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.
7 This file is part of GDB.
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.
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.
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/>. */
27 #include "breakpoint.h"
32 /* Inferior thread specific part of `struct infcall_control_state'.
34 Inferior process counterpart is `struct inferior_control_state'. */
36 struct thread_control_state
38 /* User/external stepping state. */
40 /* Step-resume or longjmp-resume breakpoint. */
41 struct breakpoint *step_resume_breakpoint;
43 /* Exception-resume breakpoint. */
44 struct breakpoint *exception_resume_breakpoint;
46 /* Range to single step within.
48 If this is nonzero, respond to a single-step signal by continuing
49 to step if the pc is in this range.
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
56 CORE_ADDR step_range_start; /* Inclusive */
57 CORE_ADDR step_range_end; /* Exclusive */
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;
64 /* Similarly, the frame ID of the underlying stack frame (skipping
65 any inlined frames). */
66 struct frame_id step_stack_frame_id;
68 /* Nonzero if we are presently stepping over a breakpoint.
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
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.
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
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
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;
96 /* Nonzero if the thread is being proceeded for an inferior function
100 enum step_over_calls_kind step_over_calls;
102 /* Nonzero if stopped due to a step command. */
105 /* Chain containing status of breakpoint(s) the thread stopped
110 /* Inferior thread specific part of `struct infcall_suspend_state'.
112 Inferior process counterpart is `struct inferior_suspend_state'. */
114 struct thread_suspend_state
116 /* Last signal that the inferior received (why it stopped). */
117 enum target_signal stop_signal;
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) */
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. */
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. */
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),
147 /* This field is internal to thread.c. Never access it directly,
148 use is_running instead. */
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. */
156 /* State of GDB control of inferior thread execution.
157 See `struct thread_control_state'. */
158 struct thread_control_state control;
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;
165 struct symtab *current_symtab;
167 /* Internal stepping state. */
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. */
175 /* Should we step over breakpoint next time keep_going is called? */
176 int stepping_over_breakpoint;
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;
189 /* Per-thread command support. */
191 /* Pointer to what is left to do for an execution command after the
192 target stops. Used only in asynchronous mode, by targets that
193 support async execution. Several execution commands use it. */
194 struct continuation *continuations;
196 /* Similar to the above, but used when a single execution command
197 requires several resume/stop iterations. Used by the step
199 struct continuation *intermediate_continuations;
201 /* If stepping, nonzero means step count is > 1 so don't print frame
202 next time inferior stops if it stops due to stepping. */
205 /* This is used to remember when a fork or vfork event was caught by
206 a catchpoint, and thus the event is to be followed at the next
207 resume of the thread, and not immediately. */
208 struct target_waitstatus pending_follow;
210 /* True if this thread has been explicitly requested to stop. */
213 /* The initiating frame of a nexting operation, used for deciding
214 which exceptions to intercept. */
215 struct frame_id initiating_frame;
217 /* Private data used by the target vector implementation. */
218 struct private_thread_info *private;
220 /* Function that is called to free PRIVATE. If this is NULL, then
221 xfree will be called on PRIVATE. */
222 void (*private_dtor) (struct private_thread_info *);
225 /* Create an empty thread list, or empty the existing one. */
226 extern void init_thread_list (void);
228 /* Add a thread to the thread list, print a message
229 that a new thread is found, and return the pointer to
230 the new thread. Caller my use this pointer to
231 initialize the private thread data. */
232 extern struct thread_info *add_thread (ptid_t ptid);
234 /* Same as add_thread, but does not print a message
236 extern struct thread_info *add_thread_silent (ptid_t ptid);
238 /* Same as add_thread, and sets the private info. */
239 extern struct thread_info *add_thread_with_info (ptid_t ptid,
240 struct private_thread_info *);
242 /* Delete an existing thread list entry. */
243 extern void delete_thread (ptid_t);
245 /* Delete an existing thread list entry, and be quiet about it. Used
246 after the process this thread having belonged to having already
247 exited, for example. */
248 extern void delete_thread_silent (ptid_t);
250 /* Delete a step_resume_breakpoint from the thread database. */
251 extern void delete_step_resume_breakpoint (struct thread_info *);
253 /* Delete an exception_resume_breakpoint from the thread database. */
254 extern void delete_exception_resume_breakpoint (struct thread_info *);
256 /* Translate the integer thread id (GDB's homegrown id, not the system's)
257 into a "pid" (which may be overloaded with extra thread information). */
258 extern ptid_t thread_id_to_pid (int);
260 /* Translate a 'pid' (which may be overloaded with extra thread information)
261 into the integer thread id (GDB's homegrown id, not the system's). */
262 extern int pid_to_thread_id (ptid_t ptid);
264 /* Boolean test for an already-known pid (which may be overloaded with
265 extra thread information). */
266 extern int in_thread_list (ptid_t ptid);
268 /* Boolean test for an already-known thread id (GDB's homegrown id,
269 not the system's). */
270 extern int valid_thread_id (int thread);
272 /* Search function to lookup a thread by 'pid'. */
273 extern struct thread_info *find_thread_ptid (ptid_t ptid);
275 /* Find thread by GDB user-visible thread number. */
276 struct thread_info *find_thread_id (int num);
278 /* Finds the first thread of the inferior given by PID. If PID is -1,
279 returns the first thread in the list. */
280 struct thread_info *first_thread_of_process (int pid);
282 /* Returns any thread of process PID. */
283 extern struct thread_info *any_thread_of_process (int pid);
285 /* Returns any non-exited thread of process PID, giving preference for
286 not executing threads. */
287 extern struct thread_info *any_live_thread_of_process (int pid);
289 /* Change the ptid of thread OLD_PTID to NEW_PTID. */
290 void thread_change_ptid (ptid_t old_ptid, ptid_t new_ptid);
292 /* Iterator function to call a user-provided callback function
293 once for each known thread. */
294 typedef int (*thread_callback_func) (struct thread_info *, void *);
295 extern struct thread_info *iterate_over_threads (thread_callback_func, void *);
297 extern int thread_count (void);
299 /* Switch from one thread to another. */
300 extern void switch_to_thread (ptid_t ptid);
302 /* Marks thread PTID is running, or stopped.
303 If PIDGET (PTID) is -1, marks all threads. */
304 extern void set_running (ptid_t ptid, int running);
306 /* Marks or clears thread(s) PTID as having been requested to stop.
307 If PTID is MINUS_ONE_PTID, applies to all threads. If
308 ptid_is_pid(PTID) is true, applies to all threads of the process
309 pointed at by PTID. If STOP, then the THREAD_STOP_REQUESTED
310 observer is called with PTID as argument. */
311 extern void set_stop_requested (ptid_t ptid, int stop);
313 /* NOTE: Since the thread state is not a boolean, most times, you do
314 not want to check it with negation. If you really want to check if
315 the thread is stopped,
319 if (is_stopped (ptid))
323 if (!is_running (ptid))
325 The latter also returns true on exited threads, most likelly not
328 /* Reports if in the frontend's perpective, thread PTID is running. */
329 extern int is_running (ptid_t ptid);
331 /* Is this thread listed, but known to have exited? We keep it listed
332 (but not visible) until it's safe to delete. */
333 extern int is_exited (ptid_t ptid);
335 /* In the frontend's perpective, is this thread stopped? */
336 extern int is_stopped (ptid_t ptid);
338 /* In the frontend's perpective is there any thread running? */
339 extern int any_running (void);
341 /* Marks thread PTID as executing, or not. If PIDGET (PTID) is -1,
344 Note that this is different from the running state. See the
345 description of state_ and executing_ fields of struct
347 extern void set_executing (ptid_t ptid, int executing);
349 /* Reports if thread PTID is executing. */
350 extern int is_executing (ptid_t ptid);
352 /* Merge the executing property of thread PTID over to its thread
353 state property (frontend running/stopped view).
355 "not executing" -> "stopped"
356 "executing" -> "running"
359 If PIDGET (PTID) is -1, go over all threads.
361 Notifications are only emitted if the thread state did change. */
362 extern void finish_thread_state (ptid_t ptid);
364 /* Same as FINISH_THREAD_STATE, but with an interface suitable to be
365 registered as a cleanup. PTID_P points to the ptid_t that is
366 passed to FINISH_THREAD_STATE. */
367 extern void finish_thread_state_cleanup (void *ptid_p);
369 /* Commands with a prefix of `thread'. */
370 extern struct cmd_list_element *thread_cmd_list;
372 /* Print notices on thread events (attach, detach, etc.), set with
373 `set print thread-events'. */
374 extern int print_thread_events;
376 extern void print_thread_info (struct ui_out *uiout, char *threads,
379 extern struct cleanup *make_cleanup_restore_current_thread (void);
381 /* Returns a pointer into the thread_info corresponding to
382 INFERIOR_PTID. INFERIOR_PTID *must* be in the thread list. */
383 extern struct thread_info* inferior_thread (void);
385 extern void update_thread_list (void);
387 #endif /* GDBTHREAD_H */