gdb/thread.c

   1 /* Multi-process/thread control for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986-1988, 1993-2004, 2007-2012 Free Software
   4    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 3 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, see <http://www.gnu.org/licenses/>.  */
  22
  23 #include "defs.h"
  24 #include "symtab.h"
  25 #include "frame.h"
  26 #include "inferior.h"
  27 #include "environ.h"
  28 #include "value.h"
  29 #include "target.h"
  30 #include "gdbthread.h"
  31 #include "exceptions.h"
  32 #include "command.h"
  33 #include "gdbcmd.h"
  34 #include "regcache.h"
  35 #include "gdb.h"
  36 #include "gdb_string.h"
  37
  38 #include <ctype.h>
  39 #include <sys/types.h>
  40 #include <signal.h>
  41 #include "ui-out.h"
  42 #include "observer.h"
  43 #include "annotate.h"
  44 #include "cli/cli-decode.h"
  45 #include "gdb_regex.h"
  46 #include "cli/cli-utils.h"
  47 #include "continuations.h"
  48
  49 /* Definition of struct thread_info exported to gdbthread.h.  */
  50
  51 /* Prototypes for exported functions.  */
  52
  53 void _initialize_thread (void);
  54
  55 /* Prototypes for local functions.  */
  56
  57 static struct thread_info *thread_list = NULL;
  58 static int highest_thread_num;
  59
  60 static void thread_command (char *tidstr, int from_tty);
  61 static void thread_apply_all_command (char *, int);
  62 static int thread_alive (struct thread_info *);
  63 static void info_threads_command (char *, int);
  64 static void thread_apply_command (char *, int);
  65 static void restore_current_thread (ptid_t);
  66 static void prune_threads (void);
  67
  68 struct thread_info*
  69 inferior_thread (void)
  70 {
  71   struct thread_info *tp = find_thread_ptid (inferior_ptid);
  72   gdb_assert (tp);
  73   return tp;
  74 }
  75
  76 void
  77 delete_step_resume_breakpoint (struct thread_info *tp)
  78 {
  79   if (tp && tp->control.step_resume_breakpoint)
  80     {
  81       delete_breakpoint (tp->control.step_resume_breakpoint);
  82       tp->control.step_resume_breakpoint = NULL;
  83     }
  84 }
  85
  86 void
  87 delete_exception_resume_breakpoint (struct thread_info *tp)
  88 {
  89   if (tp && tp->control.exception_resume_breakpoint)
  90     {
  91       delete_breakpoint (tp->control.exception_resume_breakpoint);
  92       tp->control.exception_resume_breakpoint = NULL;
  93     }
  94 }
  95
  96 static void
  97 clear_thread_inferior_resources (struct thread_info *tp)
  98 {
  99   /* NOTE: this will take care of any left-over step_resume breakpoints,
 100      but not any user-specified thread-specific breakpoints.  We can not
 101      delete the breakpoint straight-off, because the inferior might not
 102      be stopped at the moment.  */
 103   if (tp->control.step_resume_breakpoint)
 104     {
 105       tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
 106       tp->control.step_resume_breakpoint = NULL;
 107     }
 108
 109   if (tp->control.exception_resume_breakpoint)
 110     {
 111       tp->control.exception_resume_breakpoint->disposition
 112         = disp_del_at_next_stop;
 113       tp->control.exception_resume_breakpoint = NULL;
 114     }
 115
 116   bpstat_clear (&tp->control.stop_bpstat);
 117
 118   do_all_intermediate_continuations_thread (tp, 1);
 119   do_all_continuations_thread (tp, 1);
 120
 121   delete_longjmp_breakpoint (tp->num);
 122 }
 123
 124 static void
 125 free_thread (struct thread_info *tp)
 126 {
 127   if (tp->private)
 128     {
 129       if (tp->private_dtor)
 130         tp->private_dtor (tp->private);
 131       else
 132         xfree (tp->private);
 133     }
 134
 135   xfree (tp->name);
 136   xfree (tp);
 137 }
 138
 139 void
 140 init_thread_list (void)
 141 {
 142   struct thread_info *tp, *tpnext;
 143
 144   highest_thread_num = 0;
 145
 146   if (!thread_list)
 147     return;
 148
 149   for (tp = thread_list; tp; tp = tpnext)
 150     {
 151       tpnext = tp->next;
 152       free_thread (tp);
 153     }
 154
 155   thread_list = NULL;
 156 }
 157
 158 /* Allocate a new thread with target id PTID and add it to the thread
 159    list.  */
 160
 161 static struct thread_info *
 162 new_thread (ptid_t ptid)
 163 {
 164   struct thread_info *tp;
 165
 166   tp = xcalloc (1, sizeof (*tp));
 167
 168   tp->ptid = ptid;
 169   tp->num = ++highest_thread_num;
 170   tp->next = thread_list;
 171   thread_list = tp;
 172
 173   /* Nothing to follow yet.  */
 174   tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
 175   tp->state = THREAD_STOPPED;
 176
 177   return tp;
 178 }
 179
 180 struct thread_info *
 181 add_thread_silent (ptid_t ptid)
 182 {
 183   struct thread_info *tp;
 184
 185   tp = find_thread_ptid (ptid);
 186   if (tp)
 187     /* Found an old thread with the same id.  It has to be dead,
 188        otherwise we wouldn't be adding a new thread with the same id.
 189        The OS is reusing this id --- delete it, and recreate a new
 190        one.  */
 191     {
 192       /* In addition to deleting the thread, if this is the current
 193          thread, then we need to take care that delete_thread doesn't
 194          really delete the thread if it is inferior_ptid.  Create a
 195          new template thread in the list with an invalid ptid, switch
 196          to it, delete the original thread, reset the new thread's
 197          ptid, and switch to it.  */
 198
 199       if (ptid_equal (inferior_ptid, ptid))
 200         {
 201           tp = new_thread (null_ptid);
 202
 203           /* Make switch_to_thread not read from the thread.  */
 204           tp->state = THREAD_EXITED;
 205           switch_to_thread (null_ptid);
 206
 207           /* Now we can delete it.  */
 208           delete_thread (ptid);
 209
 210           /* Now reset its ptid, and reswitch inferior_ptid to it.  */
 211           tp->ptid = ptid;
 212           tp->state = THREAD_STOPPED;
 213           switch_to_thread (ptid);
 214
 215           observer_notify_new_thread (tp);
 216
 217           /* All done.  */
 218           return tp;
 219         }
 220       else
 221         /* Just go ahead and delete it.  */
 222         delete_thread (ptid);
 223     }
 224
 225   tp = new_thread (ptid);
 226   observer_notify_new_thread (tp);
 227
 228   return tp;
 229 }
 230
 231 struct thread_info *
 232 add_thread_with_info (ptid_t ptid, struct private_thread_info *private)
 233 {
 234   struct thread_info *result = add_thread_silent (ptid);
 235
 236   result->private = private;
 237
 238   if (print_thread_events)
 239     printf_unfiltered (_("[New %s]\n"), target_pid_to_str (ptid));
 240
 241   annotate_new_thread ();
 242   return result;
 243 }
 244
 245 struct thread_info *
 246 add_thread (ptid_t ptid)
 247 {
 248   return add_thread_with_info (ptid, NULL);
 249 }
 250
 251 /* Delete thread PTID.  If SILENT, don't notify the observer of this
 252    exit.  */
 253 static void
 254 delete_thread_1 (ptid_t ptid, int silent)
 255 {
 256   struct thread_info *tp, *tpprev;
 257
 258   tpprev = NULL;
 259
 260   for (tp = thread_list; tp; tpprev = tp, tp = tp->next)
 261     if (ptid_equal (tp->ptid, ptid))
 262       break;
 263
 264   if (!tp)
 265     return;
 266
 267   /* If this is the current thread, or there's code out there that
 268      relies on it existing (refcount > 0) we can't delete yet.  Mark
 269      it as exited, and notify it.  */
 270   if (tp->refcount > 0
 271       || ptid_equal (tp->ptid, inferior_ptid))
 272     {
 273       if (tp->state != THREAD_EXITED)
 274         {
 275           observer_notify_thread_exit (tp, silent);
 276
 277           /* Tag it as exited.  */
 278           tp->state = THREAD_EXITED;
 279
 280           /* Clear breakpoints, etc. associated with this thread.  */
 281           clear_thread_inferior_resources (tp);
 282         }
 283
 284        /* Will be really deleted some other time.  */
 285        return;
 286      }
 287
 288   /* Notify thread exit, but only if we haven't already.  */
 289   if (tp->state != THREAD_EXITED)
 290     observer_notify_thread_exit (tp, silent);
 291
 292   /* Tag it as exited.  */
 293   tp->state = THREAD_EXITED;
 294   clear_thread_inferior_resources (tp);
 295
 296   if (tpprev)
 297     tpprev->next = tp->next;
 298   else
 299     thread_list = tp->next;
 300
 301   free_thread (tp);
 302 }
 303
 304 /* Delete thread PTID and notify of thread exit.  If this is
 305    inferior_ptid, don't actually delete it, but tag it as exited and
 306    do the notification.  If PTID is the user selected thread, clear
 307    it.  */
 308 void
 309 delete_thread (ptid_t ptid)
 310 {
 311   delete_thread_1 (ptid, 0 /* not silent */);
 312 }
 313
 314 void
 315 delete_thread_silent (ptid_t ptid)
 316 {
 317   delete_thread_1 (ptid, 1 /* silent */);
 318 }
 319
 320 struct thread_info *
 321 find_thread_id (int num)
 322 {
 323   struct thread_info *tp;
 324
 325   for (tp = thread_list; tp; tp = tp->next)
 326     if (tp->num == num)
 327       return tp;
 328
 329   return NULL;
 330 }
 331
 332 /* Find a thread_info by matching PTID.  */
 333 struct thread_info *
 334 find_thread_ptid (ptid_t ptid)
 335 {
 336   struct thread_info *tp;
 337
 338   for (tp = thread_list; tp; tp = tp->next)
 339     if (ptid_equal (tp->ptid, ptid))
 340       return tp;
 341
 342   return NULL;
 343 }
 344
 345 /*
 346  * Thread iterator function.
 347  *
 348  * Calls a callback function once for each thread, so long as
 349  * the callback function returns false.  If the callback function
 350  * returns true, the iteration will end and the current thread
 351  * will be returned.  This can be useful for implementing a
 352  * search for a thread with arbitrary attributes, or for applying
 353  * some operation to every thread.
 354  *
 355  * FIXME: some of the existing functionality, such as
 356  * "Thread apply all", might be rewritten using this functionality.
 357  */
 358
 359 struct thread_info *
 360 iterate_over_threads (int (*callback) (struct thread_info *, void *),
 361                       void *data)
 362 {
 363   struct thread_info *tp, *next;
 364
 365   for (tp = thread_list; tp; tp = next)
 366     {
 367       next = tp->next;
 368       if ((*callback) (tp, data))
 369         return tp;
 370     }
 371
 372   return NULL;
 373 }
 374
 375 int
 376 thread_count (void)
 377 {
 378   int result = 0;
 379   struct thread_info *tp;
 380
 381   for (tp = thread_list; tp; tp = tp->next)
 382     ++result;
 383
 384   return result;
 385 }
 386
 387 int
 388 valid_thread_id (int num)
 389 {
 390   struct thread_info *tp;
 391
 392   for (tp = thread_list; tp; tp = tp->next)
 393     if (tp->num == num)
 394       return 1;
 395
 396   return 0;
 397 }
 398
 399 int
 400 pid_to_thread_id (ptid_t ptid)
 401 {
 402   struct thread_info *tp;
 403
 404   for (tp = thread_list; tp; tp = tp->next)
 405     if (ptid_equal (tp->ptid, ptid))
 406       return tp->num;
 407
 408   return 0;
 409 }
 410
 411 ptid_t
 412 thread_id_to_pid (int num)
 413 {
 414   struct thread_info *thread = find_thread_id (num);
 415
 416   if (thread)
 417     return thread->ptid;
 418   else
 419     return pid_to_ptid (-1);
 420 }
 421
 422 int
 423 in_thread_list (ptid_t ptid)
 424 {
 425   struct thread_info *tp;
 426
 427   for (tp = thread_list; tp; tp = tp->next)
 428     if (ptid_equal (tp->ptid, ptid))
 429       return 1;
 430
 431   return 0;                     /* Never heard of 'im.  */
 432 }
 433
 434 /* Finds the first thread of the inferior given by PID.  If PID is -1,
 435    return the first thread in the list.  */
 436
 437 struct thread_info *
 438 first_thread_of_process (int pid)
 439 {
 440   struct thread_info *tp, *ret = NULL;
 441
 442   for (tp = thread_list; tp; tp = tp->next)
 443     if (pid == -1 || ptid_get_pid (tp->ptid) == pid)
 444       if (ret == NULL || tp->num < ret->num)
 445         ret = tp;
 446
 447   return ret;
 448 }
 449
 450 struct thread_info *
 451 any_thread_of_process (int pid)
 452 {
 453   struct thread_info *tp;
 454
 455   for (tp = thread_list; tp; tp = tp->next)
 456     if (ptid_get_pid (tp->ptid) == pid)
 457       return tp;
 458
 459   return NULL;
 460 }
 461
 462 struct thread_info *
 463 any_live_thread_of_process (int pid)
 464 {
 465   struct thread_info *tp;
 466   struct thread_info *tp_executing = NULL;
 467
 468   for (tp = thread_list; tp; tp = tp->next)
 469     if (tp->state != THREAD_EXITED && ptid_get_pid (tp->ptid) == pid)
 470       {
 471         if (tp->executing)
 472           tp_executing = tp;
 473         else
 474           return tp;
 475       }
 476
 477   return tp_executing;
 478 }
 479
 480 /* Print a list of thread ids currently known, and the total number of
 481    threads.  To be used from within catch_errors.  */
 482 static int
 483 do_captured_list_thread_ids (struct ui_out *uiout, void *arg)
 484 {
 485   struct thread_info *tp;
 486   int num = 0;
 487   struct cleanup *cleanup_chain;
 488   int current_thread = -1;
 489
 490   update_thread_list ();
 491
 492   cleanup_chain = make_cleanup_ui_out_tuple_begin_end (uiout, "thread-ids");
 493
 494   for (tp = thread_list; tp; tp = tp->next)
 495     {
 496       if (tp->state == THREAD_EXITED)
 497         continue;
 498
 499       if (ptid_equal (tp->ptid, inferior_ptid))
 500         current_thread = tp->num;
 501
 502       num++;
 503       ui_out_field_int (uiout, "thread-id", tp->num);
 504     }
 505
 506   do_cleanups (cleanup_chain);
 507
 508   if (current_thread != -1)
 509     ui_out_field_int (uiout, "current-thread-id", current_thread);
 510   ui_out_field_int (uiout, "number-of-threads", num);
 511   return GDB_RC_OK;
 512 }
 513
 514 /* Official gdblib interface function to get a list of thread ids and
 515    the total number.  */
 516 enum gdb_rc
 517 gdb_list_thread_ids (struct ui_out *uiout, char **error_message)
 518 {
 519   if (catch_exceptions_with_msg (uiout, do_captured_list_thread_ids, NULL,
 520                                  error_message, RETURN_MASK_ALL) < 0)
 521     return GDB_RC_FAIL;
 522   return GDB_RC_OK;
 523 }
 524
 525 /* Return true if TP is an active thread.  */
 526 static int
 527 thread_alive (struct thread_info *tp)
 528 {
 529   if (tp->state == THREAD_EXITED)
 530     return 0;
 531   if (!target_thread_alive (tp->ptid))
 532     return 0;
 533   return 1;
 534 }
 535
 536 static void
 537 prune_threads (void)
 538 {
 539   struct thread_info *tp, *next;
 540
 541   for (tp = thread_list; tp; tp = next)
 542     {
 543       next = tp->next;
 544       if (!thread_alive (tp))
 545         delete_thread (tp->ptid);
 546     }
 547 }
 548
 549 void
 550 thread_change_ptid (ptid_t old_ptid, ptid_t new_ptid)
 551 {
 552   struct inferior *inf;
 553   struct thread_info *tp;
 554
 555   /* It can happen that what we knew as the target inferior id
 556      changes.  E.g, target remote may only discover the remote process
 557      pid after adding the inferior to GDB's list.  */
 558   inf = find_inferior_pid (ptid_get_pid (old_ptid));
 559   inf->pid = ptid_get_pid (new_ptid);
 560
 561   tp = find_thread_ptid (old_ptid);
 562   tp->ptid = new_ptid;
 563
 564   observer_notify_thread_ptid_changed (old_ptid, new_ptid);
 565 }
 566
 567 void
 568 set_running (ptid_t ptid, int running)
 569 {
 570   struct thread_info *tp;
 571   int all = ptid_equal (ptid, minus_one_ptid);
 572
 573   /* We try not to notify the observer if no thread has actually changed
 574      the running state -- merely to reduce the number of messages to
 575      frontend.  Frontend is supposed to handle multiple *running just fine.  */
 576   if (all || ptid_is_pid (ptid))
 577     {
 578       int any_started = 0;
 579
 580       for (tp = thread_list; tp; tp = tp->next)
 581         if (all || ptid_get_pid (tp->ptid) == ptid_get_pid (ptid))
 582           {
 583             if (tp->state == THREAD_EXITED)
 584               continue;
 585             if (running && tp->state == THREAD_STOPPED)
 586               any_started = 1;
 587             tp->state = running ? THREAD_RUNNING : THREAD_STOPPED;
 588           }
 589       if (any_started)
 590         observer_notify_target_resumed (ptid);
 591     }
 592   else
 593     {
 594       int started = 0;
 595
 596       tp = find_thread_ptid (ptid);
 597       gdb_assert (tp);
 598       gdb_assert (tp->state != THREAD_EXITED);
 599       if (running && tp->state == THREAD_STOPPED)
 600         started = 1;
 601       tp->state = running ? THREAD_RUNNING : THREAD_STOPPED;
 602       if (started)
 603         observer_notify_target_resumed (ptid);
 604     }
 605 }
 606
 607 static int
 608 is_thread_state (ptid_t ptid, enum thread_state state)
 609 {
 610   struct thread_info *tp;
 611
 612   tp = find_thread_ptid (ptid);
 613   gdb_assert (tp);
 614   return tp->state == state;
 615 }
 616
 617 int
 618 is_stopped (ptid_t ptid)
 619 {
 620   return is_thread_state (ptid, THREAD_STOPPED);
 621 }
 622
 623 int
 624 is_exited (ptid_t ptid)
 625 {
 626   return is_thread_state (ptid, THREAD_EXITED);
 627 }
 628
 629 int
 630 is_running (ptid_t ptid)
 631 {
 632   return is_thread_state (ptid, THREAD_RUNNING);
 633 }
 634
 635 int
 636 any_running (void)
 637 {
 638   struct thread_info *tp;
 639
 640   for (tp = thread_list; tp; tp = tp->next)
 641     if (tp->state == THREAD_RUNNING)
 642       return 1;
 643
 644   return 0;
 645 }
 646
 647 int
 648 is_executing (ptid_t ptid)
 649 {
 650   struct thread_info *tp;
 651
 652   tp = find_thread_ptid (ptid);
 653   gdb_assert (tp);
 654   return tp->executing;
 655 }
 656
 657 void
 658 set_executing (ptid_t ptid, int executing)
 659 {
 660   struct thread_info *tp;
 661   int all = ptid_equal (ptid, minus_one_ptid);
 662
 663   if (all || ptid_is_pid (ptid))
 664     {
 665       for (tp = thread_list; tp; tp = tp->next)
 666         if (all || ptid_get_pid (tp->ptid) == ptid_get_pid (ptid))
 667           tp->executing = executing;
 668     }
 669   else
 670     {
 671       tp = find_thread_ptid (ptid);
 672       gdb_assert (tp);
 673       tp->executing = executing;
 674     }
 675 }
 676
 677 void
 678 set_stop_requested (ptid_t ptid, int stop)
 679 {
 680   struct thread_info *tp;
 681   int all = ptid_equal (ptid, minus_one_ptid);
 682
 683   if (all || ptid_is_pid (ptid))
 684     {
 685       for (tp = thread_list; tp; tp = tp->next)
 686         if (all || ptid_get_pid (tp->ptid) == ptid_get_pid (ptid))
 687           tp->stop_requested = stop;
 688     }
 689   else
 690     {
 691       tp = find_thread_ptid (ptid);
 692       gdb_assert (tp);
 693       tp->stop_requested = stop;
 694     }
 695
 696   /* Call the stop requested observer so other components of GDB can
 697      react to this request.  */
 698   if (stop)
 699     observer_notify_thread_stop_requested (ptid);
 700 }
 701
 702 void
 703 finish_thread_state (ptid_t ptid)
 704 {
 705   struct thread_info *tp;
 706   int all;
 707   int any_started = 0;
 708
 709   all = ptid_equal (ptid, minus_one_ptid);
 710
 711   if (all || ptid_is_pid (ptid))
 712     {
 713       for (tp = thread_list; tp; tp = tp->next)
 714         {
 715           if (tp->state == THREAD_EXITED)
 716             continue;
 717           if (all || ptid_get_pid (ptid) == ptid_get_pid (tp->ptid))
 718             {
 719               if (tp->executing && tp->state == THREAD_STOPPED)
 720                 any_started = 1;
 721               tp->state = tp->executing ? THREAD_RUNNING : THREAD_STOPPED;
 722             }
 723         }
 724     }
 725   else
 726     {
 727       tp = find_thread_ptid (ptid);
 728       gdb_assert (tp);
 729       if (tp->state != THREAD_EXITED)
 730         {
 731           if (tp->executing && tp->state == THREAD_STOPPED)
 732             any_started = 1;
 733           tp->state = tp->executing ? THREAD_RUNNING : THREAD_STOPPED;
 734         }
 735     }
 736
 737   if (any_started)
 738     observer_notify_target_resumed (ptid);
 739 }
 740
 741 void
 742 finish_thread_state_cleanup (void *arg)
 743 {
 744   ptid_t *ptid_p = arg;
 745
 746   gdb_assert (arg);
 747
 748   finish_thread_state (*ptid_p);
 749 }
 750
 751 /* Prints the list of threads and their details on UIOUT.
 752    This is a version of 'info_threads_command' suitable for
 753    use from MI.
 754    If REQUESTED_THREAD is not -1, it's the GDB id of the thread
 755    that should be printed.  Otherwise, all threads are
 756    printed.
 757    If PID is not -1, only print threads from the process PID.
 758    Otherwise, threads from all attached PIDs are printed.
 759    If both REQUESTED_THREAD and PID are not -1, then the thread
 760    is printed if it belongs to the specified process.  Otherwise,
 761    an error is raised.  */
 762 void
 763 print_thread_info (struct ui_out *uiout, char *requested_threads, int pid)
 764 {
 765   struct thread_info *tp;
 766   ptid_t current_ptid;
 767   struct cleanup *old_chain;
 768   char *extra_info, *name, *target_id;
 769   int current_thread = -1;
 770
 771   update_thread_list ();
 772   current_ptid = inferior_ptid;
 773
 774   /* We'll be switching threads temporarily.  */
 775   old_chain = make_cleanup_restore_current_thread ();
 776
 777   /* For backward compatibility, we make a list for MI.  A table is
 778      preferable for the CLI, though, because it shows table
 779      headers.  */
 780   if (ui_out_is_mi_like_p (uiout))
 781     make_cleanup_ui_out_list_begin_end (uiout, "threads");
 782   else
 783     {
 784       int n_threads = 0;
 785
 786       for (tp = thread_list; tp; tp = tp->next)
 787         {
 788           if (!number_is_in_list (requested_threads, tp->num))
 789             continue;
 790
 791           if (pid != -1 && PIDGET (tp->ptid) != pid)
 792             continue;
 793
 794           if (tp->state == THREAD_EXITED)
 795             continue;
 796
 797           ++n_threads;
 798         }
 799
 800       if (n_threads == 0)
 801         {
 802           if (requested_threads == NULL || *requested_threads == '\0')
 803             ui_out_message (uiout, 0, _("No threads.\n"));
 804           else
 805             ui_out_message (uiout, 0, _("No threads match '%s'.\n"),
 806                             requested_threads);
 807           do_cleanups (old_chain);
 808           return;
 809         }
 810
 811       make_cleanup_ui_out_table_begin_end (uiout, 4, n_threads, "threads");
 812
 813       ui_out_table_header (uiout, 1, ui_left, "current", "");
 814       ui_out_table_header (uiout, 4, ui_left, "id", "Id");
 815       ui_out_table_header (uiout, 17, ui_left, "target-id", "Target Id");
 816       ui_out_table_header (uiout, 1, ui_left, "frame", "Frame");
 817       ui_out_table_body (uiout);
 818     }
 819
 820   for (tp = thread_list; tp; tp = tp->next)
 821     {
 822       struct cleanup *chain2;
 823       int core;
 824
 825       if (!number_is_in_list (requested_threads, tp->num))
 826         continue;
 827
 828       if (pid != -1 && PIDGET (tp->ptid) != pid)
 829         {
 830           if (requested_threads != NULL && *requested_threads != '\0')
 831             error (_("Requested thread not found in requested process"));
 832           continue;
 833         }
 834
 835       if (ptid_equal (tp->ptid, current_ptid))
 836         current_thread = tp->num;
 837
 838       if (tp->state == THREAD_EXITED)
 839         continue;
 840
 841       chain2 = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
 842
 843       if (ui_out_is_mi_like_p (uiout))
 844         {
 845           /* Compatibility.  */
 846           if (ptid_equal (tp->ptid, current_ptid))
 847             ui_out_text (uiout, "* ");
 848           else
 849             ui_out_text (uiout, "  ");
 850         }
 851       else
 852         {
 853           if (ptid_equal (tp->ptid, current_ptid))
 854             ui_out_field_string (uiout, "current", "*");
 855           else
 856             ui_out_field_skip (uiout, "current");
 857         }
 858
 859       ui_out_field_int (uiout, "id", tp->num);
 860
 861       /* For the CLI, we stuff everything into the target-id field.
 862          This is a gross hack to make the output come out looking
 863          correct.  The underlying problem here is that ui-out has no
 864          way to specify that a field's space allocation should be
 865          shared by several fields.  For MI, we do the right thing
 866          instead.  */
 867
 868       target_id = target_pid_to_str (tp->ptid);
 869       extra_info = target_extra_thread_info (tp);
 870       name = tp->name ? tp->name : target_thread_name (tp);
 871
 872       if (ui_out_is_mi_like_p (uiout))
 873         {
 874           ui_out_field_string (uiout, "target-id", target_id);
 875           if (extra_info)
 876             ui_out_field_string (uiout, "details", extra_info);
 877           if (name)
 878             ui_out_field_string (uiout, "name", name);
 879         }
 880       else
 881         {
 882           struct cleanup *str_cleanup;
 883           char *contents;
 884
 885           if (extra_info && name)
 886             contents = xstrprintf ("%s \"%s\" (%s)", target_id,
 887                                    name, extra_info);
 888           else if (extra_info)
 889             contents = xstrprintf ("%s (%s)", target_id, extra_info);
 890           else if (name)
 891             contents = xstrprintf ("%s \"%s\"", target_id, name);
 892           else
 893             contents = xstrdup (target_id);
 894           str_cleanup = make_cleanup (xfree, contents);
 895
 896           ui_out_field_string (uiout, "target-id", contents);
 897           do_cleanups (str_cleanup);
 898         }
 899
 900       if (tp->state == THREAD_RUNNING)
 901         ui_out_text (uiout, "(running)\n");
 902       else
 903         {
 904           /* The switch below puts us at the top of the stack (leaf
 905              frame).  */
 906           switch_to_thread (tp->ptid);
 907           print_stack_frame (get_selected_frame (NULL),
 908                              /* For MI output, print frame level.  */
 909                              ui_out_is_mi_like_p (uiout),
 910                              LOCATION);
 911         }
 912
 913       if (ui_out_is_mi_like_p (uiout))
 914         {
 915           char *state = "stopped";
 916
 917           if (tp->state == THREAD_RUNNING)
 918             state = "running";
 919           ui_out_field_string (uiout, "state", state);
 920         }
 921
 922       core = target_core_of_thread (tp->ptid);
 923       if (ui_out_is_mi_like_p (uiout) && core != -1)
 924         ui_out_field_int (uiout, "core", core);
 925
 926       do_cleanups (chain2);
 927     }
 928
 929   /* Restores the current thread and the frame selected before
 930      the "info threads" command.  */
 931   do_cleanups (old_chain);
 932
 933   if (pid == -1 && requested_threads == NULL)
 934     {
 935       gdb_assert (current_thread != -1
 936                   || !thread_list
 937                   || ptid_equal (inferior_ptid, null_ptid));
 938       if (current_thread != -1 && ui_out_is_mi_like_p (uiout))
 939         ui_out_field_int (uiout, "current-thread-id", current_thread);
 940
 941       if (current_thread != -1 && is_exited (current_ptid))
 942         ui_out_message (uiout, 0, "\n\
 943 The current thread <Thread ID %d> has terminated.  See `help thread'.\n",
 944                         current_thread);
 945       else if (thread_list
 946                && current_thread == -1
 947                && ptid_equal (current_ptid, null_ptid))
 948         ui_out_message (uiout, 0, "\n\
 949 No selected thread.  See `help thread'.\n");
 950     }
 951 }
 952
 953 /* Print information about currently known threads
 954
 955    Optional ARG is a thread id, or list of thread ids.
 956
 957    Note: this has the drawback that it _really_ switches
 958          threads, which frees the frame cache.  A no-side
 959          effects info-threads command would be nicer.  */
 960
 961 static void
 962 info_threads_command (char *arg, int from_tty)
 963 {
 964   print_thread_info (current_uiout, arg, -1);
 965 }
 966
 967 /* Switch from one thread to another.  */
 968
 969 void
 970 switch_to_thread (ptid_t ptid)
 971 {
 972   /* Switch the program space as well, if we can infer it from the now
 973      current thread.  Otherwise, it's up to the caller to select the
 974      space it wants.  */
 975   if (!ptid_equal (ptid, null_ptid))
 976     {
 977       struct inferior *inf;
 978
 979       inf = find_inferior_pid (ptid_get_pid (ptid));
 980       gdb_assert (inf != NULL);
 981       set_current_program_space (inf->pspace);
 982       set_current_inferior (inf);
 983     }
 984
 985   if (ptid_equal (ptid, inferior_ptid))
 986     return;
 987
 988   inferior_ptid = ptid;
 989   reinit_frame_cache ();
 990   registers_changed ();
 991
 992   /* We don't check for is_stopped, because we're called at times
 993      while in the TARGET_RUNNING state, e.g., while handling an
 994      internal event.  */
 995   if (!ptid_equal (inferior_ptid, null_ptid)
 996       && !is_exited (ptid)
 997       && !is_executing (ptid))
 998     stop_pc = regcache_read_pc (get_thread_regcache (ptid));
 999   else
1000     stop_pc = ~(CORE_ADDR) 0;
1001 }
1002
1003 static void
1004 restore_current_thread (ptid_t ptid)
1005 {
1006   switch_to_thread (ptid);
1007 }
1008
1009 static void
1010 restore_selected_frame (struct frame_id a_frame_id, int frame_level)
1011 {
1012   struct frame_info *frame = NULL;
1013   int count;
1014
1015   /* This means there was no selected frame.  */
1016   if (frame_level == -1)
1017     {
1018       select_frame (NULL);
1019       return;
1020     }
1021
1022   gdb_assert (frame_level >= 0);
1023
1024   /* Restore by level first, check if the frame id is the same as
1025      expected.  If that fails, try restoring by frame id.  If that
1026      fails, nothing to do, just warn the user.  */
1027
1028   count = frame_level;
1029   frame = find_relative_frame (get_current_frame (), &count);
1030   if (count == 0
1031       && frame != NULL
1032       /* The frame ids must match - either both valid or both outer_frame_id.
1033          The latter case is not failsafe, but since it's highly unlikely
1034          the search by level finds the wrong frame, it's 99.9(9)% of
1035          the time (for all practical purposes) safe.  */
1036       && frame_id_eq (get_frame_id (frame), a_frame_id))
1037     {
1038       /* Cool, all is fine.  */
1039       select_frame (frame);
1040       return;
1041     }
1042
1043   frame = frame_find_by_id (a_frame_id);
1044   if (frame != NULL)
1045     {
1046       /* Cool, refound it.  */
1047       select_frame (frame);
1048       return;
1049     }
1050
1051   /* Nothing else to do, the frame layout really changed.  Select the
1052      innermost stack frame.  */
1053   select_frame (get_current_frame ());
1054
1055   /* Warn the user.  */
1056   if (frame_level > 0 && !ui_out_is_mi_like_p (current_uiout))
1057     {
1058       warning (_("Couldn't restore frame #%d in "
1059                  "current thread, at reparsed frame #0\n"),
1060                frame_level);
1061       /* For MI, we should probably have a notification about
1062          current frame change.  But this error is not very
1063          likely, so don't bother for now.  */
1064       print_stack_frame (get_selected_frame (NULL), 1, SRC_LINE);
1065     }
1066 }
1067
1068 struct current_thread_cleanup
1069 {
1070   ptid_t inferior_ptid;
1071   struct frame_id selected_frame_id;
1072   int selected_frame_level;
1073   int was_stopped;
1074   int inf_id;
1075 };
1076
1077 static void
1078 do_restore_current_thread_cleanup (void *arg)
1079 {
1080   struct thread_info *tp;
1081   struct current_thread_cleanup *old = arg;
1082
1083   tp = find_thread_ptid (old->inferior_ptid);
1084
1085   /* If the previously selected thread belonged to a process that has
1086      in the mean time been deleted (due to normal exit, detach, etc.),
1087      then don't revert back to it, but instead simply drop back to no
1088      thread selected.  */
1089   if (tp
1090       && find_inferior_pid (ptid_get_pid (tp->ptid)) != NULL)
1091     restore_current_thread (old->inferior_ptid);
1092   else
1093     {
1094       restore_current_thread (null_ptid);
1095       set_current_inferior (find_inferior_id (old->inf_id));
1096     }
1097
1098   /* The running state of the originally selected thread may have
1099      changed, so we have to recheck it here.  */
1100   if (!ptid_equal (inferior_ptid, null_ptid)
1101       && old->was_stopped
1102       && is_stopped (inferior_ptid)
1103       && target_has_registers
1104       && target_has_stack
1105       && target_has_memory)
1106     restore_selected_frame (old->selected_frame_id,
1107                             old->selected_frame_level);
1108 }
1109
1110 static void
1111 restore_current_thread_cleanup_dtor (void *arg)
1112 {
1113   struct current_thread_cleanup *old = arg;
1114   struct thread_info *tp;
1115
1116   tp = find_thread_ptid (old->inferior_ptid);
1117   if (tp)
1118     tp->refcount--;
1119   xfree (old);
1120 }
1121
1122 struct cleanup *
1123 make_cleanup_restore_current_thread (void)
1124 {
1125   struct thread_info *tp;
1126   struct frame_info *frame;
1127   struct current_thread_cleanup *old;
1128
1129   old = xmalloc (sizeof (struct current_thread_cleanup));
1130   old->inferior_ptid = inferior_ptid;
1131   old->inf_id = current_inferior ()->num;
1132
1133   if (!ptid_equal (inferior_ptid, null_ptid))
1134     {
1135       old->was_stopped = is_stopped (inferior_ptid);
1136       if (old->was_stopped
1137           && target_has_registers
1138           && target_has_stack
1139           && target_has_memory)
1140         {
1141           /* When processing internal events, there might not be a
1142              selected frame.  If we naively call get_selected_frame
1143              here, then we can end up reading debuginfo for the
1144              current frame, but we don't generally need the debuginfo
1145              at this point.  */
1146           frame = get_selected_frame_if_set ();
1147         }
1148       else
1149         frame = NULL;
1150
1151       old->selected_frame_id = get_frame_id (frame);
1152       old->selected_frame_level = frame_relative_level (frame);
1153
1154       tp = find_thread_ptid (inferior_ptid);
1155       if (tp)
1156         tp->refcount++;
1157     }
1158
1159   return make_cleanup_dtor (do_restore_current_thread_cleanup, old,
1160                             restore_current_thread_cleanup_dtor);
1161 }
1162
1163 /* Apply a GDB command to a list of threads.  List syntax is a whitespace
1164    seperated list of numbers, or ranges, or the keyword `all'.  Ranges consist
1165    of two numbers seperated by a hyphen.  Examples:
1166
1167    thread apply 1 2 7 4 backtrace       Apply backtrace cmd to threads 1,2,7,4
1168    thread apply 2-7 9 p foo(1)  Apply p foo(1) cmd to threads 2->7 & 9
1169    thread apply all p x/i $pc   Apply x/i $pc cmd to all threads.  */
1170
1171 static void
1172 thread_apply_all_command (char *cmd, int from_tty)
1173 {
1174   struct thread_info *tp;
1175   struct cleanup *old_chain;
1176   char *saved_cmd;
1177
1178   if (cmd == NULL || *cmd == '\000')
1179     error (_("Please specify a command following the thread ID list"));
1180
1181   update_thread_list ();
1182
1183   old_chain = make_cleanup_restore_current_thread ();
1184
1185   /* Save a copy of the command in case it is clobbered by
1186      execute_command.  */
1187   saved_cmd = xstrdup (cmd);
1188   make_cleanup (xfree, saved_cmd);
1189   for (tp = thread_list; tp; tp = tp->next)
1190     if (thread_alive (tp))
1191       {
1192         switch_to_thread (tp->ptid);
1193
1194         printf_filtered (_("\nThread %d (%s):\n"),
1195                          tp->num, target_pid_to_str (inferior_ptid));
1196         execute_command (cmd, from_tty);
1197         strcpy (cmd, saved_cmd);        /* Restore exact command used
1198                                            previously.  */
1199       }
1200
1201   do_cleanups (old_chain);
1202 }
1203
1204 static void
1205 thread_apply_command (char *tidlist, int from_tty)
1206 {
1207   char *cmd;
1208   struct cleanup *old_chain;
1209   char *saved_cmd;
1210   struct get_number_or_range_state state;
1211
1212   if (tidlist == NULL || *tidlist == '\000')
1213     error (_("Please specify a thread ID list"));
1214
1215   for (cmd = tidlist; *cmd != '\000' && !isalpha (*cmd); cmd++);
1216
1217   if (*cmd == '\000')
1218     error (_("Please specify a command following the thread ID list"));
1219
1220   /* Save a copy of the command in case it is clobbered by
1221      execute_command.  */
1222   saved_cmd = xstrdup (cmd);
1223   old_chain = make_cleanup (xfree, saved_cmd);
1224
1225   init_number_or_range (&state, tidlist);
1226   while (!state.finished && state.string < cmd)
1227     {
1228       struct thread_info *tp;
1229       int start;
1230       char *p = tidlist;
1231
1232       start = get_number_or_range (&state);
1233
1234       make_cleanup_restore_current_thread ();
1235
1236       tp = find_thread_id (start);
1237
1238       if (!tp)
1239         warning (_("Unknown thread %d."), start);
1240       else if (!thread_alive (tp))
1241         warning (_("Thread %d has terminated."), start);
1242       else
1243         {
1244           switch_to_thread (tp->ptid);
1245
1246           printf_filtered (_("\nThread %d (%s):\n"), tp->num,
1247                            target_pid_to_str (inferior_ptid));
1248           execute_command (cmd, from_tty);
1249
1250           /* Restore exact command used previously.  */
1251           strcpy (cmd, saved_cmd);
1252         }
1253     }
1254
1255   do_cleanups (old_chain);
1256 }
1257
1258 /* Switch to the specified thread.  Will dispatch off to thread_apply_command
1259    if prefix of arg is `apply'.  */
1260
1261 static void
1262 thread_command (char *tidstr, int from_tty)
1263 {
1264   if (!tidstr)
1265     {
1266       if (ptid_equal (inferior_ptid, null_ptid))
1267         error (_("No thread selected"));
1268
1269       if (target_has_stack)
1270         {
1271           if (is_exited (inferior_ptid))
1272             printf_filtered (_("[Current thread is %d (%s) (exited)]\n"),
1273                              pid_to_thread_id (inferior_ptid),
1274                              target_pid_to_str (inferior_ptid));
1275           else
1276             printf_filtered (_("[Current thread is %d (%s)]\n"),
1277                              pid_to_thread_id (inferior_ptid),
1278                              target_pid_to_str (inferior_ptid));
1279         }
1280       else
1281         error (_("No stack."));
1282       return;
1283     }
1284
1285   gdb_thread_select (current_uiout, tidstr, NULL);
1286 }
1287
1288 /* Implementation of `thread name'.  */
1289
1290 static void
1291 thread_name_command (char *arg, int from_tty)
1292 {
1293   struct thread_info *info;
1294
1295   if (ptid_equal (inferior_ptid, null_ptid))
1296     error (_("No thread selected"));
1297
1298   while (arg && isspace (*arg))
1299     ++arg;
1300
1301   info = inferior_thread ();
1302   xfree (info->name);
1303   info->name = arg ? xstrdup (arg) : NULL;
1304 }
1305
1306 /* Find thread ids with a name, target pid, or extra info matching ARG.  */
1307
1308 static void
1309 thread_find_command (char *arg, int from_tty)
1310 {
1311   struct thread_info *tp;
1312   char *tmp;
1313   unsigned long match = 0;
1314
1315   if (arg == NULL || *arg == '\0')
1316     error (_("Command requires an argument."));
1317
1318   tmp = re_comp (arg);
1319   if (tmp != 0)
1320     error (_("Invalid regexp (%s): %s"), tmp, arg);
1321
1322   update_thread_list ();
1323   for (tp = thread_list; tp; tp = tp->next)
1324     {
1325       if (tp->name != NULL && re_exec (tp->name))
1326         {
1327           printf_filtered (_("Thread %d has name '%s'\n"),
1328                            tp->num, tp->name);
1329           match++;
1330         }
1331
1332       tmp = target_thread_name (tp);
1333       if (tmp != NULL && re_exec (tmp))
1334         {
1335           printf_filtered (_("Thread %d has target name '%s'\n"),
1336                            tp->num, tmp);
1337           match++;
1338         }
1339
1340       tmp = target_pid_to_str (tp->ptid);
1341       if (tmp != NULL && re_exec (tmp))
1342         {
1343           printf_filtered (_("Thread %d has target id '%s'\n"),
1344                            tp->num, tmp);
1345           match++;
1346         }
1347
1348       tmp = target_extra_thread_info (tp);
1349       if (tmp != NULL && re_exec (tmp))
1350         {
1351           printf_filtered (_("Thread %d has extra info '%s'\n"),
1352                            tp->num, tmp);
1353           match++;
1354         }
1355     }
1356   if (!match)
1357     printf_filtered (_("No threads match '%s'\n"), arg);
1358 }
1359
1360 /* Print notices when new threads are attached and detached.  */
1361 int print_thread_events = 1;
1362 static void
1363 show_print_thread_events (struct ui_file *file, int from_tty,
1364                           struct cmd_list_element *c, const char *value)
1365 {
1366   fprintf_filtered (file,
1367                     _("Printing of thread events is %s.\n"),
1368                     value);
1369 }
1370
1371 static int
1372 do_captured_thread_select (struct ui_out *uiout, void *tidstr)
1373 {
1374   int num;
1375   struct thread_info *tp;
1376
1377   num = value_as_long (parse_and_eval (tidstr));
1378
1379   tp = find_thread_id (num);
1380
1381   if (!tp)
1382     error (_("Thread ID %d not known."), num);
1383
1384   if (!thread_alive (tp))
1385     error (_("Thread ID %d has terminated."), num);
1386
1387   switch_to_thread (tp->ptid);
1388
1389   annotate_thread_changed ();
1390
1391   ui_out_text (uiout, "[Switching to thread ");
1392   ui_out_field_int (uiout, "new-thread-id", pid_to_thread_id (inferior_ptid));
1393   ui_out_text (uiout, " (");
1394   ui_out_text (uiout, target_pid_to_str (inferior_ptid));
1395   ui_out_text (uiout, ")]");
1396
1397   /* Note that we can't reach this with an exited thread, due to the
1398      thread_alive check above.  */
1399   if (tp->state == THREAD_RUNNING)
1400     ui_out_text (uiout, "(running)\n");
1401   else
1402     {
1403       ui_out_text (uiout, "\n");
1404       print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC);
1405     }
1406
1407   /* Since the current thread may have changed, see if there is any
1408      exited thread we can now delete.  */
1409   prune_threads ();
1410
1411   return GDB_RC_OK;
1412 }
1413
1414 enum gdb_rc
1415 gdb_thread_select (struct ui_out *uiout, char *tidstr, char **error_message)
1416 {
1417   if (catch_exceptions_with_msg (uiout, do_captured_thread_select, tidstr,
1418                                  error_message, RETURN_MASK_ALL) < 0)
1419     return GDB_RC_FAIL;
1420   return GDB_RC_OK;
1421 }
1422
1423 void
1424 update_thread_list (void)
1425 {
1426   prune_threads ();
1427   target_find_new_threads ();
1428 }
1429
1430 /* Return a new value for the selected thread's id.  Return a value of 0 if
1431    no thread is selected, or no threads exist.  */
1432
1433 static struct value *
1434 thread_id_make_value (struct gdbarch *gdbarch, struct internalvar *var)
1435 {
1436   struct thread_info *tp = find_thread_ptid (inferior_ptid);
1437
1438   return value_from_longest (builtin_type (gdbarch)->builtin_int,
1439                              (tp ? tp->num : 0));
1440 }
1441
1442 /* Commands with a prefix of `thread'.  */
1443 struct cmd_list_element *thread_cmd_list = NULL;
1444
1445 void
1446 _initialize_thread (void)
1447 {
1448   static struct cmd_list_element *thread_apply_list = NULL;
1449
1450   add_info ("threads", info_threads_command,
1451             _("Display currently known threads.\n\
1452 Usage: info threads [ID]...\n\
1453 Optional arguments are thread IDs with spaces between.\n\
1454 If no arguments, all threads are displayed."));
1455
1456   add_prefix_cmd ("thread", class_run, thread_command, _("\
1457 Use this command to switch between threads.\n\
1458 The new thread ID must be currently known."),
1459                   &thread_cmd_list, "thread ", 1, &cmdlist);
1460
1461   add_prefix_cmd ("apply", class_run, thread_apply_command,
1462                   _("Apply a command to a list of threads."),
1463                   &thread_apply_list, "thread apply ", 1, &thread_cmd_list);
1464
1465   add_cmd ("all", class_run, thread_apply_all_command,
1466            _("Apply a command to all threads."), &thread_apply_list);
1467
1468   add_cmd ("name", class_run, thread_name_command,
1469            _("Set the current thread's name.\n\
1470 Usage: thread name [NAME]\n\
1471 If NAME is not given, then any existing name is removed."), &thread_cmd_list);
1472
1473   add_cmd ("find", class_run, thread_find_command, _("\
1474 Find threads that match a regular expression.\n\
1475 Usage: thread find REGEXP\n\
1476 Will display thread ids whose name, target ID, or extra info matches REGEXP."),
1477            &thread_cmd_list);
1478
1479   if (!xdb_commands)
1480     add_com_alias ("t", "thread", class_run, 1);
1481
1482   add_setshow_boolean_cmd ("thread-events", no_class,
1483          &print_thread_events, _("\
1484 Set printing of thread events (such as thread start and exit)."), _("\
1485 Show printing of thread events (such as thread start and exit)."), NULL,
1486          NULL,
1487          show_print_thread_events,
1488          &setprintlist, &showprintlist);
1489
1490   create_internalvar_type_lazy ("_thread", thread_id_make_value);
1491 }