Name all the tasks! (#6726)

* Remove any implementation of `Spawn` or `Executor` from our task executors

* Fix compilation

* Rename `SpawnBlockingExecutor`

* Update primitives/core/src/traits.rs

Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>

* Fix tests

Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>

substrate/primitives/core/src/lib.rs

@@ -72,8 +72,6 @@ mod changes_trie;
 pub mod traits;
 pub mod testing;
 #[cfg(feature = "std")]
-pub mod tasks;
-#[cfg(feature = "std")]
 pub mod vrf;
 
 pub use self::hash::{H160, H256, H512, convert_hash};

substrate/primitives/core/src/tasks.rs

@@ -1,57 +0,0 @@
-// This file is part of Substrate.
-
-// Copyright (C) 2020 Parity Technologies (UK) Ltd.
-// SPDX-License-Identifier: Apache-2.0
-
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// 	http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-//! Module for low-level asynchronous processing.
-
-use crate::traits::CloneableSpawn;
-use futures::{executor, task};
-
-/// Simple task executor.
-///
-/// Uses single thread for scheduling tasks. Can be cloned and used in
-/// runtime host (implements `CloneableSpawn`).
-#[derive(Debug, Clone)]
-pub struct Executor {
-	pool: executor::ThreadPool,
-}
-
-impl Executor {
-	fn new() -> Self {
-		Self {
-			pool: executor::ThreadPool::builder().pool_size(1).create()
-				.expect("Failed to create task executor")
-		}
-	}
-}
-
-impl task::Spawn for Executor {
-	fn spawn_obj(&self, future: task::FutureObj<'static, ()>)
-	-> Result<(), task::SpawnError> {
-		self.pool.spawn_obj(future)
-	}
-}
-
-impl CloneableSpawn for Executor {
-	fn clone(&self) -> Box<dyn CloneableSpawn> {
-		Box::new(Clone::clone(self))
-	}
-}
-
-/// Create tasks executor.
-pub fn executor() -> Box<dyn CloneableSpawn> {
-	Box::new(Executor::new())
-}

substrate/primitives/core/src/testing.rs

@@ -359,16 +359,16 @@ macro_rules! wasm_export_functions {
 	};
 }
 
-/// An executor that supports spawning blocking futures in tests.
+/// A task executor that can be used in tests.
 ///
 /// Internally this just wraps a `ThreadPool` with a pool size of `8`. This
 /// should ensure that we have enough threads in tests for spawning blocking futures.
 #[cfg(feature = "std")]
 #[derive(Clone)]
-pub struct SpawnBlockingExecutor(futures::executor::ThreadPool);
+pub struct TaskExecutor(futures::executor::ThreadPool);
 
 #[cfg(feature = "std")]
-impl SpawnBlockingExecutor {
+impl TaskExecutor {
 	/// Create a new instance of `Self`.
 	pub fn new() -> Self {
 		let mut builder = futures::executor::ThreadPoolBuilder::new();
@@ -377,7 +377,7 @@ impl SpawnBlockingExecutor {
 }
 
 #[cfg(feature = "std")]
-impl crate::traits::SpawnNamed for SpawnBlockingExecutor {
+impl crate::traits::SpawnNamed for TaskExecutor {
 	fn spawn_blocking(&self, _: &'static str, future: futures::future::BoxFuture<'static, ()>) {
 		self.0.spawn_ok(future);
 	}

substrate/primitives/core/src/traits.rs

@@ -352,26 +352,21 @@ impl CallInWasmExt {
 	}
 }
 
-/// Something that can spawn tasks and also can be cloned.
-pub trait CloneableSpawn: futures::task::Spawn + Send + Sync {
-	/// Clone as heap-allocated handle.
-	fn clone(&self) -> Box<dyn CloneableSpawn>;
-}
-
 sp_externalities::decl_extension! {
 	/// Task executor extension.
-	pub struct TaskExecutorExt(Box<dyn CloneableSpawn>);
+	pub struct TaskExecutorExt(Box<dyn SpawnNamed>);
 }
 
 impl TaskExecutorExt {
 	/// New instance of task executor extension.
-	pub fn new(spawn_handle: Box<dyn CloneableSpawn>) -> Self {
-		Self(spawn_handle)
+	pub fn new(spawn_handle: impl SpawnNamed + Send + 'static) -> Self {
+		Self(Box::new(spawn_handle))
 	}
 }
 
-/// Something that can spawn futures (blocking and non-blocking) with am assigned name.
-pub trait SpawnNamed {
+/// Something that can spawn futures (blocking and non-blocking) with an assigned name.
+#[dyn_clonable::clonable]
+pub trait SpawnNamed: Clone + Send + Sync {
 	/// Spawn the given blocking future.
 	///
 	/// The given `name` is used to identify the future in tracing.
@@ -381,3 +376,13 @@ pub trait SpawnNamed {
 	/// The given `name` is used to identify the future in tracing.
 	fn spawn(&self, name: &'static str, future: futures::future::BoxFuture<'static, ()>);
 }
+
+impl SpawnNamed for Box<dyn SpawnNamed> {
+	fn spawn_blocking(&self, name: &'static str, future: futures::future::BoxFuture<'static, ()>) {
+		(**self).spawn_blocking(name, future)
+	}
+
+	fn spawn(&self, name: &'static str, future: futures::future::BoxFuture<'static, ()>) {
+		(**self).spawn(name, future)
+	}
+}