Re: [PATCH v6 2/2] tr2: log parent process name

From: Jeff Hostetler <git@jeffhostetler.com>
Date: Aug 2, 2021, 15:23 UTC
Message-ID: <48a62d5e-28e2-7103-a5bb-5db7e197a4b9@jeffhostetler.com>
In-Reply-To: <87o8agp29o.fsf@evledraar.gmail.com>

On 8/2/21 6:22 AM, Ævar Arnfjörð Bjarmason wrote: ...

Show 5 quoted lines

> 
> If anything the existing Windows version seems a bit unweildy, having to
> apparently deal with cycles etc., I don't think that happens under
> procfs, but maybe I'm missing some special-case.
>

It's been a while since I did the parent lookup on Windows, but...

Yes, on Windows we observed cases where a PID would be recycled and a child process could have the same PID as an ancient ancestor that had long since exited.

I don't think the cycle problem exists on Unix because IIRC a child process' parent-PID is set to Init when the parent exits.

Windows does not update the child's parent-PID when the parent exits, so if a recently-used PID is given to one of our child processes, we can get a loop.

Jeff