14 releases (8 breaking)
0.9.0 | Feb 21, 2021 |
---|---|
0.7.0 | Feb 18, 2021 |
#363 in WebAssembly
1,695 downloads per month
Used in 3 crates
35KB
687 lines
Async Executor for WebAssembly
There are a number of async task executors available in Rust's ecosystem. However, most (if not all?) of them rely on primitives that might not be available or optimal for WebAssembly deployment at the time.
Usage
Include this dependency in your Cargo.toml
:
[dependencies]
wasm-rs-async-executor = "0.9.0"
wasm-rs-async-executor
is expected to work on stable Rust, 1.49.0 and higher up. It may also
work on earlier versions. This hasn't been tested yet.
Supported targets
Currently, it's been only tested on wasm32-unknown-unknown
and, excluding cooperative
functionality,
it passes tests under wasmtime and wasmer with wasm32-wasi
target.
Further testing is to be completed.
Notes
Please note that this library hasn't received much analysis in terms of safety
and soundness. Some of the caveats related to that might never be resolved
completely. This is an ongoing development and the maintainer is aware of
potential pitfalls. Any productive reports of unsafeties or unsoundness are
welcomed (whether they can be resolved or simply walled with unsafe
for end-user
to note).
FAQ
Q: Why not just use wasm-bindgen-futures?
A: (short) In many cases, wasm-bindgen-futures
is just fine
A: (longer) There are some subtle differences in the way wasm-rs-async-executor
exposes its functionality. The
core idea behind it is to expose a reasonable amount of explicit controls over the its operations. You need
to run the executor explicitly, you can block on futures (again, explicitly -- which gives you a limited
ability to do scoped futures). It does come with minor trade-offs. For example, if you want to use async APIs from
your host environment, you can't simply await
on then, as the executor won't yield to the browser until told to do
so. However, this is typically solved by simply running a permanent task that loops yielding to the browser.
Ultimately, if this amount of control is beneficial for your case, then perhaps
this executor is waranted. It is also important to note that currently
wasm-rs-async-executor
does not support WebAssembly multi-threading in
any way. wasm-bindgen-futures
does, if the standard library is built with
support for it. It is planned to support this, but hasn't been high priority
so far due to current state of
things in Rust.
License
Licensed under either of
- Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
- MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT) at your option.
Dependencies
~0.6–3MB
~57K SLoC