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
  39 /*#include "lynxos-core.h" */
  40
  41 /* Definition of struct thread_info exported to gdbthread.h */
  42
  43 /* Prototypes for exported functions. */
  44
  45 void _initialize_thread PARAMS ((void));
  46
  47 /* Prototypes for local functions. */
  48
  49 static struct thread_info *thread_list = NULL;
  50 static int highest_thread_num;
  51
  52 static struct thread_info *find_thread_id PARAMS ((int num));
  53
  54 static void thread_command PARAMS ((char *tidstr, int from_tty));
  55 static void thread_apply_all_command PARAMS ((char *, int));
  56 static int thread_alive PARAMS ((struct thread_info *));
  57 static void info_threads_command PARAMS ((char *, int));
  58 static void thread_apply_command PARAMS ((char *, int));
  59 static void restore_current_thread PARAMS ((int));
  60 static void switch_to_thread PARAMS ((int pid));
  61 static void prune_threads PARAMS ((void));
  62
  63 void
  64 init_thread_list ()
  65 {
  66   struct thread_info *tp, *tpnext;
  67
  68   if (!thread_list)
  69     return;
  70
  71   for (tp = thread_list; tp; tp = tpnext)
  72     {
  73       tpnext = tp->next;
  74       free (tp);
  75     }
  76
  77   thread_list = NULL;
  78   highest_thread_num = 0;
  79 }
  80
  81 /* add_thread now returns a pointer to the new thread_info,
  82    so that back_ends can initialize their private data.  */
  83
  84 struct thread_info *
  85 add_thread (pid)
  86      int pid;
  87 {
  88   struct thread_info *tp;
  89
  90   tp = (struct thread_info *) xmalloc (sizeof (struct thread_info));
  91
  92   tp->pid = pid;
  93   tp->num = ++highest_thread_num;
  94   tp->prev_pc = 0;
  95   tp->prev_func_start = 0;
  96   tp->prev_func_name = NULL;
  97   tp->step_range_start = 0;
  98   tp->step_range_end = 0;
  99   tp->step_frame_address = 0;
 100   tp->step_resume_breakpoint = 0;
 101   tp->through_sigtramp_breakpoint = 0;
 102   tp->handling_longjmp = 0;
 103   tp->trap_expected = 0;
 104   tp->another_trap = 0;
 105   tp->stepping_through_solib_after_catch = 0;
 106   tp->stepping_through_solib_catchpoints = NULL;
 107   tp->stepping_through_sigtramp = 0;
 108   tp->next = thread_list;
 109   tp->private = NULL;
 110   thread_list = tp;
 111   return tp;
 112 }
 113
 114 void
 115 delete_thread (pid)
 116      int pid;
 117 {
 118   struct thread_info *tp, *tpprev;
 119
 120   tpprev = NULL;
 121
 122   for (tp = thread_list; tp; tpprev = tp, tp = tp->next)
 123     if (tp->pid == pid)
 124       break;
 125
 126   if (!tp)
 127     return;
 128
 129   if (tpprev)
 130     tpprev->next = tp->next;
 131   else
 132     thread_list = tp->next;
 133
 134   /* NOTE: this will take care of any left-over step_resume breakpoints,
 135      but not any user-specified thread-specific breakpoints. */
 136   if (tp->step_resume_breakpoint)
 137     delete_breakpoint (tp->step_resume_breakpoint);
 138
 139   /* FIXME: do I ever need to call the back-end to give it a
 140      chance at this private data before deleting the thread?  */
 141   if (tp->private)
 142     free (tp->private);
 143
 144   free (tp);
 145
 146   return;
 147 }
 148
 149 static struct thread_info *
 150 find_thread_id (num)
 151      int num;
 152 {
 153   struct thread_info *tp;
 154
 155   for (tp = thread_list; tp; tp = tp->next)
 156     if (tp->num == num)
 157       return tp;
 158
 159   return NULL;
 160 }
 161
 162 /* Find a thread_info by matching 'pid'.  */
 163 struct thread_info *
 164 find_thread_pid (pid)
 165      int pid;
 166 {
 167   struct thread_info *tp;
 168
 169   for (tp = thread_list; tp; tp = tp->next)
 170     if (tp->pid == pid)
 171       return tp;
 172
 173   return NULL;
 174 }
 175
 176 /*
 177  * Thread iterator function.
 178  *
 179  * Calls a callback function once for each thread, so long as
 180  * the callback function returns false.  If the callback function
 181  * returns true, the iteration will end and the current thread
 182  * will be returned.  This can be useful for implementing a
 183  * search for a thread with arbitrary attributes, or for applying
 184  * some operation to every thread.
 185  *
 186  * FIXME: some of the existing functionality, such as
 187  * "Thread apply all", might be rewritten using this functionality.
 188  */
 189
 190 struct thread_info *
 191 iterate_over_threads (callback, data)
 192      int (*callback) ();
 193      void *data;
 194 {
 195   struct thread_info *tp;
 196
 197   for (tp = thread_list; tp; tp = tp->next)
 198     if ((*callback) (tp, data))
 199       return tp;
 200
 201   return NULL;
 202 }
 203
 204 int
 205 valid_thread_id (num)
 206      int num;
 207 {
 208   struct thread_info *tp;
 209
 210   for (tp = thread_list; tp; tp = tp->next)
 211     if (tp->num == num)
 212       return 1;
 213
 214   return 0;
 215 }
 216
 217 int
 218 pid_to_thread_id (pid)
 219      int pid;
 220 {
 221   struct thread_info *tp;
 222
 223   for (tp = thread_list; tp; tp = tp->next)
 224     if (tp->pid == pid)
 225       return tp->num;
 226
 227   return 0;
 228 }
 229
 230 int
 231 thread_id_to_pid (num)
 232      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 (pid)
 243      int pid;
 244 {
 245   struct thread_info *tp;
 246
 247   for (tp = thread_list; tp; tp = tp->next)
 248     if (tp->pid == pid)
 249       return 1;
 250
 251   return 0;                     /* Never heard of 'im */
 252 }
 253
 254 /* Load infrun state for the thread PID.  */
 255
 256 void
 257 load_infrun_state (pid, prev_pc, prev_func_start, prev_func_name,
 258                    trap_expected, step_resume_breakpoint,
 259                    through_sigtramp_breakpoint, step_range_start,
 260                    step_range_end, step_frame_address,
 261                    handling_longjmp, another_trap,
 262                    stepping_through_solib_after_catch,
 263                    stepping_through_solib_catchpoints,
 264                    stepping_through_sigtramp)
 265      int pid;
 266      CORE_ADDR *prev_pc;
 267      CORE_ADDR *prev_func_start;
 268      char **prev_func_name;
 269      int *trap_expected;
 270      struct breakpoint **step_resume_breakpoint;
 271      struct breakpoint **through_sigtramp_breakpoint;
 272      CORE_ADDR *step_range_start;
 273      CORE_ADDR *step_range_end;
 274      CORE_ADDR *step_frame_address;
 275      int *handling_longjmp;
 276      int *another_trap;
 277      int *stepping_through_solib_after_catch;
 278      bpstat *stepping_through_solib_catchpoints;
 279      int *stepping_through_sigtramp;
 280 {
 281   struct thread_info *tp;
 282
 283   /* If we can't find the thread, then we're debugging a single threaded
 284      process.  No need to do anything in that case.  */
 285   tp = find_thread_id (pid_to_thread_id (pid));
 286   if (tp == NULL)
 287     return;
 288
 289   *prev_pc = tp->prev_pc;
 290   *prev_func_start = tp->prev_func_start;
 291   *prev_func_name = tp->prev_func_name;
 292   *step_resume_breakpoint = tp->step_resume_breakpoint;
 293   *step_range_start = tp->step_range_start;
 294   *step_range_end = tp->step_range_end;
 295   *step_frame_address = tp->step_frame_address;
 296   *through_sigtramp_breakpoint = tp->through_sigtramp_breakpoint;
 297   *handling_longjmp = tp->handling_longjmp;
 298   *trap_expected = tp->trap_expected;
 299   *another_trap = tp->another_trap;
 300   *stepping_through_solib_after_catch = tp->stepping_through_solib_after_catch;
 301   *stepping_through_solib_catchpoints = tp->stepping_through_solib_catchpoints;
 302   *stepping_through_sigtramp = tp->stepping_through_sigtramp;
 303 }
 304
 305 /* Save infrun state for the thread PID.  */
 306
 307 void
 308 save_infrun_state (pid, prev_pc, prev_func_start, prev_func_name,
 309                    trap_expected, step_resume_breakpoint,
 310                    through_sigtramp_breakpoint, step_range_start,
 311                    step_range_end, step_frame_address,
 312                    handling_longjmp, another_trap,
 313                    stepping_through_solib_after_catch,
 314                    stepping_through_solib_catchpoints,
 315                    stepping_through_sigtramp)
 316      int pid;
 317      CORE_ADDR prev_pc;
 318      CORE_ADDR prev_func_start;
 319      char *prev_func_name;
 320      int trap_expected;
 321      struct breakpoint *step_resume_breakpoint;
 322      struct breakpoint *through_sigtramp_breakpoint;
 323      CORE_ADDR step_range_start;
 324      CORE_ADDR step_range_end;
 325      CORE_ADDR step_frame_address;
 326      int handling_longjmp;
 327      int another_trap;
 328      int stepping_through_solib_after_catch;
 329      bpstat stepping_through_solib_catchpoints;
 330      int stepping_through_sigtramp;
 331 {
 332   struct thread_info *tp;
 333
 334   /* If we can't find the thread, then we're debugging a single-threaded
 335      process.  Nothing to do in that case.  */
 336   tp = find_thread_id (pid_to_thread_id (pid));
 337   if (tp == NULL)
 338     return;
 339
 340   tp->prev_pc = prev_pc;
 341   tp->prev_func_start = prev_func_start;
 342   tp->prev_func_name = prev_func_name;
 343   tp->step_resume_breakpoint = step_resume_breakpoint;
 344   tp->step_range_start = step_range_start;
 345   tp->step_range_end = step_range_end;
 346   tp->step_frame_address = step_frame_address;
 347   tp->through_sigtramp_breakpoint = through_sigtramp_breakpoint;
 348   tp->handling_longjmp = handling_longjmp;
 349   tp->trap_expected = trap_expected;
 350   tp->another_trap = another_trap;
 351   tp->stepping_through_solib_after_catch = stepping_through_solib_after_catch;
 352   tp->stepping_through_solib_catchpoints = stepping_through_solib_catchpoints;
 353   tp->stepping_through_sigtramp = stepping_through_sigtramp;
 354 }
 355
 356 /* Return true if TP is an active thread. */
 357 static int
 358 thread_alive (tp)
 359      struct thread_info *tp;
 360 {
 361   if (tp->pid == -1)
 362     return 0;
 363   if (!target_thread_alive (tp->pid))
 364     {
 365       tp->pid = -1;             /* Mark it as dead */
 366       return 0;
 367     }
 368   return 1;
 369 }
 370
 371 static void
 372 prune_threads ()
 373 {
 374   struct thread_info *tp, *next;
 375
 376   for (tp = thread_list; tp; tp = next)
 377     {
 378       next = tp->next;
 379       if (!thread_alive (tp))
 380         delete_thread (tp->pid);
 381     }
 382 }
 383
 384 /* Print information about currently known threads
 385
 386  * Note: this has the drawback that it _really_ switches
 387  *       threads, which frees the frame cache.  A no-side
 388  *       effects info-threads command would be nicer.
 389  */
 390
 391 static void
 392 info_threads_command (arg, from_tty)
 393      char *arg;
 394      int from_tty;
 395 {
 396   struct thread_info *tp;
 397   int current_pid;
 398   struct frame_info *cur_frame;
 399   int saved_frame_level = selected_frame_level;
 400   int counter;
 401   char *extra_info;
 402
 403   /* Avoid coredumps which would happen if we tried to access a NULL
 404      selected_frame.  */
 405   if (!target_has_stack)
 406     error ("No stack.");
 407
 408   prune_threads ();
 409   target_find_new_threads ();
 410   current_pid = inferior_pid;
 411   for (tp = thread_list; tp; tp = tp->next)
 412     {
 413       if (tp->pid == current_pid)
 414         printf_filtered ("* ");
 415       else
 416         printf_filtered ("  ");
 417
 418 #ifdef HPUXHPPA
 419       printf_filtered ("%d %s", tp->num, target_tid_to_str (tp->pid));
 420 #else
 421       printf_filtered ("%d %s", tp->num, target_pid_to_str (tp->pid));
 422 #endif
 423
 424       extra_info = target_extra_thread_info (tp);
 425       if (extra_info)
 426         printf_filtered (" (%s)", extra_info);
 427       puts_filtered ("  ");
 428
 429       switch_to_thread (tp->pid);
 430       if (selected_frame)
 431         print_only_stack_frame (selected_frame, -1, 0);
 432       else
 433         printf_filtered ("[No stack.]\n");
 434     }
 435
 436   switch_to_thread (current_pid);
 437
 438   /* Code below copied from "up_silently_base" in "stack.c".
 439    * It restores the frame set by the user before the "info threads"
 440    * command.  We have finished the info-threads display by switching
 441    * back to the current thread.  That switch has put us at the top
 442    * of the stack (leaf frame).
 443    */
 444   counter = saved_frame_level;
 445   cur_frame = find_relative_frame (selected_frame, &counter);
 446   if (counter != 0)
 447     {
 448       /* Ooops, can't restore, tell user where we are. */
 449       warning ("Couldn't restore frame in current thread, at frame 0");
 450       print_stack_frame (selected_frame, -1, 0);
 451     }
 452   else
 453     {
 454       select_frame (cur_frame, saved_frame_level);
 455     }
 456
 457   /* re-show current frame. */
 458   show_stack_frame (cur_frame);
 459 }
 460
 461 /* Switch from one thread to another. */
 462
 463 static void
 464 switch_to_thread (pid)
 465      int pid;
 466 {
 467   if (pid == inferior_pid)
 468     return;
 469
 470   inferior_pid = pid;
 471   flush_cached_frames ();
 472   registers_changed ();
 473   stop_pc = read_pc ();
 474   select_frame (get_current_frame (), 0);
 475 }
 476
 477 static void
 478 restore_current_thread (pid)
 479      int pid;
 480 {
 481   if (pid != inferior_pid)
 482     {
 483       switch_to_thread (pid);
 484       print_stack_frame (get_current_frame (), 0, -1);
 485     }
 486 }
 487
 488 /* Apply a GDB command to a list of threads.  List syntax is a whitespace
 489    seperated list of numbers, or ranges, or the keyword `all'.  Ranges consist
 490    of two numbers seperated by a hyphen.  Examples:
 491
 492    thread apply 1 2 7 4 backtrace       Apply backtrace cmd to threads 1,2,7,4
 493    thread apply 2-7 9 p foo(1)  Apply p foo(1) cmd to threads 2->7 & 9
 494    thread apply all p x/i $pc   Apply x/i $pc cmd to all threads
 495  */
 496
 497 static void
 498 thread_apply_all_command (cmd, from_tty)
 499      char *cmd;
 500      int from_tty;
 501 {
 502   struct thread_info *tp;
 503   struct cleanup *old_chain;
 504
 505   if (cmd == NULL || *cmd == '\000')
 506     error ("Please specify a command following the thread ID list");
 507
 508   old_chain = make_cleanup ((make_cleanup_func) restore_current_thread,
 509                             (void *) inferior_pid);
 510
 511   for (tp = thread_list; tp; tp = tp->next)
 512     if (thread_alive (tp))
 513       {
 514         switch_to_thread (tp->pid);
 515 #ifdef HPUXHPPA
 516         printf_filtered ("\nThread %d (%s):\n",
 517                          tp->num,
 518                          target_tid_to_str (inferior_pid));
 519 #else
 520         printf_filtered ("\nThread %d (%s):\n", tp->num,
 521                          target_pid_to_str (inferior_pid));
 522 #endif
 523         execute_command (cmd, from_tty);
 524       }
 525 }
 526
 527 static void
 528 thread_apply_command (tidlist, from_tty)
 529      char *tidlist;
 530      int from_tty;
 531 {
 532   char *cmd;
 533   char *p;
 534   struct cleanup *old_chain;
 535
 536   if (tidlist == NULL || *tidlist == '\000')
 537     error ("Please specify a thread ID list");
 538
 539   for (cmd = tidlist; *cmd != '\000' && !isalpha (*cmd); cmd++);
 540
 541   if (*cmd == '\000')
 542     error ("Please specify a command following the thread ID list");
 543
 544   old_chain = make_cleanup ((make_cleanup_func) restore_current_thread,
 545                             (void *) inferior_pid);
 546
 547   while (tidlist < cmd)
 548     {
 549       struct thread_info *tp;
 550       int start, end;
 551
 552       start = strtol (tidlist, &p, 10);
 553       if (p == tidlist)
 554         error ("Error parsing %s", tidlist);
 555       tidlist = p;
 556
 557       while (*tidlist == ' ' || *tidlist == '\t')
 558         tidlist++;
 559
 560       if (*tidlist == '-')      /* Got a range of IDs? */
 561         {
 562           tidlist++;            /* Skip the - */
 563           end = strtol (tidlist, &p, 10);
 564           if (p == tidlist)
 565             error ("Error parsing %s", tidlist);
 566           tidlist = p;
 567
 568           while (*tidlist == ' ' || *tidlist == '\t')
 569             tidlist++;
 570         }
 571       else
 572         end = start;
 573
 574       for (; start <= end; start++)
 575         {
 576           tp = find_thread_id (start);
 577
 578           if (!tp)
 579             warning ("Unknown thread %d.", start);
 580           else if (!thread_alive (tp))
 581             warning ("Thread %d has terminated.", start);
 582           else
 583             {
 584               switch_to_thread (tp->pid);
 585 #ifdef HPUXHPPA
 586               printf_filtered ("\nThread %d (%s):\n", tp->num,
 587                                target_tid_to_str (inferior_pid));
 588 #else
 589               printf_filtered ("\nThread %d (%s):\n", tp->num,
 590                                target_pid_to_str (inferior_pid));
 591 #endif
 592               execute_command (cmd, from_tty);
 593             }
 594         }
 595     }
 596 }
 597
 598 /* Switch to the specified thread.  Will dispatch off to thread_apply_command
 599    if prefix of arg is `apply'.  */
 600
 601 static void
 602 thread_command (tidstr, from_tty)
 603      char *tidstr;
 604      int from_tty;
 605 {
 606   if (!tidstr)
 607     {
 608       /* Don't generate an error, just say which thread is current. */
 609       if (target_has_stack)
 610         printf_filtered ("[Current thread is %d (%s)]\n",
 611                          pid_to_thread_id (inferior_pid),
 612 #if defined(HPUXHPPA)
 613                          target_tid_to_str (inferior_pid)
 614 #else
 615                          target_pid_to_str (inferior_pid)
 616 #endif
 617           );
 618       else
 619         error ("No stack.");
 620       return;
 621     }
 622
 623   gdb_thread_select (tidstr);
 624 }
 625
 626 static int
 627 do_captured_thread_select (void *tidstr)
 628 {
 629   int num;
 630   struct thread_info *tp;
 631
 632   num = atoi ((char *)tidstr);
 633
 634   tp = find_thread_id (num);
 635
 636   if (!tp)
 637     error ("Thread ID %d not known.  Use the \"info threads\" command to\n\
 638 see the IDs of currently known threads.", num);
 639
 640   if (!thread_alive (tp))
 641     error ("Thread ID %d has terminated.\n", num);
 642
 643   switch_to_thread (tp->pid);
 644
 645   printf_filtered ("[Switching to thread %d (%s)]\n",
 646                    pid_to_thread_id (inferior_pid),
 647 #if defined(HPUXHPPA)
 648                    target_tid_to_str (inferior_pid)
 649 #else
 650                    target_pid_to_str (inferior_pid)
 651 #endif
 652     );
 653
 654   print_stack_frame (selected_frame, selected_frame_level, 1);
 655   return GDB_RC_OK;
 656 }
 657
 658 enum gdb_rc
 659 gdb_thread_select (char *tidstr)
 660 {
 661   return catch_errors (do_captured_thread_select, tidstr,
 662                        NULL, RETURN_MASK_ALL);
 663 }
 664
 665 /* Commands with a prefix of `thread'.  */
 666 struct cmd_list_element *thread_cmd_list = NULL;
 667
 668 void
 669 _initialize_thread ()
 670 {
 671   static struct cmd_list_element *thread_apply_list = NULL;
 672
 673   add_info ("threads", info_threads_command,
 674             "IDs of currently known threads.");
 675
 676   add_prefix_cmd ("thread", class_run, thread_command,
 677                   "Use this command to switch between threads.\n\
 678 The new thread ID must be currently known.", &thread_cmd_list, "thread ", 1,
 679                   &cmdlist);
 680
 681   add_prefix_cmd ("apply", class_run, thread_apply_command,
 682                   "Apply a command to a list of threads.",
 683                   &thread_apply_list, "apply ", 1, &thread_cmd_list);
 684
 685   add_cmd ("all", class_run, thread_apply_all_command,
 686            "Apply a command to all threads.",
 687            &thread_apply_list);
 688
 689   if (!xdb_commands)
 690     add_com_alias ("t", "thread", class_run, 1);
 691 }