Elimination of manual memory management (by default and/or within an init option) via JavaScript's FinalizationRegistry/WeakRef? #115
Description
Here are the relevant MDN docs:
- https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/FinalizationRegistry
- https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WeakRef
My understanding is that using FinalizationRegistry, it would look something vaguely like this:
const finalizationRegistry = new FinalizationRegistry(wasmRef => {
// the JS-level Vec3 instance has been garbage collected, so deallocate the emscripten-level stuff
deallocateTheThing(wasmRef);
});
export class Vec3 {
constructor(x, y, z) {
// create wasmRef, etc ...
finalizationRegistry.register(this, wasmRef); // this tells the runtime to watch for when `this` is garbage collected, and when it is, call the registry callback (defined above) with `wasmRef` as the argument
}
// ...
}
// Note: The same finalization registry instance can be used for the whole Jolt module/engine IIUC.So that instead of this:
let material = new Jolt.PhysicsMaterial();
let size = new Jolt.Vec3(4, 0.5, 0.5);
let box = new Jolt.BoxShapeSettings(size, 0.05, material);
Jolt.destroy(size);
// ...We can just write this:
let material = new Jolt.PhysicsMaterial();
let size = new Jolt.Vec3(4, 0.5, 0.5);
let box = new Jolt.BoxShapeSettings(size, 0.05, material);
// ...If it'd somehow be a non-trivial perf hit or a breaking change, then maybe some sort of init option? (If my opinion is at all useful here, I think it should be default)
I'm currently using Rapier for a project and it's been great in terms of JS idiomaticity (I guess Rust's wasm-pack handles memory stuff automatically?), so I'm just posting this in the hopes that Jolt can get to a similarly pleasant DX. Thanks!