Using Threads in Interactive Systems: A Case Study
Technical Report CSL 93-16
Computer Science Laboratory
Xerox Palo Alto Research Center
3333 Coyote Hill Road
Palo Alto, CA 94304
Copyright (c) Xerox Corporation 1993.  All rights reserved.

Postscript and Interpress masters for CSL 93-16 may be found in the
directory ThreadStudyPaper/ along with the source file.

This CDROM contains (most of) the current source for the Cedar
programming environment as developed over the last ten years by the
the Computer Science Laboratory at Xerox's Palo Alto Research Center.

Our principle purpose in releasing this CDROM is to allow other
researchers to peruse the Cedar source code.  The most convenient way
to do this, if you happen to own a SPARC-based workstation running the
SunOS4.1.x or Solaris2 operating system and the X11 Window System will
be to actually start up a Cedar system and use the Cedar Tioga editor
for browsing the files.

Starting Cedar:

For SPARC-based SunOS4.1.x and Solaris2 machines, we've set things up
so that you can run the Cedar system directly from the CDROM.  Mount
it with type hsfs and on SunOS4.1.x do
	% setenv XeroxCedar <mount point>/Cedar
	% cd $XeroxCedar/cdpackage/solaris1
	% x11v
	
For SPARC-based Solaris2 machines use
	% setenv XeroxCedar <mount point>/Cedar
	% cd $XeroxCedar/cdpackage/solaris2
	% x11v
	
At this point you would do well to print the file
	$XeroxCedar/doc/CedarPrimer.ps for a general introduction to
Cedar and some hints on using it from the mouse and keyboard.  (If you
happen to have an Interpress printer you could instead print
CedarPrimer.interpress from the same directory.)

If you do not have an appropriate workstation to run Cedar you may not
be completely out of luck.  We have also included the viewtioga
package for the Andrew ez editor and some emacs elisp packages that
provide the ability to read files in tioga's format.  The viewtioga
package will require expertise in ez to install.  Look in the
viewtioga subdirectory of the top level directory.  Necessary fonts
for viewtioga can be found in the Xfonts directory.  The elisp
packages are in the emacs subdirectory and should be easy to install.
Emacs conversion is pretty slow, but it does let you look at tioga
files.

The cedarname utility also uses the XeroxCedar environment variable as
does the viewtioga package.  Unfortunately some uses of the variable
refer to ${XeroxCedar}/.. which may cause trouble if you copy the
CDROM to magnetic disk and split the contents across multiple file
systems.  The system has facilities to cope with the situation but
they require more work than simply setting a single environment
variable.

Also included on this CDROM are the interfaces of our POSIX Portable
Common Runtime (PPCR).  When you run Cedar off of this CDROM, PPCR
provides the threads and garbage collection as well as the POSIX
environment, but PPCR should itself not be too apparent.

The usual way of running Cedar at PARC is using more mature version of
the runtime called PCR.  Since PCR requires customization of the Unix
kernel and does not run on Solaris2 we decided to supply the
PPCR-based Cedar for the CDROM, even though it is not as complete a
development environment as the PCR-based version.  It has also not
seen the performance tuning that Cedar on PCR has.

The latest released version of PCR is available from parcftp.xerox.com
in directory /pub/pcr.  Several papers about PCR are available from
the same directory.

Legalities:
         Please refer to the file COPYRIGHT in the top level
         directory.

Contact:
        Recipients of this disk or the files on it are asked to please
        notify

	    PCR Coordinator
	    Xerox Palo Alto Research Center
	    3333 Coyote Hill Road
	    Palo Alto CA 94304
	    pcrcoordinator@parc.xerox.com
   
        of their postal or electronic mail address.