copy-on-write

John.Maloney at Eng.Sun.COM John.Maloney at Eng.Sun.COM
Fri Mar 25 22:56:07 UTC 1994


Re: 
   > Given their emphasis on space over speed, and given the relatively
   > small amount of RAM, I would expect ...
   > that they just make a copy that extends the object by the extra slot,
   > then do a pass over memory to redirect all pointers to the object to
   > refer to the new copy.
   
   That very well may be... but my experiments to date seem to indicate that
   the address for a frame doesn't seem to change simply because slots have been
   added, but does seem to change after events that would imply that garbage has
   been collected.  (more snooping remains to be done...)

Interesting. They could be using forwarding pointers and postponing
fixing up the pointers until the next GC (when it has to update a lot
of pointers anyway).

	-- John






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