skip passed slots and wake up service correctly (#4212)

substrate/client/service/src/builder.rs

@@ -49,7 +49,7 @@ use sr_primitives::traits::{
 use substrate_executor::{NativeExecutor, NativeExecutionDispatch};
 use std::{
 	io::{Read, Write, Seek},
-	marker::PhantomData, sync::Arc, sync::atomic::AtomicBool, time::SystemTime
+	marker::PhantomData, sync::Arc, time::SystemTime
 };
 use sysinfo::{get_current_pid, ProcessExt, System, SystemExt};
 use tel::{telemetry, SUBSTRATE_INFO};
@@ -823,6 +823,9 @@ ServiceBuilder<
 		let (to_spawn_tx, to_spawn_rx) =
 			mpsc::unbounded::<Box<dyn Future<Item = (), Error = ()> + Send>>();
 
+		// A side-channel for essential tasks to communicate shutdown.
+		let (essential_failed_tx, essential_failed_rx) = mpsc::unbounded();
+
 		let import_queue = Box::new(import_queue);
 		let chain_info = client.info().chain;
 
@@ -1163,7 +1166,7 @@ ServiceBuilder<
 
 			let _ = to_spawn_tx.unbounded_send(Box::new(future));
     }
-    
+
 		// Instrumentation
 		if let Some(tracing_targets) = config.tracing_targets.as_ref() {
 			let subscriber = substrate_tracing::ProfilingSubscriber::new(
@@ -1183,7 +1186,8 @@ ServiceBuilder<
 			transaction_pool,
 			exit,
 			signal: Some(signal),
-			essential_failed: Arc::new(AtomicBool::new(false)),
+			essential_failed_tx,
+			essential_failed_rx,
 			to_spawn_tx,
 			to_spawn_rx,
 			to_poll: Vec::new(),