Wait, why would you have to do that? Most ownership is determininstically resolved at compile time, so you can know exactly when a resource will be freed. What you do have to know is about the rare refcounted variable, and what edge cases require ownership checking at runtime.
The latency problem isn't caused by determining what to free, the latency problem is caused by actually freeing. Imagine an array with 2^31 pointers, and now fill it with with 2^31 distinct pointers to the remainder of the 2^32 bit address space. When that array goes out of scope, you can now enjoy 2^31 individual free operations, because reclamation for Rust lifetimes and reference counting are both proportional to the number of dead objects (copying collection takes zero time in this case).
If bounded latency is a goal, you have to bound the depth of of your ownership graph if you're working on a platform that doesn't impose global latency properties. C/C++ and Rust do not do this.
This is only true for pure two-space copying collectors, which are rarely used in practice because of the absurd memory overhead. Once you introduce mark/sweep for some portion of the heap (like production GCs do), you reintroduce overhead proportional to the number of dead objects during the sweep phase.
But C has this problem as well. If you've malloc(3)ed an array of 2^31 pointers, each pointing to an object, enjoy your 2^31 free(3)s, or prepare to start leaking RAM.
Yes, C/C++ and Rust have the same problems, as I said elsewhere. My ultimate point is that low latency is a property of a runtime, not a language. Using C/C++ or Rust aren't going to automatically give you bounded latency, and adding tracing GC doesn't automatically take it away.
The language and runtime typically cooperate to provide the operational semantics that developers are looking for. The case of Objective-C is especially interesting in this regard: developers evolved a number of conventions around reference counting, because reference counting allowed for controllable, minimal latency and contributed to a snappy UI. The language gradually absorbed these conventions into the compiler, such that certain patterns of use are part of the language specification (certain method names, basically) and the ARC code is generated for developers.
