Re: What's cooking in git.git (Jul 2025, #02; Mon, 7)

> On Mon, Jul 07, 2025 at 05:11:12PM -0800, Junio C Hamano wrote:
>>
>> * cb/daemon-reap-children (2025-06-26) 4 commits
>>   - daemon: explicitly allow EINTR during poll()
>>   - daemon: use sigaction() to install child_handler()
>>   - compat/mingw: allow sigaction(SIGCHLD)
>>   - compat/posix.h: track SA_RESTART fallback
>>
>>   Futz with SIGCHLD handling in "git daemon".
>>
>>   Stalled?
>>   cf. <dba9ae0d-1e43-4345-a7ec-b57a07d45a07@gmail.com>
>>   source: <pull.2002.v3.git.git.1750927988.gitgitgadget@gmail.com>
> 
> I don't think so, but definitely missing reviews (specially for patch 2)
> and slightly controversial.
> 
> I wasn't planning any further changes,

> and while I have some for the
> "related" patchset which enhances the notifications by using a self pipe
> was holding them (as well as the related feedback) to allow for this to
> mature on its own.
> 
> On the rationale on why this is independently useful, note that we are
> currently relying in at least 2 "unspecified" behaviours:
> 
> 1) using signal() means that it is implementation defined if SA_RESTART
> will be enabled or not for that signal, and
> 2) if SA_RESTART is enabled, it is implementation defined if we might get
> interrupted in poll().
> 
> both are resolved by using sigaction() instead, and it is up to us to
> decide if SA_RESTART is enabled or not (which might make patch 4 obsolete
> if we decide against).
> 
> Carlo
> 
> CC: Johannes Sixt on feedback for SIGCHLD in mingw which uses 17 instead
>      of 22 (cygwin and others) and therefore seem to cause signal to err
>      without setting errno as it should.
>