At 12:56 PM 2/23/00 -0500, Jordan Henderson wrote:
> > From: Dan Sugalski [mailto:[EMAIL PROTECTED]]
> > At 12:14 PM 2/23/00 -0500, Jordan Henderson wrote:
> > >It seems that it would be easy to "fix" this, as the call in
> > >VMS.C, safe_popen(), has a mode argument for r/w. It seems that
> > >this would be "cleaner" in that it would cause an error if some
> > >maintainer of VMS.C incorrectly caused a read to a write pipe or
> > >vice-versa. It would also save channels, which is not an
> > >insignificant consideration as you can run out of channels
> > >system-wide (MAXCHANNELCNT).
> >
> > Huh? CHANNELCNT's a per-process setting, with MAXCHANNELCNT
> > being a cap.
> > The max number of channels on a system is
> > MAXPROCESSCNT*MAXCHANNELCNT.
> > (more or less--the spelling's probably wrong)
>
>Well, I was confused, it's not MAXCHANNELCNT, the SYSGEN
>parameter is CHANNELCNT and it's the number of _permanent_
>I/O channels available to the system.
>
>These mailboxes do not have permanent I/O channels assigned
>in any case.
Weird. I looked at the 7.2 docs and that's what they say, but i could've
*sworn* the 7.1 docs said it was per-process.
>Is there a per-process limit on channels? It's not an
>Authorize setting and I don't see a SYSGEN parameter.
Sure. Fillm does it.
> > >Making these changes may also help in work toward the infamous,
> > >ice-cream-prize-winning from Dan, open2 and open3 calls. I know
> > >if I were doing the implementing, I'd want the various mbxs to
> > >be read-only or write-only to keep me from confusing them during
> > >debugging.
> >
> > I think you're right, and it makes sense.
> >
>
>Well, it gets complicated. We currently create the
>subprocesses via LIB$SPAWN. This gives no control over
>how these files are opened, so we'd have to go with setting the
>mailbox mode on the $crembx call and not on the $assign call.
>It also gives no control over SYS$ERROR at all (it always gets
>assigned the same thing as SYS$OUTPUT). So, for open3, we'd have
>to change this to a SYS$CREPRC call.
Yeah, I was figuring we'd need to switch over to creprc for the open3
version. Provably ought to do it for all methods for consistency.
Dan
--------------------------------------"it's like this"-------------------
Dan Sugalski even samurai
[EMAIL PROTECTED] have teddy bears and even
teddy bears get drunk
