[Bug libstdc++/97944] New: 30_threads/jthread/95989.cc fails randomly

[Bug libstdc++/97944] New: 30_threads/jthread/95989.cc fails randomly

[clyon at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97944

            Bug ID: 97944
           Summary: 30_threads/jthread/95989.cc fails randomly
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: clyon at gcc dot gnu.org
  Target Milestone: ---

Since this new test was introduced, it fails randomly on arm, aarch64 and other
targets (apparently powerpc, ia64, m68k according to gcc-testresults).

The logs say:
terminate called after throwing an instance of 'std::system_error'
  what():  Unknown error -8461584

[Bug libstdc++/97944] 30_threads/jthread/95989.cc fails randomly

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97944

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2020-11-23
     Ever confirmed|0                           |1
           Assignee|unassigned at gcc dot gnu.org      |redi at gcc dot gnu.org
             Status|UNCONFIRMED                 |ASSIGNED

[Bug libstdc++/97944] 30_threads/jthread/95989.cc fails randomly

[clyon at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97944

Christophe Lyon <clyon at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Version|11.0                        |10.2.1

--- Comment #1 from Christophe Lyon <clyon at gcc dot gnu.org> ---
This is also affects gcc-10

[Bug libstdc++/97944] 30_threads/jthread/95989.cc fails randomly

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97944

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
I can't reproduce this on aarch64-unknown-linux-gnu (Fedora 32) or
powerpc64le-unknown-linux-gnu (Centos 7.8.2003). I've never seen it fail :-(

Please provide the glibc and distro details for the systems where this fails
for you.

[Bug libstdc++/97944] 30_threads/jthread/95989.cc fails randomly

[clyon at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97944

--- Comment #3 from Christophe Lyon <clyon at gcc dot gnu.org> ---
My testing is with cross-compilers, binutils-2.34, glibc-2.29, host is RHEL7
x86_64.


Note that Toon reported a failure on x86_64:
https://gcc.gnu.org/pipermail/gcc-testresults/2020-November/630321.html

[Bug libstdc++/97944] 30_threads/jthread/95989.cc fails randomly

[seurer at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97944

seurer at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |seurer at gcc dot gnu.org

--- Comment #4 from seurer at gcc dot gnu.org ---
I see this natively on powerpcle for both power 8 and 9.  It started I think
with or near r11-5215.

There are some other ones that fail intermittently, too.
FAIL: 30_threads/latch/3.cc execution test
FAIL: 30_threads/semaphore/try_acquire_until.cc execution test
FAIL: 29_atomics/atomic_integral/wait_notify.cc execution test

Possibly more.

[Bug libstdc++/97944] 30_threads/jthread/95989.cc fails randomly

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97944

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to seurer from comment #4)
> I see this natively on powerpcle for both power 8 and 9.  It started I think
> with or near r11-5215.
> 
> There are some other ones that fail intermittently, too.
> FAIL: 30_threads/latch/3.cc execution test
> FAIL: 30_threads/semaphore/try_acquire_until.cc execution test
> FAIL: 29_atomics/atomic_integral/wait_notify.cc execution test
> 
> Possibly more.

That's PR 97936 which I assumed was unrelated. But maybe this bug is actually
caused by that change too.

The addition of <semaphore> and std::binary_semaphore does affect the code
tested by 30_threads/jthread/95989.cc

It would help if I could reproduce this on *any* of my test machines though.

[Bug libstdc++/97944] 30_threads/jthread/95989.cc fails randomly

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97944

--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jonathan Wakely <redi@gcc.gnu.org>:

https://gcc.gnu.org/g:a3313a2214a6253672ab4fa37a2dcf57fd0f8dce

commit r11-5326-ga3313a2214a6253672ab4fa37a2dcf57fd0f8dce
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Tue Nov 24 23:22:01 2020 +0000

    libstdc++: Disable failing tests [PR 97936]

    These tests are unstable and causing failures due to timeouts. Disable
    them until the cause can be found, so that testing doesn't have to wait
    for them to timeout.

    libstdc++-v3/ChangeLog:

            PR libstdc++/97936
            PR libstdc++/97944
            * testsuite/29_atomics/atomic_integral/wait_notify.cc: Disable.
            Do not require pthreads, but add -pthread when appropriate.
            * testsuite/30_threads/jthread/95989.cc: Likewise.
            * testsuite/30_threads/latch/3.cc: Likewise.
            * testsuite/30_threads/semaphore/try_acquire_until.cc: Likewise.

[Bug libstdc++/97944] 30_threads/jthread/95989.cc fails randomly

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97944

--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Christophe Lyon from comment #1)
> This is also affects gcc-10

Ah, but r11-5215 isn't on the gcc-10 branch, so I think this one must be a
separate issues from PR 97936.

[Bug libstdc++/97944] 30_threads/jthread/95989.cc fails randomly

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97944

--- Comment #8 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Christophe Lyon from comment #0)
> Since this new test was introduced, it fails randomly on arm, aarch64 and
> other targets (apparently powerpc, ia64, m68k according to gcc-testresults).

And hppa64-hp-hpux11.11
https://gcc.gnu.org/pipermail/gcc-testresults/2020-November/630265.html

I still haven't reproduced this, despite trying repeatedly on two different
aarch64-unknown-gnu-linux hosts (a weedy pine64 and a faster qemu vm) and
hundreds of times on powerpc64le and x86_64. Frustrating.

[Bug libstdc++/97944] 30_threads/jthread/95989.cc fails randomly

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97944

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |NEW
           Assignee|redi at gcc dot gnu.org            |unassigned at gcc dot gnu.org

[Bug libstdc++/97944] 30_threads/jthread/95989.cc fails randomly

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97944

--- Comment #9 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-10 branch has been updated by Jonathan Wakely
<redi@gcc.gnu.org>:

https://gcc.gnu.org/g:29b676bcf10b0a6c04e8acdf91f18b28bf5b1501

commit r10-10835-g29b676bcf10b0a6c04e8acdf91f18b28bf5b1501
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Tue Nov 24 23:22:01 2020 +0000

    libstdc++: Disable failing test [PR97944]

    Disable this test on the branch. It's already disabled for gcc-11 and
    later.

    libstdc++-v3/ChangeLog:

            PR libstdc++/97944
            * testsuite/30_threads/jthread/95989.cc: Mark XFAIL.