On 8/16/19 10:07 AM, Gil Tene wrote: > Classification terms evolve as the art evolves.
What I want to emphasize here that this discussion reinvents the meaning of "sweep". That definition is not used in the way you describe in the sources I know of. Granted, definitions drift over time, but we have to be careful to separate what is the "agreed on" definition, and what is whatever definition we want to be the emergent one. > On Thursday, August 15, 2019 at 1:42:23 AM UTC-7, Aleksey Shipilev wrote: > I am trying to understand what is your central argument here. This seems > to be it. Are you saying > that "sweeping" is when you visit dead objects, and non-"sweeping" is > when you do not? > > Yes. I think that's a very good summary. Would be helpful if we started from this next time around! > Is walking _dead_ objects the discriminator for "sweeping" then? So in > your book, if we take the > same Lisp2 collector, and compute-new-addresses and adjust-pointers steps > are walking the > self-parsable heap (visiting dead objects along the way), it is M-S-C? > But if it uses marking > bitmap > (thus only visiting live objects), it becomes M-C? [This would be a weird > flex, but okay]. > > > Exactly. "In my book" adding an efficient livemark bit vector with possible > summary layers would > covert the classic LISP2 GC from a Mark-Sweep-Compact to a Mark-Compact (with > no sweep). So this is what irks me here. In my Epsilon's mark-compact toy collector (https://shipilev.net/jvm/diy-gc/), changing from mark bitmaps to self-parsable heap traversal is about 5 lines of code. This does not feel like passing the bar for reclassification of the collector algo between major classes. It feels more like the implementation detail that can swing both ways, depending on circumstances. -Aleksey -- You received this message because you are subscribed to the Google Groups "mechanical-sympathy" group. To unsubscribe from this group and stop receiving emails from it, send an email to mechanical-sympathy+unsubscr...@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/mechanical-sympathy/3bc6ee45-67d2-076c-879a-4bbf487f63a4%40gmail.com.
signature.asc
Description: OpenPGP digital signature
