switch to async-executor

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>

Cargo.toml

@@ -24,13 +24,13 @@ rustdoc-args = ["--cfg", "feature=\"docs\""]
 [features]
 default = [
   "std",
+  "async-executor",
   "async-io",
   "async-task",
   "blocking",
   "futures-lite",
   "kv-log-macro",
   "log",
-  "multitask",
   "num_cpus",
   "pin-project-lite",
 ]
@@ -80,10 +80,10 @@ futures-timer = { version = "3.0.2", optional = true }
 surf = { version = "1.0.3", optional = true }
 
 [target.'cfg(not(target_os = "unknown"))'.dependencies]
+async-executor = { version = "0.1.1", features = ["async-io"], optional = true }
 async-io = { version = "0.1.5", optional = true }
 blocking = { version = "0.5.0", optional = true }
 futures-lite = { version = "0.1.8", optional = true }
-multitask = { version = "0.2.0", optional = true }
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
 futures-timer = { version = "3.0.2", optional = true, features = ["wasm-bindgen"] }

src/rt/mod.rs

@@ -27,7 +27,7 @@ pub static RUNTIME: Lazy<Runtime> = Lazy::new(|| {
     for _ in 0..thread_count {
         thread::Builder::new()
             .name(thread_name.clone())
-            .spawn(|| crate::task::block_on(future::pending::<()>()))
+            .spawn(|| crate::task::executor::run_global(future::pending::<()>()))
             .expect("cannot start a runtime thread");
     }
     Runtime {}

src/task/executor.rs

@@ -1,23 +1,13 @@
 use std::cell::RefCell;
 use std::future::Future;
-use std::task::{Context, Poll};
 
-static GLOBAL_EXECUTOR: once_cell::sync::Lazy<multitask::Executor> = once_cell::sync::Lazy::new(multitask::Executor::new);
-
-struct Executor {
-    local_executor: multitask::LocalExecutor,
-    parker: async_io::parking::Parker,
-}
+static GLOBAL_EXECUTOR: once_cell::sync::Lazy<async_executor::Executor> = once_cell::sync::Lazy::new(async_executor::Executor::new);
 
 thread_local! {
-    static EXECUTOR: RefCell<Executor> = RefCell::new({
-        let (parker, unparker) = async_io::parking::pair();
-        let local_executor = multitask::LocalExecutor::new(move || unparker.unpark());
-        Executor { local_executor, parker }
-    });
+    static EXECUTOR: RefCell<async_executor::LocalExecutor> = RefCell::new(async_executor::LocalExecutor::new());
 }
 
-pub(crate) fn spawn<F, T>(future: F) -> multitask::Task<T>
+pub(crate) fn spawn<F, T>(future: F) -> async_executor::Task<T>
 where
     F: Future<Output = T> + Send + 'static,
     T: Send + 'static,
@@ -26,35 +16,26 @@ where
 }
 
 #[cfg(feature = "unstable")]
-pub(crate) fn local<F, T>(future: F) -> multitask::Task<T>
+pub(crate) fn local<F, T>(future: F) -> async_executor::Task<T>
 where
     F: Future<Output = T> + 'static,
     T: 'static,
 {
-    EXECUTOR.with(|executor| executor.borrow().local_executor.spawn(future))
+    EXECUTOR.with(|executor| executor.borrow().spawn(future))
 }
 
 pub(crate) fn run<F, T>(future: F) -> T
 where
     F: Future<Output = T>,
 {
-    enter(|| EXECUTOR.with(|executor| {
-        let executor = executor.borrow();
-        let unparker = executor.parker.unparker();
-        let global_ticker = GLOBAL_EXECUTOR.ticker(move || unparker.unpark());
-        let unparker = executor.parker.unparker();
-        let waker = async_task::waker_fn(move || unparker.unpark());
-        let cx = &mut Context::from_waker(&waker);
-        pin_utils::pin_mut!(future);
-        loop {
-            if let Poll::Ready(res) = future.as_mut().poll(cx) {
-                return res;
-            }
-            if let Ok(false) = std::panic::catch_unwind(std::panic::AssertUnwindSafe(|| executor.local_executor.tick() || global_ticker.tick())) {
-                executor.parker.park();
-            }
-        }
-    }))
+    EXECUTOR.with(|executor| enter(|| GLOBAL_EXECUTOR.enter(|| executor.borrow().run(future))))
+}
+
+pub(crate) fn run_global<F, T>(future: F) -> T
+where
+    F: Future<Output = T>,
+{
+    enter(|| GLOBAL_EXECUTOR.run(future))
 }
 
 /// Enters the tokio context if the `tokio` feature is enabled.

src/task/join_handle.rs

@@ -18,7 +18,7 @@ pub struct JoinHandle<T> {
 }
 
 #[cfg(not(target_os = "unknown"))]
-type InnerHandle<T> = multitask::Task<T>;
+type InnerHandle<T> = async_executor::Task<T>;
 #[cfg(target_arch = "wasm32")]
 type InnerHandle<T> = futures_channel::oneshot::Receiver<T>;
 

src/task/mod.rs

@@ -149,7 +149,7 @@ cfg_default! {
     mod builder;
     mod current;
     #[cfg(not(target_os = "unknown"))]
-    mod executor;
+    pub(crate) mod executor;
     mod join_handle;
     mod sleep;
     #[cfg(not(target_os = "unknown"))]