PR threads/18127 - threads spawned by infcall end up stuck in "running" state
Refs:
https://sourceware.org/ml/gdb/2015-03/msg00024.html
https://sourceware.org/ml/gdb/2015-06/msg00005.html
On GNU/Linux, if an infcall spawns a thread, that thread ends up with
stuck running state. This happens because:
- when linux-nat.c detects a new thread, it marks them as running,
and does not report anything to the core.
- we skip finish_thread_state when the thread that is running the
infcall stops.
As result, that new thread ends up with stuck "running" state, even
though it really is stopped.
On Windows, _all_ threads end up stuck in running state, not just the
one that was spawned. That happens because when a new thread is
detected, unlike linux-nat.c, windows-nat.c reports
TARGET_WAITKIND_SPURIOUS to infrun. It's the fact that that event
does not cause a user-visible stop that triggers the problem. When
the target is re-resumed, we call set_running with a wildcard ptid,
which marks all thread as running. That set_running is not suppressed
because the (leader) thread being resumed does not have in_infcall
set. Later, when the infcall finally finishes successfully, nothing
marks all threads back to stopped.
We can trigger the same problem on all targets by having a thread
other than the one that is running the infcall report a breakpoint hit
to infrun, and then have that breakpoint not cause a stop. That's
what the included test does.
The fix is to stop GDB from suppressing the set_running calls while
doing an infcall, and then set the threads back to stopped when the
call finishes, iff they were originally stopped before the infcall
started. (Note the MI *running/*stopped event suppression isn't
affected.)
Tested on x86_64 GNU/Linux.
gdb/ChangeLog:
2015-06-29 Pedro Alves <palves@redhat.com>
PR threads/18127
* infcall.c (run_inferior_call): On infcall success, if the thread
was marked stopped before, reset it back to stopped.
* infrun.c (resume): Don't suppress the set_running calls when
doing an infcall.
(normal_stop): Only discard the finish_thread_state cleanup if the
infcall succeeded.
gdb/testsuite/ChangeLog:
2015-06-29 Pedro Alves <palves@redhat.com>
PR threads/18127
* gdb.threads/hand-call-new-thread.c: New file.
* gdb.threads/hand-call-new-thread.c: New file.
2015-06-29 15:07:57 +00:00
|
|
|
/* This testcase is part of GDB, the GNU debugger.
|
|
|
|
|
2016-01-01 04:33:14 +00:00
|
|
|
Copyright 2015-2016 Free Software Foundation, Inc.
|
PR threads/18127 - threads spawned by infcall end up stuck in "running" state
Refs:
https://sourceware.org/ml/gdb/2015-03/msg00024.html
https://sourceware.org/ml/gdb/2015-06/msg00005.html
On GNU/Linux, if an infcall spawns a thread, that thread ends up with
stuck running state. This happens because:
- when linux-nat.c detects a new thread, it marks them as running,
and does not report anything to the core.
- we skip finish_thread_state when the thread that is running the
infcall stops.
As result, that new thread ends up with stuck "running" state, even
though it really is stopped.
On Windows, _all_ threads end up stuck in running state, not just the
one that was spawned. That happens because when a new thread is
detected, unlike linux-nat.c, windows-nat.c reports
TARGET_WAITKIND_SPURIOUS to infrun. It's the fact that that event
does not cause a user-visible stop that triggers the problem. When
the target is re-resumed, we call set_running with a wildcard ptid,
which marks all thread as running. That set_running is not suppressed
because the (leader) thread being resumed does not have in_infcall
set. Later, when the infcall finally finishes successfully, nothing
marks all threads back to stopped.
We can trigger the same problem on all targets by having a thread
other than the one that is running the infcall report a breakpoint hit
to infrun, and then have that breakpoint not cause a stop. That's
what the included test does.
The fix is to stop GDB from suppressing the set_running calls while
doing an infcall, and then set the threads back to stopped when the
call finishes, iff they were originally stopped before the infcall
started. (Note the MI *running/*stopped event suppression isn't
affected.)
Tested on x86_64 GNU/Linux.
gdb/ChangeLog:
2015-06-29 Pedro Alves <palves@redhat.com>
PR threads/18127
* infcall.c (run_inferior_call): On infcall success, if the thread
was marked stopped before, reset it back to stopped.
* infrun.c (resume): Don't suppress the set_running calls when
doing an infcall.
(normal_stop): Only discard the finish_thread_state cleanup if the
infcall succeeded.
gdb/testsuite/ChangeLog:
2015-06-29 Pedro Alves <palves@redhat.com>
PR threads/18127
* gdb.threads/hand-call-new-thread.c: New file.
* gdb.threads/hand-call-new-thread.c: New file.
2015-06-29 15:07:57 +00:00
|
|
|
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
|
|
it under the terms of the GNU General Public License as published by
|
|
|
|
the Free Software Foundation; either version 3 of the License, or
|
|
|
|
(at your option) any later version.
|
|
|
|
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
|
|
GNU General Public License for more details.
|
|
|
|
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>. */
|
|
|
|
|
|
|
|
#include <unistd.h>
|
|
|
|
#include <stdlib.h>
|
|
|
|
#include <pthread.h>
|
|
|
|
#include <assert.h>
|
|
|
|
|
|
|
|
static int
|
|
|
|
foo (void)
|
|
|
|
{
|
|
|
|
usleep (1);
|
|
|
|
}
|
|
|
|
|
|
|
|
static void *
|
|
|
|
thread_function (void *arg)
|
|
|
|
{
|
|
|
|
while (1)
|
|
|
|
foo ();
|
|
|
|
}
|
|
|
|
|
|
|
|
void
|
|
|
|
new_thread (void)
|
|
|
|
{
|
|
|
|
pthread_t thread;
|
|
|
|
int res;
|
|
|
|
|
|
|
|
res = pthread_create (&thread, NULL, thread_function, NULL);
|
|
|
|
assert (res == 0);
|
|
|
|
}
|
|
|
|
|
|
|
|
int
|
|
|
|
main (int argc, char **argv)
|
|
|
|
{
|
|
|
|
return 0;
|
|
|
|
}
|