ReGc

A garbage collector that mixes Reference counting and mark sweeping

Example

Rust

```rust env_logger::init();

struct Foo<'c> { r: std::cell::RefCell>>, }

impl<'c> Drop for Foo<'c> { fn drop(&mut self) { println!("Drop for Foo"); } }

impl<'c> GcTarget<'c> for Foo<'c> { fn trace(&self, token: &mut GcTraceToken<'c>) { self.r.trace(token); } }

let context = GcContext::new(); let x = context.alloc(Foo { r: std::cell::RefCell::new(None), }); *x.r.borrowmut() = Some(x.downgrade()); context.gc(); *x.r.borrowmut() = None; ```

Output

[2023-07-18T00:56:30Z TRACE regc] alloc regc::test::Foo 0x2876afc19e0 [2023-07-18T00:56:30Z INFO regc] call gc [2023-07-18T00:56:30Z INFO regc] begin gc [2023-07-18T00:56:30Z INFO regc] trace 1 target [2023-07-18T00:56:30Z INFO regc] hold 1 target [2023-07-18T00:56:30Z INFO regc] drop 0 target [2023-07-18T00:56:30Z INFO regc] end gc 19µs [2023-07-18T00:56:30Z TRACE regc] drop 0x2876afc19e0 [2023-07-18T00:56:30Z TRACE regc] free 0x2876afc19e0 [2023-07-18T00:56:30Z INFO regc] drop gc [2023-07-18T00:56:30Z INFO regc] call gc [2023-07-18T00:56:30Z INFO regc] begin gc [2023-07-18T00:56:30Z INFO regc] end gc 200ns Drop for Foo