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   thread_list = tp;
 110   return tp;
 111 }
 112
 113 void
 114 delete_thread (pid)
 115      int pid;
 116 {
 117   struct thread_info *tp, *tpprev;
 118
 119   tpprev = NULL;
 120
 121   for (tp = thread_list; tp; tpprev = tp, tp = tp->next)
 122     if (tp->pid == pid)
 123       break;
 124
 125   if (!tp)
 126     return;
 127
 128   if (tpprev)
 129     tpprev->next = tp->next;
 130   else
 131     thread_list = tp->next;
 132
 133   /* NOTE: this will take care of any left-over step_resume breakpoints,
 134      but not any user-specified thread-specific breakpoints. */
 135   if (tp->step_resume_breakpoint)
 136     delete_breakpoint (tp->step_resume_breakpoint);
 137
 138   /* FIXME: do I ever need to call the back-end to give it a
 139      chance at this private data before deleting the thread?  */
 140   if (tp->private)
 141     free (tp->private);
 142
 143   free (tp);
 144
 145   return;
 146 }
 147
 148 static struct thread_info *
 149 find_thread_id (num)
 150      int num;
 151 {
 152   struct thread_info *tp;
 153
 154   for (tp = thread_list; tp; tp = tp->next)
 155     if (tp->num == num)
 156       return tp;
 157
 158   return NULL;
 159 }
 160
 161 /* Find a thread_info by matching 'pid'.  */
 162 struct thread_info *
 163 find_thread_pid (pid)
 164      int pid;
 165 {
 166   struct thread_info *tp;
 167
 168   for (tp = thread_list; tp; tp = tp->next)
 169     if (tp->pid == pid)
 170       return tp;
 171
 172   return NULL;
 173 }
 174
 175 /*
 176  * Thread iterator function.
 177  *
 178  * Calls a callback function once for each thread, so long as
 179  * the callback function returns false.  If the callback function
 180  * returns true, the iteration will end and the current thread
 181  * will be returned.  This can be useful for implementing a
 182  * search for a thread with arbitrary attributes, or for applying
 183  * some operation to every thread.
 184  *
 185  * FIXME: some of the existing functionality, such as
 186  * "Thread apply all", might be rewritten using this functionality.
 187  */
 188
 189 struct thread_info *
 190 iterate_over_threads (callback, data)
 191      int (*callback) ();
 192      void *data;
 193 {
 194   struct thread_info *tp;
 195
 196   for (tp = thread_list; tp; tp = tp->next)
 197     if ((*callback) (tp, data))
 198       return tp;
 199
 200   return NULL;
 201 }
 202
 203 int
 204 valid_thread_id (num)
 205      int num;
 206 {
 207   struct thread_info *tp;
 208
 209   for (tp = thread_list; tp; tp = tp->next)
 210     if (tp->num == num)
 211       return 1;
 212
 213   return 0;
 214 }
 215
 216 int
 217 pid_to_thread_id (pid)
 218      int pid;
 219 {
 220   struct thread_info *tp;
 221
 222   for (tp = thread_list; tp; tp = tp->next)
 223     if (tp->pid == pid)
 224       return tp->num;
 225
 226   return 0;
 227 }
 228
 229 int
 230 thread_id_to_pid (num)
 231      int num;
 232 {
 233   struct thread_info *thread = find_thread_id (num);
 234   if (thread)
 235     return thread->pid;
 236   else
 237     return -1;
 238 }
 239
 240 int
 241 in_thread_list (pid)
 242      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
 253 /* Load infrun state for the thread PID.  */
 254
 255 void
 256 load_infrun_state (pid, prev_pc, prev_func_start, prev_func_name,
 257                    trap_expected, step_resume_breakpoint,
 258                    through_sigtramp_breakpoint, step_range_start,
 259                    step_range_end, step_frame_address,
 260                    handling_longjmp, another_trap,
 261                    stepping_through_solib_after_catch,
 262                    stepping_through_solib_catchpoints,
 263                    stepping_through_sigtramp)
 264      int pid;
 265      CORE_ADDR *prev_pc;
 266      CORE_ADDR *prev_func_start;
 267      char **prev_func_name;
 268      int *trap_expected;
 269      struct breakpoint **step_resume_breakpoint;
 270      struct breakpoint **through_sigtramp_breakpoint;
 271      CORE_ADDR *step_range_start;
 272      CORE_ADDR *step_range_end;
 273      CORE_ADDR *step_frame_address;
 274      int *handling_longjmp;
 275      int *another_trap;
 276      int *stepping_through_solib_after_catch;
 277      bpstat *stepping_through_solib_catchpoints;
 278      int *stepping_through_sigtramp;
 279 {
 280   struct thread_info *tp;
 281
 282   /* If we can't find the thread, then we're debugging a single threaded
 283      process.  No need to do anything in that case.  */
 284   tp = find_thread_id (pid_to_thread_id (pid));
 285   if (tp == NULL)
 286     return;
 287
 288   *prev_pc = tp->prev_pc;
 289   *prev_func_start = tp->prev_func_start;
 290   *prev_func_name = tp->prev_func_name;
 291   *step_resume_breakpoint = tp->step_resume_breakpoint;
 292   *step_range_start = tp->step_range_start;
 293   *step_range_end = tp->step_range_end;
 294   *step_frame_address = tp->step_frame_address;
 295   *through_sigtramp_breakpoint = tp->through_sigtramp_breakpoint;
 296   *handling_longjmp = tp->handling_longjmp;
 297   *trap_expected = tp->trap_expected;
 298   *another_trap = tp->another_trap;
 299   *stepping_through_solib_after_catch = tp->stepping_through_solib_after_catch;
 300   *stepping_through_solib_catchpoints = tp->stepping_through_solib_catchpoints;
 301   *stepping_through_sigtramp = tp->stepping_through_sigtramp;
 302 }
 303
 304 /* Save infrun state for the thread PID.  */
 305
 306 void
 307 save_infrun_state (pid, prev_pc, prev_func_start, prev_func_name,
 308                    trap_expected, step_resume_breakpoint,
 309                    through_sigtramp_breakpoint, step_range_start,
 310                    step_range_end, step_frame_address,
 311                    handling_longjmp, another_trap,
 312                    stepping_through_solib_after_catch,
 313                    stepping_through_solib_catchpoints,
 314                    stepping_through_sigtramp)
 315      int pid;
 316      CORE_ADDR prev_pc;
 317      CORE_ADDR prev_func_start;
 318      char *prev_func_name;
 319      int trap_expected;
 320      struct breakpoint *step_resume_breakpoint;
 321      struct breakpoint *through_sigtramp_breakpoint;
 322      CORE_ADDR step_range_start;
 323      CORE_ADDR step_range_end;
 324      CORE_ADDR step_frame_address;
 325      int handling_longjmp;
 326      int another_trap;
 327      int stepping_through_solib_after_catch;
 328      bpstat stepping_through_solib_catchpoints;
 329      int stepping_through_sigtramp;
 330 {
 331   struct thread_info *tp;
 332
 333   /* If we can't find the thread, then we're debugging a single-threaded
 334      process.  Nothing to do in that case.  */
 335   tp = find_thread_id (pid_to_thread_id (pid));
 336   if (tp == NULL)
 337     return;
 338
 339   tp->prev_pc = prev_pc;
 340   tp->prev_func_start = prev_func_start;
 341   tp->prev_func_name = prev_func_name;
 342   tp->step_resume_breakpoint = step_resume_breakpoint;
 343   tp->step_range_start = step_range_start;
 344   tp->step_range_end = step_range_end;
 345   tp->step_frame_address = step_frame_address;
 346   tp->through_sigtramp_breakpoint = through_sigtramp_breakpoint;
 347   tp->handling_longjmp = handling_longjmp;
 348   tp->trap_expected = trap_expected;
 349   tp->another_trap = another_trap;
 350   tp->stepping_through_solib_after_catch = stepping_through_solib_after_catch;
 351   tp->stepping_through_solib_catchpoints = stepping_through_solib_catchpoints;
 352   tp->stepping_through_sigtramp = stepping_through_sigtramp;
 353 }
 354
 355 /* Return true if TP is an active thread. */
 356 static int
 357 thread_alive (tp)
 358      struct thread_info *tp;
 359 {
 360   if (tp->pid == -1)
 361     return 0;
 362   if (!target_thread_alive (tp->pid))
 363     {
 364       tp->pid = -1;             /* Mark it as dead */
 365       return 0;
 366     }
 367   return 1;
 368 }
 369
 370 static void
 371 prune_threads ()
 372 {
 373   struct thread_info *tp, *next;
 374
 375   for (tp = thread_list; tp; tp = next)
 376     {
 377       next = tp->next;
 378       if (!thread_alive (tp))
 379         delete_thread (tp->pid);
 380     }
 381 }
 382
 383 /* Print information about currently known threads
 384
 385  * Note: this has the drawback that it _really_ switches
 386  *       threads, which frees the frame cache.  A no-side
 387  *       effects info-threads command would be nicer.
 388  */
 389
 390 static void
 391 info_threads_command (arg, from_tty)
 392      char *arg;
 393      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 (pid)
 464      int pid;
 465 {
 466   if (pid == inferior_pid)
 467     return;
 468
 469   inferior_pid = pid;
 470   flush_cached_frames ();
 471   registers_changed ();
 472   stop_pc = read_pc ();
 473   select_frame (get_current_frame (), 0);
 474 }
 475
 476 static void
 477 restore_current_thread (pid)
 478      int pid;
 479 {
 480   if (pid != inferior_pid)
 481     {
 482       switch_to_thread (pid);
 483       print_stack_frame (get_current_frame (), 0, -1);
 484     }
 485 }
 486
 487 /* Apply a GDB command to a list of threads.  List syntax is a whitespace
 488    seperated list of numbers, or ranges, or the keyword `all'.  Ranges consist
 489    of two numbers seperated by a hyphen.  Examples:
 490
 491    thread apply 1 2 7 4 backtrace       Apply backtrace cmd to threads 1,2,7,4
 492    thread apply 2-7 9 p foo(1)  Apply p foo(1) cmd to threads 2->7 & 9
 493    thread apply all p x/i $pc   Apply x/i $pc cmd to all threads
 494  */
 495
 496 static void
 497 thread_apply_all_command (cmd, from_tty)
 498      char *cmd;
 499      int from_tty;
 500 {
 501   struct thread_info *tp;
 502   struct cleanup *old_chain;
 503
 504   if (cmd == NULL || *cmd == '\000')
 505     error ("Please specify a command following the thread ID list");
 506
 507   old_chain = make_cleanup ((make_cleanup_func) restore_current_thread,
 508                             (void *) inferior_pid);
 509
 510   for (tp = thread_list; tp; tp = tp->next)
 511     if (thread_alive (tp))
 512       {
 513         switch_to_thread (tp->pid);
 514 #ifdef HPUXHPPA
 515         printf_filtered ("\nThread %d (%s):\n",
 516                          tp->num,
 517                          target_tid_to_str (inferior_pid));
 518 #else
 519         printf_filtered ("\nThread %d (%s):\n", tp->num,
 520                          target_pid_to_str (inferior_pid));
 521 #endif
 522         execute_command (cmd, from_tty);
 523       }
 524 }
 525
 526 static void
 527 thread_apply_command (tidlist, from_tty)
 528      char *tidlist;
 529      int from_tty;
 530 {
 531   char *cmd;
 532   char *p;
 533   struct cleanup *old_chain;
 534
 535   if (tidlist == NULL || *tidlist == '\000')
 536     error ("Please specify a thread ID list");
 537
 538   for (cmd = tidlist; *cmd != '\000' && !isalpha (*cmd); cmd++);
 539
 540   if (*cmd == '\000')
 541     error ("Please specify a command following the thread ID list");
 542
 543   old_chain = make_cleanup ((make_cleanup_func) restore_current_thread,
 544                             (void *) inferior_pid);
 545
 546   while (tidlist < cmd)
 547     {
 548       struct thread_info *tp;
 549       int start, end;
 550
 551       start = strtol (tidlist, &p, 10);
 552       if (p == tidlist)
 553         error ("Error parsing %s", tidlist);
 554       tidlist = p;
 555
 556       while (*tidlist == ' ' || *tidlist == '\t')
 557         tidlist++;
 558
 559       if (*tidlist == '-')      /* Got a range of IDs? */
 560         {
 561           tidlist++;            /* Skip the - */
 562           end = strtol (tidlist, &p, 10);
 563           if (p == tidlist)
 564             error ("Error parsing %s", tidlist);
 565           tidlist = p;
 566
 567           while (*tidlist == ' ' || *tidlist == '\t')
 568             tidlist++;
 569         }
 570       else
 571         end = start;
 572
 573       for (; start <= end; start++)
 574         {
 575           tp = find_thread_id (start);
 576
 577           if (!tp)
 578             warning ("Unknown thread %d.", start);
 579           else if (!thread_alive (tp))
 580             warning ("Thread %d has terminated.", start);
 581           else
 582             {
 583               switch_to_thread (tp->pid);
 584 #ifdef HPUXHPPA
 585               printf_filtered ("\nThread %d (%s):\n", tp->num,
 586                                target_tid_to_str (inferior_pid));
 587 #else
 588               printf_filtered ("\nThread %d (%s):\n", tp->num,
 589                                target_pid_to_str (inferior_pid));
 590 #endif
 591               execute_command (cmd, from_tty);
 592             }
 593         }
 594     }
 595 }
 596
 597 /* Switch to the specified thread.  Will dispatch off to thread_apply_command
 598    if prefix of arg is `apply'.  */
 599
 600 static void
 601 thread_command (tidstr, from_tty)
 602      char *tidstr;
 603      int from_tty;
 604 {
 605   int num;
 606   struct thread_info *tp;
 607
 608   if (!tidstr)
 609     {
 610       /* Don't generate an error, just say which thread is current. */
 611       if (target_has_stack)
 612         printf_filtered ("[Current thread is %d (%s)]\n",
 613                          pid_to_thread_id (inferior_pid),
 614 #if defined(HPUXHPPA)
 615                          target_tid_to_str (inferior_pid)
 616 #else
 617                          target_pid_to_str (inferior_pid)
 618 #endif
 619           );
 620       else
 621         error ("No stack.");
 622       return;
 623     }
 624   num = atoi (tidstr);
 625
 626   tp = find_thread_id (num);
 627
 628   if (!tp)
 629     error ("Thread ID %d not known.  Use the \"info threads\" command to\n\
 630 see the IDs of currently known threads.", num);
 631
 632   if (!thread_alive (tp))
 633     error ("Thread ID %d has terminated.\n", num);
 634
 635   switch_to_thread (tp->pid);
 636
 637   if (context_hook)
 638     context_hook (num);
 639
 640   printf_filtered ("[Switching to thread %d (%s)]\n",
 641                    pid_to_thread_id (inferior_pid),
 642 #if defined(HPUXHPPA)
 643                    target_tid_to_str (inferior_pid)
 644 #else
 645                    target_pid_to_str (inferior_pid)
 646 #endif
 647     );
 648   print_stack_frame (selected_frame, selected_frame_level, 1);
 649 }
 650
 651 /* Commands with a prefix of `thread'.  */
 652 struct cmd_list_element *thread_cmd_list = NULL;
 653
 654 void
 655 _initialize_thread ()
 656 {
 657   static struct cmd_list_element *thread_apply_list = NULL;
 658
 659   add_info ("threads", info_threads_command,
 660             "IDs of currently known threads.");
 661
 662   add_prefix_cmd ("thread", class_run, thread_command,
 663                   "Use this command to switch between threads.\n\
 664 The new thread ID must be currently known.", &thread_cmd_list, "thread ", 1,
 665                   &cmdlist);
 666
 667   add_prefix_cmd ("apply", class_run, thread_apply_command,
 668                   "Apply a command to a list of threads.",
 669                   &thread_apply_list, "apply ", 1, &thread_cmd_list);
 670
 671   add_cmd ("all", class_run, thread_apply_all_command,
 672            "Apply a command to all threads.",
 673            &thread_apply_list);
 674
 675   if (!xdb_commands)
 676     add_com_alias ("t", "thread", class_run, 1);
 677 }