Upgrading Perl... Somebody just shoot me and put me out of my misery!

[Ronald F. Guilmette]

In message <CAEAhP2iW+HD4Rnnzk0RVD6iMnr+bAdeVAtGf0FQWbLpikMPz6g at mail.gmail.com>
Anton Afanasyev <aasoft at gmail.com> wrote:

>On Sat, Nov 23, 2013 at 12:17 PM, Ronald F. Guilmette <rfg at tristatelogic.com
>> wrote:
>
>>
>> OK, but please help me understand here.  What is it, exactly, that is _now_
>> being threaded, that wasn't threaded before?
>> ...
>> (Part of what is confusing about this is that I was under the impression...
>> perhaps naive... that Perl was already set up for threads support quite
>> some
>> long time ago.)
>>
>Perl _was_ set up to be threaded (although I have no idea what is actually
>threaded there), but the port option to enable it being threaded was not
>enabled by default.

(One might well ask "why not?" but we will leave that question aside for
the moment.)

>The implication is that if you compiled it with default
>options, it wasn't threaded. But now it (the option) has been changed to be
>enabled by default, and so the point of that UPDATING entry was that if you
>are running with default options, then your Perl will switch from
>non-threaded to threaded when you recompile it,

OK, that part, at least is clear.

>and you will thus need to recompile all ports that depend on Perl.

This is the part that is still utterly baffling.

Why would _anything_ that is in any way dependent upon the Perl interpreter
need to be rebuilt?  In this switch to threads=on, has the language itself
changed?  And if not, shouldn't the change to multi-threading capability
within the interpreter be utterly transparent to (and a non-event for)
any and all pre-existing Perl code?

Obviously, there's something that I'm missing, but I have no idea what it
might be.

>IF you already had this option enabled to begin with, I believe you don't
>need to recompile and reinstall anything (including Perl itself, but do
>note that the ports system will then keep thinking that Perl hasn't been
>upgraded - which isn't an issue, since the only thing changed here is the
>defaults and not any functionality, and so you can just wait to recompile
>it when something more serious changes; this is up to you though).
>
>Hope this clears it up a bit.

Well, I thank you for your attempt to help clear up the confusion, but I
do confess that the need to rebuild... or the value of rebuilding... all
of the stuff that _depends_ on Perl is still rather entirely mystifying.

I'm *not* claiming that the maintainer didn't have a good reason for
suggesting these rebuilds.  I'm only saying that *I* personally still
don't have a good understanding of what the need for this is/was.


Regards,
rfg