On Thu, Aug 06, 2020 at 12:29:36AM +0300, Peter Pentchev wrote:
> On Wed, Aug 05, 2020 at 10:52:31PM +0200, Michał Mirosław wrote:
[...]
> > Using print-debugging, I see that it stops at wait_for_child line just
> > after printing the version. It seems that something is reaping the child
> > before the main thread has a chance to wait for it.
>
> OK, so the only thing that comes to my mind now is that you may be
> hitting a crazy, crazy race between register_child() and child_reaper(),
> and I say "a crazy, crazy race", because the test has to (apparently
> reproducibly) receive the CHLD signal exactly between the check and
> the creation in register_child()'s first "$children{...} //= ...cv"
> statement.
Well, there is nothing that prevents SIGCHLD arriving between fork() and
register_child(). You could test this with more confidence (though not
100%-reliably) by putting 'exit 1' just at the start of ($pid == 0) branch.
> Can you apply the following patch and show me the output of running
> the test?
Sure, but I got no patch. :-)
Best Regards,
Michał Mirosław
