gdb/thread.c

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