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
  33 #include <sys/types.h>
  34 #include <signal.h>
  35
  36 /*#include "lynxos-core.h"*/
  37
  38 struct thread_info
  39 {
  40   struct thread_info *next;
  41   int pid;                      /* Actual process id */
  42   int num;                      /* Convenient handle */
  43 };
  44
  45 static struct thread_info *thread_list = NULL;
  46 static int highest_thread_num;
  47
  48 static void thread_command PARAMS ((char * tidstr, int from_tty));
  49
  50 static void prune_threads PARAMS ((void));
  51
  52 static void thread_switch PARAMS ((int pid));
  53
  54 void
  55 init_thread_list ()
  56 {
  57   struct thread_info *tp, *tpnext;
  58
  59   if (!thread_list)
  60     return;
  61
  62   for (tp = thread_list; tp; tp = tpnext)
  63     {
  64       tpnext = tp->next;
  65       free (tp);
  66     }
  67
  68   thread_list = NULL;
  69   highest_thread_num = 0;
  70 }
  71
  72 void
  73 add_thread (pid)
  74      int pid;
  75 {
  76   struct thread_info *tp;
  77
  78   tp = (struct thread_info *) xmalloc (sizeof (struct thread_info));
  79
  80   tp->pid = pid;
  81   tp->num = ++highest_thread_num;
  82   tp->next = thread_list;
  83   thread_list = tp;
  84 }
  85
  86 static struct thread_info *
  87 find_thread_id (num)
  88     int num;
  89 {
  90   struct thread_info *tp;
  91
  92   for (tp = thread_list; tp; tp = tp->next)
  93     if (tp->num == num)
  94       return tp;
  95
  96   return NULL;
  97 }
  98
  99 int
 100 in_thread_list (pid)
 101     int pid;
 102 {
 103   struct thread_info *tp;
 104
 105   for (tp = thread_list; tp; tp = tp->next)
 106     if (tp->pid == pid)
 107       return 1;
 108
 109   return 0;                     /* Never heard of 'im */
 110 }
 111
 112 #if 0
 113 void
 114 bfd_get_core_threads (abfd)
 115     bfd *abfd;
 116 {
 117     int i;
 118
 119     inferior_pid = BUILDPID (inferior_pid, core_thread (abfd)->pid);
 120     for (i = 0; i < core_pss (abfd).threadcnt; i++)
 121       add_thread (core_thread (abfd)[i].pid);
 122 }
 123 #endif
 124
 125 static void
 126 prune_threads ()
 127 {
 128   struct thread_info *tp, *tpprev;
 129
 130   tpprev = 0;
 131
 132   for (tp = thread_list; tp; tp = tp->next)
 133     if (tp->pid == -1)
 134       {
 135         if (tpprev)
 136           tpprev->next = tp->next;
 137         else
 138           thread_list = NULL;
 139
 140         free (tp);
 141       }
 142     else
 143       tpprev = tp;
 144 }
 145
 146 /* Print information about currently known threads */
 147
 148 static void
 149 info_threads_command (arg, from_tty)
 150      char *arg;
 151      int from_tty;
 152 {
 153   struct thread_info *tp;
 154   int current_pid = inferior_pid;
 155
 156   for (tp = thread_list; tp; tp = tp->next)
 157     {
 158       if (target_has_execution
 159           && kill (tp->pid, 0) == -1)
 160         {
 161           tp->pid = -1; /* Mark it as dead */
 162           continue;
 163         }
 164
 165       if (tp->pid == current_pid)
 166         printf_filtered ("* ");
 167       else
 168         printf_filtered ("  ");
 169
 170       printf_filtered ("%d %s  ", tp->num, target_pid_to_str (tp->pid));
 171
 172       thread_switch (tp->pid);
 173       print_stack_frame (selected_frame, -1, 0);
 174     }
 175
 176   thread_switch (current_pid);
 177   prune_threads ();
 178 }
 179
 180 /* Switch from one thread to another. */
 181
 182 static void
 183 thread_switch (pid)
 184      int pid;
 185 {
 186   if (pid == inferior_pid)
 187     return;
 188
 189   inferior_pid = pid;
 190   pc_changed = 0;
 191   flush_cached_frames ();
 192   registers_changed ();
 193   stop_pc = read_pc();
 194   set_current_frame (create_new_frame (read_fp (), stop_pc));
 195   stop_frame_address = FRAME_FP (get_current_frame ());
 196   select_frame (get_current_frame (), 0);
 197 }
 198
 199 static void
 200 thread_command (tidstr, from_tty)
 201      char *tidstr;
 202      int from_tty;
 203 {
 204   int num;
 205   struct thread_info *tp;
 206
 207   if (!tidstr)
 208     error ("Please specify a thread ID.  Use the \"info threads\" command to\n\
 209 see the IDs of currently known threads.");
 210
 211
 212   num = atoi (tidstr);
 213
 214   tp = find_thread_id (num);
 215
 216   if (!tp)
 217     error ("Thread ID %d not known.  Use the \"info threads\" command to\n\
 218 see the IDs of currently known threads.", num);
 219
 220   thread_switch (tp->pid);
 221
 222   printf_filtered ("[Switching to %s]\n", target_pid_to_str (inferior_pid));
 223   print_stack_frame (selected_frame, selected_frame_level, 1);
 224 }
 225
 226 void
 227 _initialize_thread ()
 228 {
 229   add_info ("threads", info_threads_command,
 230             "IDs of currently known threads.");
 231   add_com ("thread", class_info, thread_command,
 232            "Use this command to switch between threads.\n\
 233 The new thread ID must be currently known.");
 234 }