From mboxrd@z Thu Jan 1 00:00:00 1970 From: lars@nocrew.org (Lars Brinkhoff) Date: Mon, 27 Feb 2017 21:26:01 +0100 Subject: [TUHS] Emacs and undump In-Reply-To: <31f9e532-c59a-2d3d-1e9b-cef9a216d68e@update.uu.se> (Johnny Billquist's message of "Mon, 27 Feb 2017 21:09:33 +0100") References: <31f9e532-c59a-2d3d-1e9b-cef9a216d68e@update.uu.se> Message-ID: <86efyjpehy.fsf@molnjunk.nocrew.org> Johnny Billquist wrote: > But having the memory around for a program, even if it is not running, > is actually sometimes very useful. If ITS could handle that, while > treating them as separate processes, all associated to one terminal, > and let you select which one you were currently fooling around in, > while the others stayed around, that is something I don't think I've > seen elsewhere. And it's not just a list structure, but a tree. You can e.g. start a new DDT, which itself can have inferior jobs (subprocesses). To bring this slightly back on topic, ITS job handling was John Kulp's inspiration for Unix job control. Control-Z does pretty much the same thing in both ITS and Unix. > So, Emacs does it once, and then saves the state at the point where > you can start editing. But it does not mean that the memory is > shareable. It's full of various data structures, and code, and that > will change as you go along editing things as well. Much is sharable. There's a concept of purification (which also comes from ITS). A purecopy() function is used in temacs to put read-only data in a special memory area. That area will become sharable in the dumped Emacs.