Garbage Collection about grain HOT 3 CLOSED

I think a ref-counted GC is okay for a first implementation, but the lack of cycle detection is going to bite hard later, so you'll need to switch to a tracing GC (or similar) eventually.

If it stored a shadow stack in the linear memory, it would be possible to access the GC stack roots by using the shadow stack (this technique is already used in other languages compiled to wasm, like C, C++, and Rust).

from grain.

Note: for this to really be useful, we're going to need to essentially implement malloc on top of the WASM linear memory space.

from grain.

Update on this: the gc branch is now using an asm.js implementation of K&R C's malloc() for its memory allocation . Next on the to-do list is to implement a notion of GC-managed types in the runtime (so we can do the ref counts).

I'm brainstorming an API to try to make this extensible; the gc branch has a ManagedType class checked in, but it's currently unused. Note that, if we opt to have some form of mallocTagged function, this will have an impact on the codegen, but the exact effect is unclear.

from grain.