Simplify

client/service/src/task_manager/mod.rs

@@ -18,7 +18,7 @@ use exit_future::Signal;
 use log::{debug, error};
 use futures::{
 	Future, FutureExt, StreamExt,
-	future::{select, Either, BoxFuture, select_all, join_all},
+	future::{select, Either, BoxFuture, join_all, try_join_all, pending},
 	sink::SinkExt,
 };
 use prometheus_endpoint::{
@@ -309,28 +309,14 @@ impl TaskManager {
 		Box::pin(async move {
 			let mut t1 = self.essential_failed_rx.next().fuse();
 			let mut t2 = self.on_exit.clone().fuse();
-
-			if self.children.is_empty() {
-				loop {
-					futures::select! {
-						_ = t1 => break Err(Error::Other("Essential task failed.".into())),
-						_ = t2 => break Ok(()),
-					}
-				}
-			} else {
-				let mut t3 = select_all(self.children.iter_mut().map(|x| x.future())).fuse();
-
-				loop {
-					futures::select! {
-						_ = t1 => break Err(Error::Other("Essential task failed.".into())),
-						_ = t2 => break Ok(()),
-						(res, _, _) = t3 => if res.is_err() {
-							break res;
-						} else {
-							continue;
-						},
-					}
-				}
+			let mut t3 = try_join_all(self.children.iter_mut().map(|x| x.future()))
+				// Never end this future if there is no error
+				.then(|res| async { Ok(res.map(|_| pending::<()>())?.await) }).boxed().fuse();
+
+			futures::select! {
+				_ = t1 => Err(Error::Other("Essential task failed.".into())),
+				_ = t2 => Ok(()),
+				res = t3 => res.map(|_| ()),
 			}
 		})
 	}