Path: utzoo!utgpu!attcan!uunet!ncrlnk!ncrcae!ece-csc!mcnc!uvaarpa!haven!adm!smoke!gwyn
From: gwyn@smoke.BRL.MIL (Doug Gwyn )
Newsgroups: comp.unix.wizards
Subject: Re: Process restart.
Keywords: Fork, Process, migration, remote, a.out, core
Message-ID: <8857@smoke.BRL.MIL>
Date: 10 Nov 88 17:42:00 GMT
References: <16@elgar.UUCP> <8831@smoke.BRL.MIL> <17@elgar.UUCP>
Reply-To: gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 15

In article <17@elgar.UUCP> ag@elgar.UUCP (Keith Gabryelski) writes:
>>in general.
>What does `in general' mean?

In general, a process is quite a dynamic thing, particular with
respect to its interaction with its environment.  For example,
what is currently displayed on one or more terminal screens
might be important, or input may be coming from another process
via a pipe, etc.  The total amount of information necessary to
restore all relevant factors upon restart is impractical for the
general case.  Only rather simple-minded uses of processes can
be properly restarted from snapshots.

To take a specific example, I defy you to restart a snapshot
of the "layers" program using any general-purpose mechanism.