feat: add support for async-executor from smol-rs (#3090)

any_spawner/Cargo.toml

@@ -9,6 +9,7 @@ description = "Spawn asynchronous tasks in an executor-independent way."
 edition.workspace = true
 
 [dependencies]
+async-executor = { version = "1.13.1", optional = true }
 futures = "0.3.30"
 glib = { version = "0.20.0", optional = true }
 thiserror = "1.0"
@@ -19,12 +20,14 @@ tracing = { version = "0.1.40", optional = true }
 wasm-bindgen-futures = { version = "0.4.42", optional = true }
 
 [features]
+async-executor = ["dep:async-executor"]
 tracing = ["dep:tracing"]
 tokio = ["dep:tokio"]
 glib = ["dep:glib"]
 wasm-bindgen = ["dep:wasm-bindgen-futures"]
 futures-executor = ["futures/thread-pool", "futures/executor"]
 
+
 [package.metadata.docs.rs]
 all-features = true
 rustdoc-args = ["--cfg", "docsrs"]

any_spawner/src/lib.rs

@@ -246,6 +246,44 @@ impl Executor {
             .map_err(|_| ExecutorError::AlreadySet)?;
         Ok(())
     }
+
+    /// Globally sets the [`async_executor`] executor as the executor used to spawn tasks,
+    /// lazily creating a thread pool to spawn tasks into.
+    ///
+    /// Returns `Err(_)` if an executor has already been set.
+    ///
+    /// Requires the `async-executor` feature to be activated on this crate.
+    #[cfg(feature = "async-executor")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "async-executor")))]
+    pub fn init_async_executor() -> Result<(), ExecutorError> {
+        use async_executor::{Executor, LocalExecutor};
+
+        static THREAD_POOL: OnceLock<Executor> = OnceLock::new();
+        thread_local! {
+            static LOCAL_POOL: LocalExecutor<'static> = const { LocalExecutor::new() };
+        }
+
+        fn get_thread_pool() -> &'static Executor<'static> {
+            THREAD_POOL.get_or_init(Executor::new)
+        }
+
+        SPAWN
+            .set(|fut| {
+                get_thread_pool().spawn(fut).detach();
+            })
+            .map_err(|_| ExecutorError::AlreadySet)?;
+        SPAWN_LOCAL
+            .set(|fut| {
+                LOCAL_POOL.with(|pool| pool.spawn(fut).detach());
+            })
+            .map_err(|_| ExecutorError::AlreadySet)?;
+        POLL_LOCAL
+            .set(|| {
+                LOCAL_POOL.with(|pool| pool.try_tick());
+            })
+            .map_err(|_| ExecutorError::AlreadySet)?;
+        Ok(())
+    }
 }
 
 #[cfg(test)]