1 /* Multi-process/thread control defs for GDB, the GNU debugger.
2 Copyright (C) 1987-2014 Free Software Foundation, Inc.
3 Contributed by Lynx Real-Time Systems, Inc. Los Gatos, CA.
6 This file is part of GDB.
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.
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.
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/>. */
26 #include "breakpoint.h"
32 /* Frontend view of the thread state. Possible extensions: stepping,
33 finishing, until(ling),... */
41 /* Inferior thread specific part of `struct infcall_control_state'.
43 Inferior process counterpart is `struct inferior_control_state'. */
45 struct thread_control_state
47 /* User/external stepping state. */
49 /* Step-resume or longjmp-resume breakpoint. */
50 struct breakpoint *step_resume_breakpoint;
52 /* Exception-resume breakpoint. */
53 struct breakpoint *exception_resume_breakpoint;
55 /* Range to single step within.
57 If this is nonzero, respond to a single-step signal by continuing
58 to step if the pc is in this range.
60 If step_range_start and step_range_end are both 1, it means to
61 step for a single instruction (FIXME: it might clean up
62 wait_for_inferior in a minor way if this were changed to the
63 address of the instruction and that address plus one. But maybe
65 CORE_ADDR step_range_start; /* Inclusive */
66 CORE_ADDR step_range_end; /* Exclusive */
68 /* If GDB issues a target step request, and this is nonzero, the
69 target should single-step this thread once, and then continue
70 single-stepping it without GDB core involvement as long as the
71 thread stops in the step range above. If this is zero, the
72 target should ignore the step range, and only issue one single
76 /* Stack frame address as of when stepping command was issued.
77 This is how we know when we step into a subroutine call, and how
78 to set the frame for the breakpoint used to step out. */
79 struct frame_id step_frame_id;
81 /* Similarly, the frame ID of the underlying stack frame (skipping
82 any inlined frames). */
83 struct frame_id step_stack_frame_id;
85 /* Nonzero if we are presently stepping over a breakpoint.
87 If we hit a breakpoint or watchpoint, and then continue, we need
88 to single step the current thread with breakpoints disabled, to
89 avoid hitting the same breakpoint or watchpoint again. And we
90 should step just a single thread and keep other threads stopped,
91 so that other threads don't miss breakpoints while they are
94 So, this variable simultaneously means that we need to single
95 step the current thread, keep other threads stopped, and that
96 breakpoints should be removed while we step.
98 This variable is set either:
99 - in proceed, when we resume inferior on user's explicit request
100 - in keep_going, if handle_inferior_event decides we need to
101 step over breakpoint.
103 The variable is cleared in normal_stop. The proceed calls
104 wait_for_inferior, which calls handle_inferior_event in a loop,
105 and until wait_for_inferior exits, this variable is changed only
109 /* Nonzero if the thread is being proceeded for a "finish" command
110 or a similar situation when stop_registers should be saved. */
111 int proceed_to_finish;
113 /* Nonzero if the thread is being proceeded for an inferior function
117 enum step_over_calls_kind step_over_calls;
119 /* Nonzero if stopped due to a step command. */
122 /* Chain containing status of breakpoint(s) the thread stopped
126 /* The interpreter that issued the execution command. NULL if the
127 thread was resumed as a result of a command applied to some other
128 thread (e.g., "next" with scheduler-locking off). */
129 struct interp *command_interp;
132 /* Inferior thread specific part of `struct infcall_suspend_state'.
134 Inferior process counterpart is `struct inferior_suspend_state'. */
136 struct thread_suspend_state
138 /* Last signal that the inferior received (why it stopped). When
139 the thread is resumed, this signal is delivered. Note: the
140 target should not check whether the signal is in pass state,
141 because the signal may have been explicitly passed with the
142 "signal" command, which overrides "handle nopass". If the signal
143 should be suppressed, the core will take care of clearing this
144 before the target is resumed. */
145 enum gdb_signal stop_signal;
150 struct thread_info *next;
151 ptid_t ptid; /* "Actual process id";
152 In fact, this may be overloaded with
153 kernel thread id, etc. */
154 int num; /* Convenient handle (GDB thread id) */
156 /* The name of the thread, as specified by the user. This is NULL
157 if the thread does not have a user-given name. */
160 /* Non-zero means the thread is executing. Note: this is different
161 from saying that there is an active target and we are stopped at
162 a breakpoint, for instance. This is a real indicator whether the
163 thread is off and running. */
166 /* Frontend view of the thread state. Note that the THREAD_RUNNING/
167 THREAD_STOPPED states are different from EXECUTING. When the
168 thread is stopped internally while handling an internal event,
169 like a software single-step breakpoint, EXECUTING will be false,
170 but STATE will still be THREAD_RUNNING. */
171 enum thread_state state;
173 /* If this is > 0, then it means there's code out there that relies
174 on this thread being listed. Don't delete it from the lists even
175 if we detect it exiting. */
178 /* State of GDB control of inferior thread execution.
179 See `struct thread_control_state'. */
180 struct thread_control_state control;
182 /* State of inferior thread to restore after GDB is done with an inferior
183 call. See `struct thread_suspend_state'. */
184 struct thread_suspend_state suspend;
187 struct symtab *current_symtab;
189 /* Internal stepping state. */
191 /* Record the pc of the thread the last time it stopped. This is
192 maintained by proceed and keep_going, and used in
193 adjust_pc_after_break to distinguish a hardware single-step
194 SIGTRAP from a breakpoint SIGTRAP. */
197 /* Should we step over breakpoint next time keep_going is called? */
198 int stepping_over_breakpoint;
200 /* Set to TRUE if we should finish single-stepping over a breakpoint
201 after hitting the current step-resume breakpoint. The context here
202 is that GDB is to do `next' or `step' while signal arrives.
203 When stepping over a breakpoint and signal arrives, GDB will attempt
204 to skip signal handler, so it inserts a step_resume_breakpoint at the
205 signal return address, and resume inferior.
206 step_after_step_resume_breakpoint is set to TRUE at this moment in
207 order to keep GDB in mind that there is still a breakpoint to step over
208 when GDB gets back SIGTRAP from step_resume_breakpoint. */
209 int step_after_step_resume_breakpoint;
211 /* Per-thread command support. */
213 /* Pointer to what is left to do for an execution command after the
214 target stops. Used only in asynchronous mode, by targets that
215 support async execution. Several execution commands use it. */
216 struct continuation *continuations;
218 /* Similar to the above, but used when a single execution command
219 requires several resume/stop iterations. Used by the step
221 struct continuation *intermediate_continuations;
223 /* If stepping, nonzero means step count is > 1 so don't print frame
224 next time inferior stops if it stops due to stepping. */
227 /* This is used to remember when a fork or vfork event was caught by
228 a catchpoint, and thus the event is to be followed at the next
229 resume of the thread, and not immediately. */
230 struct target_waitstatus pending_follow;
232 /* True if this thread has been explicitly requested to stop. */
235 /* The initiating frame of a nexting operation, used for deciding
236 which exceptions to intercept. If it is null_frame_id no
237 bp_longjmp or bp_exception but longjmp has been caught just for
238 bp_longjmp_call_dummy. */
239 struct frame_id initiating_frame;
241 /* Private data used by the target vector implementation. */
242 struct private_thread_info *private;
244 /* Function that is called to free PRIVATE. If this is NULL, then
245 xfree will be called on PRIVATE. */
246 void (*private_dtor) (struct private_thread_info *);
248 /* Branch trace information for this thread. */
249 struct btrace_thread_info btrace;
252 /* Create an empty thread list, or empty the existing one. */
253 extern void init_thread_list (void);
255 /* Add a thread to the thread list, print a message
256 that a new thread is found, and return the pointer to
257 the new thread. Caller my use this pointer to
258 initialize the private thread data. */
259 extern struct thread_info *add_thread (ptid_t ptid);
261 /* Same as add_thread, but does not print a message
263 extern struct thread_info *add_thread_silent (ptid_t ptid);
265 /* Same as add_thread, and sets the private info. */
266 extern struct thread_info *add_thread_with_info (ptid_t ptid,
267 struct private_thread_info *);
269 /* Delete an existing thread list entry. */
270 extern void delete_thread (ptid_t);
272 /* Delete an existing thread list entry, and be quiet about it. Used
273 after the process this thread having belonged to having already
274 exited, for example. */
275 extern void delete_thread_silent (ptid_t);
277 /* Delete a step_resume_breakpoint from the thread database. */
278 extern void delete_step_resume_breakpoint (struct thread_info *);
280 /* Delete an exception_resume_breakpoint from the thread database. */
281 extern void delete_exception_resume_breakpoint (struct thread_info *);
283 /* Translate the integer thread id (GDB's homegrown id, not the system's)
284 into a "pid" (which may be overloaded with extra thread information). */
285 extern ptid_t thread_id_to_pid (int);
287 /* Translate a 'pid' (which may be overloaded with extra thread information)
288 into the integer thread id (GDB's homegrown id, not the system's). */
289 extern int pid_to_thread_id (ptid_t ptid);
291 /* Boolean test for an already-known pid (which may be overloaded with
292 extra thread information). */
293 extern int in_thread_list (ptid_t ptid);
295 /* Boolean test for an already-known thread id (GDB's homegrown id,
296 not the system's). */
297 extern int valid_thread_id (int thread);
299 /* Search function to lookup a thread by 'pid'. */
300 extern struct thread_info *find_thread_ptid (ptid_t ptid);
302 /* Find thread by GDB user-visible thread number. */
303 struct thread_info *find_thread_id (int num);
305 /* Finds the first thread of the inferior given by PID. If PID is -1,
306 returns the first thread in the list. */
307 struct thread_info *first_thread_of_process (int pid);
309 /* Returns any thread of process PID, giving preference to the current
311 extern struct thread_info *any_thread_of_process (int pid);
313 /* Returns any non-exited thread of process PID, giving preference to
314 the current thread, and to not executing threads. */
315 extern struct thread_info *any_live_thread_of_process (int pid);
317 /* Change the ptid of thread OLD_PTID to NEW_PTID. */
318 void thread_change_ptid (ptid_t old_ptid, ptid_t new_ptid);
320 /* Iterator function to call a user-provided callback function
321 once for each known thread. */
322 typedef int (*thread_callback_func) (struct thread_info *, void *);
323 extern struct thread_info *iterate_over_threads (thread_callback_func, void *);
325 /* Traverse all threads, except those that have THREAD_EXITED
328 #define ALL_NON_EXITED_THREADS(T) \
329 for (T = thread_list; T; T = T->next) \
330 if ((T)->state != THREAD_EXITED)
332 extern int thread_count (void);
334 /* Switch from one thread to another. */
335 extern void switch_to_thread (ptid_t ptid);
337 /* Marks thread PTID is running, or stopped.
338 If ptid_get_pid (PTID) is -1, marks all threads. */
339 extern void set_running (ptid_t ptid, int running);
341 /* Marks or clears thread(s) PTID as having been requested to stop.
342 If PTID is MINUS_ONE_PTID, applies to all threads. If
343 ptid_is_pid(PTID) is true, applies to all threads of the process
344 pointed at by PTID. If STOP, then the THREAD_STOP_REQUESTED
345 observer is called with PTID as argument. */
346 extern void set_stop_requested (ptid_t ptid, int stop);
348 /* NOTE: Since the thread state is not a boolean, most times, you do
349 not want to check it with negation. If you really want to check if
350 the thread is stopped,
354 if (is_stopped (ptid))
358 if (!is_running (ptid))
360 The latter also returns true on exited threads, most likelly not
363 /* Reports if in the frontend's perpective, thread PTID is running. */
364 extern int is_running (ptid_t ptid);
366 /* Is this thread listed, but known to have exited? We keep it listed
367 (but not visible) until it's safe to delete. */
368 extern int is_exited (ptid_t ptid);
370 /* In the frontend's perpective, is this thread stopped? */
371 extern int is_stopped (ptid_t ptid);
373 /* Marks thread PTID as executing, or not. If ptid_get_pid (PTID) is -1,
376 Note that this is different from the running state. See the
377 description of state and executing fields of struct
379 extern void set_executing (ptid_t ptid, int executing);
381 /* Reports if thread PTID is executing. */
382 extern int is_executing (ptid_t ptid);
384 /* Merge the executing property of thread PTID over to its thread
385 state property (frontend running/stopped view).
387 "not executing" -> "stopped"
388 "executing" -> "running"
391 If ptid_get_pid (PTID) is -1, go over all threads.
393 Notifications are only emitted if the thread state did change. */
394 extern void finish_thread_state (ptid_t ptid);
396 /* Same as FINISH_THREAD_STATE, but with an interface suitable to be
397 registered as a cleanup. PTID_P points to the ptid_t that is
398 passed to FINISH_THREAD_STATE. */
399 extern void finish_thread_state_cleanup (void *ptid_p);
401 /* Commands with a prefix of `thread'. */
402 extern struct cmd_list_element *thread_cmd_list;
404 /* Print notices on thread events (attach, detach, etc.), set with
405 `set print thread-events'. */
406 extern int print_thread_events;
408 extern void print_thread_info (struct ui_out *uiout, char *threads,
411 extern struct cleanup *make_cleanup_restore_current_thread (void);
413 /* Returns a pointer into the thread_info corresponding to
414 INFERIOR_PTID. INFERIOR_PTID *must* be in the thread list. */
415 extern struct thread_info* inferior_thread (void);
417 extern void update_thread_list (void);
419 /* Return true if PC is in the stepping range of THREAD. */
421 int pc_in_thread_step_range (CORE_ADDR pc, struct thread_info *thread);
423 extern struct thread_info *thread_list;
425 #endif /* GDBTHREAD_H */