Update tokio to 0.2 again and remove TaskExecutors (#786)

* upgrade tokio again

* Remove WrappedExecutor

* switch to spawn_blocking

polkadot/collator/Cargo.toml

@@ -21,8 +21,8 @@ polkadot-network = { path = "../network" }
 polkadot-validation = { path = "../validation" }
 polkadot-service = { path = "../service" }
 log = "0.4.8"
-tokio = "0.1.22"
-futures-timer = "1.0"
+tokio = "0.2.10"
+futures-timer = "2.0"
 codec = { package = "parity-scale-codec", version = "1.1.0" }
 
 [dev-dependencies]

polkadot/collator/src/lib.rs

@@ -62,7 +62,7 @@ use polkadot_primitives::{
 	}
 };
 use polkadot_cli::{
-	ProvideRuntimeApi, AbstractService, ParachainHost, IsKusama, WrappedExecutor,
+	ProvideRuntimeApi, AbstractService, ParachainHost, IsKusama,
 	service::{self, Roles, SelectChain}
 };
 use polkadot_network::validation::{LeafWorkParams, ValidationNetwork};
@@ -308,7 +308,7 @@ fn run_collator_node<S, E, P, Extrinsic>(
 		Extrinsic: service::Codec + Send + Sync + 'static,
 {
 	let runtime = tokio::runtime::Runtime::new().map_err(|e| format!("{:?}", e))?;
-	let spawner = WrappedExecutor(service.spawn_task_handle());
+	let spawner = service.spawn_task_handle();
 
 	let client = service.client();
 	let network = service.network();
@@ -427,7 +427,7 @@ fn run_collator_node<S, E, P, Extrinsic>(
 						);
 
 						let exit = inner_exit_2.clone();
-						tokio::spawn(future::select(res.boxed(), exit).map(drop).map(|_| Ok(())).compat());
+						tokio::spawn(future::select(res.boxed(), exit));
 					});
 				}
 				future::ok(())
@@ -450,7 +450,7 @@ fn run_collator_node<S, E, P, Extrinsic>(
 					inner_exit.clone()
 				).map(drop);
 
-			tokio::spawn(future.map(|_| Ok(())).compat());
+			tokio::spawn(future);
 		}
 	}.boxed();