https://trout.me.uk/gc/ - see recycler-overview.pdf and recycler-algorithm.pdf

As with /lisp/ I tend to grab my own copies of papers I think I'll want to refer to later in case the original URL vanishes in a puff of bitrot :)

Heh, neat to see you've got the Perceus paper there too. That is in fact the other part (the "ARC") of Nim's memory management for those unaware - with the only differences being Nim frees memory at the end of scope, rather than last use, and and Perceus maybe might be atomic (do not fully remember. ARC isn't atomic.)

The bacon-rajan-cc link says it's stop-the-world. Samsara seems to be fully concurrent.

The bacon-rajan-cc link has only -implemented- a stop-the-world version, but notes right at the top of the README that it -can- be concurrent, and the stop-the-world-only-ness is only 'Currently.'

https://trout.me.uk/gc/ has two Recycler papers if you want more details.

Samsara is implementing the same algorithm and seems to be further along. Though there's also 'shredder' https://github.com/Others/shredder with a different overall approach.

Ah, I see what you meant now. Thanks for mentioning Samsara, I shall try and remember it exists later today when I'm more caffeinated.