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1 /* Multi-process/thread control defs for GDB, the GNU debugger.
2  Copyright (C) 1987-2015 Free Software Foundation, Inc.
3  Contributed by Lynx Real-Time Systems, Inc. Los Gatos, CA.
4 
5 
6  This file is part of GDB.
7 
8  This program is free software; you can redistribute it and/or modify
9  it under the terms of the GNU General Public License as published by
10  the Free Software Foundation; either version 3 of the License, or
11  (at your option) any later version.
12 
13  This program is distributed in the hope that it will be useful,
14  but WITHOUT ANY WARRANTY; without even the implied warranty of
15  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16  GNU General Public License for more details.
17 
18  You should have received a copy of the GNU General Public License
19  along with this program. If not, see <http://www.gnu.org/licenses/>. */
20 
21 #ifndef GDBTHREAD_H
22 #define GDBTHREAD_H
23 
24 struct symtab;
25 
26 #include "breakpoint.h"
27 #include "frame.h"
28 #include "ui-out.h"
29 #include "inferior.h"
30 #include "btrace.h"
31 #include "common/vec.h"
32 
33 /* Frontend view of the thread state. Possible extensions: stepping,
34  finishing, until(ling),... */
36 {
40 };
41 
42 /* Inferior thread specific part of `struct infcall_control_state'.
43 
44  Inferior process counterpart is `struct inferior_control_state'. */
45 
47 {
48  /* User/external stepping state. */
49 
50  /* Step-resume or longjmp-resume breakpoint. */
52 
53  /* Exception-resume breakpoint. */
55 
56  /* Breakpoints used for software single stepping. Plural, because
57  it may have multiple locations. E.g., if stepping over a
58  conditional branch instruction we can't decode the condition for,
59  we'll need to put a breakpoint at the branch destination, and
60  another at the instruction after the branch. */
62 
63  /* Range to single step within.
64 
65  If this is nonzero, respond to a single-step signal by continuing
66  to step if the pc is in this range.
67 
68  If step_range_start and step_range_end are both 1, it means to
69  step for a single instruction (FIXME: it might clean up
70  wait_for_inferior in a minor way if this were changed to the
71  address of the instruction and that address plus one. But maybe
72  not). */
73  CORE_ADDR step_range_start; /* Inclusive */
74  CORE_ADDR step_range_end; /* Exclusive */
75 
76  /* Function the thread was in as of last it started stepping. */
78 
79  /* If GDB issues a target step request, and this is nonzero, the
80  target should single-step this thread once, and then continue
81  single-stepping it without GDB core involvement as long as the
82  thread stops in the step range above. If this is zero, the
83  target should ignore the step range, and only issue one single
84  step. */
86 
87  /* Stack frame address as of when stepping command was issued.
88  This is how we know when we step into a subroutine call, and how
89  to set the frame for the breakpoint used to step out. */
91 
92  /* Similarly, the frame ID of the underlying stack frame (skipping
93  any inlined frames). */
95 
96  /* Nonzero if we are presently stepping over a breakpoint.
97 
98  If we hit a breakpoint or watchpoint, and then continue, we need
99  to single step the current thread with breakpoints disabled, to
100  avoid hitting the same breakpoint or watchpoint again. And we
101  should step just a single thread and keep other threads stopped,
102  so that other threads don't miss breakpoints while they are
103  removed.
104 
105  So, this variable simultaneously means that we need to single
106  step the current thread, keep other threads stopped, and that
107  breakpoints should be removed while we step.
108 
109  This variable is set either:
110  - in proceed, when we resume inferior on user's explicit request
111  - in keep_going, if handle_inferior_event decides we need to
112  step over breakpoint.
113 
114  The variable is cleared in normal_stop. The proceed calls
115  wait_for_inferior, which calls handle_inferior_event in a loop,
116  and until wait_for_inferior exits, this variable is changed only
117  by keep_going. */
119 
120  /* Nonzero if the thread is being proceeded for a "finish" command
121  or a similar situation when return value should be printed. */
123 
124  /* Nonzero if the thread is being proceeded for an inferior function
125  call. */
127 
129 
130  /* Nonzero if stopped due to a step command. */
132 
133  /* Chain containing status of breakpoint(s) the thread stopped
134  at. */
136 
137  /* The interpreter that issued the execution command. NULL if the
138  thread was resumed as a result of a command applied to some other
139  thread (e.g., "next" with scheduler-locking off). */
141 
142  /* Whether the command that started the thread was a stepping
143  command. This is used to decide whether "set scheduler-locking
144  step" behaves like "on" or "off". */
146 };
147 
148 /* Inferior thread specific part of `struct infcall_suspend_state'. */
149 
151 {
152  /* Last signal that the inferior received (why it stopped). When
153  the thread is resumed, this signal is delivered. Note: the
154  target should not check whether the signal is in pass state,
155  because the signal may have been explicitly passed with the
156  "signal" command, which overrides "handle nopass". If the signal
157  should be suppressed, the core will take care of clearing this
158  before the target is resumed. */
159  enum gdb_signal stop_signal;
160 };
161 
162 typedef struct value *value_ptr;
163 DEF_VEC_P (value_ptr);
164 typedef VEC (value_ptr) value_vec;
165 
167 {
168  struct thread_info *next;
169  ptid_t ptid; /* "Actual process id";
170  In fact, this may be overloaded with
171  kernel thread id, etc. */
172  int num; /* Convenient handle (GDB thread id) */
173 
174  /* The name of the thread, as specified by the user. This is NULL
175  if the thread does not have a user-given name. */
176  char *name;
177 
178  /* Non-zero means the thread is executing. Note: this is different
179  from saying that there is an active target and we are stopped at
180  a breakpoint, for instance. This is a real indicator whether the
181  thread is off and running. */
183 
184  /* Frontend view of the thread state. Note that the THREAD_RUNNING/
185  THREAD_STOPPED states are different from EXECUTING. When the
186  thread is stopped internally while handling an internal event,
187  like a software single-step breakpoint, EXECUTING will be false,
188  but STATE will still be THREAD_RUNNING. */
190 
191  /* If this is > 0, then it means there's code out there that relies
192  on this thread being listed. Don't delete it from the lists even
193  if we detect it exiting. */
194  int refcount;
195 
196  /* State of GDB control of inferior thread execution.
197  See `struct thread_control_state'. */
198  struct thread_control_state control;
199 
200  /* State of inferior thread to restore after GDB is done with an inferior
201  call. See `struct thread_suspend_state'. */
202  struct thread_suspend_state suspend;
203 
206 
207  /* Internal stepping state. */
208 
209  /* Record the pc of the thread the last time it stopped. This is
210  maintained by proceed and keep_going, and used in
211  adjust_pc_after_break to distinguish a hardware single-step
212  SIGTRAP from a breakpoint SIGTRAP. */
214 
215  /* Did we set the thread stepping a breakpoint instruction? This is
216  used in conjunction with PREV_PC to decide whether to adjust the
217  PC. */
219 
220  /* Should we step over breakpoint next time keep_going is called? */
222 
223  /* Should we step over a watchpoint next time keep_going is called?
224  This is needed on targets with non-continuable, non-steppable
225  watchpoints. */
227 
228  /* Set to TRUE if we should finish single-stepping over a breakpoint
229  after hitting the current step-resume breakpoint. The context here
230  is that GDB is to do `next' or `step' while signal arrives.
231  When stepping over a breakpoint and signal arrives, GDB will attempt
232  to skip signal handler, so it inserts a step_resume_breakpoint at the
233  signal return address, and resume inferior.
234  step_after_step_resume_breakpoint is set to TRUE at this moment in
235  order to keep GDB in mind that there is still a breakpoint to step over
236  when GDB gets back SIGTRAP from step_resume_breakpoint. */
238 
239  /* Per-thread command support. */
240 
241  /* Pointer to what is left to do for an execution command after the
242  target stops. Used only in asynchronous mode, by targets that
243  support async execution. Several execution commands use it. */
245 
246  /* Similar to the above, but used when a single execution command
247  requires several resume/stop iterations. Used by the step
248  command. */
250 
251  /* If stepping, nonzero means step count is > 1 so don't print frame
252  next time inferior stops if it stops due to stepping. */
254 
255  /* This is used to remember when a fork or vfork event was caught by
256  a catchpoint, and thus the event is to be followed at the next
257  resume of the thread, and not immediately. */
258  struct target_waitstatus pending_follow;
259 
260  /* True if this thread has been explicitly requested to stop. */
262 
263  /* The initiating frame of a nexting operation, used for deciding
264  which exceptions to intercept. If it is null_frame_id no
265  bp_longjmp or bp_exception but longjmp has been caught just for
266  bp_longjmp_call_dummy. */
267  struct frame_id initiating_frame;
268 
269  /* Private data used by the target vector implementation. */
271 
272  /* Function that is called to free PRIVATE. If this is NULL, then
273  xfree will be called on PRIVATE. */
274  void (*private_dtor) (struct private_thread_info *);
275 
276  /* Branch trace information for this thread. */
277  struct btrace_thread_info btrace;
278 
279  /* Flag which indicates that the stack temporaries should be stored while
280  evaluating expressions. */
282 
283  /* Values that are stored as temporaries on stack while evaluating
284  expressions. */
285  value_vec *stack_temporaries;
286 };
287 
288 /* Create an empty thread list, or empty the existing one. */
289 extern void init_thread_list (void);
290 
291 /* Add a thread to the thread list, print a message
292  that a new thread is found, and return the pointer to
293  the new thread. Caller my use this pointer to
294  initialize the private thread data. */
295 extern struct thread_info *add_thread (ptid_t ptid);
296 
297 /* Same as add_thread, but does not print a message
298  about new thread. */
299 extern struct thread_info *add_thread_silent (ptid_t ptid);
300 
301 /* Same as add_thread, and sets the private info. */
303  struct private_thread_info *);
304 
305 /* Delete an existing thread list entry. */
306 extern void delete_thread (ptid_t);
307 
308 /* Delete an existing thread list entry, and be quiet about it. Used
309  after the process this thread having belonged to having already
310  exited, for example. */
311 extern void delete_thread_silent (ptid_t);
312 
313 /* Delete a step_resume_breakpoint from the thread database. */
314 extern void delete_step_resume_breakpoint (struct thread_info *);
315 
316 /* Delete an exception_resume_breakpoint from the thread database. */
317 extern void delete_exception_resume_breakpoint (struct thread_info *);
318 
319 /* Delete the single-step breakpoints of thread TP, if any. */
320 extern void delete_single_step_breakpoints (struct thread_info *tp);
321 
322 /* Check if the thread has software single stepping breakpoints
323  set. */
325 
326 /* Check whether the thread has software single stepping breakpoints
327  set at PC. */
329  struct address_space *aspace,
330  CORE_ADDR addr);
331 
332 /* Translate the integer thread id (GDB's homegrown id, not the system's)
333  into a "pid" (which may be overloaded with extra thread information). */
334 extern ptid_t thread_id_to_pid (int);
335 
336 /* Translate a 'pid' (which may be overloaded with extra thread information)
337  into the integer thread id (GDB's homegrown id, not the system's). */
338 extern int pid_to_thread_id (ptid_t ptid);
339 
340 /* Boolean test for an already-known pid (which may be overloaded with
341  extra thread information). */
342 extern int in_thread_list (ptid_t ptid);
343 
344 /* Boolean test for an already-known thread id (GDB's homegrown id,
345  not the system's). */
346 extern int valid_thread_id (int thread);
347 
348 /* Search function to lookup a thread by 'pid'. */
349 extern struct thread_info *find_thread_ptid (ptid_t ptid);
350 
351 /* Find thread by GDB user-visible thread number. */
352 struct thread_info *find_thread_id (int num);
353 
354 /* Finds the first thread of the inferior given by PID. If PID is -1,
355  returns the first thread in the list. */
357 
358 /* Returns any thread of process PID, giving preference to the current
359  thread. */
360 extern struct thread_info *any_thread_of_process (int pid);
361 
362 /* Returns any non-exited thread of process PID, giving preference to
363  the current thread, and to not executing threads. */
364 extern struct thread_info *any_live_thread_of_process (int pid);
365 
366 /* Change the ptid of thread OLD_PTID to NEW_PTID. */
367 void thread_change_ptid (ptid_t old_ptid, ptid_t new_ptid);
368 
369 /* Iterator function to call a user-provided callback function
370  once for each known thread. */
371 typedef int (*thread_callback_func) (struct thread_info *, void *);
372 extern struct thread_info *iterate_over_threads (thread_callback_func, void *);
373 
374 /* Traverse all threads, except those that have THREAD_EXITED
375  state. */
376 
377 #define ALL_NON_EXITED_THREADS(T) \
378  for (T = thread_list; T; T = T->next) \
379  if ((T)->state != THREAD_EXITED)
380 
381 /* Traverse all threads, including those that have THREAD_EXITED
382  state. Allows deleting the currently iterated thread. */
383 #define ALL_THREADS_SAFE(T, TMP) \
384  for ((T) = thread_list; \
385  (T) != NULL ? ((TMP) = (T)->next, 1): 0; \
386  (T) = (TMP))
387 
388 extern int thread_count (void);
389 
390 /* Switch from one thread to another. */
391 extern void switch_to_thread (ptid_t ptid);
392 
393 /* Marks thread PTID is running, or stopped.
394  If PTID is minus_one_ptid, marks all threads. */
395 extern void set_running (ptid_t ptid, int running);
396 
397 /* Marks or clears thread(s) PTID as having been requested to stop.
398  If PTID is MINUS_ONE_PTID, applies to all threads. If
399  ptid_is_pid(PTID) is true, applies to all threads of the process
400  pointed at by PTID. If STOP, then the THREAD_STOP_REQUESTED
401  observer is called with PTID as argument. */
402 extern void set_stop_requested (ptid_t ptid, int stop);
403 
404 /* NOTE: Since the thread state is not a boolean, most times, you do
405  not want to check it with negation. If you really want to check if
406  the thread is stopped,
407 
408  use (good):
409 
410  if (is_stopped (ptid))
411 
412  instead of (bad):
413 
414  if (!is_running (ptid))
415 
416  The latter also returns true on exited threads, most likelly not
417  what you want. */
418 
419 /* Reports if in the frontend's perpective, thread PTID is running. */
420 extern int is_running (ptid_t ptid);
421 
422 /* Is this thread listed, but known to have exited? We keep it listed
423  (but not visible) until it's safe to delete. */
424 extern int is_exited (ptid_t ptid);
425 
426 /* In the frontend's perpective, is this thread stopped? */
427 extern int is_stopped (ptid_t ptid);
428 
429 /* Marks thread PTID as executing, or not. If PTID is minus_one_ptid,
430  marks all threads.
431 
432  Note that this is different from the running state. See the
433  description of state and executing fields of struct
434  thread_info. */
435 extern void set_executing (ptid_t ptid, int executing);
436 
437 /* Reports if thread PTID is executing. */
438 extern int is_executing (ptid_t ptid);
439 
440 /* True if any (known or unknown) thread is or may be executing. */
441 extern int threads_are_executing (void);
442 
443 /* Merge the executing property of thread PTID over to its thread
444  state property (frontend running/stopped view).
445 
446  "not executing" -> "stopped"
447  "executing" -> "running"
448  "exited" -> "exited"
449 
450  If PTID is minus_one_ptid, go over all threads.
451 
452  Notifications are only emitted if the thread state did change. */
453 extern void finish_thread_state (ptid_t ptid);
454 
455 /* Same as FINISH_THREAD_STATE, but with an interface suitable to be
456  registered as a cleanup. PTID_P points to the ptid_t that is
457  passed to FINISH_THREAD_STATE. */
458 extern void finish_thread_state_cleanup (void *ptid_p);
459 
460 /* Commands with a prefix of `thread'. */
461 extern struct cmd_list_element *thread_cmd_list;
462 
463 extern void thread_command (char *tidstr, int from_tty);
464 
465 /* Print notices on thread events (attach, detach, etc.), set with
466  `set print thread-events'. */
467 extern int print_thread_events;
468 
469 extern void print_thread_info (struct ui_out *uiout, char *threads,
470  int pid);
471 
472 extern struct cleanup *make_cleanup_restore_current_thread (void);
473 
474 /* Returns a pointer into the thread_info corresponding to
475  INFERIOR_PTID. INFERIOR_PTID *must* be in the thread list. */
476 extern struct thread_info* inferior_thread (void);
477 
478 extern void update_thread_list (void);
479 
480 /* Delete any thread the target says is no longer alive. */
481 
482 extern void prune_threads (void);
483 
484 /* Delete threads marked THREAD_EXITED. Unlike prune_threads, this
485  does not consult the target about whether the thread is alive right
486  now. */
487 extern void delete_exited_threads (void);
488 
489 /* Return true if PC is in the stepping range of THREAD. */
490 
491 int pc_in_thread_step_range (CORE_ADDR pc, struct thread_info *thread);
492 
494 
496 
497 extern void push_thread_stack_temporary (ptid_t ptid, struct value *v);
498 
500 
501 extern int value_in_thread_stack_temporaries (struct value *, ptid_t);
502 
503 extern struct thread_info *thread_list;
504 
505 #endif /* GDBTHREAD_H */
int threads_are_executing(void)
Definition: thread.c:880
struct frame_id step_stack_frame_id
Definition: gdbthread.h:94
Definition: interps.c:48
struct private_thread_info * priv
Definition: gdbthread.h:270
struct thread_info * add_thread(ptid_t ptid)
Definition: thread.c:305
int pc_in_thread_step_range(CORE_ADDR pc, struct thread_info *thread)
Definition: thread.c:960
struct thread_info * find_thread_ptid(ptid_t ptid)
Definition: thread.c:393
struct thread_info * find_thread_id(int num)
Definition: thread.c:380
CORE_ADDR step_range_start
Definition: gdbthread.h:73
int refcount
Definition: gdbthread.h:194
bfd_vma CORE_ADDR
Definition: common-types.h:41
typedef VEC(value_ptr) value_vec
void delete_thread(ptid_t)
Definition: thread.c:368
void set_running(ptid_t ptid, int running)
Definition: thread.c:772
void delete_thread_silent(ptid_t)
Definition: thread.c:374
struct symtab * current_symtab
Definition: gdbthread.h:205
struct thread_info * add_thread_with_info(ptid_t ptid, struct private_thread_info *)
Definition: thread.c:291
struct thread_info * inferior_thread(void)
Definition: thread.c:85
int thread_stack_temporaries_enabled_p(ptid_t ptid)
Definition: thread.c:694
void switch_to_thread(ptid_t ptid)
Definition: thread.c:1185
int value_in_thread_stack_temporaries(struct value *, ptid_t)
Definition: thread.c:719
int stepping_over_watchpoint
Definition: gdbthread.h:226
int thread_has_single_step_breakpoint_here(struct thread_info *tp, struct address_space *aspace, CORE_ADDR addr)
Definition: thread.c:151
int current_line
Definition: gdbthread.h:204
int stepped_breakpoint
Definition: gdbthread.h:218
struct thread_info * first_thread_of_process(int pid)
Definition: thread.c:497
int step_after_step_resume_breakpoint
Definition: gdbthread.h:237
enum gdb_signal stop_signal
Definition: gdbthread.h:159
Definition: ui-out.c:99
thread_state
Definition: gdbthread.h:35
Definition: ptid.h:35
char * name
Definition: gdbthread.h:176
int valid_thread_id(int thread)
Definition: thread.c:447
int in_thread_list(ptid_t ptid)
Definition: thread.c:482
int thread_count(void)
Definition: thread.c:435
struct thread_info * iterate_over_threads(thread_callback_func, void *)
Definition: thread.c:419
int is_stopped(ptid_t ptid)
Definition: thread.c:822
ptid_t thread_id_to_pid(int)
Definition: thread.c:471
struct value * value_ptr
Definition: gdbthread.h:162
struct breakpoint * exception_resume_breakpoint
Definition: gdbthread.h:54
struct frame_id step_frame_id
Definition: gdbthread.h:90
int stack_temporaries_enabled
Definition: gdbthread.h:281
struct thread_info * any_live_thread_of_process(int pid)
Definition: thread.c:528
value_vec * stack_temporaries
Definition: gdbthread.h:285
void finish_thread_state(ptid_t ptid)
Definition: thread.c:911
int step_multi
Definition: gdbthread.h:253
void thread_change_ptid(ptid_t old_ptid, ptid_t new_ptid)
Definition: thread.c:754
void push_thread_stack_temporary(ptid_t ptid, struct value *v)
Definition: thread.c:707
struct thread_info * add_thread_silent(ptid_t ptid)
Definition: thread.c:240
void delete_step_resume_breakpoint(struct thread_info *)
Definition: thread.c:105
Definition: symtab.h:925
struct value * get_last_thread_stack_temporary(ptid_t)
Definition: thread.c:741
struct cmd_list_element * thread_cmd_list
Definition: thread.c:1755
CORE_ADDR prev_pc
Definition: gdbthread.h:213
int thread_has_single_step_breakpoints_set(struct thread_info *tp)
Definition: thread.c:143
step_over_calls_kind
Definition: inferior.h:216
void print_thread_info(struct ui_out *uiout, char *threads, int pid)
Definition: thread.c:978
struct symbol * step_start_function
Definition: gdbthread.h:77
Definition: value.c:172
void finish_thread_state_cleanup(void *ptid_p)
Definition: thread.c:950
const char const char int
Definition: command.h:229
struct continuation * continuations
Definition: gdbthread.h:244
void prune_threads(void)
Definition: thread.c:626
void update_thread_list(void)
Definition: thread.c:1735
ptid_t ptid
Definition: gdbthread.h:169
struct cleanup * enable_thread_stack_temporaries(ptid_t ptid)
Definition: thread.c:673
void delete_exception_resume_breakpoint(struct thread_info *)
Definition: thread.c:112
struct cleanup * make_cleanup_restore_current_thread(void)
Definition: thread.c:1354
struct continuation * intermediate_continuations
Definition: gdbthread.h:249
void thread_command(char *tidstr, int from_tty)
Definition: thread.c:1555
void set_stop_requested(ptid_t ptid, int stop)
Definition: thread.c:886
DEF_VEC_P(value_ptr)
struct breakpoint * single_step_breakpoints
Definition: gdbthread.h:61
struct thread_info * thread_list
Definition: thread.c:55
int is_exited(ptid_t ptid)
Definition: thread.c:828
struct interp * command_interp
Definition: gdbthread.h:140
void delete_exited_threads(void)
Definition: thread.c:640
void delete_single_step_breakpoints(struct thread_info *tp)
Definition: thread.c:121
int pid_to_thread_id(ptid_t ptid)
Definition: thread.c:459
int stepping_over_breakpoint
Definition: gdbthread.h:221
Definition: symtab.h:703
int(* thread_callback_func)(struct thread_info *, void *)
Definition: gdbthread.h:371
enum thread_state state
Definition: gdbthread.h:189
enum step_over_calls_kind step_over_calls
Definition: gdbthread.h:128
struct breakpoint * step_resume_breakpoint
Definition: gdbthread.h:51
int stop_requested
Definition: gdbthread.h:261
int is_running(ptid_t ptid)
Definition: thread.c:834
int executing
Definition: gdbthread.h:182
void set_executing(ptid_t ptid, int executing)
Definition: thread.c:850
struct thread_info * any_thread_of_process(int pid)
Definition: thread.c:510
mach_port_t mach_port_t name mach_port_t mach_port_t name error_t int int rusage_t pid_t pid
Definition: gnu-nat.c:1818
int print_thread_events
Definition: thread.c:1653
int is_executing(ptid_t ptid)
Definition: thread.c:840
CORE_ADDR step_range_end
Definition: gdbthread.h:74
void init_thread_list(void)
Definition: thread.c:198
struct thread_info * next
Definition: gdbthread.h:168