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 wasmer-cli to use the new Context API #2913

Closed
Tracked by #2892
syrusakbary opened this issue Jun 1, 2022 · 1 comment
Closed
Tracked by #2892

Update wasmer-cli to use the new Context API #2913

syrusakbary opened this issue Jun 1, 2022 · 1 comment
Assignees
Labels
🎉 enhancement New feature!
Milestone

Comments

@syrusakbary
Copy link
Member

Improving the PR #2892 by updating the wasmer-cli crate

@epilys
Copy link
Contributor

epilys commented Jul 1, 2022

Closed by #2927

@epilys epilys closed this as completed Jul 1, 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 <amanieu@gmail.com>
Co-authored-by: ptitSeb <sebastien.chev@gmail.com>
Co-authored-by: Manos Pitsidianakis <manos@wasmer.io>
Co-authored-by: Syrus Akbary <me@syrusakbary.com>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
🎉 enhancement New feature!
Projects
None yet
Development

No branches or pull requests

3 participants