Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!auspex!guy
From: guy@auspex.auspex.com (Guy Harris)
Newsgroups: comp.windows.x
Subject: Re: UNIX V.4 local transport - subroutine call?
Message-ID: <3847@auspex.auspex.com>
Date: 7 Aug 90 18:37:47 GMT
References: <32514@cup.portal.com>
Distribution: na
Organization: Auspex Systems, Santa Clara
Lines: 24

>I've heard through the grapevine, but am not sure yet, that UNIX V.4
>shared libraries are fully paged, that is, you don't have to have
>the whole library in RAM when a program was using it.  (As opposed
>to the sorry situation in UNIX V.3)

Is that *really* the case in S5R3?  In any case, S5R4 shared libraries
are SunOS 4.x shared libraries with sugar and cream on top, basically;
they are fully paged.

>If this is true, do V.4 ports of X just stuff the server into a giant
>shared library?

I would be extremely surprised if they did; I don't think it's a trivial
change, since...

>You need to have each run-time copy of the code share control of the
>screen, using a semaphore (or two to avoid race conditions) for a baton
>will do the trick.

...and they'd have to share control of assorted global data structures
as well.  In addition, doing the locking necessary to enable the N
processes to share the screen and other data structures could
conceivably squander any performance gain you get from not doing IPC to
a separate server process....