From bfe53477247adacec7e04cfd391673c30b071994 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bastian=20K=C3=B6cher?= <bkchr@users.noreply.github.com>
Date: Tue, 2 Jul 2019 10:39:41 +0200
Subject: [PATCH] Adds a `SpawnTaskHandle` to core service (#2992)

* Adds a `SpawnTaskHandle` to core service

* Fixes compilation

* Remove `into()`
---
 substrate/core/service/src/lib.rs | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/substrate/core/service/src/lib.rs b/substrate/core/service/src/lib.rs
index 4e6fb35508..3cadd1d406 100644
--- a/substrate/core/service/src/lib.rs
+++ b/substrate/core/service/src/lib.rs
@@ -110,6 +110,19 @@ pub fn new_client<Factory: components::ServiceFactory>(config: &FactoryFullConfi
 	Ok(client)
 }
 
+/// An handle for spawning tasks in the service.
+#[derive(Clone)]
+pub struct SpawnTaskHandle {
+	sender: mpsc::UnboundedSender<Box<dyn Future<Item = (), Error = ()> + Send>>,
+}
+
+impl SpawnTaskHandle {
+	/// Spawn a task to run the given future.
+	pub fn spawn_task(&self, task: impl Future<Item = (), Error = ()> + Send + 'static) {
+		let _ = self.sender.unbounded_send(Box::new(task));
+	}
+}
+
 /// Stream of events for connection established to a telemetry server.
 pub type TelemetryOnConnectNotifications = mpsc::UnboundedReceiver<()>;
 
@@ -512,8 +525,15 @@ impl<Components: components::Components> Service<Components> {
 	}
 
 	/// Spawns a task in the background that runs the future passed as parameter.
-	pub fn spawn_task(&self, task: Box<dyn Future<Item = (), Error = ()> + Send>) {
-		let _ = self.to_spawn_tx.unbounded_send(task);
+	pub fn spawn_task(&self, task: impl Future<Item = (), Error = ()> + Send + 'static) {
+		let _ = self.to_spawn_tx.unbounded_send(Box::new(task));
+	}
+
+	/// Returns a handle for spawning tasks.
+	pub fn spawn_task_handle(&self) -> SpawnTaskHandle {
+		SpawnTaskHandle {
+			sender: self.to_spawn_tx.clone(),
+		}
 	}
 
 	/// Get shared client instance.