gdb/thread.c

   1 /* Multi-process/thread control for GDB, the GNU debugger.
   2    Copyright 1986, 1987, 1988, 1993
   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., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  22
  23 #include "defs.h"
  24 #include "symtab.h"
  25 #include "frame.h"
  26 #include "inferior.h"
  27 #include "environ.h"
  28 #include "value.h"
  29 #include "target.h"
  30 #include "thread.h"
  31 #include "command.h"
  32 #include "gdbcmd.h"
  33
  34 #include <ctype.h>
  35 #include <sys/types.h>
  36 #include <signal.h>
  37
  38 /*#include "lynxos-core.h"*/
  39
  40 struct thread_info
  41 {
  42   struct thread_info *next;
  43   int pid;                      /* Actual process id */
  44   int num;                      /* Convenient handle */
  45 };
  46
  47 static struct thread_info *thread_list = NULL;
  48 static int highest_thread_num;
  49
  50 static void thread_command PARAMS ((char * tidstr, int from_tty));
  51
  52 static void prune_threads PARAMS ((void));
  53
  54 static void thread_switch PARAMS ((int pid));
  55
  56 static struct thread_info * find_thread_id PARAMS ((int num));
  57
  58 void
  59 init_thread_list ()
  60 {
  61   struct thread_info *tp, *tpnext;
  62
  63   if (!thread_list)
  64     return;
  65
  66   for (tp = thread_list; tp; tp = tpnext)
  67     {
  68       tpnext = tp->next;
  69       free (tp);
  70     }
  71
  72   thread_list = NULL;
  73   highest_thread_num = 0;
  74 }
  75
  76 void
  77 add_thread (pid)
  78      int pid;
  79 {
  80   struct thread_info *tp;
  81
  82   tp = (struct thread_info *) xmalloc (sizeof (struct thread_info));
  83
  84   tp->pid = pid;
  85   tp->num = ++highest_thread_num;
  86   tp->next = thread_list;
  87   thread_list = tp;
  88 }
  89
  90 static struct thread_info *
  91 find_thread_id (num)
  92     int num;
  93 {
  94   struct thread_info *tp;
  95
  96   for (tp = thread_list; tp; tp = tp->next)
  97     if (tp->num == num)
  98       return tp;
  99
 100   return NULL;
 101 }
 102
 103 int
 104 valid_thread_id (num)
 105     int num;
 106 {
 107   struct thread_info *tp;
 108
 109   for (tp = thread_list; tp; tp = tp->next)
 110     if (tp->num == num)
 111       return 1;
 112
 113   return 0;
 114 }
 115
 116 int
 117 pid_to_thread_id (pid)
 118     int pid;
 119 {
 120   struct thread_info *tp;
 121
 122   for (tp = thread_list; tp; tp = tp->next)
 123     if (tp->pid == pid)
 124       return tp->num;
 125
 126   return 0;
 127 }
 128
 129 int
 130 in_thread_list (pid)
 131     int pid;
 132 {
 133   struct thread_info *tp;
 134
 135   for (tp = thread_list; tp; tp = tp->next)
 136     if (tp->pid == pid)
 137       return 1;
 138
 139   return 0;                     /* Never heard of 'im */
 140 }
 141
 142 static void
 143 prune_threads ()
 144 {
 145   struct thread_info *tp, *tpprev;
 146
 147   tpprev = 0;
 148
 149   for (tp = thread_list; tp; tp = tp->next)
 150     if (tp->pid == -1)
 151       {
 152         if (tpprev)
 153           tpprev->next = tp->next;
 154         else
 155           thread_list = NULL;
 156
 157         free (tp);
 158       }
 159     else
 160       tpprev = tp;
 161 }
 162
 163 /* Print information about currently known threads */
 164
 165 static void
 166 info_threads_command (arg, from_tty)
 167      char *arg;
 168      int from_tty;
 169 {
 170   struct thread_info *tp;
 171   int current_pid = inferior_pid;
 172
 173   /* Avoid coredumps which would happen if we tried to access a NULL
 174      selected_frame.  */
 175   if (!target_has_stack) error ("No stack.");
 176
 177   for (tp = thread_list; tp; tp = tp->next)
 178     {
 179       /* FIXME: need to figure out a way to do this for remote too,
 180          or else the print_stack_frame below will fail with a bogus
 181          thread ID.  */
 182       if (!STREQ (current_target.to_shortname, "remote")
 183           && target_has_execution
 184           && kill (tp->pid, 0) == -1)
 185         {
 186           tp->pid = -1; /* Mark it as dead */
 187           continue;
 188         }
 189
 190       if (tp->pid == current_pid)
 191         printf_filtered ("* ");
 192       else
 193         printf_filtered ("  ");
 194
 195       printf_filtered ("%d %s  ", tp->num, target_pid_to_str (tp->pid));
 196
 197       thread_switch (tp->pid);
 198       print_stack_frame (selected_frame, -1, 0);
 199     }
 200
 201   thread_switch (current_pid);
 202   prune_threads ();
 203 }
 204
 205 /* Switch from one thread to another. */
 206
 207 static void
 208 thread_switch (pid)
 209      int pid;
 210 {
 211   if (pid == inferior_pid)
 212     return;
 213
 214   inferior_pid = pid;
 215   flush_cached_frames ();
 216   registers_changed ();
 217   stop_pc = read_pc();
 218   select_frame (get_current_frame (), 0);
 219 }
 220
 221 static void
 222 restore_current_thread (pid)
 223      int pid;
 224 {
 225   if (pid != inferior_pid)
 226     thread_switch (pid);
 227 }
 228
 229 /* Apply a GDB command to a list of threads.  List syntax is a whitespace
 230    seperated list of numbers, or ranges, or the keyword `all'.  Ranges consist
 231    of two numbers seperated by a hyphen.  Examples:
 232
 233         thread apply 1 2 7 4 backtrace  Apply backtrace cmd to threads 1,2,7,4
 234         thread apply 2-7 9 p foo(1)     Apply p foo(1) cmd to threads 2->7 & 9
 235         thread apply all p x/i $pc      Apply x/i $pc cmd to all threads
 236 */
 237
 238 static void
 239 thread_apply_all_command (cmd, from_tty)
 240      char *cmd;
 241      int from_tty;
 242 {
 243   struct thread_info *tp;
 244   struct cleanup *old_chain;
 245
 246   if (cmd == NULL || *cmd == '\000')
 247     error ("Please specify a command following the thread ID list");
 248
 249   old_chain = make_cleanup (restore_current_thread, inferior_pid);
 250
 251   for (tp = thread_list; tp; tp = tp->next)
 252     {
 253       thread_switch (tp->pid);
 254       printf_filtered ("\nThread %d (%s):\n", tp->num,
 255                        target_pid_to_str (inferior_pid));
 256       execute_command (cmd, from_tty);
 257     }
 258 }
 259
 260 static void
 261 thread_apply_command (tidlist, from_tty)
 262      char *tidlist;
 263      int from_tty;
 264 {
 265   char *cmd;
 266   char *p;
 267   struct cleanup *old_chain;
 268
 269   if (tidlist == NULL || *tidlist == '\000')
 270     error ("Please specify a thread ID list");
 271
 272   for (cmd = tidlist; *cmd != '\000' && !isalpha(*cmd); cmd++);
 273
 274   if (*cmd == '\000')
 275     error ("Please specify a command following the thread ID list");
 276
 277   old_chain = make_cleanup (restore_current_thread, inferior_pid);
 278
 279   while (tidlist < cmd)
 280     {
 281       struct thread_info *tp;
 282       int start, end;
 283
 284       start = strtol (tidlist, &p, 10);
 285       if (p == tidlist)
 286         error ("Error parsing %s", tidlist);
 287       tidlist = p;
 288
 289       while (*tidlist == ' ' || *tidlist == '\t')
 290         tidlist++;
 291
 292       if (*tidlist == '-')      /* Got a range of IDs? */
 293         {
 294           tidlist++;    /* Skip the - */
 295           end = strtol (tidlist, &p, 10);
 296           if (p == tidlist)
 297             error ("Error parsing %s", tidlist);
 298           tidlist = p;
 299
 300           while (*tidlist == ' ' || *tidlist == '\t')
 301             tidlist++;
 302         }
 303       else
 304         end = start;
 305
 306       for (; start <= end; start++)
 307         {
 308           tp = find_thread_id (start);
 309
 310           if (!tp)
 311             {
 312               warning ("Unknown thread %d.", start);
 313               continue;
 314             }
 315
 316           thread_switch (tp->pid);
 317           printf_filtered ("\nThread %d (%s):\n", tp->num,
 318                            target_pid_to_str (inferior_pid));
 319           execute_command (cmd, from_tty);
 320         }
 321     }
 322 }
 323
 324 /* Switch to the specified thread.  Will dispatch off to thread_apply_command
 325    if prefix of arg is `apply'.  */
 326
 327 static void
 328 thread_command (tidstr, from_tty)
 329      char *tidstr;
 330      int from_tty;
 331 {
 332   int num;
 333   struct thread_info *tp;
 334
 335   if (!tidstr)
 336     error ("Please specify a thread ID.  Use the \"info threads\" command to\n\
 337 see the IDs of currently known threads.");
 338
 339   num = atoi (tidstr);
 340
 341   tp = find_thread_id (num);
 342
 343   if (!tp)
 344     error ("Thread ID %d not known.  Use the \"info threads\" command to\n\
 345 see the IDs of currently known threads.", num);
 346
 347   thread_switch (tp->pid);
 348
 349   printf_filtered ("[Switching to %s]\n", target_pid_to_str (inferior_pid));
 350   print_stack_frame (selected_frame, selected_frame_level, 1);
 351 }
 352
 353 void
 354 _initialize_thread ()
 355 {
 356   static struct cmd_list_element *thread_cmd_list = NULL;
 357   static struct cmd_list_element *thread_apply_list = NULL;
 358   extern struct cmd_list_element *cmdlist;
 359
 360   add_info ("threads", info_threads_command,
 361             "IDs of currently known threads.");
 362
 363   add_prefix_cmd ("thread", class_run, thread_command,
 364                   "Use this command to switch between threads.\n\
 365 The new thread ID must be currently known.", &thread_cmd_list, "thread ", 1,
 366                   &cmdlist);
 367
 368   add_prefix_cmd ("apply", class_run, thread_apply_command,
 369                   "Apply a command to a list of threads.",
 370                   &thread_apply_list, "apply ", 1, &thread_cmd_list);
 371
 372   add_cmd ("all", class_run, thread_apply_all_command,
 373            "Apply a command to all threads.",
 374            &thread_apply_list);
 375
 376   add_com_alias ("t", "thread", class_run, 1);
 377 }