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
  87   /* Similarly, the frame ID of the underlying stack frame (skipping
  88      any inlined frames).  */
  89   struct frame_id step_stack_frame_id;
  90
  91   int current_line;
  92   struct symtab *current_symtab;
  93
  94   /* Internal stepping state.  */
  95
  96   /* Record the pc of the thread the last time it stopped.  This is
  97      maintained by proceed and keep_going, and used in
  98      adjust_pc_after_break to distinguish a hardware single-step
  99      SIGTRAP from a breakpoint SIGTRAP.  */
 100   CORE_ADDR prev_pc;
 101
 102   /* Nonzero if we are presently stepping over a breakpoint.
 103
 104      If we hit a breakpoint or watchpoint, and then continue, we need
 105      to single step the current thread with breakpoints disabled, to
 106      avoid hitting the same breakpoint or watchpoint again.  And we
 107      should step just a single thread and keep other threads stopped,
 108      so that other threads don't miss breakpoints while they are
 109      removed.
 110
 111      So, this variable simultaneously means that we need to single
 112      step the current thread, keep other threads stopped, and that
 113      breakpoints should be removed while we step.
 114
 115      This variable is set either:
 116      - in proceed, when we resume inferior on user's explicit request
 117      - in keep_going, if handle_inferior_event decides we need to
 118      step over breakpoint.
 119
 120      The variable is cleared in normal_stop.  The proceed calls
 121      wait_for_inferior, which calls handle_inferior_event in a loop,
 122      and until wait_for_inferior exits, this variable is changed only
 123      by keep_going.  */
 124   int trap_expected;
 125
 126   /* Should we step over breakpoint next time keep_going is called?  */
 127   int stepping_over_breakpoint;
 128
 129   /* Set to TRUE if we should finish single-stepping over a breakpoint
 130      after hitting the current step-resume breakpoint.  */
 131   int step_after_step_resume_breakpoint;
 132
 133   /* This is set TRUE when a catchpoint of a shared library event
 134      triggers.  Since we don't wish to leave the inferior in the
 135      solib hook when we report the event, we step the inferior
 136      back to user code before stopping and reporting the event.  */
 137   int stepping_through_solib_after_catch;
 138
 139   /* When stepping_through_solib_after_catch is TRUE, this is a
 140      list of the catchpoints that should be reported as triggering
 141      when we finally do stop stepping.  */
 142   bpstat stepping_through_solib_catchpoints;
 143
 144   /* Per-thread command support.  */
 145
 146   /* Pointer to what is left to do for an execution command after the
 147      target stops.  Used only in asynchronous mode, by targets that
 148      support async execution.  Several execution commands use it.  */
 149   struct continuation *continuations;
 150
 151   /* Similar to the above, but used when a single execution command
 152      requires several resume/stop iterations.  Used by the step
 153      command.  */
 154   struct continuation *intermediate_continuations;
 155
 156   /* Nonzero if the thread is being proceeded for a "finish" command
 157      or a similar situation when stop_registers should be saved.  */
 158   int proceed_to_finish;
 159
 160   /* Nonzero if the thread is being proceeded for an inferior function
 161      call.  */
 162   int in_infcall;
 163
 164   enum step_over_calls_kind step_over_calls;
 165
 166   /* Nonzero if stopped due to a step command.  */
 167   int stop_step;
 168
 169   /* If stepping, nonzero means step count is > 1 so don't print frame
 170      next time inferior stops if it stops due to stepping.  */
 171   int step_multi;
 172
 173   /* This is used to remember when a fork or vfork event was caught by
 174      a catchpoint, and thus the event is to be followed at the next
 175      resume of the thread, and not immediately.  */
 176   struct target_waitstatus pending_follow;
 177
 178   /* Last signal that the inferior received (why it stopped).  */
 179   enum target_signal stop_signal;
 180
 181   /* Chain containing status of breakpoint(s) the thread stopped
 182      at.  */
 183   bpstat stop_bpstat;
 184
 185   /* True if this thread has been explicitly requested to stop.  */
 186   int stop_requested;
 187
 188   /* Private data used by the target vector implementation.  */
 189   struct private_thread_info *private;
 190 };
 191
 192 /* Create an empty thread list, or empty the existing one.  */
 193 extern void init_thread_list (void);
 194
 195 /* Add a thread to the thread list, print a message
 196    that a new thread is found, and return the pointer to
 197    the new thread.  Caller my use this pointer to
 198    initialize the private thread data.  */
 199 extern struct thread_info *add_thread (ptid_t ptid);
 200
 201 /* Same as add_thread, but does not print a message
 202    about new thread.  */
 203 extern struct thread_info *add_thread_silent (ptid_t ptid);
 204
 205 /* Same as add_thread, and sets the private info.  */
 206 extern struct thread_info *add_thread_with_info (ptid_t ptid,
 207                                                  struct private_thread_info *);
 208
 209 /* Delete an existing thread list entry.  */
 210 extern void delete_thread (ptid_t);
 211
 212 /* Delete an existing thread list entry, and be quiet about it.  Used
 213    after the process this thread having belonged to having already
 214    exited, for example.  */
 215 extern void delete_thread_silent (ptid_t);
 216
 217 /* Delete a step_resume_breakpoint from the thread database. */
 218 extern void delete_step_resume_breakpoint (struct thread_info *);
 219
 220 /* Translate the integer thread id (GDB's homegrown id, not the system's)
 221    into a "pid" (which may be overloaded with extra thread information).  */
 222 extern ptid_t thread_id_to_pid (int);
 223
 224 /* Translate a 'pid' (which may be overloaded with extra thread information)
 225    into the integer thread id (GDB's homegrown id, not the system's).  */
 226 extern int pid_to_thread_id (ptid_t ptid);
 227
 228 /* Boolean test for an already-known pid (which may be overloaded with
 229    extra thread information).  */
 230 extern int in_thread_list (ptid_t ptid);
 231
 232 /* Boolean test for an already-known thread id (GDB's homegrown id,
 233    not the system's).  */
 234 extern int valid_thread_id (int thread);
 235
 236 /* Search function to lookup a thread by 'pid'.  */
 237 extern struct thread_info *find_thread_ptid (ptid_t ptid);
 238
 239 /* Find thread by GDB user-visible thread number.  */
 240 struct thread_info *find_thread_id (int num);
 241
 242 /* Finds the first thread of the inferior given by PID.  If PID is -1,
 243    returns the first thread in the list.  */
 244 struct thread_info *first_thread_of_process (int pid);
 245
 246 /* Returns any thread of process PID.  */
 247 extern struct thread_info *any_thread_of_process (int pid);
 248
 249 /* Returns any non-exited thread of process PID, giving preference for
 250    already stopped threads.  */
 251 extern struct thread_info *any_live_thread_of_process (int pid);
 252
 253 /* Change the ptid of thread OLD_PTID to NEW_PTID.  */
 254 void thread_change_ptid (ptid_t old_ptid, ptid_t new_ptid);
 255
 256 /* Iterator function to call a user-provided callback function
 257    once for each known thread.  */
 258 typedef int (*thread_callback_func) (struct thread_info *, void *);
 259 extern struct thread_info *iterate_over_threads (thread_callback_func, void *);
 260
 261 extern int thread_count (void);
 262
 263 /* Switch from one thread to another.  */
 264 extern void switch_to_thread (ptid_t ptid);
 265
 266 /* Marks thread PTID is running, or stopped.
 267    If PIDGET (PTID) is -1, marks all threads.  */
 268 extern void set_running (ptid_t ptid, int running);
 269
 270 /* Marks or clears thread(s) PTID as having been requested to stop.
 271    If PTID is MINUS_ONE_PTID, applies to all threads.  If
 272    ptid_is_pid(PTID) is true, applies to all threads of the process
 273    pointed at by PTID.  If STOP, then the THREAD_STOP_REQUESTED
 274    observer is called with PTID as argument.  */
 275 extern void set_stop_requested (ptid_t ptid, int stop);
 276
 277 /* NOTE: Since the thread state is not a boolean, most times, you do
 278    not want to check it with negation.  If you really want to check if
 279    the thread is stopped,
 280
 281     use (good):
 282
 283      if (is_stopped (ptid))
 284
 285     instead of (bad):
 286
 287      if (!is_running (ptid))
 288
 289    The latter also returns true on exited threads, most likelly not
 290    what you want.  */
 291
 292 /* Reports if in the frontend's perpective, thread PTID is running.  */
 293 extern int is_running (ptid_t ptid);
 294
 295 /* Is this thread listed, but known to have exited?  We keep it listed
 296    (but not visible) until it's safe to delete.  */
 297 extern int is_exited (ptid_t ptid);
 298
 299 /* In the frontend's perpective, is this thread stopped?  */
 300 extern int is_stopped (ptid_t ptid);
 301
 302 /* In the frontend's perpective is there any thread running?  */
 303 extern int any_running (void);
 304
 305 /* Marks thread PTID as executing, or not.  If PIDGET (PTID) is -1,
 306    marks all threads.
 307
 308    Note that this is different from the running state.  See the
 309    description of state_ and executing_ fields of struct
 310    thread_info.  */
 311 extern void set_executing (ptid_t ptid, int executing);
 312
 313 /* Reports if thread PTID is executing.  */
 314 extern int is_executing (ptid_t ptid);
 315
 316 /* Merge the executing property of thread PTID over to its thread
 317    state property (frontend running/stopped view).
 318
 319    "not executing" -> "stopped"
 320    "executing"     -> "running"
 321    "exited"        -> "exited"
 322
 323    If PIDGET (PTID) is -1, go over all threads.
 324
 325    Notifications are only emitted if the thread state did change.  */
 326 extern void finish_thread_state (ptid_t ptid);
 327
 328 /* Same as FINISH_THREAD_STATE, but with an interface suitable to be
 329    registered as a cleanup.  PTID_P points to the ptid_t that is
 330    passed to FINISH_THREAD_STATE.  */
 331 extern void finish_thread_state_cleanup (void *ptid_p);
 332
 333 /* Commands with a prefix of `thread'.  */
 334 extern struct cmd_list_element *thread_cmd_list;
 335
 336 /* Print notices on thread events (attach, detach, etc.), set with
 337    `set print thread-events'.  */
 338 extern int print_thread_events;
 339
 340 extern void print_thread_info (struct ui_out *uiout, int thread,
 341                                int pid);
 342
 343 extern struct cleanup *make_cleanup_restore_current_thread (void);
 344
 345 /* Returns a pointer into the thread_info corresponding to
 346    INFERIOR_PTID.  INFERIOR_PTID *must* be in the thread list.  */
 347 extern struct thread_info* inferior_thread (void);
 348
 349 #endif /* GDBTHREAD_H */