At 12:16 PM 2/23/00 -0500, Jordan Henderson wrote:
> > From: Dan Sugalski [mailto:[EMAIL PROTECTED]]
> > At 10:39 AM 2/23/00 -0600, Craig A. Berry wrote:
> > >At 10:56 AM 2/23/00 -0500, Jordan Henderson wrote:
> > > >It appears that the pipe is being opened as a RW mbx (new
> > to some recent
> > > version
> > > >of OpenVMS), so the perl has READ channels and WRITE
> > channels on the mbx. I
> > > >could be wrong about this, but I have reason to believe it
> > (I did an
> > > ANAL/SYS
> > > >"SHO PROC/CHAN" on a perl that was hung and saw several channels
> > > assigned to the
> > > >mailbox that it was trying to write the EOF to). I don't
> > see why this
> > > should be
> > > >necessary. It seems to me that a given pipe mbx should be
> > either READ
> > > or WRITE,
> > > >but not both.
> > >
> > >I'm not sure I understand how you could have 2-way
> > communication if the
> > >mailbox is not RW. I don't know if vmsperl uses the pipe()
> > function from
> > >the C RTL or cooks its own, but there is a description of
> > how the parent
> > >and child communicate through a mailbox in the RTL version at:
> >
> > We cook our own for `` and magic open. Communication with the
> > child process
> > is a one-way thing, though if I ever get a chance to implement
> > open(FOO,"|bar|") it won't...
>
>Communication is one-way, but I believe you'll find that we
>have r/w channels open to the mailboxes in every case. I would
>implement open(FOO,"|bar|") as two mailboxes, one in, one out.
>If you didn't do this, how could you possibly coordinate the
>reading/writing with bar?
And that's what I'm planning. (Three mailboxes actually, if I can manage
the magic--that way open3 will work) This is going to be some sort of
mutant thingie that mixes code for magic open, ``, open2 and open3. (What
the heck, it's already there for magic open, so open3's not much of a big deal)
Dan
--------------------------------------"it's like this"-------------------
Dan Sugalski even samurai
[EMAIL PROTECTED] have teddy bears and even
teddy bears get drunk
