cleanup stream polls (#3397)

* metered-channel: remove dead code

* we don't need no fuse

* even more

polkadot/node/core/provisioner/src/lib.rs

@@ -191,7 +191,7 @@ impl ProvisioningJob {
 		};
 		loop {
 			futures::select! {
-				msg = self.receiver.next().fuse() => match msg {
+				msg = self.receiver.next() => match msg {
 					Some(RequestInherentData(_, return_sender)) => {
 						let _span = span.child("req-inherent-data");
 						let _timer = self.metrics.time_request_inherent_data();

polkadot/node/metered-channel/src/bounded.rs

@@ -153,34 +153,3 @@ impl<T> MeteredSender<T> {
 		})
 	}
 }
-
-impl<T> futures::sink::Sink<T> for MeteredSender<T> {
-	type Error = mpsc::SendError;
-
-	fn start_send(mut self: Pin<&mut Self>, item: T) -> Result<(), Self::Error> {
-		Pin::new(&mut self.inner).start_send(item)
-	}
-
-	fn poll_ready(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-		Pin::new(&mut self.inner).poll_ready(cx)
-	}
-
-	fn poll_close(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-		match Pin::new(&mut self.inner).poll_close(cx) {
-			val @ Poll::Ready(_)=> {
-				val
-			}
-			other => other,
-		}
-	}
-
-	fn poll_flush(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-		match Pin::new(&mut self.inner).poll_flush(cx) {
-			val @ Poll::Ready(_)=> {
-				self.meter.note_sent();
-				val
-			}
-			other => other,
-		}
-	}
-}

polkadot/node/network/bridge/src/lib.rs

@@ -830,7 +830,7 @@ async fn handle_network_messages<AD: validator_discovery::AuthorityDiscovery>(
 					}
 				}
 			},
-			req_res_event = request_multiplexer.next().fuse() => match req_res_event {
+			req_res_event = request_multiplexer.next() => match req_res_event {
 				None => return Err(UnexpectedAbort::RequestStreamConcluded),
 				Some(Err(err)) => {
 					network_service.report_peer(err.peer, MALFORMED_MESSAGE_COST);

polkadot/node/network/statement-distribution/src/lib.rs

@@ -595,14 +595,14 @@ impl Message {
 		// We are only fusing here to make `select` happy, in reality we will quit if one of those
 		// streams end:
 		let from_overseer = ctx.recv().fuse();
-		let from_requester = from_requester.next().fuse();
-		let from_responder = from_responder.next().fuse();
+		let from_requester = from_requester.next();
+		let from_responder = from_responder.next();
 		futures::pin_mut!(from_overseer, from_requester, from_responder);
-		futures::select!(
+		futures::select! {
 			msg = from_overseer => Message::Subsystem(msg.map_err(Fatal::SubsystemReceive)),
 			msg = from_requester => Message::Requester(msg),
 			msg = from_responder => Message::Responder(msg),
-		)
+		}
 	}
 }
 

polkadot/node/overseer/src/lib.rs

@@ -909,8 +909,8 @@ impl<M: Send + 'static> SubsystemContext for OverseerSubsystemContext<M> {
 				}
 			}
 
-			let mut await_message = self.messages.next().fuse();
-			let mut await_signal = self.signals.next().fuse();
+			let mut await_message = self.messages.next();
+			let mut await_signal = self.signals.next();
 			let signals_received = self.signals_received.load();
 			let pending_incoming = &mut self.pending_incoming;
 
@@ -1901,13 +1901,7 @@ where
 
 		loop {
 			select! {
-				msg = self.events_rx.next().fuse() => {
-					let msg = if let Some(msg) = msg {
-						msg
-					} else {
-						continue
-					};
-
+				msg = self.events_rx.select_next_some() => {
 					match msg {
 						Event::MsgToSubsystem(msg) => {
 							self.route_message(msg.into()).await?;
@@ -1927,16 +1921,7 @@ where
 						}
 					}
 				},
-				msg = self.to_overseer_rx.next() => {
-					let msg = match msg {
-						Some(m) => m,
-						None => {
-							// This is a fused stream so we will shut down after receiving all
-							// shutdown notifications.
-							continue
-						}
-					};
-
+				msg = self.to_overseer_rx.select_next_some() => {
 					match msg {
 						ToOverseer::SpawnJob { name, s } => {
 							self.spawn_job(name, s);
@@ -1946,16 +1931,14 @@ where
 						}
 					}
 				},
-				res = self.running_subsystems.next().fuse() => {
-					let finished = if let Some(finished) = res {
-						finished
-					} else {
-						continue
-					};
-
-					tracing::error!(target: LOG_TARGET, subsystem = ?finished, "subsystem finished unexpectedly");
+				res = self.running_subsystems.select_next_some() => {
+					tracing::error!(
+						target: LOG_TARGET,
+						subsystem = ?res,
+						"subsystem finished unexpectedly",
+					);
 					self.stop().await;
-					return finished;
+					return res;
 				},
 			}
 		}