Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Update wit-bindgen to use the new Context API #2911

Closed
epilys opened this issue Jun 1, 2022 · 1 comment · Fixed by wasmerio/wai#5
Closed

Update wit-bindgen to use the new Context API #2911

epilys opened this issue Jun 1, 2022 · 1 comment · Fixed by wasmerio/wai#5
Assignees
Labels
🎉 enhancement New feature! priority-medium Medium priority issue
Milestone

Comments

@epilys
Copy link
Contributor

epilys commented Jun 1, 2022

Improve on #2892.

WIT Bindgen allows defining bindings through a DSL (WIT) into different programming languages.
Wasmer provides a way to allow the bindings to use Wasmer (Wasmer Rust, Wasmer Python, Wasmer Go, ...) under the hood.

We need to adapt https://github.com/wasmerio/wit-bindgen to use the new Context api of Wasmer and pass the tests

@epilys epilys added this to the v3.0 milestone Jun 1, 2022
@epilys epilys added the 🎉 enhancement New feature! label Jun 1, 2022
@syrusakbary
Copy link
Member

This issue should be resolved in the wasmer3/context_api branch.

@syrusakbary syrusakbary added the priority-medium Medium priority issue label Jul 5, 2022
bors bot added a commit that referenced this issue Jul 19, 2022
2892: Implement new Context API for Wasmer 3.0 r=epilys a=Amanieu

### Overview

This PR reworks the way Wasmer manages objects used by instances, specifically: `Instance`, `Memory`, `Table`, `Function`, `Global` and `ExternRef`. Previously these were tracked using reference counting, but this cannot work fully because Wasm code can manipulate references to functions (and by implication the instance that function is from) using tables. 

The new approach uses a `Context` type which owns all of the objects listed above: objects are only freed when the `Context` is dropped. The `Instance`, `Memory`, `Table`, `Function`, `Global` and `ExternRef` types are now simply wrappers around an integer which indexes a vector in the `Context`. As a result, any function on those "handle" types now need to take a `&Context` or `&mut Context` as a parameter to access the actual data in the context. This also vastly simplifies Wasmer's thread-safety story: since all mutating operations require a `&mut Context`, no synchronization or internal locks are needed.

Additionally, the way host functions are represented is also changed. The `WasmerEnv` trait is removed since it was unergonomic and hard to use correctly. Instead, the state for host functions is stored directly as the `T` in `Context<T>`. This state is initialized when the context is created, and can be accessed through the `data` and `data_mut` methods on `Context<T>`. All host functions receive a `ContextMut<'_, T>` as their first argument, which gives them access to the host state of the context. This is much better than the old approach since it provides mutable access without locks and allows all host functions to share the same state.

This design is heavily inspired by [this RFC](https://github.com/bytecodealliance/rfcs/blob/main/accepted/new-api.md) from Wasmtime.

### TODO

- [x] #2985
- [x] #2908
- [x] #2973 Upgrade `c-api` to use the new API
- [x] Update wasmer-wasi to use the new API
- [x] #2909
- [x] #2913
- [x] #2912 
- #2911  (Non blocking)
- [ ] #2910

Fixes #2893
Fixes #2873 
Fixes #2866
Fixes #1840 
Fixes #1734
Fixes #1632
Fixes #1522
Fixes #1630 
Fixes #2838
Fixes #2856 
Fixes #2544
Fixes #2816 

Co-authored-by: Amanieu d'Antras <[email protected]>
Co-authored-by: ptitSeb <[email protected]>
Co-authored-by: Manos Pitsidianakis <[email protected]>
Co-authored-by: Syrus Akbary <[email protected]>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
🎉 enhancement New feature! priority-medium Medium priority issue
Projects
None yet
Development

Successfully merging a pull request may close this issue.

3 participants