Why LispOS?

Kragen kragen@pobox.com
Wed, 25 Mar 1998 21:03:24 -0500 (EST)


On Wed, 25 Mar 1998, David Tillman wrote:
>     Also, I would like to do something like: (shutdown) and have
>     everything frozen as it is. The next time I start the OS I want
>     all of the windows, files, processes, etc. to be just like I left
>     them.

A persistent store that included the OS's data structures would make
this possible.

>     I realize that there is some complexity to doing this with a multiuser
>     OS. It may be that only local sessions would have their state saved
>     and remote sessions would have their's destroyed.

Not difficult.  You need only have a `broker' object that maintains
state across disconnections, provides an illusion of continuous
connection to your applications, and lets you connect and disconnect to
it when you like.

Such a thing for Unix is called `dislocate' (there are two others, `screen' and
`pty') and is 340 lines long, written in Expect.

If it were running on a machine with a persistent virtual memory, it
would maintain state across reboots as easily as across telephone
hangups.

KeyKOS apparently worked this way.

Kragen