/* Multi-process/thread control for GDB, the GNU debugger.
- Copyright (C) 1986-2020 Free Software Foundation, Inc.
+ Copyright (C) 1986-2021 Free Software Foundation, Inc.
Contributed by Lynx Real-Time Systems, Inc. Los Gatos, CA.
static int highest_thread_num;
-/* RAII type used to increase / decrease the refcount of each thread
- in a given list of threads. */
+/* The current/selected thread. */
+static thread_info *current_thread_;
-class scoped_inc_dec_ref
-{
-public:
- explicit scoped_inc_dec_ref (const std::vector<thread_info *> &thrds)
- : m_thrds (thrds)
- {
- for (thread_info *thr : m_thrds)
- thr->incref ();
- }
-
- ~scoped_inc_dec_ref ()
- {
- for (thread_info *thr : m_thrds)
- thr->decref ();
- }
-
-private:
- const std::vector<thread_info *> &m_thrds;
-};
+/* Returns true if THR is the current thread. */
+static bool
+is_current_thread (const thread_info *thr)
+{
+ return thr == current_thread_;
+}
struct thread_info*
inferior_thread (void)
{
- struct thread_info *tp = find_thread_ptid (current_inferior (), inferior_ptid);
- gdb_assert (tp);
- return tp;
+ gdb_assert (current_thread_ != nullptr);
+ return current_thread_;
}
/* Delete the breakpoint pointed at by BP_P, if there's one. */
/* Set the TP's state as exited. */
static void
-set_thread_exited (thread_info *tp, int silent)
+set_thread_exited (thread_info *tp, bool silent)
{
- /* Dead threads don't need to step-over. Remove from queue. */
+ /* Dead threads don't need to step-over. Remove from chain. */
if (tp->step_over_next != NULL)
- thread_step_over_chain_remove (tp);
+ global_thread_step_over_chain_remove (tp);
if (tp->state != THREAD_EXITED)
{
struct thread_info *last;
for (last = inf->thread_list; last->next != NULL; last = last->next)
- ;
+ gdb_assert (ptid != last->ptid
+ || last->state == THREAD_EXITED);
+
+ gdb_assert (ptid != last->ptid
+ || last->state == THREAD_EXITED);
+
last->next = tp;
}
struct thread_info *
add_thread_silent (process_stratum_target *targ, ptid_t ptid)
{
- inferior *inf;
-
- thread_info *tp = find_thread_ptid (targ, ptid);
- if (tp)
- /* Found an old thread with the same id. It has to be dead,
- otherwise we wouldn't be adding a new thread with the same id.
- The OS is reusing this id --- delete it, and recreate a new
- one. */
- {
- /* In addition to deleting the thread, if this is the current
- thread, then we need to take care that delete_thread doesn't
- really delete the thread if it is inferior_ptid. Create a
- new template thread in the list with an invalid ptid, switch
- to it, delete the original thread, reset the new thread's
- ptid, and switch to it. */
-
- if (inferior_ptid == ptid)
- {
- thread_info *new_thr = new_thread (tp->inf, null_ptid);
-
- /* Make switch_to_thread not read from the thread. */
- new_thr->state = THREAD_EXITED;
- switch_to_no_thread ();
-
- /* Now we can delete it. */
- delete_thread (tp);
-
- /* Now reset its ptid, and reswitch inferior_ptid to it. */
- new_thr->ptid = ptid;
- new_thr->state = THREAD_STOPPED;
- switch_to_thread (new_thr);
-
- gdb::observers::new_thread.notify (new_thr);
+ gdb_assert (targ != nullptr);
- /* All done. */
- return new_thr;
- }
+ inferior *inf = find_inferior_ptid (targ, ptid);
- inf = tp->inf;
-
- /* Just go ahead and delete it. */
- delete_thread (tp);
- }
- else
- inf = find_inferior_ptid (targ, ptid);
+ /* We may have an old thread with the same id in the thread list.
+ If we do, it must be dead, otherwise we wouldn't be adding a new
+ thread with the same id. The OS is reusing this id --- delete
+ the old thread, and create a new one. */
+ thread_info *tp = find_thread_ptid (inf, ptid);
+ if (tp != nullptr)
+ delete_thread (tp);
tp = new_thread (inf, ptid);
gdb::observers::new_thread.notify (tp);
xfree (this->name);
}
-/* Returns true if THR is the current thread. */
-
-static bool
-is_current_thread (const thread_info *thr)
-{
- return thr->inf == current_inferior () && thr->ptid == inferior_ptid;
-}
-
/* See gdbthread.h. */
bool
}
}
-/* Remove TP from step-over chain LIST_P. */
+/* See gdbthread.h. */
-static void
-step_over_chain_remove (struct thread_info **list_p, struct thread_info *tp)
+void
+thread_step_over_chain_remove (thread_info **list_p, thread_info *tp)
{
gdb_assert (tp->step_over_next != NULL);
gdb_assert (tp->step_over_prev != NULL);
/* See gdbthread.h. */
-struct thread_info *
-thread_step_over_chain_next (struct thread_info *tp)
+thread_info *
+thread_step_over_chain_next (thread_info *chain_head, thread_info *tp)
{
- struct thread_info *next = tp->step_over_next;
+ thread_info *next = tp->step_over_next;
+
+ return next == chain_head ? NULL : next;
+}
+
+/* See gdbthread.h. */
- return (next == step_over_queue_head ? NULL : next);
+struct thread_info *
+global_thread_step_over_chain_next (struct thread_info *tp)
+{
+ return thread_step_over_chain_next (global_thread_step_over_chain_head, tp);
}
/* See gdbthread.h. */
/* See gdbthread.h. */
+int
+thread_step_over_chain_length (thread_info *tp)
+{
+ if (tp == nullptr)
+ return 0;
+
+ gdb_assert (thread_is_in_step_over_chain (tp));
+
+ int num = 1;
+
+ for (thread_info *iter = tp->step_over_next;
+ iter != tp;
+ iter = iter->step_over_next)
+ ++num;
+
+ return num;
+}
+
+/* See gdbthread.h. */
+
+void
+global_thread_step_over_chain_enqueue (struct thread_info *tp)
+{
+ infrun_debug_printf ("enqueueing thread %s in global step over chain",
+ target_pid_to_str (tp->ptid).c_str ());
+
+ step_over_chain_enqueue (&global_thread_step_over_chain_head, tp);
+}
+
+/* See gdbthread.h. */
+
void
-thread_step_over_chain_enqueue (struct thread_info *tp)
+global_thread_step_over_chain_enqueue_chain (thread_info *chain_head)
{
- step_over_chain_enqueue (&step_over_queue_head, tp);
+ gdb_assert (chain_head->step_over_next != nullptr);
+ gdb_assert (chain_head->step_over_prev != nullptr);
+
+ if (global_thread_step_over_chain_head == nullptr)
+ global_thread_step_over_chain_head = chain_head;
+ else
+ {
+ thread_info *global_last = global_thread_step_over_chain_head->step_over_prev;
+ thread_info *chain_last = chain_head->step_over_prev;
+
+ chain_last->step_over_next = global_thread_step_over_chain_head;
+ global_last->step_over_next = chain_head;
+ global_thread_step_over_chain_head->step_over_prev = chain_last;
+ chain_head->step_over_prev = global_last;
+ }
}
/* See gdbthread.h. */
void
-thread_step_over_chain_remove (struct thread_info *tp)
+global_thread_step_over_chain_remove (struct thread_info *tp)
{
- step_over_chain_remove (&step_over_queue_head, tp);
+ infrun_debug_printf ("removing thread %s from global step over chain",
+ target_pid_to_str (tp->ptid).c_str ());
+
+ thread_step_over_chain_remove (&global_thread_step_over_chain_head, tp);
}
/* Delete the thread referenced by THR. If SILENT, don't notify
delete tp;
}
-/* Delete thread THREAD and notify of thread exit. If this is the
- current thread, don't actually delete it, but tag it as exited and
- do the notification. If this is the user selected thread, clear
- it. */
+/* See gdbthread.h. */
void
delete_thread (thread_info *thread)
struct thread_info *
find_thread_ptid (inferior *inf, ptid_t ptid)
{
- for (thread_info *tp : inf->threads ())
+ gdb_assert (inf != nullptr);
+
+ for (thread_info *tp : inf->non_exited_threads ())
if (tp->ptid == ptid)
return tp;
tp = find_thread_ptid (inf, old_ptid);
tp->ptid = new_ptid;
- gdb::observers::thread_ptid_changed.notify (old_ptid, new_ptid);
+ gdb::observers::thread_ptid_changed.notify (targ, old_ptid, new_ptid);
}
/* See gdbthread.h. */
the step-over queue, so that we don't try to resume
it until the user wants it to. */
if (tp->step_over_next != NULL)
- thread_step_over_chain_remove (tp);
+ global_thread_step_over_chain_remove (tp);
}
return started;
set_current_program_space (inf->pspace);
set_current_inferior (inf);
- inferior_ptid = thread->ptid;
+ current_thread_ = thread;
+ inferior_ptid = current_thread_->ptid;
}
/* See gdbthread.h. */
void
switch_to_no_thread ()
{
- if (inferior_ptid == null_ptid)
+ if (current_thread_ == nullptr)
return;
+ current_thread_ = nullptr;
inferior_ptid = null_ptid;
reinit_frame_cache ();
}
switch_to_thread (thr);
}
-static void
-restore_selected_frame (struct frame_id a_frame_id, int frame_level)
-{
- struct frame_info *frame = NULL;
- int count;
-
- /* This means there was no selected frame. */
- if (frame_level == -1)
- {
- select_frame (NULL);
- return;
- }
-
- gdb_assert (frame_level >= 0);
-
- /* Restore by level first, check if the frame id is the same as
- expected. If that fails, try restoring by frame id. If that
- fails, nothing to do, just warn the user. */
-
- count = frame_level;
- frame = find_relative_frame (get_current_frame (), &count);
- if (count == 0
- && frame != NULL
- /* The frame ids must match - either both valid or both outer_frame_id.
- The latter case is not failsafe, but since it's highly unlikely
- the search by level finds the wrong frame, it's 99.9(9)% of
- the time (for all practical purposes) safe. */
- && frame_id_eq (get_frame_id (frame), a_frame_id))
- {
- /* Cool, all is fine. */
- select_frame (frame);
- return;
- }
-
- frame = frame_find_by_id (a_frame_id);
- if (frame != NULL)
- {
- /* Cool, refound it. */
- select_frame (frame);
- return;
- }
-
- /* Nothing else to do, the frame layout really changed. Select the
- innermost stack frame. */
- select_frame (get_current_frame ());
-
- /* Warn the user. */
- if (frame_level > 0 && !current_uiout->is_mi_like_p ())
- {
- warning (_("Couldn't restore frame #%d in "
- "current thread. Bottom (innermost) frame selected:"),
- frame_level);
- /* For MI, we should probably have a notification about
- current frame change. But this error is not very
- likely, so don't bother for now. */
- print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC, 1);
- }
-}
+/* See frame.h. */
void
scoped_restore_current_thread::restore ()
in the mean time exited (or killed, detached, etc.), then don't revert
back to it, but instead simply drop back to no thread selected. */
&& m_inf->pid != 0)
- switch_to_thread (m_thread);
+ switch_to_thread (m_thread.get ());
else
- switch_to_inferior_no_thread (m_inf);
+ switch_to_inferior_no_thread (m_inf.get ());
/* The running state of the originally selected thread may have
changed, so we have to recheck it here. */
if (inferior_ptid != null_ptid
&& m_was_stopped
&& m_thread->state == THREAD_STOPPED
- && target_has_registers
- && target_has_stack
- && target_has_memory)
+ && target_has_registers ()
+ && target_has_stack ()
+ && target_has_memory ())
restore_selected_frame (m_selected_frame_id, m_selected_frame_level);
+
+ set_language (m_lang);
}
scoped_restore_current_thread::~scoped_restore_current_thread ()
{
if (!m_dont_restore)
- {
- try
- {
- restore ();
- }
- catch (const gdb_exception &ex)
- {
- /* We're in a dtor, there's really nothing else we can do
- but swallow the exception. */
- }
- }
-
- if (m_thread != NULL)
- m_thread->decref ();
- m_inf->decref ();
+ restore ();
}
scoped_restore_current_thread::scoped_restore_current_thread ()
{
- m_thread = NULL;
- m_inf = current_inferior ();
+ m_inf = inferior_ref::new_reference (current_inferior ());
+
+ m_lang = current_language->la_language;
if (inferior_ptid != null_ptid)
{
- thread_info *tp = inferior_thread ();
- struct frame_info *frame;
+ m_thread = thread_info_ref::new_reference (inferior_thread ());
- m_was_stopped = tp->state == THREAD_STOPPED;
- if (m_was_stopped
- && target_has_registers
- && target_has_stack
- && target_has_memory)
- {
- /* When processing internal events, there might not be a
- selected frame. If we naively call get_selected_frame
- here, then we can end up reading debuginfo for the
- current frame, but we don't generally need the debuginfo
- at this point. */
- frame = get_selected_frame_if_set ();
- }
- else
- frame = NULL;
-
- m_selected_frame_id = get_frame_id (frame);
- m_selected_frame_level = frame_relative_level (frame);
-
- tp->incref ();
- m_thread = tp;
+ m_was_stopped = m_thread->state == THREAD_STOPPED;
+ save_selected_frame (&m_selected_frame_id, &m_selected_frame_level);
}
-
- m_inf->incref ();
}
/* See gdbthread.h. */
ascending order. */
static bool
-tp_array_compar_ascending (const thread_info *a, const thread_info *b)
+tp_array_compar_ascending (const thread_info_ref &a, const thread_info_ref &b)
{
if (a->inf->num != b->inf->num)
return a->inf->num < b->inf->num;
descending order. */
static bool
-tp_array_compar_descending (const thread_info *a, const thread_info *b)
+tp_array_compar_descending (const thread_info_ref &a, const thread_info_ref &b)
{
if (a->inf->num != b->inf->num)
return a->inf->num > b->inf->num;
return (a->per_inf_num > b->per_inf_num);
}
-/* Switch to thread THR and execute CMD.
+/* Assuming that THR is the current thread, execute CMD.
FLAGS.QUIET controls the printing of the thread information.
- FLAGS.CONT and FLAGS.SILENT control how to handle errors. */
+ FLAGS.CONT and FLAGS.SILENT control how to handle errors. Can throw an
+ exception if !FLAGS.SILENT and !FLAGS.CONT and CMD fails. */
static void
thr_try_catch_cmd (thread_info *thr, const char *cmd, int from_tty,
const qcs_flags &flags)
{
- switch_to_thread (thr);
+ gdb_assert (is_current_thread (thr));
/* The thread header is computed before running the command since
the command can change the inferior, which is not permitted
thread, in case the command is one that wipes threads. E.g.,
detach, kill, disconnect, etc., or even normally continuing
over an inferior or thread exit. */
- std::vector<thread_info *> thr_list_cpy;
+ std::vector<thread_info_ref> thr_list_cpy;
thr_list_cpy.reserve (tc);
for (thread_info *tp : all_non_exited_threads ())
- thr_list_cpy.push_back (tp);
+ thr_list_cpy.push_back (thread_info_ref::new_reference (tp));
gdb_assert (thr_list_cpy.size () == tc);
- /* Increment the refcounts, and restore them back on scope
- exit. */
- scoped_inc_dec_ref inc_dec_ref (thr_list_cpy);
-
auto *sorter = (ascending
? tp_array_compar_ascending
: tp_array_compar_descending);
scoped_restore_current_thread restore_thread;
- for (thread_info *thr : thr_list_cpy)
- if (switch_to_thread_if_alive (thr))
- thr_try_catch_cmd (thr, cmd, from_tty, flags);
+ for (thread_info_ref &thr : thr_list_cpy)
+ if (switch_to_thread_if_alive (thr.get ()))
+ thr_try_catch_cmd (thr.get (), cmd, from_tty, flags);
}
}
if (inferior_ptid == null_ptid)
error (_("No thread selected"));
- if (target_has_stack)
+ if (target_has_stack ())
{
struct thread_info *tp = inferior_thread ();
if (tmp != 0)
error (_("Invalid regexp (%s): %s"), tmp, arg);
+ /* We're going to be switching threads. */
+ scoped_restore_current_thread restore_thread;
+
update_thread_list ();
+
for (thread_info *tp : all_threads ())
{
+ switch_to_inferior_no_thread (tp->inf);
+
if (tp->name != NULL && re_exec (tp->name))
{
printf_filtered (_("Thread %s has name '%s'\n"),
/* Since the current thread may have changed, see if there is any
exited thread we can now delete. */
- prune_threads ();
+ delete_exited_threads ();
}
/* Print thread and frame switch command response. */
= gdb::option::build_help (_("\
Display currently known threads.\n\
Usage: info threads [OPTION]... [ID]...\n\
+If ID is given, it is a space-separated list of IDs of threads to display.\n\
+Otherwise, all threads are displayed.\n\
\n\
Options:\n\
-%OPTIONS%\
-If ID is given, it is a space-separated list of IDs of threads to display.\n\
-Otherwise, all threads are displayed."),
+%OPTIONS%"),
info_threads_opts);
c = add_info ("threads", info_threads_command, info_threads_help.c_str ());