Re: [PATCH] Cygwin: Implement 'reserved' marker in fdtable entries

On 08/06/2026 13:10, Christian Franke wrote:
> On Sat, 30 May 2026 12:33, Jon Turney wrote:
>> On 22/05/2026 15:21, Christian Franke wrote:
>>> Jon Turney wrote:
>>>> On 22/05/2026 08:28, Mark Geisert wrote:
>>>>> ...
>>>>>
>>>>> The notion is that an fdtable entry provided by cygheap_fdnew is 
>>>>> marked
>>>>> so that another thread can't obtain it.  Care is taken to reset the
>>>>> marker when the entry is no longer needed.  Actually, in the usual 
>>>>> case
>>>>> the marker is overwritten with a pointer to an fhandler_base 
>>>>> structure,
>>>>> by the reserving thread, as the syscall completes.
>>>>>
>>>>> Reported-by: Christian Franke <[email protected]>
>>>>> Addresses: https://cygwin.com/pipermail/cygwin/2026-May/259664.html
>>>>> Signed-off-by: Mark Geisert <[email protected]>
>>>>> Fixes: e859706578ba (* autoload.cc (NtCreateFile): Add.)
>>>>
>>>> Thanks!
>>>>
>>>> This all seems fine and reasonable, but I have a couple of small 
>>>> comments.
>>>
>>> A test with an enhanced version of the STC was successful.
>>> I could push this version (attached) to cygwin-apps/stc if desired.
>>
>> Yes, that would be great. Please do so.
> 
> Done.
> 
> 
>>
>> (I guess ideally after the fix is committed so it stays green, but 
>> it's red at the moment and I severely lack the time to investigate 
>> why...)
> 
> Some STC (e.g. trace-sigsegv) ocasionally fail when run as part of the 
> Cygwin CI workflow. Timing issues?
> 
> Could not reproduce this neither locally nor at GH.

That one seems to sporadically fail, but only on aarch64 runner.

> I would suggest to add this to stc.yml to allow manual tests independent 
> from push:
> https://github.com/chrfranke/cygwin-stc/commit/5c157ff6

Yes, that seems like a good idea.

Oh lol, it seems like I meant to have this run the x86_64 tests on an 
aarch64 runner as well as an x86_64 runner, but got distracted halfway 
through...

I've tweaked your change slightly so we just run on both always.

Thanks very much!