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   int proceed_to_finish;
 144   enum step_over_calls_kind step_over_calls;
 145   int stop_step;
 146   int step_multi;
 147
 148   enum target_signal stop_signal;
 149   /* Used in continue_command to set the proceed count of the
 150      breakpoint the thread stopped at.  */
 151   bpstat stop_bpstat;
 152
 153   /* Private data used by the target vector implementation.  */
 154   struct private_thread_info *private;
 155 };
 156
 157 /* Create an empty thread list, or empty the existing one.  */
 158 extern void init_thread_list (void);
 159
 160 /* Add a thread to the thread list, print a message
 161    that a new thread is found, and return the pointer to
 162    the new thread.  Caller my use this pointer to
 163    initialize the private thread data.  */
 164 extern struct thread_info *add_thread (ptid_t ptid);
 165
 166 /* Same as add_thread, but does not print a message
 167    about new thread.  */
 168 extern struct thread_info *add_thread_silent (ptid_t ptid);
 169
 170 /* Same as add_thread, and sets the private info.  */
 171 extern struct thread_info *add_thread_with_info (ptid_t ptid,
 172                                                  struct private_thread_info *);
 173
 174 /* Delete an existing thread list entry.  */
 175 extern void delete_thread (ptid_t);
 176
 177 /* Delete an existing thread list entry, and be quiet about it.  Used
 178    after the process this thread having belonged to having already
 179    exited, for example.  */
 180 extern void delete_thread_silent (ptid_t);
 181
 182 /* Delete a step_resume_breakpoint from the thread database. */
 183 extern void delete_step_resume_breakpoint (struct thread_info *);
 184
 185 /* Translate the integer thread id (GDB's homegrown id, not the system's)
 186    into a "pid" (which may be overloaded with extra thread information).  */
 187 extern ptid_t thread_id_to_pid (int);
 188
 189 /* Translate a 'pid' (which may be overloaded with extra thread information)
 190    into the integer thread id (GDB's homegrown id, not the system's).  */
 191 extern int pid_to_thread_id (ptid_t ptid);
 192
 193 /* Boolean test for an already-known pid (which may be overloaded with
 194    extra thread information).  */
 195 extern int in_thread_list (ptid_t ptid);
 196
 197 /* Boolean test for an already-known thread id (GDB's homegrown id,
 198    not the system's).  */
 199 extern int valid_thread_id (int thread);
 200
 201 /* Search function to lookup a thread by 'pid'.  */
 202 extern struct thread_info *find_thread_pid (ptid_t ptid);
 203
 204 /* Find thread by GDB user-visible thread number.  */
 205 struct thread_info *find_thread_id (int num);
 206
 207 /* Change the ptid of thread OLD_PTID to NEW_PTID.  */
 208 void thread_change_ptid (ptid_t old_ptid, ptid_t new_ptid);
 209
 210 /* Iterator function to call a user-provided callback function
 211    once for each known thread.  */
 212 typedef int (*thread_callback_func) (struct thread_info *, void *);
 213 extern struct thread_info *iterate_over_threads (thread_callback_func, void *);
 214
 215 extern int thread_count (void);
 216
 217 /* infrun context switch: save the debugger state for the given thread.  */
 218 extern void save_infrun_state (ptid_t ptid,
 219                                struct continuation *continuations,
 220                                struct continuation *intermediate_continuations,
 221                                int proceed_to_finish,
 222                                int stop_step,
 223                                int step_multi,
 224                                enum target_signal stop_signal,
 225                                bpstat stop_bpstat);
 226
 227 /* infrun context switch: load the debugger state previously saved
 228    for the given thread.  */
 229 extern void load_infrun_state (ptid_t ptid,
 230                                struct continuation **continuations,
 231                                struct continuation **intermediate_continuations,
 232                                int *proceed_to_finish,
 233                                int *stop_step,
 234                                int *step_multi,
 235                                enum target_signal *stop_signal,
 236                                bpstat *stop_bpstat);
 237
 238 /* Switch from one thread to another.  */
 239 extern void switch_to_thread (ptid_t ptid);
 240
 241 /* Marks thread PTID is running, or stopped.
 242    If PIDGET (PTID) is -1, marks all threads.  */
 243 extern void set_running (ptid_t ptid, int running);
 244
 245 /* NOTE: Since the thread state is not a boolean, most times, you do
 246    not want to check it with negation.  If you really want to check if
 247    the thread is stopped,
 248
 249     use (good):
 250
 251      if (is_stopped (ptid))
 252
 253     instead of (bad):
 254
 255      if (!is_running (ptid))
 256
 257    The latter also returns true on exited threads, most likelly not
 258    what you want.  */
 259
 260 /* Reports if in the frontend's perpective, thread PTID is running.  */
 261 extern int is_running (ptid_t ptid);
 262
 263 /* Is this thread listed, but known to have exited?  We keep it listed
 264    (but not visible) until it's safe to delete.  */
 265 extern int is_exited (ptid_t ptid);
 266
 267 /* In the frontend's perpective, is this thread stopped?  */
 268 extern int is_stopped (ptid_t ptid);
 269
 270 /* In the frontend's perpective is there any thread running?  */
 271 extern int any_running (void);
 272
 273 /* Marks thread PTID as executing, or not.  If PIDGET (PTID) is -1,
 274    marks all threads.
 275
 276    Note that this is different from the running state.  See the
 277    description of state_ and executing_ fields of struct
 278    thread_info.  */
 279 extern void set_executing (ptid_t ptid, int executing);
 280
 281 /* Reports if thread PTID is executing.  */
 282 extern int is_executing (ptid_t ptid);
 283
 284 /* Commands with a prefix of `thread'.  */
 285 extern struct cmd_list_element *thread_cmd_list;
 286
 287 /* Print notices on thread events (attach, detach, etc.), set with
 288    `set print thread-events'.  */
 289 extern int print_thread_events;
 290
 291 extern void print_thread_info (struct ui_out *uiout, int thread);
 292
 293 extern struct cleanup *make_cleanup_restore_current_thread (void);
 294
 295 /* Returns a pointer into the thread_info corresponding to
 296    INFERIOR_PTID.  INFERIOR_PTID *must* be in the thread list.  */
 297 extern struct thread_info* inferior_thread (void);
 298
 299 #endif /* GDBTHREAD_H */