Re: [PATCH] pthread_kill.3: Update to match POSIX.

[enh <enh@google.com>]

any comment from either of the maintainers?

i think what we currently have on this page is factually incorrect,
and this patch better matches reality.

On Tue, Nov 12, 2019 at 10:10 PM Florian Weimer <fw@deneb.enyo.de> wrote:
>
> * enh:
>
> > On Tue, Nov 12, 2019 at 9:51 PM Florian Weimer <fw@deneb.enyo.de> wrote:
> >>
> >> * enh:
> >>
> >> > no, because the C library has two choices when a thread exits:
> >> >
> >> > 1. unmap the thread.
> >> >
> >> > 2. keep the thread around for recycling.
> >> >
> >> > if you choose 1 (optimizing for space, like Android), your dereference
> >> > is illegal.
> >>
> >> This choice is only available for threads in a detached state.  For
> >> joinable threads, a conforming implementation cannot immediately
> >> deallocate all data structures on thread termination.  Among other
> >> things, it has to store the future return value of pthread_join
> >> somewhere.
> >
> > ah, you're trying to say "signal 0 is potentially usable for a
> > joinable thread that's waiting to be joined"? that's true, but i'm not
> > sure how that's relevant to this patch. that wouldn't be an "invalid
> > thread ID" until it's joined.
>
> Correct.  That's POSIX's argument why ESRCH wouldn't be valid to
> return here.  It's still a forceful loss of information, and
> particularly annoying since POSIX doesn't specify pthread_tryjoin.
>
> But I'm glad we've brought our discussion to a conclusion. 8-)