"Araq" <rump...@web.de> wrote: > On Thursday, 17 July 2014 at 15:38:44 UTC, Tobias Müller wrote: >> "Araq" <rump...@web.de> wrote: >>> The paper focusses on RC vs "tracing". My point is "tracing" >> vs "copying" >>> is another tradeoff. Here is a mark&sweep algorithm: >>>>> - Trace live objects. >>> - For each dead object: Deallocate. >>>>> Here is a copying GC: >>>>> - Trace and copy live objects. >>> - There is no deallocation step. The old region is free for >> further >>> usage. >> >> It's more like: ... > > Your description is still naive and as such your post is more misleading > than helpful. My description is naive to get the basic point across, I > have no idea what the point of your post is.
Since you snipped everything, my points are: 1. "There is no deallocation" is just plain wrong. 2. The cost of complex object graphs vs simple objects lies in the mark, not in the sweep. mark-copy has no advantage vs. mark sweep in that respect. Same cost applies for RC. 3. The real difference between mark-sweep and mark-copy lies in number of dead objects vs number of live objects. 4. Your comparison with a region allocator is moot, because _really_ just bulk-deallocate, without a mark step. Tobi
