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Squeak does 1-phase snapshots
Last updated at 10:31 pm UTC on 3 September 2004
Squeak does 1-phase snapshots
lex@cc.gatech.edu July 12, 2004 [Re: kill -9 is usually not a good way to terminate apps ]

But shouldn't it be? If people kill -9'ed with regularity, then the bugs would be found and software would be more reliable. And anyway, software should tolerate it, and once it does tolerate it, -9'ing is very convienient. If you all can forgive me for a moment of heresy: a very nice feature of MS-DOS 2.11 was that you could in fact turn the machine off and not be afraid of losing data, so long as you had hit "save" recently. Further, EROS is an experimental OS that will have this same feature, but you don't even need to press "save". http://www.eros-os.org

(And, since this is Squeak-List, let me mention that EROS is going back to the future, too: Squeak itself has had automatic persistence, and KeyKOS is an operating system that had automatic snapshotting.)

Anyway, history aside, there's a very practical reason I mention all

Squeak itself does 1-phase snapshots!

If you turn the power off while Squeak is mid-save, you can lose your image completely. I posted a changeset to fix this long ago, but it probably needs to be revisited. It is a fairly portable changeset, even though it is at the VM level. Probably it would need some tinkering to work in current Squeak's, but it may interest people even in its current state.