RFR: JDK-8274320: os::fork_and_exec() should be using posix_spawn

[David Holmes]

Hi Thomas,

On 29/10/2021 8:47 pm, Thomas Stuefe wrote:
> On Fri, 29 Oct 2021 10:29:14 GMT, Martin Doerr <mdoerr at openjdk.org> wrote:
> 
>> Change looks technically good to me, but I can not judge if we can rely on async-signal-safety of posix_spawn. I guess we have to wait until glibc folks have discussed that.
> 
> Thank you Martin.
> 
> @dholmes-ora : do you have an idea how we could resolve this deadlock? Even with input from the glibc folks, a number of questions will remain unanswered (eg what about the other libcs).

I've withdrawn my objection to this patch (see response to Florian). 
Given the advantage of posix_spawn in terms of memory management, and 
the fact no solution is guaranteed async-signal-safe, you may as well 
give this a go.

Cheers,
David

> Still, I think my patch would improve the situation, which is murky UB now and will remain somewhat murky. But I also think this is not worth many more brain cycles from either one of us, so if you prefer I can withdraw this PR. I am fine either way.
> 
> Cheers, Thomas
> 
> -------------
> 
> PR: https://git.openjdk.java.net/jdk/pull/5698
>