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 static void
 113 prune_threads ()
 114 {
 115   struct thread_info *tp, *tpprev;
 116
 117   tpprev = 0;
 118
 119   for (tp = thread_list; tp; tp = tp->next)
 120     if (tp->pid == -1)
 121       {
 122         if (tpprev)
 123           tpprev->next = tp->next;
 124         else
 125           thread_list = NULL;
 126
 127         free (tp);
 128       }
 129     else
 130       tpprev = tp;
 131 }
 132
 133 /* Print information about currently known threads */
 134
 135 static void
 136 info_threads_command (arg, from_tty)
 137      char *arg;
 138      int from_tty;
 139 {
 140   struct thread_info *tp;
 141   int current_pid = inferior_pid;
 142
 143   for (tp = thread_list; tp; tp = tp->next)
 144     {
 145       if (target_has_execution
 146           && kill (tp->pid, 0) == -1)
 147         {
 148           tp->pid = -1; /* Mark it as dead */
 149           continue;
 150         }
 151
 152       if (tp->pid == current_pid)
 153         printf_filtered ("* ");
 154       else
 155         printf_filtered ("  ");
 156
 157       printf_filtered ("%d %s  ", tp->num, target_pid_to_str (tp->pid));
 158
 159       thread_switch (tp->pid);
 160       print_stack_frame (selected_frame, -1, 0);
 161     }
 162
 163   thread_switch (current_pid);
 164   prune_threads ();
 165 }
 166
 167 /* Switch from one thread to another. */
 168
 169 static void
 170 thread_switch (pid)
 171      int pid;
 172 {
 173   if (pid == inferior_pid)
 174     return;
 175
 176   inferior_pid = pid;
 177   flush_cached_frames ();
 178   registers_changed ();
 179   stop_pc = read_pc();
 180   set_current_frame (create_new_frame (read_fp (), stop_pc));
 181   stop_frame_address = FRAME_FP (get_current_frame ());
 182   select_frame (get_current_frame (), 0);
 183 }
 184
 185 static void
 186 thread_command (tidstr, from_tty)
 187      char *tidstr;
 188      int from_tty;
 189 {
 190   int num;
 191   struct thread_info *tp;
 192
 193   if (!tidstr)
 194     error ("Please specify a thread ID.  Use the \"info threads\" command to\n\
 195 see the IDs of currently known threads.");
 196
 197
 198   num = atoi (tidstr);
 199
 200   tp = find_thread_id (num);
 201
 202   if (!tp)
 203     error ("Thread ID %d not known.  Use the \"info threads\" command to\n\
 204 see the IDs of currently known threads.", num);
 205
 206   thread_switch (tp->pid);
 207
 208   printf_filtered ("[Switching to %s]\n", target_pid_to_str (inferior_pid));
 209   print_stack_frame (selected_frame, selected_frame_level, 1);
 210 }
 211
 212 void
 213 _initialize_thread ()
 214 {
 215   add_info ("threads", info_threads_command,
 216             "IDs of currently known threads.");
 217   add_com ("thread", class_info, thread_command,
 218            "Use this command to switch between threads.\n\
 219 The new thread ID must be currently known.");
 220 }