Hey Ludo,

> Woow, good catch!

Thanks :)

>> The work-around here is to save the installed SIGTERM handler and reset
>> it. Then, after forking, the parent can restore the SIGTERM handler. The
>> child will use the default SIGTERM handler that terminates the process.
>
> OK, makes sense.  (Another occasion to see how something like
> ‘posix_spawn’ would be more appropriate than fork + exec…)

Didn't know about that function, but it seems way easier to manipulate
and less error prone indeed!

> Shouldn’t it be:
>
>   (let ((pgid (getpgid pid)))
>     (if (= (getpgid 0) pgid)
>         (kill pid signal)  ;don't kill ourself
>         (kill (-p pgid) signal)))

Yes, I changed it.

> Note: Use the most specific comparison procedure, ‘=’ in this case,
> because we know we’re dealing with numbers (it enables proper type
> checking, better compiler optimizations, etc.).  More importantly, ‘eq?’
> performs pointer comparison, so it shouldn’t be used with numbers (in
> practice it works with “fixnums” but not with bignums).

Ok, noted!

>> +# Try to trigger eventual race conditions, when killing a process between fork
>> +# and execv calls.
>> +for i in {1..50}
>> +do
>> +    $herd restart test3
>> +done
>
> Would it reproduce the problem well enough?

On a slow machine one time out of two, and on a faster machine,
never. The 'reproducer' I used, was to add a 'sleep' between fork and
exec, it works way better!

Tell me if you think its better to drop it.

> Could you send an updated patch?

Here it is!

> Thanks for the bug hunting and for the patch!

Thanks for the fast review :)

Mathieu