmd_list_element *c, const char *value)
1470 {
1471   fprintf_filtered (file,
1472                     _("Printing of thread events is %s.\n"),
1473                     value);
1474 }
1475
1476 static int
1477 do_captured_thread_select (struct ui_out *uiout, void *tidstr)
1478 {
1479   int num;
1480   struct thread_info *tp;
1481
1482   num = value_as_long (parse_and_eval (tidstr));
1483
1484   tp = find_thread_id (num);
1485
1486   if (!tp)
1487     error (_("Thread ID %d not known."), num);
1488
1489   if (!thread_alive (tp))
1490     error (_("Thread ID %d has terminated."), num);
1491
1492   switch_to_thread (tp->ptid);
1493
1494   annotate_thread_changed ();
1495
1496   ui_out_text (uiout, "[Switching to thread ");
1497   ui_out_field_int (uiout, "new-thread-id", pid_to_thread_id (inferior_ptid));
1498   ui_out_text (uiout, " (");
1499   ui_out_text (uiout, target_pid_to_str (inferior_ptid));
1500   ui_out_text (uiout, ")]");
1501
1502   /* Note that we can't reach this with an exited thread, due to the
1503      thread_alive check above.  */
1504   if (tp->state == THREAD_RUNNING)
1505     ui_out_text (uiout, "(running)\n");
1506   else
1507     {
1508       ui_out_text (uiout, "\n");
1509       print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC, 1);
1510     }
1511
1512   /* Since the current thread may have changed, see if there is any
1513      exited thread we can now delete.  */
1514   prune_threads ();
1515
1516   return GDB_RC_OK;
1517 }
1518
1519 enum gdb_rc
1520 gdb_thread_select (struct ui_out *uiout, char *tidstr, char **error_message)
1521 {
1522   if (catch_exceptions_with_msg (uiout, do_captured_thread_select, tidstr,
1523                                  error_message, RETURN_MASK_ALL) < 0)
1524     return GDB_RC_FAIL;
1525   return GDB_RC_OK;
1526 }
1527
1528 /* Update the 'threads_executing' global based on the threads we know
1529    about right now.  */
1530
1531 static void
1532 update_threads_executing (void)
1533 {
1534   struct thread_info *tp;
1535
1536   threads_executing = 0;
1537   ALL_NON_EXITED_THREADS (tp)
1538     {
1539       if (tp->executing)
1540         {
1541           threads_executing = 1;
1542           break;
1543         }
1544     }
1545 }
1546
1547 void
1548 update_thread_list (void)
1549 {
1550   prune_threads ();
1551   target_find_new_threads ();
1552   update_threads_executing ();
1553 }
1554
1555 /* Return a new value for the selected thread's id.  Return a value of 0 if
1556    no thread is selected, or no threads exist.  */
1557
1558 static struct value *
1559 thread_id_make_value (struct gdbarch *gdbarch, struct internalvar *var,
1560                       void *ignore)
1561 {
1562   struct thread_info *tp = find_thread_ptid (inferior_ptid);
1563
1564   return value_from_longest (builtin_type (gdbarch)->builtin_int,
1565                              (tp ? tp->num : 0));
1566 }
1567
1568 /* Commands with a prefix of `thread'.  */
1569 struct cmd_list_element *thread_cmd_list = NULL;
1570
1571 /* Implementation of `thread' variable.  */
1572
1573 static const struct internalvar_funcs thread_funcs =
1574 {
1575   thread_id_make_value,
1576   NULL,
1577   NULL
1578 };
1579
1580 void
1581 _initialize_thread (void)
1582 {
1583   static struct cmd_list_element *thread_apply_list = NULL;
1584
1585   add_info ("threads", info_threads_command,
1586             _("Display currently known threads.\n\
1587 Usage: info threads [ID]...\n\
1588 Optional arguments are thread IDs with spaces between.\n\
1589 If no arguments, all threads are displayed."));
1590
1591   add_prefix_cmd ("thread", class_run, thread_command, _("\
1592 Use this command to switch between threads.\n\
1593 The new thread ID must be currently known."),
1594                   &thread_cmd_list, "thread ", 1, &cmdlist);
1595
1596   add_prefix_cmd ("apply", class_run, thread_apply_command,
1597                   _("Apply a command to a list of threads."),
1598                   &thread_apply_list, "thread apply ", 1, &thread_cmd_list);
1599
1600   add_cmd ("all", class_run, thread_apply_all_command,
1601            _("Apply a command to all threads."), &thread_apply_list);
1602
1603   add_cmd ("name", class_run, thread_name_command,
1604            _("Set the current thread's name.\n\
1605 Usage: thread name [NAME]\n\
1606 If NAME is not given, then any existing name is removed."), &thread_cmd_list);
1607
1608   add_cmd ("find", class_run, thread_find_command, _("\
1609 Find threads that match a regular expression.\n\
1610 Usage: thread find REGEXP\n\
1611 Will display thread ids whose name, target ID, or extra info matches REGEXP."),
1612            &thread_cmd_list);
1613
1614   if (!xdb_commands)
1615     add_com_alias ("t", "thread", class_run, 1);
1616
1617   add_setshow_boolean_cmd ("thread-events", no_class,
1618          &print_thread_events, _("\
1619 Set printing of thread events (such as thread start and exit)."), _("\
1620 Show printing of thread events (such as thread start and exit)."), NULL,
1621          NULL,
1622          show_print_thread_events,
1623          &setprintlist, &showprintlist);
1624
1625   create_internalvar_type_lazy ("_thread", &thread_funcs, NULL);
1626 }