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   /* Nonzero if the thread is being proceeded for an inferior function
 156      call.  */
 157   int in_infcall;
 158
 159   enum step_over_calls_kind step_over_calls;
 160
 161   /* Nonzero if stopped due to a step command.  */
 162   int stop_step;
 163
 164   /* If stepping, nonzero means step count is > 1 so don't print frame
 165      next time inferior stops if it stops due to stepping.  */
 166   int step_multi;
 167
 168   /* This is used to remember when a fork or vfork event was caught by
 169      a catchpoint, and thus the event is to be followed at the next
 170      resume of the thread, and not immediately.  */
 171   struct target_waitstatus pending_follow;
 172
 173   /* Last signal that the inferior received (why it stopped).  */
 174   enum target_signal stop_signal;
 175
 176   /* Chain containing status of breakpoint(s) the thread stopped
 177      at.  */
 178   bpstat stop_bpstat;
 179
 180   /* True if this thread has been explicitly requested to stop.  */
 181   int stop_requested;
 182
 183   /* Private data used by the target vector implementation.  */
 184   struct private_thread_info *private;
 185 };
 186
 187 /* Create an empty thread list, or empty the existing one.  */
 188 extern void init_thread_list (void);
 189
 190 /* Add a thread to the thread list, print a message
 191    that a new thread is found, and return the pointer to
 192    the new thread.  Caller my use this pointer to
 193    initialize the private thread data.  */
 194 extern struct thread_info *add_thread (ptid_t ptid);
 195
 196 /* Same as add_thread, but does not print a message
 197    about new thread.  */
 198 extern struct thread_info *add_thread_silent (ptid_t ptid);
 199
 200 /* Same as add_thread, and sets the private info.  */
 201 extern struct thread_info *add_thread_with_info (ptid_t ptid,
 202                                                  struct private_thread_info *);
 203
 204 /* Delete an existing thread list entry.  */
 205 extern void delete_thread (ptid_t);
 206
 207 /* Delete an existing thread list entry, and be quiet about it.  Used
 208    after the process this thread having belonged to having already
 209    exited, for example.  */
 210 extern void delete_thread_silent (ptid_t);
 211
 212 /* Delete a step_resume_breakpoint from the thread database. */
 213 extern void delete_step_resume_breakpoint (struct thread_info *);
 214
 215 /* Translate the integer thread id (GDB's homegrown id, not the system's)
 216    into a "pid" (which may be overloaded with extra thread information).  */
 217 extern ptid_t thread_id_to_pid (int);
 218
 219 /* Translate a 'pid' (which may be overloaded with extra thread information)
 220    into the integer thread id (GDB's homegrown id, not the system's).  */
 221 extern int pid_to_thread_id (ptid_t ptid);
 222
 223 /* Boolean test for an already-known pid (which may be overloaded with
 224    extra thread information).  */
 225 extern int in_thread_list (ptid_t ptid);
 226
 227 /* Boolean test for an already-known thread id (GDB's homegrown id,
 228    not the system's).  */
 229 extern int valid_thread_id (int thread);
 230
 231 /* Search function to lookup a thread by 'pid'.  */
 232 extern struct thread_info *find_thread_pid (ptid_t ptid);
 233
 234 /* Find thread by GDB user-visible thread number.  */
 235 struct thread_info *find_thread_id (int num);
 236
 237 /* Finds the first thread of the inferior given by PID.  If PID is -1,
 238    returns the first thread in the list.  */
 239 struct thread_info *first_thread_of_process (int pid);
 240
 241 /* Change the ptid of thread OLD_PTID to NEW_PTID.  */
 242 void thread_change_ptid (ptid_t old_ptid, ptid_t new_ptid);
 243
 244 /* Iterator function to call a user-provided callback function
 245    once for each known thread.  */
 246 typedef int (*thread_callback_func) (struct thread_info *, void *);
 247 extern struct thread_info *iterate_over_threads (thread_callback_func, void *);
 248
 249 extern int thread_count (void);
 250
 251 /* Switch from one thread to another.  */
 252 extern void switch_to_thread (ptid_t ptid);
 253
 254 /* Marks thread PTID is running, or stopped.
 255    If PIDGET (PTID) is -1, marks all threads.  */
 256 extern void set_running (ptid_t ptid, int running);
 257
 258 /* Marks or clears thread(s) PTID as having been requested to stop.
 259    If PTID is MINUS_ONE_PTID, applies to all threads.  If
 260    ptid_is_pid(PTID) is true, applies to all threads of the process
 261    pointed at by PTID.  If STOP, then the THREAD_STOP_REQUESTED
 262    observer is called with PTID as argument.  */
 263 extern void set_stop_requested (ptid_t ptid, int stop);
 264
 265 /* NOTE: Since the thread state is not a boolean, most times, you do
 266    not want to check it with negation.  If you really want to check if
 267    the thread is stopped,
 268
 269     use (good):
 270
 271      if (is_stopped (ptid))
 272
 273     instead of (bad):
 274
 275      if (!is_running (ptid))
 276
 277    The latter also returns true on exited threads, most likelly not
 278    what you want.  */
 279
 280 /* Reports if in the frontend's perpective, thread PTID is running.  */
 281 extern int is_running (ptid_t ptid);
 282
 283 /* Is this thread listed, but known to have exited?  We keep it listed
 284    (but not visible) until it's safe to delete.  */
 285 extern int is_exited (ptid_t ptid);
 286
 287 /* In the frontend's perpective, is this thread stopped?  */
 288 extern int is_stopped (ptid_t ptid);
 289
 290 /* In the frontend's perpective is there any thread running?  */
 291 extern int any_running (void);
 292
 293 /* Marks thread PTID as executing, or not.  If PIDGET (PTID) is -1,
 294    marks all threads.
 295
 296    Note that this is different from the running state.  See the
 297    description of state_ and executing_ fields of struct
 298    thread_info.  */
 299 extern void set_executing (ptid_t ptid, int executing);
 300
 301 /* Reports if thread PTID is executing.  */
 302 extern int is_executing (ptid_t ptid);
 303
 304 /* Merge the executing property of thread PTID over to its thread
 305    state property (frontend running/stopped view).
 306
 307    "not executing" -> "stopped"
 308    "executing"     -> "running"
 309    "exited"        -> "exited"
 310
 311    If PIDGET (PTID) is -1, go over all threads.
 312
 313    Notifications are only emitted if the thread state did change.  */
 314 extern void finish_thread_state (ptid_t ptid);
 315
 316 /* Same as FINISH_THREAD_STATE, but with an interface suitable to be
 317    registered as a cleanup.  PTID_P points to the ptid_t that is
 318    passed to FINISH_THREAD_STATE.  */
 319 extern void finish_thread_state_cleanup (void *ptid_p);
 320
 321 /* Commands with a prefix of `thread'.  */
 322 extern struct cmd_list_element *thread_cmd_list;
 323
 324 /* Print notices on thread events (attach, detach, etc.), set with
 325    `set print thread-events'.  */
 326 extern int print_thread_events;
 327
 328 extern void print_thread_info (struct ui_out *uiout, int thread,
 329                                int pid);
 330
 331 extern struct cleanup *make_cleanup_restore_current_thread (void);
 332
 333 /* Returns a pointer into the thread_info corresponding to
 334    INFERIOR_PTID.  INFERIOR_PTID *must* be in the thread list.  */
 335 extern struct thread_info* inferior_thread (void);
 336
 337 #endif /* GDBTHREAD_H */