Process restart.

[Doug Gwyn]

In article <18 at elgar.UUCP> ag at elgar.UUCP (Keith Gabryelski) writes:
>Let's say we have this process computing prime numbers (or some other
>simple case) and the system needs to be shutdown because of some fatal
>error.  Can a snapshot be done?

Well, now that you're restricting yourself to the "doable" cases,
these are the sort of programs for which I make them periodically
write out useful intermediate stuff that they can later use to
resume, PORTABLY without needing any special help from the system,
linker, etc.  In fact I had one of these I ran at night on Rice's
IBM 1620 back in 1968; when someone else wanted to use the machine
he could just flip a sense switch and the program would soon punch
out an intermediate set of data that I used next time to continue
the job where it had been interrupted.  Ah, for the good old days.