gdb/gdbthread.h

   1 /* Multi-process/thread control defs for GDB, the GNU debugger.
   2    Copyright (C) 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1997, 1998, 1999,
   3    2000, 2007, 2008 Free Software Foundation, Inc.
   4    Contributed by Lynx Real-Time Systems, Inc.  Los Gatos, CA.
   5
   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 3 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, see <http://www.gnu.org/licenses/>.  */
  21
  22 #ifndef GDBTHREAD_H
  23 #define GDBTHREAD_H
  24
  25 struct symtab;
  26
  27 #include "breakpoint.h"
  28 #include "frame.h"
  29 #include "ui-out.h"
  30 #include "inferior.h"
  31
  32 struct thread_info
  33 {
  34   struct thread_info *next;
  35   ptid_t ptid;                  /* "Actual process id";
  36                                     In fact, this may be overloaded with
  37                                     kernel thread id, etc.  */
  38   int num;                      /* Convenient handle (GDB thread id) */
  39
  40   /* Non-zero means the thread is executing.  Note: this is different
  41      from saying that there is an active target and we are stopped at
  42      a breakpoint, for instance.  This is a real indicator whether the
  43      thread is off and running.  */
  44   /* This field is internal to thread.c.  Never access it directly,
  45      use is_executing instead.  */
  46   int executing_;
  47
  48   /* Frontend view of the thread state.  Note that the RUNNING/STOPPED
  49      states are different from EXECUTING.  When the thread is stopped
  50      internally while handling an internal event, like a software
  51      single-step breakpoint, EXECUTING will be false, but running will
  52      still be true.  As a possible future extension, this could turn
  53      into enum { stopped, exited, stepping, finishing, until(ling),
  54      running ... }  */
  55   /* This field is internal to thread.c.  Never access it directly,
  56      use is_running instead.  */
  57   int state_;
  58
  59   /* If this is > 0, then it means there's code out there that relies
  60      on this thread being listed.  Don't delete it from the lists even
  61      if we detect it exiting.  */
  62   int refcount;
  63
  64   /* User/external stepping state.  */
  65
  66   /* Step-resume or longjmp-resume breakpoint.  */
  67   struct breakpoint *step_resume_breakpoint;
  68
  69   /* Range to single step within.
  70
  71      If this is nonzero, respond to a single-step signal by continuing
  72      to step if the pc is in this range.
  73
  74      If step_range_start and step_range_end are both 1, it means to
  75      step for a single instruction (FIXME: it might clean up
  76      wait_for_inferior in a minor way if this were changed to the
  77      address of the instruction and that address plus one.  But maybe
  78      not.).  */
  79   CORE_ADDR step_range_start;   /* Inclusive */
  80   CORE_ADDR step_range_end;     /* Exclusive */
  81
  82   /* Stack frame address as of when stepping command was issued.
  83      This is how we know when we step into a subroutine call, and how
  84      to set the frame for the breakpoint used to step out.  */
  85   struct frame_id step_frame_id;
  86   int current_line;
  87   struct symtab *current_symtab;
  88
  89   /* Internal stepping state.  */
  90
  91   /* Record the pc of the thread the last time it stopped.  This is
  92      maintained by proceed and keep_going, and used in
  93      adjust_pc_after_break to distinguish a hardware single-step
  94      SIGTRAP from a breakpoint SIGTRAP.  */
  95   CORE_ADDR prev_pc;
  96
  97   /* Nonzero if we are presently stepping over a breakpoint.
  98
  99      If we hit a breakpoint or watchpoint, and then continue, we need
 100      to single step the current thread with breakpoints disabled, to
 101      avoid hitting the same breakpoint or watchpoint again.  And we
 102      should step just a single thread and keep other threads stopped,
 103      so that other threads don't miss breakpoints while they are
 104      removed.
 105
 106      So, this variable simultaneously means that we need to single
 107      step the current thread, keep other threads stopped, and that
 108      breakpoints should be removed while we step.
 109
 110      This variable is set either:
 111      - in proceed, when we resume inferior on user's explicit request
 112      - in keep_going, if handle_inferior_event decides we need to
 113      step over breakpoint.
 114
 115      The variable is cleared in normal_stop.  The proceed calls
 116      wait_for_inferior, which calls handle_inferior_event in a loop,
 117      and until wait_for_inferior exits, this variable is changed only
 118      by keep_going.  */
 119   int trap_expected;
 120
 121   /* Should we step over breakpoint next time keep_going is called?  */
 122   int stepping_over_breakpoint;
 123
 124   /* Set to TRUE if we should finish single-stepping over a breakpoint
 125      after hitting the current step-resume breakpoint.  */
 126   int step_after_step_resume_breakpoint;
 127
 128   /* This is set TRUE when a catchpoint of a shared library event
 129      triggers.  Since we don't wish to leave the inferior in the
 130      solib hook when we report the event, we step the inferior
 131      back to user code before stopping and reporting the event.  */
 132   int stepping_through_solib_after_catch;
 133
 134   /* When stepping_through_solib_after_catch is TRUE, this is a
 135      list of the catchpoints that should be reported as triggering
 136      when we finally do stop stepping.  */
 137   bpstat stepping_through_solib_catchpoints;
 138
 139   /* The below are only per-thread in non-stop mode.  */
 140   /* Per-thread command support.  */
 141   struct continuation *continuations;
 142   struct continuation *intermediate_continuations;
 143
 144   /* Nonzero if the thread is being proceeded for a "finish" command
 145      or a similar situation when stop_registers should be saved.  */
 146   int proceed_to_finish;
 147
 148   enum step_over_calls_kind step_over_calls;
 149
 150   /* Nonzero if stopped due to a step command.  */
 151   int stop_step;
 152
 153   /* If stepping, nonzero means step count is > 1 so don't print frame
 154      next time inferior stops if it stops due to stepping.  */
 155   int step_multi;
 156
 157   /* Last signal that the inferior received (why it stopped).  */
 158   enum target_signal stop_signal;
 159
 160   /* Chain containing status of breakpoint(s) the thread stopped
 161      at.  */
 162   bpstat stop_bpstat;
 163
 164   /* Private data used by the target vector implementation.  */
 165   struct private_thread_info *private;
 166 };
 167
 168 /* Create an empty thread list, or empty the existing one.  */
 169 extern void init_thread_list (void);
 170
 171 /* Add a thread to the thread list, print a message
 172    that a new thread is found, and return the pointer to
 173    the new thread.  Caller my use this pointer to
 174    initialize the private thread data.  */
 175 extern struct thread_info *add_thread (ptid_t ptid);
 176
 177 /* Same as add_thread, but does not print a message
 178    about new thread.  */
 179 extern struct thread_info *add_thread_silent (ptid_t ptid);
 180
 181 /* Same as add_thread, and sets the private info.  */
 182 extern struct thread_info *add_thread_with_info (ptid_t ptid,
 183                                                  struct private_thread_info *);
 184
 185 /* Delete an existing thread list entry.  */
 186 extern void delete_thread (ptid_t);
 187
 188 /* Delete an existing thread list entry, and be quiet about it.  Used
 189    after the process this thread having belonged to having already
 190    exited, for example.  */
 191 extern void delete_thread_silent (ptid_t);
 192
 193 /* Delete a step_resume_breakpoint from the thread database. */
 194 extern void delete_step_resume_breakpoint (struct thread_info *);
 195
 196 /* Translate the integer thread id (GDB's homegrown id, not the system's)
 197    into a "pid" (which may be overloaded with extra thread information).  */
 198 extern ptid_t thread_id_to_pid (int);
 199
 200 /* Translate a 'pid' (which may be overloaded with extra thread information)
 201    into the integer thread id (GDB's homegrown id, not the system's).  */
 202 extern int pid_to_thread_id (ptid_t ptid);
 203
 204 /* Boolean test for an already-known pid (which may be overloaded with
 205    extra thread information).  */
 206 extern int in_thread_list (ptid_t ptid);
 207
 208 /* Boolean test for an already-known thread id (GDB's homegrown id,
 209    not the system's).  */
 210 extern int valid_thread_id (int thread);
 211
 212 /* Search function to lookup a thread by 'pid'.  */
 213 extern struct thread_info *find_thread_pid (ptid_t ptid);
 214
 215 /* Find thread by GDB user-visible thread number.  */
 216 struct thread_info *find_thread_id (int num);
 217
 218 /* Change the ptid of thread OLD_PTID to NEW_PTID.  */
 219 void thread_change_ptid (ptid_t old_ptid, ptid_t new_ptid);
 220
 221 /* Iterator function to call a user-provided callback function
 222    once for each known thread.  */
 223 typedef int (*thread_callback_func) (struct thread_info *, void *);
 224 extern struct thread_info *iterate_over_threads (thread_callback_func, void *);
 225
 226 extern int thread_count (void);
 227
 228 /* infrun context switch: save the debugger state for the given thread.  */
 229 extern void save_infrun_state (ptid_t ptid,
 230                                struct continuation *continuations,
 231                                struct continuation *intermediate_continuations);
 232
 233 /* infrun context switch: load the debugger state previously saved
 234    for the given thread.  */
 235 extern void load_infrun_state (ptid_t ptid,
 236                                struct continuation **continuations,
 237                                struct continuation **intermediate_continuations);
 238
 239 /* Switch from one thread to another.  */
 240 extern void switch_to_thread (ptid_t ptid);
 241
 242 /* Marks thread PTID is running, or stopped.
 243    If PIDGET (PTID) is -1, marks all threads.  */
 244 extern void set_running (ptid_t ptid, int running);
 245
 246 /* NOTE: Since the thread state is not a boolean, most times, you do
 247    not want to check it with negation.  If you really want to check if
 248    the thread is stopped,
 249
 250     use (good):
 251
 252      if (is_stopped (ptid))
 253
 254     instead of (bad):
 255
 256      if (!is_running (ptid))
 257
 258    The latter also returns true on exited threads, most likelly not
 259    what you want.  */
 260
 261 /* Reports if in the frontend's perpective, thread PTID is running.  */
 262 extern int is_running (ptid_t ptid);
 263
 264 /* Is this thread listed, but known to have exited?  We keep it listed
 265    (but not visible) until it's safe to delete.  */
 266 extern int is_exited (ptid_t ptid);
 267
 268 /* In the frontend's perpective, is this thread stopped?  */
 269 extern int is_stopped (ptid_t ptid);
 270
 271 /* In the frontend's perpective is there any thread running?  */
 272 extern int any_running (void);
 273
 274 /* Marks thread PTID as executing, or not.  If PIDGET (PTID) is -1,
 275    marks all threads.
 276
 277    Note that this is different from the running state.  See the
 278    description of state_ and executing_ fields of struct
 279    thread_info.  */
 280 extern void set_executing (ptid_t ptid, int executing);
 281
 282 /* Reports if thread PTID is executing.  */
 283 extern int is_executing (ptid_t ptid);
 284
 285 /* Commands with a prefix of `thread'.  */
 286 extern struct cmd_list_element *thread_cmd_list;
 287
 288 /* Print notices on thread events (attach, detach, etc.), set with
 289    `set print thread-events'.  */
 290 extern int print_thread_events;
 291
 292 extern void print_thread_info (struct ui_out *uiout, int thread);
 293
 294 extern struct cleanup *make_cleanup_restore_current_thread (void);
 295
 296 /* Returns a pointer into the thread_info corresponding to
 297    INFERIOR_PTID.  INFERIOR_PTID *must* be in the thread list.  */
 298 extern struct thread_info* inferior_thread (void);
 299
 300 #endif /* GDBTHREAD_H */