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, 2009 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   /* Per-thread command support.  */
 140
 141   /* Pointer to what is left to do for an execution command after the
 142      target stops.  Used only in asynchronous mode, by targets that
 143      support async execution.  Several execution commands use it.  */
 144   struct continuation *continuations;
 145
 146   /* Similar to the above, but used when a single execution command
 147      requires several resume/stop iterations.  Used by the step
 148      command.  */
 149   struct continuation *intermediate_continuations;
 150
 151   /* Nonzero if the thread is being proceeded for a "finish" command
 152      or a similar situation when stop_registers should be saved.  */
 153   int proceed_to_finish;
 154
 155   enum step_over_calls_kind step_over_calls;
 156
 157   /* Nonzero if stopped due to a step command.  */
 158   int stop_step;
 159
 160   /* If stepping, nonzero means step count is > 1 so don't print frame
 161      next time inferior stops if it stops due to stepping.  */
 162   int step_multi;
 163
 164   /* Last signal that the inferior received (why it stopped).  */
 165   enum target_signal stop_signal;
 166
 167   /* Chain containing status of breakpoint(s) the thread stopped
 168      at.  */
 169   bpstat stop_bpstat;
 170
 171   /* True if this thread has been explicitly requested to stop.  */
 172   int stop_requested;
 173
 174   /* Private data used by the target vector implementation.  */
 175   struct private_thread_info *private;
 176 };
 177
 178 /* Create an empty thread list, or empty the existing one.  */
 179 extern void init_thread_list (void);
 180
 181 /* Add a thread to the thread list, print a message
 182    that a new thread is found, and return the pointer to
 183    the new thread.  Caller my use this pointer to
 184    initialize the private thread data.  */
 185 extern struct thread_info *add_thread (ptid_t ptid);
 186
 187 /* Same as add_thread, but does not print a message
 188    about new thread.  */
 189 extern struct thread_info *add_thread_silent (ptid_t ptid);
 190
 191 /* Same as add_thread, and sets the private info.  */
 192 extern struct thread_info *add_thread_with_info (ptid_t ptid,
 193                                                  struct private_thread_info *);
 194
 195 /* Delete an existing thread list entry.  */
 196 extern void delete_thread (ptid_t);
 197
 198 /* Delete an existing thread list entry, and be quiet about it.  Used
 199    after the process this thread having belonged to having already
 200    exited, for example.  */
 201 extern void delete_thread_silent (ptid_t);
 202
 203 /* Delete a step_resume_breakpoint from the thread database. */
 204 extern void delete_step_resume_breakpoint (struct thread_info *);
 205
 206 /* Translate the integer thread id (GDB's homegrown id, not the system's)
 207    into a "pid" (which may be overloaded with extra thread information).  */
 208 extern ptid_t thread_id_to_pid (int);
 209
 210 /* Translate a 'pid' (which may be overloaded with extra thread information)
 211    into the integer thread id (GDB's homegrown id, not the system's).  */
 212 extern int pid_to_thread_id (ptid_t ptid);
 213
 214 /* Boolean test for an already-known pid (which may be overloaded with
 215    extra thread information).  */
 216 extern int in_thread_list (ptid_t ptid);
 217
 218 /* Boolean test for an already-known thread id (GDB's homegrown id,
 219    not the system's).  */
 220 extern int valid_thread_id (int thread);
 221
 222 /* Search function to lookup a thread by 'pid'.  */
 223 extern struct thread_info *find_thread_pid (ptid_t ptid);
 224
 225 /* Find thread by GDB user-visible thread number.  */
 226 struct thread_info *find_thread_id (int num);
 227
 228 /* Change the ptid of thread OLD_PTID to NEW_PTID.  */
 229 void thread_change_ptid (ptid_t old_ptid, ptid_t new_ptid);
 230
 231 /* Iterator function to call a user-provided callback function
 232    once for each known thread.  */
 233 typedef int (*thread_callback_func) (struct thread_info *, void *);
 234 extern struct thread_info *iterate_over_threads (thread_callback_func, void *);
 235
 236 extern int thread_count (void);
 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 /* Marks or clears thread(s) PTID as having been requested to stop.
 246    If PTID is MINUS_ONE_PTID, applies to all threads.  If
 247    ptid_is_pid(PTID) is true, applies to all threads of the process
 248    pointed at by PTID.  If STOP, then the THREAD_STOP_REQUESTED
 249    observer is called with PTID as argument.  */
 250 extern void set_stop_requested (ptid_t ptid, int stop);
 251
 252 /* NOTE: Since the thread state is not a boolean, most times, you do
 253    not want to check it with negation.  If you really want to check if
 254    the thread is stopped,
 255
 256     use (good):
 257
 258      if (is_stopped (ptid))
 259
 260     instead of (bad):
 261
 262      if (!is_running (ptid))
 263
 264    The latter also returns true on exited threads, most likelly not
 265    what you want.  */
 266
 267 /* Reports if in the frontend's perpective, thread PTID is running.  */
 268 extern int is_running (ptid_t ptid);
 269
 270 /* Is this thread listed, but known to have exited?  We keep it listed
 271    (but not visible) until it's safe to delete.  */
 272 extern int is_exited (ptid_t ptid);
 273
 274 /* In the frontend's perpective, is this thread stopped?  */
 275 extern int is_stopped (ptid_t ptid);
 276
 277 /* In the frontend's perpective is there any thread running?  */
 278 extern int any_running (void);
 279
 280 /* Marks thread PTID as executing, or not.  If PIDGET (PTID) is -1,
 281    marks all threads.
 282
 283    Note that this is different from the running state.  See the
 284    description of state_ and executing_ fields of struct
 285    thread_info.  */
 286 extern void set_executing (ptid_t ptid, int executing);
 287
 288 /* Reports if thread PTID is executing.  */
 289 extern int is_executing (ptid_t ptid);
 290
 291 /* Merge the executing property of thread PTID over to its thread
 292    state property (frontend running/stopped view).
 293
 294    "not executing" -> "stopped"
 295    "executing"     -> "running"
 296    "exited"        -> "exited"
 297
 298    If PIDGET (PTID) is -1, go over all threads.
 299
 300    Notifications are only emitted if the thread state did change.  */
 301 extern void finish_thread_state (ptid_t ptid);
 302
 303 /* Same as FINISH_THREAD_STATE, but with an interface suitable to be
 304    registered as a cleanup.  PTID_P points to the ptid_t that is
 305    passed to FINISH_THREAD_STATE.  */
 306 extern void finish_thread_state_cleanup (void *ptid_p);
 307
 308 /* Commands with a prefix of `thread'.  */
 309 extern struct cmd_list_element *thread_cmd_list;
 310
 311 /* Print notices on thread events (attach, detach, etc.), set with
 312    `set print thread-events'.  */
 313 extern int print_thread_events;
 314
 315 extern void print_thread_info (struct ui_out *uiout, int thread,
 316                                int pid);
 317
 318 extern struct cleanup *make_cleanup_restore_current_thread (void);
 319
 320 /* Returns a pointer into the thread_info corresponding to
 321    INFERIOR_PTID.  INFERIOR_PTID *must* be in the thread list.  */
 322 extern struct thread_info* inferior_thread (void);
 323
 324 #endif /* GDBTHREAD_H */