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, 2011 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   /* Exception-resume breakpoint.  */
  44   struct breakpoint *exception_resume_breakpoint;
  45
  46   /* Range to single step within.
  47
  48      If this is nonzero, respond to a single-step signal by continuing
  49      to step if the pc is in this range.
  50
  51      If step_range_start and step_range_end are both 1, it means to
  52      step for a single instruction (FIXME: it might clean up
  53      wait_for_inferior in a minor way if this were changed to the
  54      address of the instruction and that address plus one.  But maybe
  55      not).  */
  56   CORE_ADDR step_range_start;   /* Inclusive */
  57   CORE_ADDR step_range_end;     /* Exclusive */
  58
  59   /* Stack frame address as of when stepping command was issued.
  60      This is how we know when we step into a subroutine call, and how
  61      to set the frame for the breakpoint used to step out.  */
  62   struct frame_id step_frame_id;
  63
  64   /* Similarly, the frame ID of the underlying stack frame (skipping
  65      any inlined frames).  */
  66   struct frame_id step_stack_frame_id;
  67
  68   /* Nonzero if we are presently stepping over a breakpoint.
  69
  70      If we hit a breakpoint or watchpoint, and then continue, we need
  71      to single step the current thread with breakpoints disabled, to
  72      avoid hitting the same breakpoint or watchpoint again.  And we
  73      should step just a single thread and keep other threads stopped,
  74      so that other threads don't miss breakpoints while they are
  75      removed.
  76
  77      So, this variable simultaneously means that we need to single
  78      step the current thread, keep other threads stopped, and that
  79      breakpoints should be removed while we step.
  80
  81      This variable is set either:
  82      - in proceed, when we resume inferior on user's explicit request
  83      - in keep_going, if handle_inferior_event decides we need to
  84      step over breakpoint.
  85
  86      The variable is cleared in normal_stop.  The proceed calls
  87      wait_for_inferior, which calls handle_inferior_event in a loop,
  88      and until wait_for_inferior exits, this variable is changed only
  89      by keep_going.  */
  90   int trap_expected;
  91
  92   /* Nonzero if the thread is being proceeded for a "finish" command
  93      or a similar situation when stop_registers should be saved.  */
  94   int proceed_to_finish;
  95
  96   /* Nonzero if the thread is being proceeded for an inferior function
  97      call.  */
  98   int in_infcall;
  99
 100   enum step_over_calls_kind step_over_calls;
 101
 102   /* Nonzero if stopped due to a step command.  */
 103   int stop_step;
 104
 105   /* Chain containing status of breakpoint(s) the thread stopped
 106      at.  */
 107   bpstat stop_bpstat;
 108 };
 109
 110 /* Inferior thread specific part of `struct infcall_suspend_state'.
 111
 112    Inferior process counterpart is `struct inferior_suspend_state'.  */
 113
 114 struct thread_suspend_state
 115 {
 116   /* Last signal that the inferior received (why it stopped).  */
 117   enum target_signal stop_signal;
 118 };
 119
 120 struct thread_info
 121 {
 122   struct thread_info *next;
 123   ptid_t ptid;                  /* "Actual process id";
 124                                     In fact, this may be overloaded with
 125                                     kernel thread id, etc.  */
 126   int num;                      /* Convenient handle (GDB thread id) */
 127
 128   /* The name of the thread, as specified by the user.  This is NULL
 129      if the thread does not have a user-given name.  */
 130   char *name;
 131
 132   /* Non-zero means the thread is executing.  Note: this is different
 133      from saying that there is an active target and we are stopped at
 134      a breakpoint, for instance.  This is a real indicator whether the
 135      thread is off and running.  */
 136   /* This field is internal to thread.c.  Never access it directly,
 137      use is_executing instead.  */
 138   int executing_;
 139
 140   /* Frontend view of the thread state.  Note that the RUNNING/STOPPED
 141      states are different from EXECUTING.  When the thread is stopped
 142      internally while handling an internal event, like a software
 143      single-step breakpoint, EXECUTING will be false, but running will
 144      still be true.  As a possible future extension, this could turn
 145      into enum { stopped, exited, stepping, finishing, until(ling),
 146      running ... }  */
 147   /* This field is internal to thread.c.  Never access it directly,
 148      use is_running instead.  */
 149   int state_;
 150
 151   /* If this is > 0, then it means there's code out there that relies
 152      on this thread being listed.  Don't delete it from the lists even
 153      if we detect it exiting.  */
 154   int refcount;
 155
 156   /* State of GDB control of inferior thread execution.
 157      See `struct thread_control_state'.  */
 158   struct thread_control_state control;
 159
 160   /* State of inferior thread to restore after GDB is done with an inferior
 161      call.  See `struct thread_suspend_state'.  */
 162   struct thread_suspend_state suspend;
 163
 164   int current_line;
 165   struct symtab *current_symtab;
 166
 167   /* Internal stepping state.  */
 168
 169   /* Record the pc of the thread the last time it stopped.  This is
 170      maintained by proceed and keep_going, and used in
 171      adjust_pc_after_break to distinguish a hardware single-step
 172      SIGTRAP from a breakpoint SIGTRAP.  */
 173   CORE_ADDR prev_pc;
 174
 175   /* Should we step over breakpoint next time keep_going is called?  */
 176   int stepping_over_breakpoint;
 177
 178   /* Set to TRUE if we should finish single-stepping over a breakpoint
 179      after hitting the current step-resume breakpoint.  The context here
 180      is that GDB is to do `next' or `step' while signal arrives.
 181      When stepping over a breakpoint and signal arrives, GDB will attempt
 182      to skip signal handler, so it inserts a step_resume_breakpoint at the
 183      signal return address, and resume inferior.
 184      step_after_step_resume_breakpoint is set to TRUE at this moment in
 185      order to keep GDB in mind that there is still a breakpoint to step over
 186      when GDB gets back SIGTRAP from step_resume_breakpoint.  */
 187   int step_after_step_resume_breakpoint;
 188
 189   /* This is set TRUE when a catchpoint of a shared library event
 190      triggers.  Since we don't wish to leave the inferior in the
 191      solib hook when we report the event, we step the inferior
 192      back to user code before stopping and reporting the event.  */
 193   int stepping_through_solib_after_catch;
 194
 195   /* When stepping_through_solib_after_catch is TRUE, this is a
 196      list of the catchpoints that should be reported as triggering
 197      when we finally do stop stepping.  */
 198   bpstat stepping_through_solib_catchpoints;
 199
 200   /* Per-thread command support.  */
 201
 202   /* Pointer to what is left to do for an execution command after the
 203      target stops.  Used only in asynchronous mode, by targets that
 204      support async execution.  Several execution commands use it.  */
 205   struct continuation *continuations;
 206
 207   /* Similar to the above, but used when a single execution command
 208      requires several resume/stop iterations.  Used by the step
 209      command.  */
 210   struct continuation *intermediate_continuations;
 211
 212   /* If stepping, nonzero means step count is > 1 so don't print frame
 213      next time inferior stops if it stops due to stepping.  */
 214   int step_multi;
 215
 216   /* This is used to remember when a fork or vfork event was caught by
 217      a catchpoint, and thus the event is to be followed at the next
 218      resume of the thread, and not immediately.  */
 219   struct target_waitstatus pending_follow;
 220
 221   /* True if this thread has been explicitly requested to stop.  */
 222   int stop_requested;
 223
 224   /* The initiating frame of a nexting operation, used for deciding
 225      which exceptions to intercept.  */
 226   struct frame_id initiating_frame;
 227
 228   /* Private data used by the target vector implementation.  */
 229   struct private_thread_info *private;
 230
 231   /* Function that is called to free PRIVATE.  If this is NULL, then
 232      xfree will be called on PRIVATE.  */
 233   void (*private_dtor) (struct private_thread_info *);
 234 };
 235
 236 /* Create an empty thread list, or empty the existing one.  */
 237 extern void init_thread_list (void);
 238
 239 /* Add a thread to the thread list, print a message
 240    that a new thread is found, and return the pointer to
 241    the new thread.  Caller my use this pointer to
 242    initialize the private thread data.  */
 243 extern struct thread_info *add_thread (ptid_t ptid);
 244
 245 /* Same as add_thread, but does not print a message
 246    about new thread.  */
 247 extern struct thread_info *add_thread_silent (ptid_t ptid);
 248
 249 /* Same as add_thread, and sets the private info.  */
 250 extern struct thread_info *add_thread_with_info (ptid_t ptid,
 251                                                  struct private_thread_info *);
 252
 253 /* Delete an existing thread list entry.  */
 254 extern void delete_thread (ptid_t);
 255
 256 /* Delete an existing thread list entry, and be quiet about it.  Used
 257    after the process this thread having belonged to having already
 258    exited, for example.  */
 259 extern void delete_thread_silent (ptid_t);
 260
 261 /* Delete a step_resume_breakpoint from the thread database.  */
 262 extern void delete_step_resume_breakpoint (struct thread_info *);
 263
 264 /* Delete an exception_resume_breakpoint from the thread database.  */
 265 extern void delete_exception_resume_breakpoint (struct thread_info *);
 266
 267 /* Translate the integer thread id (GDB's homegrown id, not the system's)
 268    into a "pid" (which may be overloaded with extra thread information).  */
 269 extern ptid_t thread_id_to_pid (int);
 270
 271 /* Translate a 'pid' (which may be overloaded with extra thread information)
 272    into the integer thread id (GDB's homegrown id, not the system's).  */
 273 extern int pid_to_thread_id (ptid_t ptid);
 274
 275 /* Boolean test for an already-known pid (which may be overloaded with
 276    extra thread information).  */
 277 extern int in_thread_list (ptid_t ptid);
 278
 279 /* Boolean test for an already-known thread id (GDB's homegrown id,
 280    not the system's).  */
 281 extern int valid_thread_id (int thread);
 282
 283 /* Search function to lookup a thread by 'pid'.  */
 284 extern struct thread_info *find_thread_ptid (ptid_t ptid);
 285
 286 /* Find thread by GDB user-visible thread number.  */
 287 struct thread_info *find_thread_id (int num);
 288
 289 /* Finds the first thread of the inferior given by PID.  If PID is -1,
 290    returns the first thread in the list.  */
 291 struct thread_info *first_thread_of_process (int pid);
 292
 293 /* Returns any thread of process PID.  */
 294 extern struct thread_info *any_thread_of_process (int pid);
 295
 296 /* Returns any non-exited thread of process PID, giving preference for
 297    not executing threads.  */
 298 extern struct thread_info *any_live_thread_of_process (int pid);
 299
 300 /* Change the ptid of thread OLD_PTID to NEW_PTID.  */
 301 void thread_change_ptid (ptid_t old_ptid, ptid_t new_ptid);
 302
 303 /* Iterator function to call a user-provided callback function
 304    once for each known thread.  */
 305 typedef int (*thread_callback_func) (struct thread_info *, void *);
 306 extern struct thread_info *iterate_over_threads (thread_callback_func, void *);
 307
 308 extern int thread_count (void);
 309
 310 /* Switch from one thread to another.  */
 311 extern void switch_to_thread (ptid_t ptid);
 312
 313 /* Marks thread PTID is running, or stopped.
 314    If PIDGET (PTID) is -1, marks all threads.  */
 315 extern void set_running (ptid_t ptid, int running);
 316
 317 /* Marks or clears thread(s) PTID as having been requested to stop.
 318    If PTID is MINUS_ONE_PTID, applies to all threads.  If
 319    ptid_is_pid(PTID) is true, applies to all threads of the process
 320    pointed at by PTID.  If STOP, then the THREAD_STOP_REQUESTED
 321    observer is called with PTID as argument.  */
 322 extern void set_stop_requested (ptid_t ptid, int stop);
 323
 324 /* NOTE: Since the thread state is not a boolean, most times, you do
 325    not want to check it with negation.  If you really want to check if
 326    the thread is stopped,
 327
 328     use (good):
 329
 330      if (is_stopped (ptid))
 331
 332     instead of (bad):
 333
 334      if (!is_running (ptid))
 335
 336    The latter also returns true on exited threads, most likelly not
 337    what you want.  */
 338
 339 /* Reports if in the frontend's perpective, thread PTID is running.  */
 340 extern int is_running (ptid_t ptid);
 341
 342 /* Is this thread listed, but known to have exited?  We keep it listed
 343    (but not visible) until it's safe to delete.  */
 344 extern int is_exited (ptid_t ptid);
 345
 346 /* In the frontend's perpective, is this thread stopped?  */
 347 extern int is_stopped (ptid_t ptid);
 348
 349 /* In the frontend's perpective is there any thread running?  */
 350 extern int any_running (void);
 351
 352 /* Marks thread PTID as executing, or not.  If PIDGET (PTID) is -1,
 353    marks all threads.
 354
 355    Note that this is different from the running state.  See the
 356    description of state_ and executing_ fields of struct
 357    thread_info.  */
 358 extern void set_executing (ptid_t ptid, int executing);
 359
 360 /* Reports if thread PTID is executing.  */
 361 extern int is_executing (ptid_t ptid);
 362
 363 /* Merge the executing property of thread PTID over to its thread
 364    state property (frontend running/stopped view).
 365
 366    "not executing" -> "stopped"
 367    "executing"     -> "running"
 368    "exited"        -> "exited"
 369
 370    If PIDGET (PTID) is -1, go over all threads.
 371
 372    Notifications are only emitted if the thread state did change.  */
 373 extern void finish_thread_state (ptid_t ptid);
 374
 375 /* Same as FINISH_THREAD_STATE, but with an interface suitable to be
 376    registered as a cleanup.  PTID_P points to the ptid_t that is
 377    passed to FINISH_THREAD_STATE.  */
 378 extern void finish_thread_state_cleanup (void *ptid_p);
 379
 380 /* Commands with a prefix of `thread'.  */
 381 extern struct cmd_list_element *thread_cmd_list;
 382
 383 /* Print notices on thread events (attach, detach, etc.), set with
 384    `set print thread-events'.  */
 385 extern int print_thread_events;
 386
 387 extern void print_thread_info (struct ui_out *uiout, char *threads,
 388                                int pid);
 389
 390 extern struct cleanup *make_cleanup_restore_current_thread (void);
 391
 392 /* Returns a pointer into the thread_info corresponding to
 393    INFERIOR_PTID.  INFERIOR_PTID *must* be in the thread list.  */
 394 extern struct thread_info* inferior_thread (void);
 395
 396 extern void update_thread_list (void);
 397
 398 #endif /* GDBTHREAD_H */