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, 2009 5 Free Software Foundation, Inc. 6 7 Contributed by Lynx Real-Time Systems, Inc. Los Gatos, CA. 8 9 This file is part of GDB. 10 11 This program is free software; you can redistribute it and/or modify 12 it under the terms of the GNU General Public License as published by 13 the Free Software Foundation; either version 3 of the License, or 14 (at your option) any later version. 15 16 This program is distributed in the hope that it will be useful, 17 but WITHOUT ANY WARRANTY; without even the implied warranty of 18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19 GNU General Public License for more details. 20 21 You should have received a copy of the GNU General Public License 22 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 23 24 #include "defs.h" 25 #include "symtab.h" 26 #include "frame.h" 27 #include "inferior.h" 28 #include "environ.h" 29 #include "value.h" 30 #include "target.h" 31 #include "gdbthread.h" 32 #include "exceptions.h" 33 #include "command.h" 34 #include "gdbcmd.h" 35 #include "regcache.h" 36 #include "gdb.h" 37 #include "gdb_string.h" 38 39 #include <ctype.h> 40 #include <sys/types.h> 41 #include <signal.h> 42 #include "ui-out.h" 43 #include "observer.h" 44 #include "annotate.h" 45 #include "cli/cli-decode.h" 46 47 /* Definition of struct thread_info exported to gdbthread.h */ 48 49 /* Prototypes for exported functions. */ 50 51 void _initialize_thread (void); 52 53 /* Prototypes for local functions. */ 54 55 static struct thread_info *thread_list = NULL; 56 static int highest_thread_num; 57 58 static void thread_command (char *tidstr, int from_tty); 59 static void thread_apply_all_command (char *, int); 60 static int thread_alive (struct thread_info *); 61 static void info_threads_command (char *, int); 62 static void thread_apply_command (char *, int); 63 static void restore_current_thread (ptid_t); 64 static void prune_threads (void); 65 66 /* Frontend view of the thread state. Possible extensions: stepping, 67 finishing, until(ling),... */ 68 enum thread_state 69 { 70 THREAD_STOPPED, 71 THREAD_RUNNING, 72 THREAD_EXITED, 73 }; 74 75 struct thread_info* 76 inferior_thread (void) 77 { 78 struct thread_info *tp = find_thread_ptid (inferior_ptid); 79 gdb_assert (tp); 80 return tp; 81 } 82 83 void 84 delete_step_resume_breakpoint (struct thread_info *tp) 85 { 86 if (tp && tp->step_resume_breakpoint) 87 { 88 delete_breakpoint (tp->step_resume_breakpoint); 89 tp->step_resume_breakpoint = NULL; 90 } 91 } 92 93 static void 94 clear_thread_inferior_resources (struct thread_info *tp) 95 { 96 /* NOTE: this will take care of any left-over step_resume breakpoints, 97 but not any user-specified thread-specific breakpoints. We can not 98 delete the breakpoint straight-off, because the inferior might not 99 be stopped at the moment. */ 100 if (tp->step_resume_breakpoint) 101 { 102 tp->step_resume_breakpoint->disposition = disp_del_at_next_stop; 103 tp->step_resume_breakpoint = NULL; 104 } 105 106 bpstat_clear (&tp->stop_bpstat); 107 108 discard_all_intermediate_continuations_thread (tp); 109 discard_all_continuations_thread (tp); 110 } 111 112 static void 113 free_thread (struct thread_info *tp) 114 { 115 clear_thread_inferior_resources (tp); 116 117 /* FIXME: do I ever need to call the back-end to give it a 118 chance at this private data before deleting the thread? */ 119 if (tp->private) 120 xfree (tp->private); 121 122 xfree (tp); 123 } 124 125 void 126 init_thread_list (void) 127 { 128 struct thread_info *tp, *tpnext; 129 130 highest_thread_num = 0; 131 132 if (!thread_list) 133 return; 134 135 for (tp = thread_list; tp; tp = tpnext) 136 { 137 tpnext = tp->next; 138 free_thread (tp); 139 } 140 141 thread_list = NULL; 142 } 143 144 /* Allocate a new thread with target id PTID and add it to the thread 145 list. */ 146 147 static struct thread_info * 148 new_thread (ptid_t ptid) 149 { 150 struct thread_info *tp; 151 152 tp = xcalloc (1, sizeof (*tp)); 153 154 tp->ptid = ptid; 155 tp->num = ++highest_thread_num; 156 tp->next = thread_list; 157 thread_list = tp; 158 159 /* Nothing to follow yet. */ 160 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS; 161 tp->state_ = THREAD_STOPPED; 162 163 return tp; 164 } 165 166 struct thread_info * 167 add_thread_silent (ptid_t ptid) 168 { 169 struct thread_info *tp; 170 171 tp = find_thread_ptid (ptid); 172 if (tp) 173 /* Found an old thread with the same id. It has to be dead, 174 otherwise we wouldn't be adding a new thread with the same id. 175 The OS is reusing this id --- delete it, and recreate a new 176 one. */ 177 { 178 /* In addition to deleting the thread, if this is the current 179 thread, then we need to take care that delete_thread doesn't 180 really delete the thread if it is inferior_ptid. Create a 181 new template thread in the list with an invalid ptid, switch 182 to it, delete the original thread, reset the new thread's 183 ptid, and switch to it. */ 184 185 if (ptid_equal (inferior_ptid, ptid)) 186 { 187 tp = new_thread (ptid); 188 189 /* Make switch_to_thread not read from the thread. */ 190 tp->state_ = THREAD_EXITED; 191 switch_to_thread (minus_one_ptid); 192 193 /* Now we can delete it. */ 194 delete_thread (ptid); 195 196 /* Now reset its ptid, and reswitch inferior_ptid to it. */ 197 tp->ptid = ptid; 198 tp->state_ = THREAD_STOPPED; 199 switch_to_thread (ptid); 200 201 observer_notify_new_thread (tp); 202 203 /* All done. */ 204 return tp; 205 } 206 else 207 /* Just go ahead and delete it. */ 208 delete_thread (ptid); 209 } 210 211 tp = new_thread (ptid); 212 observer_notify_new_thread (tp); 213 214 return tp; 215 } 216 217 struct thread_info * 218 add_thread_with_info (ptid_t ptid, struct private_thread_info *private) 219 { 220 struct thread_info *result = add_thread_silent (ptid); 221 222 result->private = private; 223 224 if (print_thread_events) 225 printf_unfiltered (_("[New %s]\n"), target_pid_to_str (ptid)); 226 227 annotate_new_thread (); 228 return result; 229 } 230 231 struct thread_info * 232 add_thread (ptid_t ptid) 233 { 234 return add_thread_with_info (ptid, NULL); 235 } 236 237 /* Delete thread PTID. If SILENT, don't notify the observer of this 238 exit. */ 239 static void 240 delete_thread_1 (ptid_t ptid, int silent) 241 { 242 struct thread_info *tp, *tpprev; 243 244 tpprev = NULL; 245 246 for (tp = thread_list; tp; tpprev = tp, tp = tp->next) 247 if (ptid_equal (tp->ptid, ptid)) 248 break; 249 250 if (!tp) 251 return; 252 253 /* If this is the current thread, or there's code out there that 254 relies on it existing (refcount > 0) we can't delete yet. Mark 255 it as exited, and notify it. */ 256 if (tp->refcount > 0 257 || ptid_equal (tp->ptid, inferior_ptid)) 258 { 259 if (tp->state_ != THREAD_EXITED) 260 { 261 observer_notify_thread_exit (tp, silent); 262 263 /* Tag it as exited. */ 264 tp->state_ = THREAD_EXITED; 265 266 /* Clear breakpoints, etc. associated with this thread. */ 267 clear_thread_inferior_resources (tp); 268 } 269 270 /* Will be really deleted some other time. */ 271 return; 272 } 273 274 if (tpprev) 275 tpprev->next = tp->next; 276 else 277 thread_list = tp->next; 278 279 /* Notify thread exit, but only if we haven't already. */ 280 if (tp->state_ != THREAD_EXITED) 281 observer_notify_thread_exit (tp, silent); 282 283 free_thread (tp); 284 } 285 286 /* Delete thread PTID and notify of thread exit. If this is 287 inferior_ptid, don't actually delete it, but tag it as exited and 288 do the notification. If PTID is the user selected thread, clear 289 it. */ 290 void 291 delete_thread (ptid_t ptid) 292 { 293 delete_thread_1 (ptid, 0 /* not silent */); 294 } 295 296 void 297 delete_thread_silent (ptid_t ptid) 298 { 299 delete_thread_1 (ptid, 1 /* silent */); 300 } 301 302 struct thread_info * 303 find_thread_id (int num) 304 { 305 struct thread_info *tp; 306 307 for (tp = thread_list; tp; tp = tp->next) 308 if (tp->num == num) 309 return tp; 310 311 return NULL; 312 } 313 314 /* Find a thread_info by matching PTID. */ 315 struct thread_info * 316 find_thread_ptid (ptid_t ptid) 317 { 318 struct thread_info *tp; 319 320 for (tp = thread_list; tp; tp = tp->next) 321 if (ptid_equal (tp->ptid, ptid)) 322 return tp; 323 324 return NULL; 325 } 326 327 /* 328 * Thread iterator function. 329 * 330 * Calls a callback function once for each thread, so long as 331 * the callback function returns false. If the callback function 332 * returns true, the iteration will end and the current thread 333 * will be returned. This can be useful for implementing a 334 * search for a thread with arbitrary attributes, or for applying 335 * some operation to every thread. 336 * 337 * FIXME: some of the existing functionality, such as 338 * "Thread apply all", might be rewritten using this functionality. 339 */ 340 341 struct thread_info * 342 iterate_over_threads (int (*callback) (struct thread_info *, void *), 343 void *data) 344 { 345 struct thread_info *tp, *next; 346 347 for (tp = thread_list; tp; tp = next) 348 { 349 next = tp->next; 350 if ((*callback) (tp, data)) 351 return tp; 352 } 353 354 return NULL; 355 } 356 357 int 358 thread_count (void) 359 { 360 int result = 0; 361 struct thread_info *tp; 362 363 for (tp = thread_list; tp; tp = tp->next) 364 ++result; 365 366 return result; 367 } 368 369 int 370 valid_thread_id (int num) 371 { 372 struct thread_info *tp; 373 374 for (tp = thread_list; tp; tp = tp->next) 375 if (tp->num == num) 376 return 1; 377 378 return 0; 379 } 380 381 int 382 pid_to_thread_id (ptid_t ptid) 383 { 384 struct thread_info *tp; 385 386 for (tp = thread_list; tp; tp = tp->next) 387 if (ptid_equal (tp->ptid, ptid)) 388 return tp->num; 389 390 return 0; 391 } 392 393 ptid_t 394 thread_id_to_pid (int num) 395 { 396 struct thread_info *thread = find_thread_id (num); 397 if (thread) 398 return thread->ptid; 399 else 400 return pid_to_ptid (-1); 401 } 402 403 int 404 in_thread_list (ptid_t ptid) 405 { 406 struct thread_info *tp; 407 408 for (tp = thread_list; tp; tp = tp->next) 409 if (ptid_equal (tp->ptid, ptid)) 410 return 1; 411 412 return 0; /* Never heard of 'im */ 413 } 414 415 /* Finds the first thread of the inferior given by PID. If PID is -1, 416 return the first thread in the list. */ 417 418 struct thread_info * 419 first_thread_of_process (int pid) 420 { 421 struct thread_info *tp, *ret = NULL; 422 423 for (tp = thread_list; tp; tp = tp->next) 424 if (pid == -1 || ptid_get_pid (tp->ptid) == pid) 425 if (ret == NULL || tp->num < ret->num) 426 ret = tp; 427 428 return ret; 429 } 430 431 struct thread_info * 432 any_thread_of_process (int pid) 433 { 434 struct thread_info *tp; 435 436 for (tp = thread_list; tp; tp = tp->next) 437 if (ptid_get_pid (tp->ptid) == pid) 438 return tp; 439 440 return NULL; 441 } 442 443 /* Print a list of thread ids currently known, and the total number of 444 threads. To be used from within catch_errors. */ 445 static int 446 do_captured_list_thread_ids (struct ui_out *uiout, void *arg) 447 { 448 struct thread_info *tp; 449 int num = 0; 450 struct cleanup *cleanup_chain; 451 int current_thread = -1; 452 453 prune_threads (); 454 target_find_new_threads (); 455 456 cleanup_chain = make_cleanup_ui_out_tuple_begin_end (uiout, "thread-ids"); 457 458 for (tp = thread_list; tp; tp = tp->next) 459 { 460 if (tp->state_ == THREAD_EXITED) 461 continue; 462 463 if (ptid_equal (tp->ptid, inferior_ptid)) 464 current_thread = tp->num; 465 466 num++; 467 ui_out_field_int (uiout, "thread-id", tp->num); 468 } 469 470 do_cleanups (cleanup_chain); 471 472 if (current_thread != -1) 473 ui_out_field_int (uiout, "current-thread-id", current_thread); 474 ui_out_field_int (uiout, "number-of-threads", num); 475 return GDB_RC_OK; 476 } 477 478 /* Official gdblib interface function to get a list of thread ids and 479 the total number. */ 480 enum gdb_rc 481 gdb_list_thread_ids (struct ui_out *uiout, char **error_message) 482 { 483 if (catch_exceptions_with_msg (uiout, do_captured_list_thread_ids, NULL, 484 error_message, RETURN_MASK_ALL) < 0) 485 return GDB_RC_FAIL; 486 return GDB_RC_OK; 487 } 488 489 /* Return true if TP is an active thread. */ 490 static int 491 thread_alive (struct thread_info *tp) 492 { 493 if (tp->state_ == THREAD_EXITED) 494 return 0; 495 if (!target_thread_alive (tp->ptid)) 496 return 0; 497 return 1; 498 } 499 500 static void 501 prune_threads (void) 502 { 503 struct thread_info *tp, *next; 504 505 for (tp = thread_list; tp; tp = next) 506 { 507 next = tp->next; 508 if (!thread_alive (tp)) 509 delete_thread (tp->ptid); 510 } 511 } 512 513 void 514 thread_change_ptid (ptid_t old_ptid, ptid_t new_ptid) 515 { 516 struct inferior *inf; 517 struct thread_info *tp; 518 519 /* It can happen that what we knew as the target inferior id 520 changes. E.g, target remote may only discover the remote process 521 pid after adding the inferior to GDB's list. */ 522 inf = find_inferior_pid (ptid_get_pid (old_ptid)); 523 inf->pid = ptid_get_pid (new_ptid); 524 525 tp = find_thread_ptid (old_ptid); 526 tp->ptid = new_ptid; 527 528 observer_notify_thread_ptid_changed (old_ptid, new_ptid); 529 } 530 531 void 532 set_running (ptid_t ptid, int running) 533 { 534 struct thread_info *tp; 535 int all = ptid_equal (ptid, minus_one_ptid); 536 537 /* We try not to notify the observer if no thread has actually changed 538 the running state -- merely to reduce the number of messages to 539 frontend. Frontend is supposed to handle multiple *running just fine. */ 540 if (all || ptid_is_pid (ptid)) 541 { 542 int any_started = 0; 543 for (tp = thread_list; tp; tp = tp->next) 544 if (all || ptid_get_pid (tp->ptid) == ptid_get_pid (ptid)) 545 { 546 if (tp->state_ == THREAD_EXITED) 547 continue; 548 if (running && tp->state_ == THREAD_STOPPED) 549 any_started = 1; 550 tp->state_ = running ? THREAD_RUNNING : THREAD_STOPPED; 551 } 552 if (any_started) 553 observer_notify_target_resumed (ptid); 554 } 555 else 556 { 557 int started = 0; 558 tp = find_thread_ptid (ptid); 559 gdb_assert (tp); 560 gdb_assert (tp->state_ != THREAD_EXITED); 561 if (running && tp->state_ == THREAD_STOPPED) 562 started = 1; 563 tp->state_ = running ? THREAD_RUNNING : THREAD_STOPPED; 564 if (started) 565 observer_notify_target_resumed (ptid); 566 } 567 } 568 569 static int 570 is_thread_state (ptid_t ptid, enum thread_state state) 571 { 572 struct thread_info *tp; 573 574 tp = find_thread_ptid (ptid); 575 gdb_assert (tp); 576 return tp->state_ == state; 577 } 578 579 int 580 is_stopped (ptid_t ptid) 581 { 582 return is_thread_state (ptid, THREAD_STOPPED); 583 } 584 585 int 586 is_exited (ptid_t ptid) 587 { 588 return is_thread_state (ptid, THREAD_EXITED); 589 } 590 591 int 592 is_running (ptid_t ptid) 593 { 594 return is_thread_state (ptid, THREAD_RUNNING); 595 } 596 597 int 598 any_running (void) 599 { 600 struct thread_info *tp; 601 602 for (tp = thread_list; tp; tp = tp->next) 603 if (tp->state_ == THREAD_RUNNING) 604 return 1; 605 606 return 0; 607 } 608 609 int 610 is_executing (ptid_t ptid) 611 { 612 struct thread_info *tp; 613 614 tp = find_thread_ptid (ptid); 615 gdb_assert (tp); 616 return tp->executing_; 617 } 618 619 void 620 set_executing (ptid_t ptid, int executing) 621 { 622 struct thread_info *tp; 623 int all = ptid_equal (ptid, minus_one_ptid); 624 625 if (all || ptid_is_pid (ptid)) 626 { 627 for (tp = thread_list; tp; tp = tp->next) 628 if (all || ptid_get_pid (tp->ptid) == ptid_get_pid (ptid)) 629 tp->executing_ = executing; 630 } 631 else 632 { 633 tp = find_thread_ptid (ptid); 634 gdb_assert (tp); 635 tp->executing_ = executing; 636 } 637 } 638 639 void 640 set_stop_requested (ptid_t ptid, int stop) 641 { 642 struct thread_info *tp; 643 int all = ptid_equal (ptid, minus_one_ptid); 644 645 if (all || ptid_is_pid (ptid)) 646 { 647 for (tp = thread_list; tp; tp = tp->next) 648 if (all || ptid_get_pid (tp->ptid) == ptid_get_pid (ptid)) 649 tp->stop_requested = stop; 650 } 651 else 652 { 653 tp = find_thread_ptid (ptid); 654 gdb_assert (tp); 655 tp->stop_requested = stop; 656 } 657 658 /* Call the stop requested observer so other components of GDB can 659 react to this request. */ 660 if (stop) 661 observer_notify_thread_stop_requested (ptid); 662 } 663 664 void 665 finish_thread_state (ptid_t ptid) 666 { 667 struct thread_info *tp; 668 int all; 669 int any_started = 0; 670 671 all = ptid_equal (ptid, minus_one_ptid); 672 673 if (all || ptid_is_pid (ptid)) 674 { 675 for (tp = thread_list; tp; tp = tp->next) 676 { 677 if (tp->state_ == THREAD_EXITED) 678 continue; 679 if (all || ptid_get_pid (ptid) == ptid_get_pid (tp->ptid)) 680 { 681 if (tp->executing_ && tp->state_ == THREAD_STOPPED) 682 any_started = 1; 683 tp->state_ = tp->executing_ ? THREAD_RUNNING : THREAD_STOPPED; 684 } 685 } 686 } 687 else 688 { 689 tp = find_thread_ptid (ptid); 690 gdb_assert (tp); 691 if (tp->state_ != THREAD_EXITED) 692 { 693 if (tp->executing_ && tp->state_ == THREAD_STOPPED) 694 any_started = 1; 695 tp->state_ = tp->executing_ ? THREAD_RUNNING : THREAD_STOPPED; 696 } 697 } 698 699 if (any_started) 700 observer_notify_target_resumed (ptid); 701 } 702 703 void 704 finish_thread_state_cleanup (void *arg) 705 { 706 ptid_t *ptid_p = arg; 707 708 gdb_assert (arg); 709 710 finish_thread_state (*ptid_p); 711 } 712 713 /* Prints the list of threads and their details on UIOUT. 714 This is a version of 'info_thread_command' suitable for 715 use from MI. 716 If REQUESTED_THREAD is not -1, it's the GDB id of the thread 717 that should be printed. Otherwise, all threads are 718 printed. 719 If PID is not -1, only print threads from the process PID. 720 Otherwise, threads from all attached PIDs are printed. 721 If both REQUESTED_THREAD and PID are not -1, then the thread 722 is printed if it belongs to the specified process. Otherwise, 723 an error is raised. */ 724 void 725 print_thread_info (struct ui_out *uiout, int requested_thread, int pid) 726 { 727 struct thread_info *tp; 728 ptid_t current_ptid; 729 struct cleanup *old_chain; 730 char *extra_info; 731 int current_thread = -1; 732 733 prune_threads (); 734 target_find_new_threads (); 735 current_ptid = inferior_ptid; 736 737 /* We'll be switching threads temporarily. */ 738 old_chain = make_cleanup_restore_current_thread (); 739 740 make_cleanup_ui_out_list_begin_end (uiout, "threads"); 741 for (tp = thread_list; tp; tp = tp->next) 742 { 743 struct cleanup *chain2; 744 745 if (requested_thread != -1 && tp->num != requested_thread) 746 continue; 747 748 if (pid != -1 && PIDGET (tp->ptid) != pid) 749 { 750 if (requested_thread != -1) 751 error (_("Requested thread not found in requested process")); 752 continue; 753 } 754 755 if (ptid_equal (tp->ptid, current_ptid)) 756 current_thread = tp->num; 757 758 if (tp->state_ == THREAD_EXITED) 759 continue; 760 761 chain2 = make_cleanup_ui_out_tuple_begin_end (uiout, NULL); 762 763 if (ptid_equal (tp->ptid, current_ptid)) 764 ui_out_text (uiout, "* "); 765 else 766 ui_out_text (uiout, " "); 767 768 ui_out_field_int (uiout, "id", tp->num); 769 ui_out_text (uiout, " "); 770 ui_out_field_string (uiout, "target-id", target_pid_to_str (tp->ptid)); 771 772 extra_info = target_extra_thread_info (tp); 773 if (extra_info) 774 { 775 ui_out_text (uiout, " ("); 776 ui_out_field_string (uiout, "details", extra_info); 777 ui_out_text (uiout, ")"); 778 } 779 ui_out_text (uiout, " "); 780 781 if (tp->state_ == THREAD_RUNNING) 782 ui_out_text (uiout, "(running)\n"); 783 else 784 { 785 /* The switch below puts us at the top of the stack (leaf 786 frame). */ 787 switch_to_thread (tp->ptid); 788 print_stack_frame (get_selected_frame (NULL), 789 /* For MI output, print frame level. */ 790 ui_out_is_mi_like_p (uiout), 791 LOCATION); 792 } 793 794 if (ui_out_is_mi_like_p (uiout)) 795 { 796 char *state = "stopped"; 797 if (tp->state_ == THREAD_RUNNING) 798 state = "running"; 799 ui_out_field_string (uiout, "state", state); 800 } 801 802 do_cleanups (chain2); 803 } 804 805 /* Restores the current thread and the frame selected before 806 the "info threads" command. */ 807 do_cleanups (old_chain); 808 809 if (pid == -1 && requested_thread == -1) 810 { 811 gdb_assert (current_thread != -1 812 || !thread_list 813 || ptid_equal (inferior_ptid, null_ptid)); 814 if (current_thread != -1 && ui_out_is_mi_like_p (uiout)) 815 ui_out_field_int (uiout, "current-thread-id", current_thread); 816 817 if (current_thread != -1 && is_exited (current_ptid)) 818 ui_out_message (uiout, 0, "\n\ 819 The current thread <Thread ID %d> has terminated. See `help thread'.\n", 820 current_thread); 821 else if (thread_list 822 && current_thread == -1 823 && ptid_equal (current_ptid, null_ptid)) 824 ui_out_message (uiout, 0, "\n\ 825 No selected thread. See `help thread'.\n"); 826 } 827 } 828 829 830 /* Print information about currently known threads 831 832 * Note: this has the drawback that it _really_ switches 833 * threads, which frees the frame cache. A no-side 834 * effects info-threads command would be nicer. 835 */ 836 837 static void 838 info_threads_command (char *arg, int from_tty) 839 { 840 print_thread_info (uiout, -1, -1); 841 } 842 843 /* Switch from one thread to another. */ 844 845 void 846 switch_to_thread (ptid_t ptid) 847 { 848 if (ptid_equal (ptid, inferior_ptid)) 849 return; 850 851 inferior_ptid = ptid; 852 reinit_frame_cache (); 853 registers_changed (); 854 855 /* We don't check for is_stopped, because we're called at times 856 while in the TARGET_RUNNING state, e.g., while handling an 857 internal event. */ 858 if (!ptid_equal (inferior_ptid, null_ptid) 859 && !is_exited (ptid) 860 && !is_executing (ptid)) 861 stop_pc = regcache_read_pc (get_thread_regcache (ptid)); 862 else 863 stop_pc = ~(CORE_ADDR) 0; 864 } 865 866 static void 867 restore_current_thread (ptid_t ptid) 868 { 869 switch_to_thread (ptid); 870 } 871 872 static void 873 restore_selected_frame (struct frame_id a_frame_id, int frame_level) 874 { 875 struct frame_info *frame = NULL; 876 int count; 877 878 gdb_assert (frame_level >= 0); 879 880 /* Restore by level first, check if the frame id is the same as 881 expected. If that fails, try restoring by frame id. If that 882 fails, nothing to do, just warn the user. */ 883 884 count = frame_level; 885 frame = find_relative_frame (get_current_frame (), &count); 886 if (count == 0 887 && frame != NULL 888 /* The frame ids must match - either both valid or both outer_frame_id. 889 The latter case is not failsafe, but since it's highly unlikely 890 the search by level finds the wrong frame, it's 99.9(9)% of 891 the time (for all practical purposes) safe. */ 892 && frame_id_eq (get_frame_id (frame), a_frame_id)) 893 { 894 /* Cool, all is fine. */ 895 select_frame (frame); 896 return; 897 } 898 899 frame = frame_find_by_id (a_frame_id); 900 if (frame != NULL) 901 { 902 /* Cool, refound it. */ 903 select_frame (frame); 904 return; 905 } 906 907 /* Nothing else to do, the frame layout really changed. Select the 908 innermost stack frame. */ 909 select_frame (get_current_frame ()); 910 911 /* Warn the user. */ 912 if (!ui_out_is_mi_like_p (uiout)) 913 { 914 warning (_("\ 915 Couldn't restore frame #%d in current thread, at reparsed frame #0\n"), 916 frame_level); 917 /* For MI, we should probably have a notification about 918 current frame change. But this error is not very 919 likely, so don't bother for now. */ 920 print_stack_frame (get_selected_frame (NULL), 1, SRC_LINE); 921 } 922 } 923 924 struct current_thread_cleanup 925 { 926 ptid_t inferior_ptid; 927 struct frame_id selected_frame_id; 928 int selected_frame_level; 929 int was_stopped; 930 }; 931 932 static void 933 do_restore_current_thread_cleanup (void *arg) 934 { 935 struct thread_info *tp; 936 struct current_thread_cleanup *old = arg; 937 938 tp = find_thread_ptid (old->inferior_ptid); 939 940 /* If the previously selected thread belonged to a process that has 941 in the mean time been deleted (due to normal exit, detach, etc.), 942 then don't revert back to it, but instead simply drop back to no 943 thread selected. */ 944 if (tp 945 && find_inferior_pid (ptid_get_pid (tp->ptid)) != NULL) 946 restore_current_thread (old->inferior_ptid); 947 else 948 restore_current_thread (null_ptid); 949 950 /* The running state of the originally selected thread may have 951 changed, so we have to recheck it here. */ 952 if (!ptid_equal (inferior_ptid, null_ptid) 953 && old->was_stopped 954 && is_stopped (inferior_ptid) 955 && target_has_registers 956 && target_has_stack 957 && target_has_memory) 958 restore_selected_frame (old->selected_frame_id, 959 old->selected_frame_level); 960 } 961 962 static void 963 restore_current_thread_cleanup_dtor (void *arg) 964 { 965 struct current_thread_cleanup *old = arg; 966 struct thread_info *tp; 967 tp = find_thread_ptid (old->inferior_ptid); 968 if (tp) 969 tp->refcount--; 970 xfree (old); 971 } 972 973 struct cleanup * 974 make_cleanup_restore_current_thread (void) 975 { 976 struct thread_info *tp; 977 struct frame_info *frame; 978 struct current_thread_cleanup *old; 979 980 old = xmalloc (sizeof (struct current_thread_cleanup)); 981 old->inferior_ptid = inferior_ptid; 982 983 if (!ptid_equal (inferior_ptid, null_ptid)) 984 { 985 old->was_stopped = is_stopped (inferior_ptid); 986 if (old->was_stopped 987 && target_has_registers 988 && target_has_stack 989 && target_has_memory) 990 frame = get_selected_frame (NULL); 991 else 992 frame = NULL; 993 994 old->selected_frame_id = get_frame_id (frame); 995 old->selected_frame_level = frame_relative_level (frame); 996 997 tp = find_thread_ptid (inferior_ptid); 998 if (tp) 999 tp->refcount++; 1000 } 1001 1002 return make_cleanup_dtor (do_restore_current_thread_cleanup, old, 1003 restore_current_thread_cleanup_dtor); 1004 } 1005 1006 /* Apply a GDB command to a list of threads. List syntax is a whitespace 1007 seperated list of numbers, or ranges, or the keyword `all'. Ranges consist 1008 of two numbers seperated by a hyphen. Examples: 1009 1010 thread apply 1 2 7 4 backtrace Apply backtrace cmd to threads 1,2,7,4 1011 thread apply 2-7 9 p foo(1) Apply p foo(1) cmd to threads 2->7 & 9 1012 thread apply all p x/i $pc Apply x/i $pc cmd to all threads 1013 */ 1014 1015 static void 1016 thread_apply_all_command (char *cmd, int from_tty) 1017 { 1018 struct thread_info *tp; 1019 struct cleanup *old_chain; 1020 char *saved_cmd; 1021 1022 if (cmd == NULL || *cmd == '\000') 1023 error (_("Please specify a command following the thread ID list")); 1024 1025 prune_threads (); 1026 target_find_new_threads (); 1027 1028 old_chain = make_cleanup_restore_current_thread (); 1029 1030 /* Save a copy of the command in case it is clobbered by 1031 execute_command */ 1032 saved_cmd = xstrdup (cmd); 1033 make_cleanup (xfree, saved_cmd); 1034 for (tp = thread_list; tp; tp = tp->next) 1035 if (thread_alive (tp)) 1036 { 1037 switch_to_thread (tp->ptid); 1038 1039 printf_filtered (_("\nThread %d (%s):\n"), 1040 tp->num, target_pid_to_str (inferior_ptid)); 1041 execute_command (cmd, from_tty); 1042 strcpy (cmd, saved_cmd); /* Restore exact command used previously */ 1043 } 1044 1045 do_cleanups (old_chain); 1046 } 1047 1048 static void 1049 thread_apply_command (char *tidlist, int from_tty) 1050 { 1051 char *cmd; 1052 char *p; 1053 struct cleanup *old_chain; 1054 char *saved_cmd; 1055 1056 if (tidlist == NULL || *tidlist == '\000') 1057 error (_("Please specify a thread ID list")); 1058 1059 for (cmd = tidlist; *cmd != '\000' && !isalpha (*cmd); cmd++); 1060 1061 if (*cmd == '\000') 1062 error (_("Please specify a command following the thread ID list")); 1063 1064 /* Save a copy of the command in case it is clobbered by 1065 execute_command */ 1066 saved_cmd = xstrdup (cmd); 1067 old_chain = make_cleanup (xfree, saved_cmd); 1068 while (tidlist < cmd) 1069 { 1070 struct thread_info *tp; 1071 int start, end; 1072 1073 start = strtol (tidlist, &p, 10); 1074 if (p == tidlist) 1075 error (_("Error parsing %s"), tidlist); 1076 tidlist = p; 1077 1078 while (*tidlist == ' ' || *tidlist == '\t') 1079 tidlist++; 1080 1081 if (*tidlist == '-') /* Got a range of IDs? */ 1082 { 1083 tidlist++; /* Skip the - */ 1084 end = strtol (tidlist, &p, 10); 1085 if (p == tidlist) 1086 error (_("Error parsing %s"), tidlist); 1087 tidlist = p; 1088 1089 while (*tidlist == ' ' || *tidlist == '\t') 1090 tidlist++; 1091 } 1092 else 1093 end = start; 1094 1095 make_cleanup_restore_current_thread (); 1096 1097 for (; start <= end; start++) 1098 { 1099 tp = find_thread_id (start); 1100 1101 if (!tp) 1102 warning (_("Unknown thread %d."), start); 1103 else if (!thread_alive (tp)) 1104 warning (_("Thread %d has terminated."), start); 1105 else 1106 { 1107 switch_to_thread (tp->ptid); 1108 1109 printf_filtered (_("\nThread %d (%s):\n"), tp->num, 1110 target_pid_to_str (inferior_ptid)); 1111 execute_command (cmd, from_tty); 1112 1113 /* Restore exact command used previously. */ 1114 strcpy (cmd, saved_cmd); 1115 } 1116 } 1117 } 1118 1119 do_cleanups (old_chain); 1120 } 1121 1122 /* Switch to the specified thread. Will dispatch off to thread_apply_command 1123 if prefix of arg is `apply'. */ 1124 1125 static void 1126 thread_command (char *tidstr, int from_tty) 1127 { 1128 if (!tidstr) 1129 { 1130 if (ptid_equal (inferior_ptid, null_ptid)) 1131 error (_("No thread selected")); 1132 1133 if (target_has_stack) 1134 { 1135 if (is_exited (inferior_ptid)) 1136 printf_filtered (_("[Current thread is %d (%s) (exited)]\n"), 1137 pid_to_thread_id (inferior_ptid), 1138 target_pid_to_str (inferior_ptid)); 1139 else 1140 printf_filtered (_("[Current thread is %d (%s)]\n"), 1141 pid_to_thread_id (inferior_ptid), 1142 target_pid_to_str (inferior_ptid)); 1143 } 1144 else 1145 error (_("No stack.")); 1146 return; 1147 } 1148 1149 gdb_thread_select (uiout, tidstr, NULL); 1150 } 1151 1152 /* Print notices when new threads are attached and detached. */ 1153 int print_thread_events = 1; 1154 static void 1155 show_print_thread_events (struct ui_file *file, int from_tty, 1156 struct cmd_list_element *c, const char *value) 1157 { 1158 fprintf_filtered (file, _("\ 1159 Printing of thread events is %s.\n"), 1160 value); 1161 } 1162 1163 static int 1164 do_captured_thread_select (struct ui_out *uiout, void *tidstr) 1165 { 1166 int num; 1167 struct thread_info *tp; 1168 1169 num = value_as_long (parse_and_eval (tidstr)); 1170 1171 tp = find_thread_id (num); 1172 1173 if (!tp) 1174 error (_("Thread ID %d not known."), num); 1175 1176 if (!thread_alive (tp)) 1177 error (_("Thread ID %d has terminated."), num); 1178 1179 switch_to_thread (tp->ptid); 1180 1181 annotate_thread_changed (); 1182 1183 ui_out_text (uiout, "[Switching to thread "); 1184 ui_out_field_int (uiout, "new-thread-id", pid_to_thread_id (inferior_ptid)); 1185 ui_out_text (uiout, " ("); 1186 ui_out_text (uiout, target_pid_to_str (inferior_ptid)); 1187 ui_out_text (uiout, ")]"); 1188 1189 /* Note that we can't reach this with an exited thread, due to the 1190 thread_alive check above. */ 1191 if (tp->state_ == THREAD_RUNNING) 1192 ui_out_text (uiout, "(running)\n"); 1193 else 1194 print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC); 1195 1196 /* Since the current thread may have changed, see if there is any 1197 exited thread we can now delete. */ 1198 prune_threads (); 1199 1200 return GDB_RC_OK; 1201 } 1202 1203 enum gdb_rc 1204 gdb_thread_select (struct ui_out *uiout, char *tidstr, char **error_message) 1205 { 1206 if (catch_exceptions_with_msg (uiout, do_captured_thread_select, tidstr, 1207 error_message, RETURN_MASK_ALL) < 0) 1208 return GDB_RC_FAIL; 1209 return GDB_RC_OK; 1210 } 1211 1212 /* Commands with a prefix of `thread'. */ 1213 struct cmd_list_element *thread_cmd_list = NULL; 1214 1215 void 1216 _initialize_thread (void) 1217 { 1218 static struct cmd_list_element *thread_apply_list = NULL; 1219 1220 add_info ("threads", info_threads_command, 1221 _("IDs of currently known threads.")); 1222 1223 add_prefix_cmd ("thread", class_run, thread_command, _("\ 1224 Use this command to switch between threads.\n\ 1225 The new thread ID must be currently known."), 1226 &thread_cmd_list, "thread ", 1, &cmdlist); 1227 1228 add_prefix_cmd ("apply", class_run, thread_apply_command, 1229 _("Apply a command to a list of threads."), 1230 &thread_apply_list, "thread apply ", 1, &thread_cmd_list); 1231 1232 add_cmd ("all", class_run, thread_apply_all_command, 1233 _("Apply a command to all threads."), &thread_apply_list); 1234 1235 if (!xdb_commands) 1236 add_com_alias ("t", "thread", class_run, 1); 1237 1238 add_setshow_boolean_cmd ("thread-events", no_class, 1239 &print_thread_events, _("\ 1240 Set printing of thread events (such as thread start and exit)."), _("\ 1241 Show printing of thread events (such as thread start and exit)."), NULL, 1242 NULL, 1243 show_print_thread_events, 1244 &setprintlist, &showprintlist); 1245 } 1246