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
  32 #include <sys/types.h>
  33 #include <signal.h>
  34
  35 /*#include "lynxos-core.h"*/
  36
  37 struct thread_info
  38 {
  39   struct thread_info *next;
  40   int pid;                      /* Actual process id */
  41   int num;                      /* Convenient handle */
  42 };
  43
  44 static struct thread_info *thread_list = NULL;
  45 static int highest_thread_num;
  46
  47 static void thread_info PARAMS ((void));
  48
  49 static void thread_command PARAMS ((char * tidstr, int from_tty));
  50
  51 static void prune_threads PARAMS ((void));
  52
  53 static void thread_switch PARAMS ((int pid));
  54
  55 void
  56 init_thread_list ()
  57 {
  58   struct thread_info *tp, *tpnext;
  59
  60   if (!thread_list)
  61     return;
  62
  63   for (tp = thread_list; tp; tp = tpnext)
  64     {
  65       tpnext = tp->next;
  66       free (tp);
  67     }
  68
  69   thread_list = NULL;
  70   highest_thread_num = 0;
  71 }
  72
  73 void
  74 add_thread (pid)
  75      int pid;
  76 {
  77   struct thread_info *tp;
  78
  79   tp = xmalloc (sizeof (struct thread_info));
  80
  81   tp->pid = pid;
  82   tp->num = ++highest_thread_num;
  83   tp->next = thread_list;
  84   thread_list = tp;
  85 }
  86
  87 static struct thread_info *
  88 find_thread_id (num)
  89     int num;
  90 {
  91   struct thread_info *tp;
  92
  93   for (tp = thread_list; tp; tp = tp->next)
  94     if (tp->num == num)
  95       return tp;
  96
  97   return NULL;
  98 }
  99
 100 int
 101 in_thread_list (pid)
 102     int pid;
 103 {
 104   struct thread_info *tp;
 105
 106   for (tp = thread_list; tp; tp = tp->next)
 107     if (tp->pid == pid)
 108       return 1;
 109
 110   return 0;                     /* Never heard of 'im */
 111 }
 112
 113 #if 0
 114 void
 115 bfd_get_core_threads (abfd)
 116     bfd *abfd;
 117 {
 118     int i;
 119
 120     inferior_pid = BUILDPID (inferior_pid, core_thread (abfd)->pid);
 121     for (i = 0; i < core_pss (abfd).threadcnt; i++)
 122       add_thread (core_thread (abfd)[i].pid);
 123 }
 124 #endif
 125
 126 static void
 127 prune_threads ()
 128 {
 129   struct thread_info *tp, *tpprev;
 130
 131   tpprev = 0;
 132
 133   for (tp = thread_list; tp; tp = tp->next)
 134     if (tp->pid == -1)
 135       {
 136         if (tpprev)
 137           tpprev->next = tp->next;
 138         else
 139           thread_list = NULL;
 140
 141         free (tp);
 142       }
 143     else
 144       tpprev = tp;
 145 }
 146
 147 /* Print information about currently known threads */
 148
 149 static void
 150 info_threads_command (arg, from_tty)
 151      char *arg;
 152      int from_tty;
 153 {
 154   struct thread_info *tp;
 155   int current_pid = inferior_pid;
 156
 157   for (tp = thread_list; tp; tp = tp->next)
 158     {
 159       if (target_has_execution
 160           && kill (tp->pid, 0) == -1)
 161         {
 162           tp->pid == -1;        /* Mark it as dead */
 163           continue;
 164         }
 165
 166       if (tp->pid == current_pid)
 167         printf_filtered ("* ");
 168       else
 169         printf_filtered ("  ");
 170
 171       printf_filtered ("%d %s  ", tp->num, target_pid_to_str (tp->pid));
 172
 173       thread_switch (tp->pid);
 174       print_stack_frame (selected_frame, -1, 0);
 175     }
 176
 177   thread_switch (current_pid);
 178   prune_threads ();
 179 }
 180
 181 /* Switch from one thread to another. */
 182
 183 void
 184 thread_switch (pid)
 185      int pid;
 186 {
 187   if (pid == inferior_pid)
 188     return;
 189
 190   inferior_pid = pid;
 191   pc_changed = 0;
 192   flush_cached_frames ();
 193   registers_changed ();
 194   stop_pc = read_pc();
 195   set_current_frame (create_new_frame (read_fp (), stop_pc));
 196   stop_frame_address = FRAME_FP (get_current_frame ());
 197   select_frame (get_current_frame (), 0);
 198 }
 199
 200 static void
 201 thread_command (tidstr, from_tty)
 202      char *tidstr;
 203      int from_tty;
 204 {
 205   int num;
 206   struct thread_info *tp;
 207
 208   if (!tidstr)
 209     error ("Please specify a thread ID.  Use the \"info threads\" command to\n\
 210 see the IDs of currently known threads.");
 211
 212
 213   num = atoi (tidstr);
 214
 215   tp = find_thread_id (num);
 216
 217   if (!tp)
 218     error ("Thread ID %d not known.  Use the \"info threads\" command to\n\
 219 see the IDs of currently known threads.", num);
 220
 221   thread_switch (tp->pid);
 222
 223   printf_filtered ("[Switching to %s]\n", target_pid_to_str (inferior_pid));
 224   print_stack_frame (selected_frame, selected_frame_level, 1);
 225 }
 226
 227 void
 228 _initialize_thread ()
 229 {
 230   add_info ("threads", info_threads_command,
 231             "IDs of currently known threads.");
 232   add_com ("thread", class_info, thread_command,
 233            "Use this command to switch between threads.\n\
 234 The new thread ID must be currently known.");
 235 }