Separate Yew Platform (#2893)

* Remove pinned module.

* Create Yew Platform.

* Remove some additional dependencies.

* Fix clippy.

* Restore wasm-bindgen-futures.

* Fix docs.

* Migrate to prokio.

* Fix docs warnings.

* Fix dependencies.

ci/feature-soundness-release.sh

@@ -18,15 +18,3 @@ cargo clippy --release --no-default-features --features default,ssr -- --deny=wa
 cargo clippy --release --no-default-features --features csr,default,ssr -- --deny=warnings
 cargo clippy --release --no-default-features --features hydration,ssr -- --deny=warnings
 cargo clippy --release --no-default-features --features default,hydration,ssr -- --deny=warnings
-cargo clippy --release --no-default-features --features tokio -- --deny=warnings
-cargo clippy --release --no-default-features --features csr,tokio -- --deny=warnings
-cargo clippy --release --no-default-features --features default,tokio -- --deny=warnings
-cargo clippy --release --no-default-features --features csr,default,tokio -- --deny=warnings
-cargo clippy --release --no-default-features --features hydration,tokio -- --deny=warnings
-cargo clippy --release --no-default-features --features default,hydration,tokio -- --deny=warnings
-cargo clippy --release --no-default-features --features ssr,tokio -- --deny=warnings
-cargo clippy --release --no-default-features --features csr,ssr,tokio -- --deny=warnings
-cargo clippy --release --no-default-features --features default,ssr,tokio -- --deny=warnings
-cargo clippy --release --no-default-features --features csr,default,ssr,tokio -- --deny=warnings
-cargo clippy --release --no-default-features --features hydration,ssr,tokio -- --deny=warnings
-cargo clippy --release --no-default-features --features default,hydration,ssr,tokio -- --deny=warnings

ci/feature-soundness.sh

@@ -18,15 +18,3 @@ cargo clippy --no-default-features --features default,ssr -- --deny=warnings
 cargo clippy --no-default-features --features csr,default,ssr -- --deny=warnings
 cargo clippy --no-default-features --features hydration,ssr -- --deny=warnings
 cargo clippy --no-default-features --features default,hydration,ssr -- --deny=warnings
-cargo clippy --no-default-features --features tokio -- --deny=warnings
-cargo clippy --no-default-features --features csr,tokio -- --deny=warnings
-cargo clippy --no-default-features --features default,tokio -- --deny=warnings
-cargo clippy --no-default-features --features csr,default,tokio -- --deny=warnings
-cargo clippy --no-default-features --features hydration,tokio -- --deny=warnings
-cargo clippy --no-default-features --features default,hydration,tokio -- --deny=warnings
-cargo clippy --no-default-features --features ssr,tokio -- --deny=warnings
-cargo clippy --no-default-features --features csr,ssr,tokio -- --deny=warnings
-cargo clippy --no-default-features --features default,ssr,tokio -- --deny=warnings
-cargo clippy --no-default-features --features csr,default,ssr,tokio -- --deny=warnings
-cargo clippy --no-default-features --features hydration,ssr,tokio -- --deny=warnings
-cargo clippy --no-default-features --features default,hydration,ssr,tokio -- --deny=warnings

examples/futures/Cargo.toml

@@ -9,7 +9,7 @@ license = "MIT OR Apache-2.0"
 pulldown-cmark = { version = "0.9", default-features = false }
 wasm-bindgen = "0.2"
 wasm-bindgen-futures = "0.4"
-yew = { path = "../../packages/yew", features = ["tokio", "csr"] }
+yew = { path = "../../packages/yew", features = ["csr"] }
 gloo = "0.8"
 
 [dependencies.web-sys]

examples/js_callback/Cargo.toml

@@ -7,7 +7,7 @@ license = "MIT OR Apache-2.0"
 
 [dependencies]
 wasm-bindgen = "0.2"
-yew = { path = "../../packages/yew", features = ["csr", "tokio"] }
+yew = { path = "../../packages/yew", features = ["csr"] }
 wasm-bindgen-futures = "0.4"
 js-sys = "0.3"
 once_cell = "1"

examples/simple_ssr/Cargo.toml

@@ -32,4 +32,4 @@ clap = { version = "3.1.7", features = ["derive"] }
 
 [features]
 hydration = ["yew/hydration"]
-ssr = ["yew/ssr", "yew/tokio"]
+ssr = ["yew/ssr"]

examples/ssr_router/Cargo.toml

@@ -34,5 +34,5 @@ hyper = { version = "0.14", features = ["server", "http1"] }
 jemallocator = "0.5"
 
 [features]
-ssr = ["yew/ssr", "yew/tokio"]
+ssr = ["yew/ssr"]
 hydration = ["yew/hydration"]

packages/yew/Cargo.toml

@@ -25,16 +25,23 @@ slab = "0.4"
 wasm-bindgen = "0.2"
 yew-macro = { version = "^0.19.0", path = "../yew-macro" }
 thiserror = "1.0"
-futures = { version = "0.3", default-features = false, features = ["std", "async-await"] }
+futures = { version = "0.3", default-features = false, features = ["std"] }
 html-escape = { version = "0.2.9", optional = true }
 implicit-clone = { version = "0.3", features = ["map"] }
 base64ct = { version = "1.5.0", features = ["std"], optional = true }
 bincode = { version = "1.3.3", optional = true }
 serde = { version = "1", features = ["derive"] }
 tracing = "0.1.36"
-pin-project = "1.0.11"
+prokio = "0.1.0"
 rustversion = "1"
 
+[target.'cfg(target_arch = "wasm32")'.dependencies]
+wasm-bindgen-futures = "0.4"
+
+[target.'cfg(not(target_arch = "wasm32"))'.dependencies]
+# We still need tokio as we have docs linked to it.
+tokio = { version = "1.19", features = ["rt"] }
+
 [dependencies.web-sys]
 version = "^0.3.59"
 features = [
@@ -70,16 +77,8 @@ features = [
   "SubmitEvent"
 ]
 
-[target.'cfg(target_arch = "wasm32")'.dependencies]
-# we move it here so no promise-based spawn_local can present for
-# non-wasm32 targets.
-wasm-bindgen-futures = "0.4"
-
-[target.'cfg(not(target_arch = "wasm32"))'.dependencies]
-num_cpus = { version = "1.13", optional = true }
-once_cell = "1"
-tokio = { version = "1.21.1", features = ["rt", "time"], optional = true }
-tokio-stream = { version = "0.1", features = ["time"], optional = true }
+[target.'cfg(not(target_arch = "wasm32"))'.dev-dependencies]
+tokio = { version = "1.19", features = ["full"] }
 
 [dev-dependencies]
 wasm-bindgen-test = "0.3"
@@ -95,15 +94,11 @@ features = [
 ]
 
 [features]
-tokio = ["dep:tokio", "dep:num_cpus", "dep:tokio-stream"]
 ssr = ["dep:html-escape", "dep:base64ct", "dep:bincode"]
 csr = []
 hydration = ["csr", "dep:bincode"]
 default = []
 
-[target.'cfg(not(target_arch = "wasm32"))'.dev-dependencies]
-tokio = { version = "1.19", features = ["full"] }
-
 [package.metadata.docs.rs]
 all-features = true
 rustdoc-args = ["--cfg", "documenting"]

packages/yew/Makefile.toml

@@ -1,6 +1,6 @@
 [tasks.native-test]
 command = "cargo"
-args = ["test", "--features", "csr,ssr,hydration,tokio"]
+args = ["test", "--features", "csr,ssr,hydration"]
 
 [tasks.wasm-test]
 command = "wasm-pack"

packages/yew/src/html/component/scope.rs

@@ -248,9 +248,9 @@ impl<COMP: BaseComponent> Scope<COMP> {
     ///
     /// This method will not notify the component when the stream has been fully exhausted. If
     /// you want this feature, you can add an EOF message variant for your component and use
-    /// [`StreamExt::chain`] and [`stream::once`] to chain an EOF message to the original stream.
-    /// If your stream is produced by another crate, you can use [`StreamExt::map`] to transform
-    /// the stream's item type to the component message type.
+    /// [`StreamExt::chain`] and [`stream::once`](futures::stream::once) to chain an EOF message to
+    /// the original stream. If your stream is produced by another crate, you can use
+    /// [`StreamExt::map`] to transform the stream's item type to the component message type.
     pub fn send_stream<S, M>(&self, stream: S)
     where
         M: Into<COMP::Message>,

packages/yew/src/lib.rs

@@ -26,7 +26,6 @@
 //! - `csr`: Enables Client-side Rendering support and [`Renderer`]. Only enable this feature if you
 //!   are making a Yew application (not a library).
 //! - `ssr`: Enables Server-side Rendering support and [`ServerRenderer`].
-//! - `tokio`: Enables future-based APIs on non-wasm32 targets with tokio runtime.
 //! - `hydration`: Enables Hydration support.
 //!
 //! ## Example

packages/yew/src/platform.rs

@@ -0,0 +1,48 @@
+//! Yew's compatibility between JavaScript Runtime and Native Runtimes.
+//!
+//! This module is also published under the name [prokio] on crates.io.
+//!
+//! # Rationale
+//!
+//! When designing components and libraries that works on both WebAssembly targets backed by
+//! JavaScript Runtime and non-WebAssembly targets with Native Runtimes. Developers usually face
+//! challenges that requires applying multiple feature flags throughout their application:
+//!
+//! 1. Select I/O and timers that works with the target runtime.
+//! 2. Native Runtimes usually require `Send` futures and WebAssembly types are usually `!Send`.
+//!
+//! # Implementation
+//!
+//! To alleviate these issues, Yew implements a single-threaded runtime that executes `?Send`
+//! (`Send` or `!Send`) futures.
+//!
+//! On platforms with multi-threading support, Yew spawns multiple independent runtimes
+//! proportional to the CPU core number. When tasks are spawned with a runtime handle, it will
+//! randomly select a worker thread from the internal pool. All tasks spawned with `spawn_local`
+//! will run on the same thread as the thread the task was running. When the runtime runs in a
+//! WebAssembly target, all tasks will be scheduled on the main thread.
+//!
+//! This runtime is designed in favour of IO-bounded workload with similar runtime cost.
+//! When running I/O workloads, it would produce a slightly better performance as tasks are
+//! never moved to another thread. However, If a worker thread is busy,
+//! other threads will not be able to steal tasks scheduled on the busy thread.
+//! When you have a CPU-bounded task where CPU time is significantly
+//! more expensive, it should be spawned with a dedicated thread (or Web Worker) and communicates
+//! with the application using channels.
+//!
+//! Yew platform provides the following components:
+//!
+//! 1. A Task Scheduler that is capable of running non-Send tasks.
+//! 2. A Timer that is compatible with the scheduler backend.
+//! 3. Task Synchronisation Mechanisms.
+//!
+//! # Runtime Backend
+//!
+//! The Yew runtime is implemented with different runtimes depending on the target platform and can
+//! use all features (timers / IO / task synchronisation) from the selected native runtime:
+//!
+//! - `wasm-bindgen-futures` (WebAssembly targets)
+//! - `tokio` (non-WebAssembly targets)
+
+#[doc(inline)]
+pub use prokio::*;