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, 2010 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 /* Inferior thread specific part of `struct infcall_control_state'.
  33
  34    Inferior process counterpart is `struct inferior_control_state'.  */
  35
  36 struct thread_control_state
  37 {
  38   /* User/external stepping state.  */
  39
  40   /* Step-resume or longjmp-resume breakpoint.  */
  41   struct breakpoint *step_resume_breakpoint;
  42
  43   /* Range to single step within.
  44
  45      If this is nonzero, respond to a single-step signal by continuing
  46      to step if the pc is in this range.
  47
  48      If step_range_start and step_range_end are both 1, it means to
  49      step for a single instruction (FIXME: it might clean up
  50      wait_for_inferior in a minor way if this were changed to the
  51      address of the instruction and that address plus one.  But maybe
  52      not.).  */
  53   CORE_ADDR step_range_start;   /* Inclusive */
  54   CORE_ADDR step_range_end;     /* Exclusive */
  55
  56   /* Stack frame address as of when stepping command was issued.
  57      This is how we know when we step into a subroutine call, and how
  58      to set the frame for the breakpoint used to step out.  */
  59   struct frame_id step_frame_id;
  60
  61   /* Similarly, the frame ID of the underlying stack frame (skipping
  62      any inlined frames).  */
  63   struct frame_id step_stack_frame_id;
  64
  65   /* Nonzero if we are presently stepping over a breakpoint.
  66
  67      If we hit a breakpoint or watchpoint, and then continue, we need
  68      to single step the current thread with breakpoints disabled, to
  69      avoid hitting the same breakpoint or watchpoint again.  And we
  70      should step just a single thread and keep other threads stopped,
  71      so that other threads don't miss breakpoints while they are
  72      removed.
  73
  74      So, this variable simultaneously means that we need to single
  75      step the current thread, keep other threads stopped, and that
  76      breakpoints should be removed while we step.
  77
  78      This variable is set either:
  79      - in proceed, when we resume inferior on user's explicit request
  80      - in keep_going, if handle_inferior_event decides we need to
  81      step over breakpoint.
  82
  83      The variable is cleared in normal_stop.  The proceed calls
  84      wait_for_inferior, which calls handle_inferior_event in a loop,
  85      and until wait_for_inferior exits, this variable is changed only
  86      by keep_going.  */
  87   int trap_expected;
  88
  89   /* Nonzero if the thread is being proceeded for a "finish" command
  90      or a similar situation when stop_registers should be saved.  */
  91   int proceed_to_finish;
  92
  93   /* Nonzero if the thread is being proceeded for an inferior function
  94      call.  */
  95   int in_infcall;
  96
  97   enum step_over_calls_kind step_over_calls;
  98
  99   /* Nonzero if stopped due to a step command.  */
 100   int stop_step;
 101
 102   /* Chain containing status of breakpoint(s) the thread stopped
 103      at.  */
 104   bpstat stop_bpstat;
 105 };
 106
 107 /* Inferior thread specific part of `struct infcall_suspend_state'.
 108
 109    Inferior process counterpart is `struct inferior_suspend_state'.  */
 110
 111 struct thread_suspend_state
 112 {
 113   /* Last signal that the inferior received (why it stopped).  */
 114   enum target_signal stop_signal;
 115 };
 116
 117 struct thread_info
 118 {
 119   struct thread_info *next;
 120   ptid_t ptid;                  /* "Actual process id";
 121                                     In fact, this may be overloaded with
 122                                     kernel thread id, etc.  */
 123   int num;                      /* Convenient handle (GDB thread id) */
 124
 125   /* Non-zero means the thread is executing.  Note: this is different
 126      from saying that there is an active target and we are stopped at
 127      a breakpoint, for instance.  This is a real indicator whether the
 128      thread is off and running.  */
 129   /* This field is internal to thread.c.  Never access it directly,
 130      use is_executing instead.  */
 131   int executing_;
 132
 133   /* Frontend view of the thread state.  Note that the RUNNING/STOPPED
 134      states are different from EXECUTING.  When the thread is stopped
 135      internally while handling an internal event, like a software
 136      single-step breakpoint, EXECUTING will be false, but running will
 137      still be true.  As a possible future extension, this could turn
 138      into enum { stopped, exited, stepping, finishing, until(ling),
 139      running ... }  */
 140   /* This field is internal to thread.c.  Never access it directly,
 141      use is_running instead.  */
 142   int state_;
 143
 144   /* If this is > 0, then it means there's code out there that relies
 145      on this thread being listed.  Don't delete it from the lists even
 146      if we detect it exiting.  */
 147   int refcount;
 148
 149   /* State of GDB control of inferior thread execution.
 150      See `struct thread_control_state'.  */
 151   struct thread_control_state control;
 152
 153   /* State of inferior thread to restore after GDB is done with an inferior
 154      call.  See `struct thread_suspend_state'.  */
 155   struct thread_suspend_state suspend;
 156
 157   int current_line;
 158   struct symtab *current_symtab;
 159
 160   /* Internal stepping state.  */
 161
 162   /* Record the pc of the thread the last time it stopped.  This is
 163      maintained by proceed and keep_going, and used in
 164      adjust_pc_after_break to distinguish a hardware single-step
 165      SIGTRAP from a breakpoint SIGTRAP.  */
 166   CORE_ADDR prev_pc;
 167
 168   /* Should we step over breakpoint next time keep_going is called?  */
 169   int stepping_over_breakpoint;
 170
 171   /* Set to TRUE if we should finish single-stepping over a breakpoint
 172      after hitting the current step-resume breakpoint.  */
 173   int step_after_step_resume_breakpoint;
 174
 175   /* This is set TRUE when a catchpoint of a shared library event
 176      triggers.  Since we don't wish to leave the inferior in the
 177      solib hook when we report the event, we step the inferior
 178      back to user code before stopping and reporting the event.  */
 179   int stepping_through_solib_after_catch;
 180
 181   /* When stepping_through_solib_after_catch is TRUE, this is a
 182      list of the catchpoints that should be reported as triggering
 183      when we finally do stop stepping.  */
 184   bpstat stepping_through_solib_catchpoints;
 185
 186   /* Per-thread command support.  */
 187
 188   /* Pointer to what is left to do for an execution command after the
 189      target stops.  Used only in asynchronous mode, by targets that
 190      support async execution.  Several execution commands use it.  */
 191   struct continuation *continuations;
 192
 193   /* Similar to the above, but used when a single execution command
 194      requires several resume/stop iterations.  Used by the step
 195      command.  */
 196   struct continuation *intermediate_continuations;
 197
 198   /* If stepping, nonzero means step count is > 1 so don't print frame
 199      next time inferior stops if it stops due to stepping.  */
 200   int step_multi;
 201
 202   /* This is used to remember when a fork or vfork event was caught by
 203      a catchpoint, and thus the event is to be followed at the next
 204      resume of the thread, and not immediately.  */
 205   struct target_waitstatus pending_follow;
 206
 207   /* True if this thread has been explicitly requested to stop.  */
 208   int stop_requested;
 209
 210   /* Private data used by the target vector implementation.  */
 211   struct private_thread_info *private;
 212
 213   /* Function that is called to free PRIVATE.  If this is NULL, then
 214      xfree will be called on PRIVATE.  */
 215   void (*private_dtor) (struct private_thread_info *);
 216 };
 217
 218 /* Create an empty thread list, or empty the existing one.  */
 219 extern void init_thread_list (void);
 220
 221 /* Add a thread to the thread list, print a message
 222    that a new thread is found, and return the pointer to
 223    the new thread.  Caller my use this pointer to
 224    initialize the private thread data.  */
 225 extern struct thread_info *add_thread (ptid_t ptid);
 226
 227 /* Same as add_thread, but does not print a message
 228    about new thread.  */
 229 extern struct thread_info *add_thread_silent (ptid_t ptid);
 230
 231 /* Same as add_thread, and sets the private info.  */
 232 extern struct thread_info *add_thread_with_info (ptid_t ptid,
 233                                                  struct private_thread_info *);
 234
 235 /* Delete an existing thread list entry.  */
 236 extern void delete_thread (ptid_t);
 237
 238 /* Delete an existing thread list entry, and be quiet about it.  Used
 239    after the process this thread having belonged to having already
 240    exited, for example.  */
 241 extern void delete_thread_silent (ptid_t);
 242
 243 /* Delete a step_resume_breakpoint from the thread database. */
 244 extern void delete_step_resume_breakpoint (struct thread_info *);
 245
 246 /* Translate the integer thread id (GDB's homegrown id, not the system's)
 247    into a "pid" (which may be overloaded with extra thread information).  */
 248 extern ptid_t thread_id_to_pid (int);
 249
 250 /* Translate a 'pid' (which may be overloaded with extra thread information)
 251    into the integer thread id (GDB's homegrown id, not the system's).  */
 252 extern int pid_to_thread_id (ptid_t ptid);
 253
 254 /* Boolean test for an already-known pid (which may be overloaded with
 255    extra thread information).  */
 256 extern int in_thread_list (ptid_t ptid);
 257
 258 /* Boolean test for an already-known thread id (GDB's homegrown id,
 259    not the system's).  */
 260 extern int valid_thread_id (int thread);
 261
 262 /* Search function to lookup a thread by 'pid'.  */
 263 extern struct thread_info *find_thread_ptid (ptid_t ptid);
 264
 265 /* Find thread by GDB user-visible thread number.  */
 266 struct thread_info *find_thread_id (int num);
 267
 268 /* Finds the first thread of the inferior given by PID.  If PID is -1,
 269    returns the first thread in the list.  */
 270 struct thread_info *first_thread_of_process (int pid);
 271
 272 /* Returns any thread of process PID.  */
 273 extern struct thread_info *any_thread_of_process (int pid);
 274
 275 /* Returns any non-exited thread of process PID, giving preference for
 276    already stopped threads.  */
 277 extern struct thread_info *any_live_thread_of_process (int pid);
 278
 279 /* Change the ptid of thread OLD_PTID to NEW_PTID.  */
 280 void thread_change_ptid (ptid_t old_ptid, ptid_t new_ptid);
 281
 282 /* Iterator function to call a user-provided callback function
 283    once for each known thread.  */
 284 typedef int (*thread_callback_func) (struct thread_info *, void *);
 285 extern struct thread_info *iterate_over_threads (thread_callback_func, void *);
 286
 287 extern int thread_count (void);
 288
 289 /* Switch from one thread to another.  */
 290 extern void switch_to_thread (ptid_t ptid);
 291
 292 /* Marks thread PTID is running, or stopped.
 293    If PIDGET (PTID) is -1, marks all threads.  */
 294 extern void set_running (ptid_t ptid, int running);
 295
 296 /* Marks or clears thread(s) PTID as having been requested to stop.
 297    If PTID is MINUS_ONE_PTID, applies to all threads.  If
 298    ptid_is_pid(PTID) is true, applies to all threads of the process
 299    pointed at by PTID.  If STOP, then the THREAD_STOP_REQUESTED
 300    observer is called with PTID as argument.  */
 301 extern void set_stop_requested (ptid_t ptid, int stop);
 302
 303 /* NOTE: Since the thread state is not a boolean, most times, you do
 304    not want to check it with negation.  If you really want to check if
 305    the thread is stopped,
 306
 307     use (good):
 308
 309      if (is_stopped (ptid))
 310
 311     instead of (bad):
 312
 313      if (!is_running (ptid))
 314
 315    The latter also returns true on exited threads, most likelly not
 316    what you want.  */
 317
 318 /* Reports if in the frontend's perpective, thread PTID is running.  */
 319 extern int is_running (ptid_t ptid);
 320
 321 /* Is this thread listed, but known to have exited?  We keep it listed
 322    (but not visible) until it's safe to delete.  */
 323 extern int is_exited (ptid_t ptid);
 324
 325 /* In the frontend's perpective, is this thread stopped?  */
 326 extern int is_stopped (ptid_t ptid);
 327
 328 /* In the frontend's perpective is there any thread running?  */
 329 extern int any_running (void);
 330
 331 /* Marks thread PTID as executing, or not.  If PIDGET (PTID) is -1,
 332    marks all threads.
 333
 334    Note that this is different from the running state.  See the
 335    description of state_ and executing_ fields of struct
 336    thread_info.  */
 337 extern void set_executing (ptid_t ptid, int executing);
 338
 339 /* Reports if thread PTID is executing.  */
 340 extern int is_executing (ptid_t ptid);
 341
 342 /* Merge the executing property of thread PTID over to its thread
 343    state property (frontend running/stopped view).
 344
 345    "not executing" -> "stopped"
 346    "executing"     -> "running"
 347    "exited"        -> "exited"
 348
 349    If PIDGET (PTID) is -1, go over all threads.
 350
 351    Notifications are only emitted if the thread state did change.  */
 352 extern void finish_thread_state (ptid_t ptid);
 353
 354 /* Same as FINISH_THREAD_STATE, but with an interface suitable to be
 355    registered as a cleanup.  PTID_P points to the ptid_t that is
 356    passed to FINISH_THREAD_STATE.  */
 357 extern void finish_thread_state_cleanup (void *ptid_p);
 358
 359 /* Commands with a prefix of `thread'.  */
 360 extern struct cmd_list_element *thread_cmd_list;
 361
 362 /* Print notices on thread events (attach, detach, etc.), set with
 363    `set print thread-events'.  */
 364 extern int print_thread_events;
 365
 366 extern void print_thread_info (struct ui_out *uiout, int thread,
 367                                int pid);
 368
 369 extern struct cleanup *make_cleanup_restore_current_thread (void);
 370
 371 /* Returns a pointer into the thread_info corresponding to
 372    INFERIOR_PTID.  INFERIOR_PTID *must* be in the thread list.  */
 373 extern struct thread_info* inferior_thread (void);
 374
 375 extern void update_thread_list (void);
 376
 377 #endif /* GDBTHREAD_H */