https://issues.dlang.org/show_bug.cgi?id=13416

Brad Roberts <braddr@puremagic.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Hardware|x86_64                      |All
            Summary|frequent auto-tester hangs  |frequent auto-tester hangs
                   |in core.thread on freebsd   |in core.thread on freebsd
                   |64                          |32 and 64

--- Comment #1 from Brad Roberts <braddr@puremagic.com> ---
Same behavior and stacktraces on the new 8 core freebsd 32 bit box as well. Both are running freebsd 8.4, same as the other freebsd testers.

--

https://issues.dlang.org/show_bug.cgi?id=13416

--- Comment #2 from Sobirari Muhomori <dfj1esp02@sneakemail.com> ---
pthread_kill hangs? Shouldn't it be asynchronous?

--

https://issues.dlang.org/show_bug.cgi?id=13416

monarchdodra@gmail.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |monarchdodra@gmail.com
           Severity|critical                    |blocker

--- Comment #3 from monarchdodra@gmail.com ---
Upgraded to "BLOCKER", as this (relativelly frequently) trips up the
auto-testers.

--

https://issues.dlang.org/show_bug.cgi?id=13416

Martin Nowak <code@dawg.eu> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |code@dawg.eu

--- Comment #4 from Martin Nowak <code@dawg.eu> ---
That's a dead-lock in the pthread library.
Both pthread_attr_get_np and pthread_kill lock the same thread mutex.

_pthread_attr_get_np: https://github.com/freebsd/freebsd/blob/428b45aa532260e8c6ddf0217ec31db2234d29a8/lib/libthr/thread/thr_attr.c#L154 _pthread_kill: https://github.com/freebsd/freebsd/blob/428b45aa532260e8c6ddf0217ec31db2234d29a8/lib/libthr/thread/thr_kill.c#L64

_thr_find_thread: https://github.com/freebsd/freebsd/blob/428b45aa532260e8c6ddf0217ec31db2234d29a8/lib/libthr/thread/thr_list.c#L351

We should try to use pthread_suspend_np or pthread_suspend_all_np instead.
Without a signal handler we'd still need to obtain the stack top.
There seems to be a function on OpenBSD pthread_stackseg_np, not sure how to do
it on FreeBSD.

--

https://issues.dlang.org/show_bug.cgi?id=13416

Martin Nowak <code@dawg.eu> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|frequent auto-tester hangs  |dead-lock in FreeBSD
                   |in core.thread on freebsd   |suspend handler
                   |32 and 64                   |

--

https://issues.dlang.org/show_bug.cgi?id=13416

--- Comment #5 from Martin Nowak <code@dawg.eu> ---
Fairly simple to reproduce the problem.

cat > bug.d << CODE
import core.thread, core.sys.posix.pthread, core.stdc.stdio;

void loop()
{
  pthread_attr_t attr;
  pthread_attr_init(&attr);
  auto thr = pthread_self();
  while (true)
    pthread_attr_get_np(thr, &attr);
}

void main()
{
  auto thr = new Thread(&loop).start();
  while (true)
  {
      thread_suspendAll();
      thread_resumeAll();
      printf(".");
  }
}
CODE

dmd -run bug

--

https://issues.dlang.org/show_bug.cgi?id=13416

Martin Nowak <code@dawg.eu> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |pull

--- Comment #6 from Martin Nowak <code@dawg.eu> ---
Using pthread_suspend_np didn't work out, because there is no way to get the current stack top of a suspended thread. I also tried to override SIGCANCEL which is used for pthread_suspend_np but that didn't work.

https://github.com/D-Programming-Language/druntime/pull/1061

--

https://issues.dlang.org/show_bug.cgi?id=13416

--- Comment #7 from github-bugzilla@puremagic.com ---
Commits pushed to master at https://github.com/D-Programming-Language/druntime

https://github.com/D-Programming-Language/druntime/commit/ad8662d65fe8f24be2c64c721eabe4da7f78b31f fix Issue 13416 - dead-lock in FreeBSD suspend handler

- use pthread internal THR_IN_CRITICAL to retry suspend

https://github.com/D-Programming-Language/druntime/commit/513ba191f3e8b78aeb99336e27212dfdcacb39c5 Merge pull request #1061 from MartinNowak/fix13416

fix Issue 13416 - dead-lock in FreeBSD suspend handler

--

https://issues.dlang.org/show_bug.cgi?id=13416

github-bugzilla@puremagic.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED

--

https://issues.dlang.org/show_bug.cgi?id=13416

--- Comment #8 from github-bugzilla@puremagic.com ---
Commits pushed to 2.067 at https://github.com/D-Programming-Language/druntime

https://github.com/D-Programming-Language/druntime/commit/ad8662d65fe8f24be2c64c721eabe4da7f78b31f fix Issue 13416 - dead-lock in FreeBSD suspend handler

https://github.com/D-Programming-Language/druntime/commit/513ba191f3e8b78aeb99336e27212dfdcacb39c5 Merge pull request #1061 from MartinNowak/fix13416

--