Computer science is absolutely a formal science in every sense of the word.
>If Boehm GCs really leak as much as you claim then nobody would use them.
I mean if anything this argument applies more to your characterization that reference counting easily leads to memory exhaustion due to cycles than it does to conservative garbage collectors. If RC based garbage collectors leaked as much as your post implies then nobody would use them. And yet Swift, a language that is almost exclusively used with large graphs(that's how most UIs are represented in memory) and that exhibits all kinds of non-deterministic shared ownership uses RC based garbage collection. Objects involved in UI code are shared in wildly unpredictable ways with no clear hierarchy among layouts, event handlers, observables, IO systems, etc...
>A definition of GC that excludes this capability does not have the contract of “You only have to worry about reachability from roots”.
Exactly, because that's not part of the contract for a GC. That's part of the contract for a tracing garbage collector:
Computer science is absolutely a formal science in every sense of the word.
>If Boehm GCs really leak as much as you claim then nobody would use them.
I mean if anything this argument applies more to your characterization that reference counting easily leads to memory exhaustion due to cycles than it does to conservative garbage collectors. If RC based garbage collectors leaked as much as your post implies then nobody would use them. And yet Swift, a language that is almost exclusively used with large graphs(that's how most UIs are represented in memory) and that exhibits all kinds of non-deterministic shared ownership uses RC based garbage collection. Objects involved in UI code are shared in wildly unpredictable ways with no clear hierarchy among layouts, event handlers, observables, IO systems, etc...
>A definition of GC that excludes this capability does not have the contract of “You only have to worry about reachability from roots”.
Exactly, because that's not part of the contract for a GC. That's part of the contract for a tracing garbage collector:
https://en.wikipedia.org/wiki/Tracing_garbage_collection
When your definitions don't fit reality then it's time to adjust your definitions, not reality.