From: Yao Qi <yao@codesourcery.com>
To: Pedro Alves <palves@redhat.com>
Cc: <gdb-patches@sourceware.org>
Subject: Re: [PATCH 1/8] gdb.threads/{siginfo-thread.c,watchthreads-reorder.c,ia64-sigill.c} races with GDB
Date: Tue, 06 Jan 2015 06:20:00 -0000 [thread overview]
Message-ID: <87egr8v39h.fsf@codesourcery.com> (raw)
In-Reply-To: <1419625871-28848-2-git-send-email-palves@redhat.com> (Pedro Alves's message of "Fri, 26 Dec 2014 20:31:04 +0000")
Pedro Alves <palves@redhat.com> writes:
> The issue is that the test program stops GDB before it had a chance of
> processing the new thread's clone event:
>
> (gdb) PASS: gdb.threads/siginfo-threads.exp: get pid
> continue
> Continuing.
> Stopping GDB PID 21541.
> Waiting till the threads initialize their TIDs.
> FAIL: gdb.threads/siginfo-threads.exp: catch signal 0 (timeout)
>
> On Linux (at least), new threads start stopped, and the debugger must
> resume them. The fix is to make the test program wait for the new
> threads to be running before stopping GDB.
Looks there is a deadlock. main thread sends SIGSTOP to gdb and calls
pthread_cond_wait to wait for being notified by child thread. Child
thread is stopped (should be resumed by gdb) and can't notify main
thread. The patch looks right to me.
--
Yao (齐尧)
next prev parent reply other threads:[~2015-01-06 6:20 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-26 20:31 [PATCH 0/8] Linux: starvation avoidance in non-stop mode Pedro Alves
2014-12-26 20:31 ` [PATCH 3/8] cleanup and speed up (software_)breakpoint_inserted_here_p Pedro Alves
2014-12-26 20:31 ` [PATCH 1/8] gdb.threads/{siginfo-thread.c,watchthreads-reorder.c,ia64-sigill.c} races with GDB Pedro Alves
2015-01-06 6:20 ` Yao Qi [this message]
2014-12-26 20:31 ` [PATCH 2/8] watch_thread_num.exp and targets with fairer event reporting Pedro Alves
2014-12-26 20:32 ` [PATCH 6/8] linux-nat.c: better starvation avoidance, handle non-stop mode too Pedro Alves
2015-01-07 7:06 ` Yao Qi
2015-01-07 13:22 ` Pedro Alves
2015-01-07 14:08 ` Yao Qi
2015-01-07 14:36 ` Pedro Alves
2014-12-26 20:32 ` [PATCH 8/8] add non-stop test that stresses thread starvation issues Pedro Alves
2015-04-02 14:53 ` Yao Qi
2015-04-06 11:26 ` Pedro Alves
2015-04-07 10:10 ` Yao Qi
2015-04-07 10:22 ` Pedro Alves
2015-04-07 10:31 ` Yao Qi
2014-12-26 20:32 ` [PATCH 5/8] linux-nat.c: always mark execing LWP as resumed Pedro Alves
2014-12-26 20:32 ` [PATCH 4/8] linux-nat.c: clean up pending status checking and resuming LWPs Pedro Alves
2015-01-06 8:12 ` Yao Qi
2015-01-07 13:22 ` Pedro Alves
2015-01-07 14:10 ` Yao Qi
2014-12-26 20:32 ` [PATCH 7/8] [gdbserver] linux-low.c: better starvation avoidance, handle non-stop mode too Pedro Alves
2015-01-09 15:07 ` [PATCH 0/8] Linux: starvation avoidance in non-stop mode Pedro Alves
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