Re: [PATCH v2 0/7] CLONE_FD: Task exit notification via file descriptor

[Florian Weimer <fweimer-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

On 05/29/2015 10:27 PM, Thiago Macieira wrote:

>> It has been suggested (e.g.,
>> <https://sourceware.org/bugzilla/show_bug.cgi?id=15661#c3>) that you can
>> use the existing clone(2) without specifying SIGCHLD to create a new
>> process.  The resulting child process is not supposed to show up in
>> wait(2), only in a waitpid(2) (or similar) explicitly specifying the
>> PID.  Is this not the case?
> 
> Hi Florian
> 
> That sounds orthogonal to what we're looking for. Our objective is to get 
> notification of when the child exited without resorting to SIGCHLD. If we use 
> the regular clone(2) without SIGCHLD and without CLONE_FD, we get no 
> notification. The only way to know of the child's termination is by a blocking 
> waitpid(2), like you indicated, which is counter productive to our needs.
> 
> We need something we can select(2)/poll(2) on.

Thanks for the clarification.  I agree that this is a separate and quite
sensible use case.

-- 
Florian Weimer / Red Hat Product Security