gdb/thread.c

   1 /* Multi-process/thread control for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986, 1987, 1988, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
   4    2000, 2001, 2002, 2003, 2004, 2007, 2008 Free Software Foundation, Inc.
   5
   6    Contributed by Lynx Real-Time Systems, Inc.  Los Gatos, CA.
   7
   8    This file is part of GDB.
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 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
  44 /* Definition of struct thread_info exported to gdbthread.h */
  45
  46 /* Prototypes for exported functions. */
  47
  48 void _initialize_thread (void);
  49
  50 /* Prototypes for local functions. */
  51
  52 static struct thread_info *thread_list = NULL;
  53 static int highest_thread_num;
  54
  55 static struct thread_info *find_thread_id (int num);
  56
  57 static void thread_command (char *tidstr, int from_tty);
  58 static void thread_apply_all_command (char *, int);
  59 static int thread_alive (struct thread_info *);
  60 static void info_threads_command (char *, int);
  61 static void thread_apply_command (char *, int);
  62 static void restore_current_thread (ptid_t);
  63 static void prune_threads (void);
  64
  65 void
  66 delete_step_resume_breakpoint (void *arg)
  67 {
  68   struct breakpoint **breakpointp = (struct breakpoint **) arg;
  69   struct thread_info *tp;
  70
  71   if (*breakpointp != NULL)
  72     {
  73       delete_breakpoint (*breakpointp);
  74       for (tp = thread_list; tp; tp = tp->next)
  75         if (tp->step_resume_breakpoint == *breakpointp)
  76           tp->step_resume_breakpoint = NULL;
  77
  78       *breakpointp = NULL;
  79     }
  80 }
  81
  82 static void
  83 free_thread (struct thread_info *tp)
  84 {
  85   /* NOTE: this will take care of any left-over step_resume breakpoints,
  86      but not any user-specified thread-specific breakpoints.  We can not
  87      delete the breakpoint straight-off, because the inferior might not
  88      be stopped at the moment.  */
  89   if (tp->step_resume_breakpoint)
  90     tp->step_resume_breakpoint->disposition = disp_del_at_next_stop;
  91
  92   /* FIXME: do I ever need to call the back-end to give it a
  93      chance at this private data before deleting the thread?  */
  94   if (tp->private)
  95     xfree (tp->private);
  96
  97   xfree (tp);
  98 }
  99
 100 void
 101 init_thread_list (void)
 102 {
 103   struct thread_info *tp, *tpnext;
 104
 105   highest_thread_num = 0;
 106   if (!thread_list)
 107     return;
 108
 109   for (tp = thread_list; tp; tp = tpnext)
 110     {
 111       tpnext = tp->next;
 112       free_thread (tp);
 113     }
 114
 115   thread_list = NULL;
 116 }
 117
 118 struct thread_info *
 119 add_thread_silent (ptid_t ptid)
 120 {
 121   struct thread_info *tp;
 122
 123   tp = (struct thread_info *) xmalloc (sizeof (*tp));
 124   memset (tp, 0, sizeof (*tp));
 125   tp->ptid = ptid;
 126   tp->num = ++highest_thread_num;
 127   tp->next = thread_list;
 128   thread_list = tp;
 129   return tp;
 130 }
 131
 132 struct thread_info *
 133 add_thread_with_info (ptid_t ptid, struct private_thread_info *private)
 134 {
 135   struct thread_info *result = add_thread_silent (ptid);
 136
 137   result->private = private;
 138
 139   if (print_thread_events)
 140     printf_unfiltered (_("[New %s]\n"), target_pid_to_str (ptid));
 141
 142   observer_notify_new_thread (result);
 143
 144   return result;
 145 }
 146
 147 struct thread_info *
 148 add_thread (ptid_t ptid)
 149 {
 150   return add_thread_with_info (ptid, NULL);
 151 }
 152
 153 void
 154 delete_thread (ptid_t ptid)
 155 {
 156   struct thread_info *tp, *tpprev;
 157
 158   tpprev = NULL;
 159
 160   for (tp = thread_list; tp; tpprev = tp, tp = tp->next)
 161     if (ptid_equal (tp->ptid, ptid))
 162       break;
 163
 164   if (!tp)
 165     return;
 166
 167   if (tpprev)
 168     tpprev->next = tp->next;
 169   else
 170     thread_list = tp->next;
 171
 172   free_thread (tp);
 173 }
 174
 175 static struct thread_info *
 176 find_thread_id (int num)
 177 {
 178   struct thread_info *tp;
 179
 180   for (tp = thread_list; tp; tp = tp->next)
 181     if (tp->num == num)
 182       return tp;
 183
 184   return NULL;
 185 }
 186
 187 /* Find a thread_info by matching PTID.  */
 188 struct thread_info *
 189 find_thread_pid (ptid_t ptid)
 190 {
 191   struct thread_info *tp;
 192
 193   for (tp = thread_list; tp; tp = tp->next)
 194     if (ptid_equal (tp->ptid, ptid))
 195       return tp;
 196
 197   return NULL;
 198 }
 199
 200 /*
 201  * Thread iterator function.
 202  *
 203  * Calls a callback function once for each thread, so long as
 204  * the callback function returns false.  If the callback function
 205  * returns true, the iteration will end and the current thread
 206  * will be returned.  This can be useful for implementing a
 207  * search for a thread with arbitrary attributes, or for applying
 208  * some operation to every thread.
 209  *
 210  * FIXME: some of the existing functionality, such as
 211  * "Thread apply all", might be rewritten using this functionality.
 212  */
 213
 214 struct thread_info *
 215 iterate_over_threads (int (*callback) (struct thread_info *, void *),
 216                       void *data)
 217 {
 218   struct thread_info *tp;
 219
 220   for (tp = thread_list; tp; tp = tp->next)
 221     if ((*callback) (tp, data))
 222       return tp;
 223
 224   return NULL;
 225 }
 226
 227 int
 228 valid_thread_id (int num)
 229 {
 230   struct thread_info *tp;
 231
 232   for (tp = thread_list; tp; tp = tp->next)
 233     if (tp->num == num)
 234       return 1;
 235
 236   return 0;
 237 }
 238
 239 int
 240 pid_to_thread_id (ptid_t ptid)
 241 {
 242   struct thread_info *tp;
 243
 244   for (tp = thread_list; tp; tp = tp->next)
 245     if (ptid_equal (tp->ptid, ptid))
 246       return tp->num;
 247
 248   return 0;
 249 }
 250
 251 ptid_t
 252 thread_id_to_pid (int num)
 253 {
 254   struct thread_info *thread = find_thread_id (num);
 255   if (thread)
 256     return thread->ptid;
 257   else
 258     return pid_to_ptid (-1);
 259 }
 260
 261 int
 262 in_thread_list (ptid_t ptid)
 263 {
 264   struct thread_info *tp;
 265
 266   for (tp = thread_list; tp; tp = tp->next)
 267     if (ptid_equal (tp->ptid, ptid))
 268       return 1;
 269
 270   return 0;                     /* Never heard of 'im */
 271 }
 272
 273 /* Print a list of thread ids currently known, and the total number of
 274    threads. To be used from within catch_errors. */
 275 static int
 276 do_captured_list_thread_ids (struct ui_out *uiout, void *arg)
 277 {
 278   struct thread_info *tp;
 279   int num = 0;
 280   struct cleanup *cleanup_chain;
 281
 282   prune_threads ();
 283   target_find_new_threads ();
 284
 285   cleanup_chain = make_cleanup_ui_out_tuple_begin_end (uiout, "thread-ids");
 286
 287   for (tp = thread_list; tp; tp = tp->next)
 288     {
 289       num++;
 290       ui_out_field_int (uiout, "thread-id", tp->num);
 291     }
 292
 293   do_cleanups (cleanup_chain);
 294   ui_out_field_int (uiout, "number-of-threads", num);
 295   return GDB_RC_OK;
 296 }
 297
 298 /* Official gdblib interface function to get a list of thread ids and
 299    the total number. */
 300 enum gdb_rc
 301 gdb_list_thread_ids (struct ui_out *uiout, char **error_message)
 302 {
 303   if (catch_exceptions_with_msg (uiout, do_captured_list_thread_ids, NULL,
 304                                  error_message, RETURN_MASK_ALL) < 0)
 305     return GDB_RC_FAIL;
 306   return GDB_RC_OK;
 307 }
 308
 309 /* Load infrun state for the thread PID.  */
 310
 311 void
 312 load_infrun_state (ptid_t ptid,
 313                    CORE_ADDR *prev_pc,
 314                    int *trap_expected,
 315                    struct breakpoint **step_resume_breakpoint,
 316                    CORE_ADDR *step_range_start,
 317                    CORE_ADDR *step_range_end,
 318                    struct frame_id *step_frame_id,
 319                    int *handling_longjmp,
 320                    int *stepping_over_breakpoint,
 321                    int *stepping_through_solib_after_catch,
 322                    bpstat *stepping_through_solib_catchpoints,
 323                    int *current_line,
 324                    struct symtab **current_symtab)
 325 {
 326   struct thread_info *tp;
 327
 328   /* If we can't find the thread, then we're debugging a single threaded
 329      process.  No need to do anything in that case.  */
 330   tp = find_thread_id (pid_to_thread_id (ptid));
 331   if (tp == NULL)
 332     return;
 333
 334   *prev_pc = tp->prev_pc;
 335   *trap_expected = tp->trap_expected;
 336   *step_resume_breakpoint = tp->step_resume_breakpoint;
 337   *step_range_start = tp->step_range_start;
 338   *step_range_end = tp->step_range_end;
 339   *step_frame_id = tp->step_frame_id;
 340   *handling_longjmp = tp->handling_longjmp;
 341   *stepping_over_breakpoint = tp->stepping_over_breakpoint;
 342   *stepping_through_solib_after_catch =
 343     tp->stepping_through_solib_after_catch;
 344   *stepping_through_solib_catchpoints =
 345     tp->stepping_through_solib_catchpoints;
 346   *current_line = tp->current_line;
 347   *current_symtab = tp->current_symtab;
 348 }
 349
 350 /* Save infrun state for the thread PID.  */
 351
 352 void
 353 save_infrun_state (ptid_t ptid,
 354                    CORE_ADDR prev_pc,
 355                    int trap_expected,
 356                    struct breakpoint *step_resume_breakpoint,
 357                    CORE_ADDR step_range_start,
 358                    CORE_ADDR step_range_end,
 359                    const struct frame_id *step_frame_id,
 360                    int handling_longjmp,
 361                    int stepping_over_breakpoint,
 362                    int stepping_through_solib_after_catch,
 363                    bpstat stepping_through_solib_catchpoints,
 364                    int current_line,
 365                    struct symtab *current_symtab)
 366 {
 367   struct thread_info *tp;
 368
 369   /* If we can't find the thread, then we're debugging a single-threaded
 370      process.  Nothing to do in that case.  */
 371   tp = find_thread_id (pid_to_thread_id (ptid));
 372   if (tp == NULL)
 373     return;
 374
 375   tp->prev_pc = prev_pc;
 376   tp->trap_expected = trap_expected;
 377   tp->step_resume_breakpoint = step_resume_breakpoint;
 378   tp->step_range_start = step_range_start;
 379   tp->step_range_end = step_range_end;
 380   tp->step_frame_id = (*step_frame_id);
 381   tp->handling_longjmp = handling_longjmp;
 382   tp->stepping_over_breakpoint = stepping_over_breakpoint;
 383   tp->stepping_through_solib_after_catch = stepping_through_solib_after_catch;
 384   tp->stepping_through_solib_catchpoints = stepping_through_solib_catchpoints;
 385   tp->current_line = current_line;
 386   tp->current_symtab = current_symtab;
 387 }
 388
 389 /* Return true if TP is an active thread. */
 390 static int
 391 thread_alive (struct thread_info *tp)
 392 {
 393   if (PIDGET (tp->ptid) == -1)
 394     return 0;
 395   if (!target_thread_alive (tp->ptid))
 396     {
 397       tp->ptid = pid_to_ptid (-1);      /* Mark it as dead */
 398       return 0;
 399     }
 400   return 1;
 401 }
 402
 403 static void
 404 prune_threads (void)
 405 {
 406   struct thread_info *tp, *next;
 407
 408   for (tp = thread_list; tp; tp = next)
 409     {
 410       next = tp->next;
 411       if (!thread_alive (tp))
 412         delete_thread (tp->ptid);
 413     }
 414 }
 415
 416 /* Prints the list of threads and their details on UIOUT.
 417    This is a version of 'info_thread_command' suitable for
 418    use from MI.
 419    If REQESTED_THREAD is not -1, it's the GDB id of the thread
 420    that should be printed.  Otherwise, all threads are
 421    printed.  */
 422 void
 423 print_thread_info (struct ui_out *uiout, int requested_thread)
 424 {
 425   struct thread_info *tp;
 426   ptid_t current_ptid;
 427   struct frame_info *cur_frame;
 428   struct cleanup *old_chain;
 429   struct frame_id saved_frame_id;
 430   char *extra_info;
 431   int current_thread = -1;
 432
 433   /* Backup current thread and selected frame.  */
 434   saved_frame_id = get_frame_id (get_selected_frame (NULL));
 435   old_chain = make_cleanup_restore_current_thread (inferior_ptid, saved_frame_id);
 436
 437   make_cleanup_ui_out_list_begin_end (uiout, "threads");
 438
 439   prune_threads ();
 440   target_find_new_threads ();
 441   current_ptid = inferior_ptid;
 442   for (tp = thread_list; tp; tp = tp->next)
 443     {
 444       struct cleanup *chain2;
 445
 446       if (requested_thread != -1 && tp->num != requested_thread)
 447         continue;
 448
 449       chain2 = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
 450
 451       if (ptid_equal (tp->ptid, current_ptid))
 452         {
 453           current_thread = tp->num;
 454           ui_out_text (uiout, "* ");
 455         }
 456       else
 457         ui_out_text (uiout, "  ");
 458
 459       ui_out_field_int (uiout, "id", tp->num);
 460       ui_out_text (uiout, " ");
 461       ui_out_field_string (uiout, "target-id", target_tid_to_str (tp->ptid));
 462
 463       extra_info = target_extra_thread_info (tp);
 464       if (extra_info)
 465         {
 466           ui_out_text (uiout, " (");
 467           ui_out_field_string (uiout, "details", extra_info);
 468           ui_out_text (uiout, ")");
 469         }
 470       ui_out_text (uiout, "  ");
 471       /* That switch put us at the top of the stack (leaf frame).  */
 472       switch_to_thread (tp->ptid);
 473       print_stack_frame (get_selected_frame (NULL),
 474                          /* For MI output, print frame level.  */
 475                          ui_out_is_mi_like_p (uiout),
 476                          LOCATION);
 477
 478       do_cleanups (chain2);
 479     }
 480
 481   /* Restores the current thread and the frame selected before
 482      the "info threads" command.  */
 483   do_cleanups (old_chain);
 484
 485   if (requested_thread == -1)
 486     {
 487       gdb_assert (current_thread != -1 || !thread_list);
 488       if (current_thread != -1 && ui_out_is_mi_like_p (uiout))
 489         ui_out_field_int (uiout, "current-thread-id", current_thread);
 490     }
 491
 492   /*  If case we were not able to find the original frame, print the
 493       new selected frame.  */
 494   if (frame_find_by_id (saved_frame_id) == NULL)
 495     {
 496       warning (_("Couldn't restore frame in current thread, at frame 0"));
 497       /* For MI, we should probably have a notification about
 498          current frame change.  But this error is not very likely, so
 499          don't bother for now.  */
 500       if (!ui_out_is_mi_like_p (uiout))
 501         print_stack_frame (get_selected_frame (NULL), 0, LOCATION);
 502     }
 503 }
 504
 505
 506 /* Print information about currently known threads
 507
 508  * Note: this has the drawback that it _really_ switches
 509  *       threads, which frees the frame cache.  A no-side
 510  *       effects info-threads command would be nicer.
 511  */
 512
 513 static void
 514 info_threads_command (char *arg, int from_tty)
 515 {
 516   print_thread_info (uiout, -1);
 517 }
 518
 519 /* Switch from one thread to another. */
 520
 521 void
 522 switch_to_thread (ptid_t ptid)
 523 {
 524   if (ptid_equal (ptid, inferior_ptid))
 525     return;
 526
 527   inferior_ptid = ptid;
 528   reinit_frame_cache ();
 529   registers_changed ();
 530   stop_pc = read_pc ();
 531 }
 532
 533 static void
 534 restore_current_thread (ptid_t ptid)
 535 {
 536   if (!ptid_equal (ptid, inferior_ptid))
 537     {
 538       switch_to_thread (ptid);
 539     }
 540 }
 541
 542 static void
 543 restore_selected_frame (struct frame_id a_frame_id)
 544 {
 545   struct frame_info *selected_frame_info = NULL;
 546
 547   if (frame_id_eq (a_frame_id, null_frame_id))
 548     return;
 549
 550   if ((selected_frame_info = frame_find_by_id (a_frame_id)) != NULL)
 551     {
 552       select_frame (selected_frame_info);
 553     }
 554 }
 555
 556 struct current_thread_cleanup
 557 {
 558   ptid_t inferior_ptid;
 559   struct frame_id selected_frame_id;
 560 };
 561
 562 static void
 563 do_restore_current_thread_cleanup (void *arg)
 564 {
 565   struct current_thread_cleanup *old = arg;
 566   restore_current_thread (old->inferior_ptid);
 567   restore_selected_frame (old->selected_frame_id);
 568   xfree (old);
 569 }
 570
 571 struct cleanup *
 572 make_cleanup_restore_current_thread (ptid_t inferior_ptid,
 573                                      struct frame_id a_frame_id)
 574 {
 575   struct current_thread_cleanup *old
 576     = xmalloc (sizeof (struct current_thread_cleanup));
 577   old->inferior_ptid = inferior_ptid;
 578   old->selected_frame_id = a_frame_id;
 579   return make_cleanup (do_restore_current_thread_cleanup, old);
 580 }
 581
 582 /* Apply a GDB command to a list of threads.  List syntax is a whitespace
 583    seperated list of numbers, or ranges, or the keyword `all'.  Ranges consist
 584    of two numbers seperated by a hyphen.  Examples:
 585
 586    thread apply 1 2 7 4 backtrace       Apply backtrace cmd to threads 1,2,7,4
 587    thread apply 2-7 9 p foo(1)  Apply p foo(1) cmd to threads 2->7 & 9
 588    thread apply all p x/i $pc   Apply x/i $pc cmd to all threads
 589  */
 590
 591 static void
 592 thread_apply_all_command (char *cmd, int from_tty)
 593 {
 594   struct thread_info *tp;
 595   struct cleanup *old_chain;
 596   struct cleanup *saved_cmd_cleanup_chain;
 597   char *saved_cmd;
 598   struct frame_id saved_frame_id;
 599   ptid_t current_ptid;
 600   int thread_has_changed = 0;
 601
 602   if (cmd == NULL || *cmd == '\000')
 603     error (_("Please specify a command following the thread ID list"));
 604
 605   current_ptid = inferior_ptid;
 606   saved_frame_id = get_frame_id (get_selected_frame (NULL));
 607   old_chain = make_cleanup_restore_current_thread (inferior_ptid, saved_frame_id);
 608
 609   /* It is safe to update the thread list now, before
 610      traversing it for "thread apply all".  MVS */
 611   target_find_new_threads ();
 612
 613   /* Save a copy of the command in case it is clobbered by
 614      execute_command */
 615   saved_cmd = xstrdup (cmd);
 616   saved_cmd_cleanup_chain = make_cleanup (xfree, (void *) saved_cmd);
 617   for (tp = thread_list; tp; tp = tp->next)
 618     if (thread_alive (tp))
 619       {
 620         switch_to_thread (tp->ptid);
 621         printf_filtered (_("\nThread %d (%s):\n"),
 622                          tp->num, target_tid_to_str (inferior_ptid));
 623         execute_command (cmd, from_tty);
 624         strcpy (cmd, saved_cmd);        /* Restore exact command used previously */
 625       }
 626
 627   if (!ptid_equal (current_ptid, inferior_ptid))
 628     thread_has_changed = 1;
 629
 630   do_cleanups (saved_cmd_cleanup_chain);
 631   do_cleanups (old_chain);
 632   /* Print stack frame only if we changed thread.  */
 633   if (thread_has_changed)
 634     print_stack_frame (get_current_frame (), 1, SRC_LINE);
 635
 636 }
 637
 638 static void
 639 thread_apply_command (char *tidlist, int from_tty)
 640 {
 641   char *cmd;
 642   char *p;
 643   struct cleanup *old_chain;
 644   struct cleanup *saved_cmd_cleanup_chain;
 645   char *saved_cmd;
 646   struct frame_id saved_frame_id;
 647   ptid_t current_ptid;
 648   int thread_has_changed = 0;
 649
 650   if (tidlist == NULL || *tidlist == '\000')
 651     error (_("Please specify a thread ID list"));
 652
 653   for (cmd = tidlist; *cmd != '\000' && !isalpha (*cmd); cmd++);
 654
 655   if (*cmd == '\000')
 656     error (_("Please specify a command following the thread ID list"));
 657
 658   current_ptid = inferior_ptid;
 659   saved_frame_id = get_frame_id (get_selected_frame (NULL));
 660   old_chain = make_cleanup_restore_current_thread (inferior_ptid, saved_frame_id);
 661
 662   /* Save a copy of the command in case it is clobbered by
 663      execute_command */
 664   saved_cmd = xstrdup (cmd);
 665   saved_cmd_cleanup_chain = make_cleanup (xfree, (void *) saved_cmd);
 666   while (tidlist < cmd)
 667     {
 668       struct thread_info *tp;
 669       int start, end;
 670
 671       start = strtol (tidlist, &p, 10);
 672       if (p == tidlist)
 673         error (_("Error parsing %s"), tidlist);
 674       tidlist = p;
 675
 676       while (*tidlist == ' ' || *tidlist == '\t')
 677         tidlist++;
 678
 679       if (*tidlist == '-')      /* Got a range of IDs? */
 680         {
 681           tidlist++;            /* Skip the - */
 682           end = strtol (tidlist, &p, 10);
 683           if (p == tidlist)
 684             error (_("Error parsing %s"), tidlist);
 685           tidlist = p;
 686
 687           while (*tidlist == ' ' || *tidlist == '\t')
 688             tidlist++;
 689         }
 690       else
 691         end = start;
 692
 693       for (; start <= end; start++)
 694         {
 695           tp = find_thread_id (start);
 696
 697           if (!tp)
 698             warning (_("Unknown thread %d."), start);
 699           else if (!thread_alive (tp))
 700             warning (_("Thread %d has terminated."), start);
 701           else
 702             {
 703               switch_to_thread (tp->ptid);
 704               printf_filtered (_("\nThread %d (%s):\n"), tp->num,
 705                                target_tid_to_str (inferior_ptid));
 706               execute_command (cmd, from_tty);
 707               strcpy (cmd, saved_cmd);  /* Restore exact command used previously */
 708             }
 709         }
 710     }
 711
 712   if (!ptid_equal (current_ptid, inferior_ptid))
 713     thread_has_changed = 1;
 714
 715   do_cleanups (saved_cmd_cleanup_chain);
 716   do_cleanups (old_chain);
 717   /* Print stack frame only if we changed thread.  */
 718   if (thread_has_changed)
 719     print_stack_frame (get_current_frame (), 1, SRC_LINE);
 720 }
 721
 722 /* Switch to the specified thread.  Will dispatch off to thread_apply_command
 723    if prefix of arg is `apply'.  */
 724
 725 static void
 726 thread_command (char *tidstr, int from_tty)
 727 {
 728   if (!tidstr)
 729     {
 730       /* Don't generate an error, just say which thread is current. */
 731       if (target_has_stack)
 732         printf_filtered (_("[Current thread is %d (%s)]\n"),
 733                          pid_to_thread_id (inferior_ptid),
 734                          target_tid_to_str (inferior_ptid));
 735       else
 736         error (_("No stack."));
 737       return;
 738     }
 739
 740   gdb_thread_select (uiout, tidstr, NULL);
 741 }
 742
 743 /* Print notices when new threads are attached and detached.  */
 744 int print_thread_events = 1;
 745 static void
 746 show_print_thread_events (struct ui_file *file, int from_tty,
 747                           struct cmd_list_element *c, const char *value)
 748 {
 749   fprintf_filtered (file, _("\
 750 Printing of thread events is %s.\n"),
 751                     value);
 752 }
 753
 754 static int
 755 do_captured_thread_select (struct ui_out *uiout, void *tidstr)
 756 {
 757   int num;
 758   struct thread_info *tp;
 759
 760   num = value_as_long (parse_and_eval (tidstr));
 761
 762   tp = find_thread_id (num);
 763
 764   if (!tp)
 765     error (_("Thread ID %d not known."), num);
 766
 767   if (!thread_alive (tp))
 768     error (_("Thread ID %d has terminated."), num);
 769
 770   switch_to_thread (tp->ptid);
 771
 772   ui_out_text (uiout, "[Switching to thread ");
 773   ui_out_field_int (uiout, "new-thread-id", pid_to_thread_id (inferior_ptid));
 774   ui_out_text (uiout, " (");
 775   ui_out_text (uiout, target_tid_to_str (inferior_ptid));
 776   ui_out_text (uiout, ")]");
 777
 778   print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC);
 779   return GDB_RC_OK;
 780 }
 781
 782 enum gdb_rc
 783 gdb_thread_select (struct ui_out *uiout, char *tidstr, char **error_message)
 784 {
 785   if (catch_exceptions_with_msg (uiout, do_captured_thread_select, tidstr,
 786                                  error_message, RETURN_MASK_ALL) < 0)
 787     return GDB_RC_FAIL;
 788   return GDB_RC_OK;
 789 }
 790
 791 /* Commands with a prefix of `thread'.  */
 792 struct cmd_list_element *thread_cmd_list = NULL;
 793
 794 void
 795 _initialize_thread (void)
 796 {
 797   static struct cmd_list_element *thread_apply_list = NULL;
 798
 799   add_info ("threads", info_threads_command,
 800             _("IDs of currently known threads."));
 801
 802   add_prefix_cmd ("thread", class_run, thread_command, _("\
 803 Use this command to switch between threads.\n\
 804 The new thread ID must be currently known."),
 805                   &thread_cmd_list, "thread ", 1, &cmdlist);
 806
 807   add_prefix_cmd ("apply", class_run, thread_apply_command,
 808                   _("Apply a command to a list of threads."),
 809                   &thread_apply_list, "thread apply ", 1, &thread_cmd_list);
 810
 811   add_cmd ("all", class_run, thread_apply_all_command,
 812            _("Apply a command to all threads."), &thread_apply_list);
 813
 814   if (!xdb_commands)
 815     add_com_alias ("t", "thread", class_run, 1);
 816
 817   add_setshow_boolean_cmd ("thread-events", no_class,
 818          &print_thread_events, _("\
 819 Set printing of thread events (e.g., thread start and exit)."), _("\
 820 Show printing of thread events (e.g., thread start and exit)."), NULL,
 821          NULL,
 822          show_print_thread_events,
 823          &setprintlist, &showprintlist);
 824 }