Don't wait for dispute coordinator (#5157)

* Don't wait for dispute coordinator

in backing and approval-voting - we are single threaded there, so this
is blocking everything.

* Add missing import.

* Don't warn on dropped receiver.

polkadot/node/core/approval-voting/src/lib.rs

@@ -35,7 +35,7 @@ use polkadot_node_subsystem::{
 		ApprovalVotingMessage, AssignmentCheckError, AssignmentCheckResult,
 		AvailabilityRecoveryMessage, BlockDescription, CandidateValidationMessage, ChainApiMessage,
 		ChainSelectionMessage, DisputeCoordinatorMessage, HighestApprovedAncestorBlock,
-		ImportStatementsResult, RuntimeApiMessage, RuntimeApiRequest,
+		RuntimeApiMessage, RuntimeApiRequest,
 	},
 	overseer::{self, SubsystemSender as _},
 	FromOverseer, OverseerSignal, SpawnedSubsystem, SubsystemContext, SubsystemError,
@@ -950,7 +950,9 @@ async fn handle_actions(
 				dispute_statement,
 				validator_index,
 			} => {
-				let (pending_confirmation, confirmation_rx) = oneshot::channel();
+				// TODO: Log confirmation results in an efficient way:
+				// https://github.com/paritytech/polkadot/issues/5156
+				let (pending_confirmation, _confirmation_rx) = oneshot::channel();
 				ctx.send_message(DisputeCoordinatorMessage::ImportStatements {
 					candidate_hash,
 					candidate_receipt,
@@ -959,15 +961,6 @@ async fn handle_actions(
 					pending_confirmation,
 				})
 				.await;
-
-				match confirmation_rx.await {
-					Err(oneshot::Canceled) => {
-						gum::debug!(target: LOG_TARGET, "Dispute coordinator confirmation lost",)
-					},
-					Ok(ImportStatementsResult::ValidImport) => {},
-					Ok(ImportStatementsResult::InvalidImport) =>
-						gum::warn!(target: LOG_TARGET, "Failed to import statements of validity",),
-				}
 			},
 			Action::NoteApprovedInChainSelection(block_hash) => {
 				ctx.send_message(ChainSelectionMessage::Approved(block_hash)).await;

polkadot/node/core/approval-voting/src/tests.rs

@@ -25,6 +25,7 @@ use polkadot_node_primitives::{
 use polkadot_node_subsystem::{
 	messages::{
 		AllMessages, ApprovalVotingMessage, AssignmentCheckResult, AvailabilityRecoveryMessage,
+		ImportStatementsResult,
 	},
 	ActivatedLeaf, ActiveLeavesUpdate, LeafStatus,
 };