Simplify bevy_tasks Features
#19091
Simplify bevy_tasks Features
#19091
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| Self(receiver.into_future()) | ||
| Self(receiver) |
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This did nothing, just an identity function. I'm not sure why it was being called other than just nobody noticed.
| /// Re-exports of crates that are useful across Bevy. | ||
| /// Not intended for external crates to use. | ||
| #[doc(hidden)] | ||
| pub mod exports { | ||
| crate::cfg::web! { | ||
| pub use js_sys; | ||
| pub use wasm_bindgen; | ||
| pub use wasm_bindgen_futures; | ||
| } | ||
| } |
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This addition is what will allow the web feature in particular to be brought under control. But there is room for adding other fundamental crates too (e.g., maybe serde to remove serialize features, etc.).
A similar technique could be used to remove bevy_reflect features as well.
| @@ -43,7 +47,14 @@ critical-section = ["dep:critical-section", "portable-atomic/critical-section"] | |||
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| ## Enables use of browser APIs. | |||
| ## Note this is currently only applicable on `wasm32` architectures. | |||
| web = ["dep:web-time", "dep:getrandom"] | |||
| web = [ | |||
| "std", | |||
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I noticed that thanks to web-time, our web feature isn't no_std at this moment. There is no_std support on their GitHub repo already merged though, so hopefully we can bring that functionality soon.
It's frustrating, because ideally we would just enable web-time iff std and web are enabled, but there is no way to do that with Cargo features at this time.
| #[cfg(all(not(target_arch = "wasm32"), feature = "multi_threaded"))] => { | ||
| /// Indicates multithreading support. | ||
| multi_threaded | ||
| } |
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Since aliases can be defined for arbitrary cfg statements, we can build in that multi_threaded only works on non-WASM, rather than needing to repeat this entire statement. Should make downstream consumption nicer too.
| /// Blocks on the supplied `future`. | ||
| /// This implementation will busy-wait until it is completed. | ||
| /// Consider enabling the `async-io` or `futures-lite` features. | ||
| pub fn block_on<T>(future: impl Future<Output = T>) -> T { | ||
| use core::task::{Poll, Context}; | ||
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| // Pin the future on the stack. | ||
| let mut future = core::pin::pin!(future); | ||
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| // We don't care about the waker as we're just going to poll as fast as possible. | ||
| let waker = futures::noop_waker(); | ||
| let cx = &mut Context::from_waker(&waker); | ||
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| // Keep polling until the future is ready. | ||
| loop { | ||
| match future.as_mut().poll(cx) { | ||
| Poll::Ready(output) => return output, | ||
| Poll::Pending => core::hint::spin_loop(), | ||
| } | ||
| } | ||
| } |
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This is new functionality just to make the feature gates less hideous. Now consumers can always use block_on, the features just improve performance for particular environments.
janhohenheim
added
C-Usability
Objective
Now that
bevy_platform::cfgis merged, we can start tidying up features. This PR starts withbevy_tasks.Solution
critical-sectionfeature (it was just a re-export ofbevy_platformanyway)stdandwebfeatures, relying onbevy_platform::cfgto check for availability.futures-litefeature to provide access to theblock_onimplementation fromfutures-lite.block_onthat just busy-waits.wasm-bindgenrelated dependencies out ofbevy_tasksand moved them intobevy_platformunder a newexportsmodule.async-ioimplicit feature explicit.Testing