gdb/gdbthread.h - gdb

Global variables defined

Data types defined

Macros defined

Source code

  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.


  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/>.  */

  21. #ifndef GDBTHREAD_H
  22. ‌#define GDBTHREAD_H

  24. struct symtab;

  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"

  33. /* Frontend view of the thread state.  Possible extensions: stepping,
  34.    finishing, until(ling),...  */
  35. ‌enum thread_state
  36. {
  37.   THREAD_STOPPED,
  38.   THREAD_RUNNING,
  39.   THREAD_EXITED,
  40. };

  42. /* Inferior thread specific part of `struct infcall_control_state'.

  44.    Inferior process counterpart is `struct inferior_control_state'.  */

  46. ‌struct thread_control_state
  47. {
  48.   /* User/external stepping state.  */

  50.   /* Step-resume or longjmp-resume breakpoint.  */
  51.   struct breakpoint *step_resume_breakpoint;

  53.   /* Exception-resume breakpoint.  */
  54.   struct breakpoint *exception_resume_breakpoint;

  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.  */
  61.   struct breakpoint *single_step_breakpoints;

  63.   /* Range to single step within.

  65.      If this is nonzero, respond to a single-step signal by continuing
  66.      to step if the pc is in this range.

  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 */

  76.   /* If GDB issues a target step request, and this is nonzero, the
  77.      target should single-step this thread once, and then continue
  78.      single-stepping it without GDB core involvement as long as the
  79.      thread stops in the step range above.  If this is zero, the
  80.      target should ignore the step range, and only issue one single
  81.      step.  */
  82.   int may_range_step;

  84.   /* Stack frame address as of when stepping command was issued.
  85.      This is how we know when we step into a subroutine call, and how
  86.      to set the frame for the breakpoint used to step out.  */
  87.   struct frame_id step_frame_id;

  89.   /* Similarly, the frame ID of the underlying stack frame (skipping
  90.      any inlined frames).  */
  91.   struct frame_id step_stack_frame_id;

  93.   /* Nonzero if we are presently stepping over a breakpoint.

  95.      If we hit a breakpoint or watchpoint, and then continue, we need
  96.      to single step the current thread with breakpoints disabled, to
  97.      avoid hitting the same breakpoint or watchpoint again.  And we
  98.      should step just a single thread and keep other threads stopped,
  99.      so that other threads don't miss breakpoints while they are
  100.      removed.

  102.      So, this variable simultaneously means that we need to single
  103.      step the current thread, keep other threads stopped, and that
  104.      breakpoints should be removed while we step.

  106.      This variable is set either:
  107.      - in proceed, when we resume inferior on user's explicit request
  108.      - in keep_going, if handle_inferior_event decides we need to
  109.      step over breakpoint.

  111.      The variable is cleared in normal_stop.  The proceed calls
  112.      wait_for_inferior, which calls handle_inferior_event in a loop,
  113.      and until wait_for_inferior exits, this variable is changed only
  114.      by keep_going.  */
  115.   int trap_expected;

  117.   /* Nonzero if the thread is being proceeded for a "finish" command
  118.      or a similar situation when stop_registers should be saved.  */
  119.   int proceed_to_finish;

  121.   /* Nonzero if the thread is being proceeded for an inferior function
  122.      call.  */
  123.   int in_infcall;

  125.   enum step_over_calls_kind step_over_calls;

  127.   /* Nonzero if stopped due to a step command.  */
  128.   int stop_step;

  130.   /* Chain containing status of breakpoint(s) the thread stopped
  131.      at.  */
  132.   bpstat stop_bpstat;

  134.   /* The interpreter that issued the execution command.  NULL if the
  135.      thread was resumed as a result of a command applied to some other
  136.      thread (e.g., "next" with scheduler-locking off).  */
  137.   struct interp *command_interp;
  138. };

  140. /* Inferior thread specific part of `struct infcall_suspend_state'.

  142.    Inferior process counterpart is `struct inferior_suspend_state'.  */

  144. ‌struct thread_suspend_state
  145. {
  146.   /* Last signal that the inferior received (why it stopped).  When
  147.      the thread is resumed, this signal is delivered.  Note: the
  148.      target should not check whether the signal is in pass state,
  149.      because the signal may have been explicitly passed with the
  150.      "signal" command, which overrides "handle nopass".  If the signal
  151.      should be suppressed, the core will take care of clearing this
  152.      before the target is resumed.  */
  153.   enum gdb_signal stop_signal;
  154. };

  156. ‌typedef struct value *value_ptr;
  157. ‌DEF_VEC_P (value_ptr);
  158. ‌typedef VEC (value_ptr) value_vec;

  160. ‌struct thread_info
  161. {
  162.   struct thread_info *next;
  163.   ptid_t ptid;                        /* "Actual process id";
  164.                                     In fact, this may be overloaded with
  165.                                     kernel thread id, etc.  */
  166.   int num;                        /* Convenient handle (GDB thread id) */

  168.   /* The name of the thread, as specified by the user.  This is NULL
  169.      if the thread does not have a user-given name.  */
  170.   char *name;

  172.   /* Non-zero means the thread is executing.  Note: this is different
  173.      from saying that there is an active target and we are stopped at
  174.      a breakpoint, for instance.  This is a real indicator whether the
  175.      thread is off and running.  */
  176.   int executing;

  178.   /* Frontend view of the thread state.  Note that the THREAD_RUNNING/
  179.      THREAD_STOPPED states are different from EXECUTING.  When the
  180.      thread is stopped internally while handling an internal event,
  181.      like a software single-step breakpoint, EXECUTING will be false,
  182.      but STATE will still be THREAD_RUNNING.  */
  183.   enum thread_state state;

  185.   /* If this is > 0, then it means there's code out there that relies
  186.      on this thread being listed.  Don't delete it from the lists even
  187.      if we detect it exiting.  */
  188.   int refcount;

  190.   /* State of GDB control of inferior thread execution.
  191.      See `struct thread_control_state'.  */
  192.   struct thread_control_state control;

  194.   /* State of inferior thread to restore after GDB is done with an inferior
  195.      call.  See `struct thread_suspend_state'.  */
  196.   struct thread_suspend_state suspend;

  198.   int current_line;
  199.   struct symtab *current_symtab;

  201.   /* Internal stepping state.  */

  203.   /* Record the pc of the thread the last time it stopped.  This is
  204.      maintained by proceed and keep_going, and used in
  205.      adjust_pc_after_break to distinguish a hardware single-step
  206.      SIGTRAP from a breakpoint SIGTRAP.  */
  207.   CORE_ADDR prev_pc;

  209.   /* Did we set the thread stepping a breakpoint instruction?  This is
  210.      used in conjunction with PREV_PC to decide whether to adjust the
  211.      PC.  */
  212.   int stepped_breakpoint;

  214.   /* Should we step over breakpoint next time keep_going is called?  */
  215.   int stepping_over_breakpoint;

  217.   /* Should we step over a watchpoint next time keep_going is called?
  218.      This is needed on targets with non-continuable, non-steppable
  219.      watchpoints.  */
  220.   int stepping_over_watchpoint;

  222.   /* Set to TRUE if we should finish single-stepping over a breakpoint
  223.      after hitting the current step-resume breakpoint.  The context here
  224.      is that GDB is to do `next' or `step' while signal arrives.
  225.      When stepping over a breakpoint and signal arrives, GDB will attempt
  226.      to skip signal handler, so it inserts a step_resume_breakpoint at the
  227.      signal return address, and resume inferior.
  228.      step_after_step_resume_breakpoint is set to TRUE at this moment in
  229.      order to keep GDB in mind that there is still a breakpoint to step over
  230.      when GDB gets back SIGTRAP from step_resume_breakpoint.  */
  231.   int step_after_step_resume_breakpoint;

  233.   /* Per-thread command support.  */

  235.   /* Pointer to what is left to do for an execution command after the
  236.      target stops.  Used only in asynchronous mode, by targets that
  237.      support async execution.  Several execution commands use it.  */
  238.   struct continuation *continuations;

  240.   /* Similar to the above, but used when a single execution command
  241.      requires several resume/stop iterations.  Used by the step
  242.      command.  */
  243.   struct continuation *intermediate_continuations;

  245.   /* If stepping, nonzero means step count is > 1 so don't print frame
  246.      next time inferior stops if it stops due to stepping.  */
  247.   int step_multi;

  249.   /* This is used to remember when a fork or vfork event was caught by
  250.      a catchpoint, and thus the event is to be followed at the next
  251.      resume of the thread, and not immediately.  */
  252.   struct target_waitstatus pending_follow;

  254.   /* True if this thread has been explicitly requested to stop.  */
  255.   int stop_requested;

  257.   /* The initiating frame of a nexting operation, used for deciding
  258.      which exceptions to intercept.  If it is null_frame_id no
  259.      bp_longjmp or bp_exception but longjmp has been caught just for
  260.      bp_longjmp_call_dummy.  */
  261.   struct frame_id initiating_frame;

  263.   /* Private data used by the target vector implementation.  */
  264.   struct private_thread_info *private;

  266.   /* Function that is called to free PRIVATE.  If this is NULL, then
  267.      xfree will be called on PRIVATE.  */
  268.   void (*private_dtor) (struct private_thread_info *);

  270.   /* Branch trace information for this thread.  */
  271.   struct btrace_thread_info btrace;

  273.   /* Flag which indicates that the stack temporaries should be stored while
  274.      evaluating expressions.  */
  275.   int stack_temporaries_enabled;

  277.   /* Values that are stored as temporaries on stack while evaluating
  278.      expressions.  */
  279.   value_vec *stack_temporaries;
  280. };

  282. /* Create an empty thread list, or empty the existing one.  */
  283. extern void init_thread_list (void);

  285. /* Add a thread to the thread list, print a message
  286.    that a new thread is found, and return the pointer to
  287.    the new thread.  Caller my use this pointer to
  288.    initialize the private thread data.  */
  289. extern struct thread_info *add_thread (ptid_t ptid);

  291. /* Same as add_thread, but does not print a message
  292.    about new thread.  */
  293. extern struct thread_info *add_thread_silent (ptid_t ptid);

  295. /* Same as add_thread, and sets the private info.  */
  296. extern struct thread_info *add_thread_with_info (ptid_t ptid,
  297.                                                  struct private_thread_info *);

  299. /* Delete an existing thread list entry.  */
  300. extern void delete_thread (ptid_t);

  302. /* Delete an existing thread list entry, and be quiet about it.  Used
  303.    after the process this thread having belonged to having already
  304.    exited, for example.  */
  305. extern void delete_thread_silent (ptid_t);

  307. /* Delete a step_resume_breakpoint from the thread database.  */
  308. extern void delete_step_resume_breakpoint (struct thread_info *);

  310. /* Delete an exception_resume_breakpoint from the thread database.  */
  311. extern void delete_exception_resume_breakpoint (struct thread_info *);

  313. /* Delete the single-step breakpoints of thread TP, if any.  */
  314. extern void delete_single_step_breakpoints (struct thread_info *tp);

  316. /* Check if the thread has software single stepping breakpoints
  317.    set.  */
  318. extern int thread_has_single_step_breakpoints_set (struct thread_info *tp);

  320. /* Check whether the thread has software single stepping breakpoints
  321.    set at PC.  */
  322. extern int thread_has_single_step_breakpoint_here (struct thread_info *tp,
  323.                                                    struct address_space *aspace,
  324.                                                    CORE_ADDR addr);

  326. /* Translate the integer thread id (GDB's homegrown id, not the system's)
  327.    into a "pid" (which may be overloaded with extra thread information).  */
  328. extern ptid_t thread_id_to_pid (int);

  330. /* Translate a 'pid' (which may be overloaded with extra thread information)
  331.    into the integer thread id (GDB's homegrown id, not the system's).  */
  332. extern int pid_to_thread_id (ptid_t ptid);

  334. /* Boolean test for an already-known pid (which may be overloaded with
  335.    extra thread information).  */
  336. extern int in_thread_list (ptid_t ptid);

  338. /* Boolean test for an already-known thread id (GDB's homegrown id,
  339.    not the system's).  */
  340. extern int valid_thread_id (int thread);

  342. /* Search function to lookup a thread by 'pid'.  */
  343. extern struct thread_info *find_thread_ptid (ptid_t ptid);

  345. /* Find thread by GDB user-visible thread number.  */
  346. struct thread_info *find_thread_id (int num);

  348. /* Finds the first thread of the inferior given by PID.  If PID is -1,
  349.    returns the first thread in the list.  */
  350. struct thread_info *first_thread_of_process (int pid);

  352. /* Returns any thread of process PID, giving preference to the current
  353.    thread.  */
  354. extern struct thread_info *any_thread_of_process (int pid);

  356. /* Returns any non-exited thread of process PID, giving preference to
  357.    the current thread, and to not executing threads.  */
  358. extern struct thread_info *any_live_thread_of_process (int pid);

  360. /* Change the ptid of thread OLD_PTID to NEW_PTID.  */
  361. void thread_change_ptid (ptid_t old_ptid, ptid_t new_ptid);

  363. /* Iterator function to call a user-provided callback function
  364.    once for each known thread.  */
  365. ‌typedef int (*thread_callback_func) (struct thread_info *, void *);
  366. extern struct thread_info *iterate_over_threads (thread_callback_func, void *);

  368. /* Traverse all threads, except those that have THREAD_EXITED
  369.    state.  */

  371. ‌#define ALL_NON_EXITED_THREADS(T)                                \
  372.   for (T = thread_list; T; T = T->next) \
  373.     if ((T)->state != THREAD_EXITED)

  375. /* Like ALL_NON_EXITED_THREADS, but allows deleting the currently
  376.    iterated thread.  */
  377. ‌#define ALL_NON_EXITED_THREADS_SAFE(T, TMP)        \
  378.   for ((T) = thread_list;                        \
  379.        (T) != NULL ? ((TMP) = (T)->next, 1): 0;        \
  380.        (T) = (TMP))                                \
  381.     if ((T)->state != THREAD_EXITED)

  383. extern int thread_count (void);

  385. /* Switch from one thread to another.  */
  386. extern void switch_to_thread (ptid_t ptid);

  388. /* Marks thread PTID is running, or stopped.
  389.    If PTID is minus_one_ptid, marks all threads.  */
  390. extern void set_running (ptid_t ptid, int running);

  392. /* Marks or clears thread(s) PTID as having been requested to stop.
  393.    If PTID is MINUS_ONE_PTID, applies to all threads.  If
  394.    ptid_is_pid(PTID) is true, applies to all threads of the process
  395.    pointed at by PTID.  If STOP, then the THREAD_STOP_REQUESTED
  396.    observer is called with PTID as argument.  */
  397. extern void set_stop_requested (ptid_t ptid, int stop);

  399. /* NOTE: Since the thread state is not a boolean, most times, you do
  400.    not want to check it with negation.  If you really want to check if
  401.    the thread is stopped,

  403.     use (good):

  405.      if (is_stopped (ptid))

  407.     instead of (bad):

  409.      if (!is_running (ptid))

  411.    The latter also returns true on exited threads, most likelly not
  412.    what you want.  */

  414. /* Reports if in the frontend's perpective, thread PTID is running.  */
  415. extern int is_running (ptid_t ptid);

  417. /* Is this thread listed, but known to have exited?  We keep it listed
  418.    (but not visible) until it's safe to delete.  */
  419. extern int is_exited (ptid_t ptid);

  421. /* In the frontend's perpective, is this thread stopped?  */
  422. extern int is_stopped (ptid_t ptid);

  424. /* Marks thread PTID as executing, or not.  If PTID is minus_one_ptid,
  425.    marks all threads.

  427.    Note that this is different from the running state.  See the
  428.    description of state and executing fields of struct
  429.    thread_info.  */
  430. extern void set_executing (ptid_t ptid, int executing);

  432. /* Reports if thread PTID is executing.  */
  433. extern int is_executing (ptid_t ptid);

  435. /* True if any (known or unknown) thread is or may be executing.  */
  436. extern int threads_are_executing (void);

  438. /* Merge the executing property of thread PTID over to its thread
  439.    state property (frontend running/stopped view).

  441.    "not executing" -> "stopped"
  442.    "executing"     -> "running"
  443.    "exited"        -> "exited"

  445.    If PTID is minus_one_ptid, go over all threads.

  447.    Notifications are only emitted if the thread state did change.  */
  448. extern void finish_thread_state (ptid_t ptid);

  450. /* Same as FINISH_THREAD_STATE, but with an interface suitable to be
  451.    registered as a cleanup.  PTID_P points to the ptid_t that is
  452.    passed to FINISH_THREAD_STATE.  */
  453. extern void finish_thread_state_cleanup (void *ptid_p);

  455. /* Commands with a prefix of `thread'.  */
  456. extern struct cmd_list_element *thread_cmd_list;

  458. /* Print notices on thread events (attach, detach, etc.), set with
  459.    `set print thread-events'.  */
  460. extern int print_thread_events;

  462. extern void print_thread_info (struct ui_out *uiout, char *threads,
  463.                                int pid);

  465. extern struct cleanup *make_cleanup_restore_current_thread (void);

  467. /* Returns a pointer into the thread_info corresponding to
  468.    INFERIOR_PTID.  INFERIOR_PTID *must* be in the thread list.  */
  469. extern struct thread_info* inferior_thread (void);

  471. extern void update_thread_list (void);

  473. /* Delete any thread the target says is no longer alive.  */

  475. extern void prune_threads (void);

  477. /* Return true if PC is in the stepping range of THREAD.  */

  479. int pc_in_thread_step_range (CORE_ADDR pc, struct thread_info *thread);

  481. extern struct cleanup *enable_thread_stack_temporaries (ptid_t ptid);

  483. extern int thread_stack_temporaries_enabled_p (ptid_t ptid);

  485. extern void push_thread_stack_temporary (ptid_t ptid, struct value *v);

  487. extern struct value *get_last_thread_stack_temporary (ptid_t);

  489. extern int value_in_thread_stack_temporaries (struct value *, ptid_t);

  491. extern struct thread_info *thread_list;

  493. #endif /* GDBTHREAD_H */