enable disputes (#3478)

* initial integration and migration code

* fix tests

* fix counting test

* assume the current version on missing file

* use SelectRelayChain

* remove duplicate metric

* Update node/service/src/lib.rs

Co-authored-by: Robert Habermeier <rphmeier@gmail.com>

* remove ApprovalCheckingVotingRule

* address my concern

* never mode for StagnantCheckInterval

* REVERTME: some logs

* w00t

* it's ugly but it works

* Revert "REVERTME: some logs"

This reverts commit e210505a2e83e31c381394924500b69277bb042e.

* it's handle, not handler

* fix a few typos

Co-authored-by: Robert Habermeier <rphmeier@gmail.com>

polkadot/Cargo.lock

@@ -6631,6 +6631,7 @@ dependencies = [
  "kv-log-macro",
  "lru",
  "metered-channel",
+ "parking_lot 0.11.1",
  "polkadot-node-metrics",
  "polkadot-node-network-protocol",
  "polkadot-node-primitives",
@@ -6976,6 +6977,9 @@ dependencies = [
  "polkadot-node-core-bitfield-signing",
  "polkadot-node-core-candidate-validation",
  "polkadot-node-core-chain-api",
+ "polkadot-node-core-chain-selection",
+ "polkadot-node-core-dispute-coordinator",
+ "polkadot-node-core-dispute-participation",
  "polkadot-node-core-parachains-inherent",
  "polkadot-node-core-provisioner",
  "polkadot-node-core-runtime-api",

polkadot/node/core/chain-selection/src/lib.rs

@@ -28,6 +28,7 @@ use polkadot_node_subsystem::{
 use kvdb::KeyValueDB;
 use parity_scale_codec::Error as CodecError;
 use futures::channel::oneshot;
+use futures::future::Either;
 use futures::prelude::*;
 
 use std::time::{UNIX_EPOCH, Duration,SystemTime};
@@ -244,7 +245,7 @@ impl Clock for SystemClock {
 
 /// The interval, in seconds to check for stagnant blocks.
 #[derive(Debug, Clone)]
-pub struct StagnantCheckInterval(Duration);
+pub struct StagnantCheckInterval(Option<Duration>);
 
 impl Default for StagnantCheckInterval {
 	fn default() -> Self {
@@ -255,28 +256,37 @@ impl Default for StagnantCheckInterval {
 		// between 2 validators is D + 5s.
 		const DEFAULT_STAGNANT_CHECK_INTERVAL: Duration = Duration::from_secs(5);
 
-		StagnantCheckInterval(DEFAULT_STAGNANT_CHECK_INTERVAL)
+		StagnantCheckInterval(Some(DEFAULT_STAGNANT_CHECK_INTERVAL))
 	}
 }
 
 impl StagnantCheckInterval {
 	/// Create a new stagnant-check interval wrapping the given duration.
 	pub fn new(interval: Duration) -> Self {
-		StagnantCheckInterval(interval)
+		StagnantCheckInterval(Some(interval))
+	}
+
+	/// Create a `StagnantCheckInterval` which never triggers.
+	pub fn never() -> Self {
+		StagnantCheckInterval(None)
 	}
 
 	fn timeout_stream(&self) -> impl Stream<Item = ()> {
-		let interval = self.0;
-		let mut delay = futures_timer::Delay::new(interval);
+		match self.0 {
+			Some(interval) => Either::Left({
+				let mut delay = futures_timer::Delay::new(interval);
 
-		futures::stream::poll_fn(move |cx| {
-			let poll = delay.poll_unpin(cx);
-			if poll.is_ready() {
-				delay.reset(interval)
-			}
+				futures::stream::poll_fn(move |cx| {
+					let poll = delay.poll_unpin(cx);
+					if poll.is_ready() {
+						delay.reset(interval)
+					}
 
-			poll.map(Some)
-		})
+					poll.map(Some)
+				})
+			}),
+			None => Either::Right(futures::stream::pending()),
+		}
 	}
 }
 

polkadot/node/malus/src/variant-a.rs

@@ -27,7 +27,7 @@ use polkadot_cli::{
 	create_default_subsystems,
 	service::{
 		AuthorityDiscoveryApi, AuxStore, BabeApi, Block, Error, HeaderBackend, Overseer,
-		OverseerGen, OverseerGenArgs, Handle, ParachainHost, ProvideRuntimeApi,
+		OverseerGen, OverseerGenArgs, OverseerHandle, ParachainHost, ProvideRuntimeApi,
 		SpawnNamed,
 	},
 	Cli,
@@ -73,7 +73,7 @@ impl OverseerGen for BehaveMaleficient {
 	fn generate<'a, Spawner, RuntimeClient>(
 		&self,
 		args: OverseerGenArgs<'a, Spawner, RuntimeClient>,
-	) -> Result<(Overseer<Spawner, Arc<RuntimeClient>>, Handle), Error>
+	) -> Result<(Overseer<Spawner, Arc<RuntimeClient>>, OverseerHandle), Error>
 	where
 		RuntimeClient: 'static + ProvideRuntimeApi<Block> + HeaderBackend<Block> + AuxStore,
 		RuntimeClient::Api: ParachainHost<Block> + BabeApi<Block> + AuthorityDiscoveryApi<Block>,

polkadot/node/overseer/Cargo.toml

@@ -10,6 +10,7 @@ client = { package = "sc-client-api", git = "https://github.com/paritytech/subst
 sp-api = { git = "https://github.com/paritytech/substrate", branch = "master" }
 futures = "0.3.15"
 futures-timer = "3.0.2"
+parking_lot = "0.11.1"
 polkadot-node-network-protocol = { path = "../network/protocol" }
 polkadot-node-primitives = { path = "../primitives" }
 polkadot-node-subsystem-types = { path = "../subsystem-types" }

polkadot/node/overseer/examples/minimal-example.rs

@@ -174,7 +174,7 @@ fn main() {
 			.replace_candidate_backing(Subsystem1)
 			;
 
-		let (overseer, _handler) = Overseer::new(
+		let (overseer, _handle) = Overseer::new(
 			vec![],
 			all_subsystems,
 			None,

polkadot/node/overseer/overseer-gen/examples/dummy.rs

@@ -123,7 +123,7 @@ impl SpawnNamed for DummySpawner{
 struct DummyCtx;
 
 fn main() {
-	let (overseer, _handler): (Xxx<_>, _) = Xxx::builder()
+	let (overseer, _handle): (Xxx<_>, _) = Xxx::builder()
 		.sub0(AwesomeSubSys::default())
 		.plinkos(GoblinTower::default())
 		.i_like_pi(::std::f64::consts::PI)

polkadot/node/overseer/src/lib.rs

@@ -73,6 +73,7 @@ use futures::{
 	Future, FutureExt, StreamExt,
 };
 use lru::LruCache;
+use parking_lot::RwLock;
 
 use polkadot_primitives::v1::{Block, BlockId,BlockNumber, Hash, ParachainHost};
 use client::{BlockImportNotification, BlockchainEvents, FinalityNotification};
@@ -159,13 +160,24 @@ impl<Client> HeadSupportsParachains for Arc<Client> where
 }
 
 
-/// A handler used to communicate with the [`Overseer`].
+/// A handle used to communicate with the [`Overseer`].
 ///
 /// [`Overseer`]: struct.Overseer.html
 #[derive(Clone)]
-pub struct Handle(pub OverseerHandle);
+pub enum Handle {
+	/// Used only at initialization to break the cyclic dependency.
+	// TODO: refactor in https://github.com/paritytech/polkadot/issues/3427
+	Disconnected(Arc<RwLock<Option<OverseerHandle>>>),
+	/// A handle to the overseer.
+	Connected(OverseerHandle),
+}
 
 impl Handle {
+	/// Create a new disconnected [`Handle`].
+	pub fn new_disconnected() -> Self {
+		Self::Disconnected(Arc::new(RwLock::new(None)))
+	}
+
 	/// Inform the `Overseer` that that some block was imported.
 	pub async fn block_imported(&mut self, block: BlockInfo) {
 		self.send_and_log_error(Event::BlockImported(block)).await
@@ -207,25 +219,59 @@ impl Handle {
 
 	/// Most basic operation, to stop a server.
 	async fn send_and_log_error(&mut self, event: Event) {
-		if self.0.send(event).await.is_err() {
-			tracing::info!(target: LOG_TARGET, "Failed to send an event to Overseer");
+		self.try_connect();
+		if let Self::Connected(ref mut handle) = self {
+			if handle.send(event).await.is_err() {
+				tracing::info!(target: LOG_TARGET, "Failed to send an event to Overseer");
+			}
+		} else {
+			tracing::warn!(target: LOG_TARGET, "Using a disconnected Handle to send to Overseer");
 		}
 	}
 
-	/// Whether the overseer handler is connected to an overseer.
-	pub fn is_connected(&self) -> bool {
-		true
-	}
-
-	/// Whether the handler is disconnected.
+	/// Whether the handle is disconnected.
 	pub fn is_disconnected(&self) -> bool {
-		false
+		match self {
+			Self::Disconnected(ref x) => x.read().is_none(),
+			_ => false,
+		}
 	}
 
-	/// Using this handler, connect another handler to the same
-	/// overseer, if any.
-	pub fn connect_other(&self, other: &mut Handle) {
-		*other = self.clone();
+	/// Connect this handle and all disconnected clones of it to the overseer.
+	pub fn connect_to_overseer(&mut self, handle: OverseerHandle) {
+		match self {
+			Self::Disconnected(ref mut x) => {
+				let mut maybe_handle = x.write();
+				if maybe_handle.is_none() {
+					tracing::info!(target: LOG_TARGET, "🖇️ Connecting all Handles to Overseer");
+					*maybe_handle = Some(handle);
+				} else {
+					tracing::warn!(
+						target: LOG_TARGET,
+						"Attempting to connect a clone of a connected Handle",
+					);
+				}
+			},
+			_ => {
+				tracing::warn!(
+					target: LOG_TARGET,
+					"Attempting to connect an already connected Handle",
+				);
+			},
+		}
+	}
+
+	/// Try upgrading from `Self::Disconnected` to `Self::Connected` state
+	/// after calling `connect_to_overseer` on `self` or a clone of `self`.
+	fn try_connect(&mut self) {
+		if let Self::Disconnected(ref mut x) = self {
+			let guard = x.write();
+			if let Some(ref h) = *guard {
+				let handle = h.clone();
+				drop(guard);
+				*self = Self::Connected(handle);
+			}
+		}
 	}
 }
 
@@ -301,7 +347,7 @@ pub enum ExternalRequest {
 /// import and finality notifications into the [`OverseerHandle`].
 pub async fn forward_events<P: BlockchainEvents<Block>>(
 	client: Arc<P>,
-	mut handler: Handle,
+	mut handle: Handle,
 ) {
 	let mut finality = client.finality_notification_stream();
 	let mut imports = client.import_notification_stream();
@@ -311,7 +357,7 @@ pub async fn forward_events<P: BlockchainEvents<Block>>(
 			f = finality.next() => {
 				match f {
 					Some(block) => {
-						handler.block_finalized(block.into()).await;
+						handle.block_finalized(block.into()).await;
 					}
 					None => break,
 				}
@@ -319,7 +365,7 @@ pub async fn forward_events<P: BlockchainEvents<Block>>(
 			i = imports.next() => {
 				match i {
 					Some(block) => {
-						handler.block_imported(block.into()).await;
+						handle.block_imported(block.into()).await;
 					}
 					None => break,
 				}
@@ -338,7 +384,6 @@ pub async fn forward_events<P: BlockchainEvents<Block>>(
 	network=NetworkBridgeEvent<protocol_v1::ValidationProtocol>,
 )]
 pub struct Overseer<SupportsParachains> {
-
 	#[subsystem(no_dispatch, CandidateValidationMessage)]
 	candidate_validation: CandidateValidation,
 
@@ -390,16 +435,16 @@ pub struct Overseer<SupportsParachains> {
 	#[subsystem(no_dispatch, GossipSupportMessage)]
 	gossip_support: GossipSupport,
 
-	#[subsystem(no_dispatch, wip, DisputeCoordinatorMessage)]
-	dipute_coordinator: DisputeCoordinator,
+	#[subsystem(no_dispatch, DisputeCoordinatorMessage)]
+	dispute_coordinator: DisputeCoordinator,
 
-	#[subsystem(no_dispatch, wip, DisputeParticipationMessage)]
+	#[subsystem(no_dispatch, DisputeParticipationMessage)]
 	dispute_participation: DisputeParticipation,
 
-	#[subsystem(no_dispatch, wip, DisputeDistributionMessage)]
-	dipute_distribution: DisputeDistribution,
+	#[subsystem(no_dispatch, DisputeDistributionMessage)]
+	dispute_distribution: DisputeDistribution,
 
-	#[subsystem(no_dispatch, wip, ChainSelectionMessage)]
+	#[subsystem(no_dispatch, ChainSelectionMessage)]
 	chain_selection: ChainSelection,
 
 	/// External listeners waiting for a hash to be in the active-leave set.
@@ -436,7 +481,7 @@ where
 	/// This returns the overseer along with an [`OverseerHandle`] which can
 	/// be used to send messages from external parts of the codebase.
 	///
-	/// The [`OverseerHandler`] returned from this function is connected to
+	/// The [`OverseerHandle`] returned from this function is connected to
 	/// the returned [`Overseer`].
 	///
 	/// ```text
@@ -527,7 +572,7 @@ where
 	/// let spawner = sp_core::testing::TaskExecutor::new();
 	/// let all_subsystems = AllSubsystems::<()>::dummy()
 	///		.replace_candidate_validation(ValidationSubsystem);
-	/// let (overseer, _handler) = Overseer::new(
+	/// let (overseer, _handle) = Overseer::new(
 	///     vec![],
 	///     all_subsystems,
 	///     None,
@@ -549,13 +594,13 @@ where
 	/// # 	});
 	/// # }
 	/// ```
-	pub fn new<CV, CB, SD, AD, AR, BS, BD, P, RA, AS, NB, CA, CG, CP, ApD, ApV, GS>(
+	pub fn new<CV, CB, SD, AD, AR, BS, BD, P, RA, AS, NB, CA, CG, CP, ApD, ApV, GS, DC, DP, DD, CS>(
 		leaves: impl IntoIterator<Item = BlockInfo>,
-		all_subsystems: AllSubsystems<CV, CB, SD, AD, AR, BS, BD, P, RA, AS, NB, CA, CG, CP, ApD, ApV, GS>,
+		all_subsystems: AllSubsystems<CV, CB, SD, AD, AR, BS, BD, P, RA, AS, NB, CA, CG, CP, ApD, ApV, GS, DC, DP, DD, CS>,
 		prometheus_registry: Option<&prometheus::Registry>,
 		supports_parachains: SupportsParachains,
 		s: S,
-	) -> SubsystemResult<(Self, Handle)>
+	) -> SubsystemResult<(Self, OverseerHandle)>
 	where
 		CV: Subsystem<OverseerSubsystemContext<CandidateValidationMessage>, SubsystemError> + Send,
 		CB: Subsystem<OverseerSubsystemContext<CandidateBackingMessage>, SubsystemError> + Send,
@@ -574,11 +619,15 @@ where
 		ApD: Subsystem<OverseerSubsystemContext<ApprovalDistributionMessage>, SubsystemError> + Send,
 		ApV: Subsystem<OverseerSubsystemContext<ApprovalVotingMessage>, SubsystemError> + Send,
 		GS: Subsystem<OverseerSubsystemContext<GossipSupportMessage>, SubsystemError> + Send,
+		DC: Subsystem<OverseerSubsystemContext<DisputeCoordinatorMessage>, SubsystemError> + Send,
+		DP: Subsystem<OverseerSubsystemContext<DisputeParticipationMessage>, SubsystemError> + Send,
+		DD: Subsystem<OverseerSubsystemContext<DisputeDistributionMessage>, SubsystemError> + Send,
+		CS: Subsystem<OverseerSubsystemContext<ChainSelectionMessage>, SubsystemError> + Send,
 		S: SpawnNamed,
 	{
 		let metrics: Metrics = <Metrics as MetricsTrait>::register(prometheus_registry)?;
 
-		let (mut overseer, handler) = Self::builder()
+		let (mut overseer, handle) = Self::builder()
 			.candidate_validation(all_subsystems.candidate_validation)
 			.candidate_backing(all_subsystems.candidate_backing)
 			.statement_distribution(all_subsystems.statement_distribution)
@@ -596,6 +645,10 @@ where
 			.approval_distribution(all_subsystems.approval_distribution)
 			.approval_voting(all_subsystems.approval_voting)
 			.gossip_support(all_subsystems.gossip_support)
+			.dispute_coordinator(all_subsystems.dispute_coordinator)
+			.dispute_participation(all_subsystems.dispute_participation)
+			.dispute_distribution(all_subsystems.dispute_distribution)
+			.chain_selection(all_subsystems.chain_selection)
 			.leaves(Vec::from_iter(
 				leaves.into_iter().map(|BlockInfo { hash, parent_hash: _, number }| (hash, number))
 			))
@@ -647,7 +700,7 @@ where
 			overseer.spawner().spawn("metrics_metronome", Box::pin(metronome));
 		}
 
-		Ok((overseer, Handle(handler)))
+		Ok((overseer, handle))
 	}
 
 	/// Stop the overseer.

polkadot/node/overseer/src/subsystems.rs

@@ -77,7 +77,7 @@ where
 pub struct AllSubsystems<
 	CV = (), CB = (), SD = (), AD = (), AR = (), BS = (), BD = (), P = (),
 	RA = (), AS = (), NB = (), CA = (), CG = (), CP = (), ApD = (), ApV = (),
-	GS = (),
+	GS = (), DC = (), DP = (), DD = (), CS = (),
 > {
 	/// A candidate validation subsystem.
 	pub candidate_validation: CV,
@@ -113,10 +113,18 @@ pub struct AllSubsystems<
 	pub approval_voting: ApV,
 	/// A Connection Request Issuer subsystem.
 	pub gossip_support: GS,
+	/// A Dispute Coordinator subsystem.
+	pub dispute_coordinator: DC,
+	/// A Dispute Participation subsystem.
+	pub dispute_participation: DP,
+	/// A Dispute Distribution subsystem.
+	pub dispute_distribution: DD,
+	/// A Chain Selection subsystem.
+	pub chain_selection: CS,
 }
 
-impl<CV, CB, SD, AD, AR, BS, BD, P, RA, AS, NB, CA, CG, CP, ApD, ApV, GS>
-	AllSubsystems<CV, CB, SD, AD, AR, BS, BD, P, RA, AS, NB, CA, CG, CP, ApD, ApV, GS>
+impl<CV, CB, SD, AD, AR, BS, BD, P, RA, AS, NB, CA, CG, CP, ApD, ApV, GS, DC, DP, DD, CS>
+	AllSubsystems<CV, CB, SD, AD, AR, BS, BD, P, RA, AS, NB, CA, CG, CP, ApD, ApV, GS, DC, DP, DD, CS>
 {
 	/// Create a new instance of [`AllSubsystems`].
 	///
@@ -148,6 +156,10 @@ impl<CV, CB, SD, AD, AR, BS, BD, P, RA, AS, NB, CA, CG, CP, ApD, ApV, GS>
 		DummySubsystem,
 		DummySubsystem,
 		DummySubsystem,
+		DummySubsystem,
+		DummySubsystem,
+		DummySubsystem,
+		DummySubsystem,
 	> {
 		AllSubsystems {
 			candidate_validation: DummySubsystem,
@@ -167,11 +179,15 @@ impl<CV, CB, SD, AD, AR, BS, BD, P, RA, AS, NB, CA, CG, CP, ApD, ApV, GS>
 			approval_distribution: DummySubsystem,
 			approval_voting: DummySubsystem,
 			gossip_support: DummySubsystem,
+			dispute_coordinator: DummySubsystem,
+			dispute_participation: DummySubsystem,
+			dispute_distribution: DummySubsystem,
+			chain_selection: DummySubsystem,
 		}
 	}
 
 	/// Reference every individual subsystem.
-	pub fn as_ref(&self) -> AllSubsystems<&'_ CV, &'_ CB, &'_ SD, &'_ AD, &'_ AR, &'_ BS, &'_ BD, &'_ P, &'_ RA, &'_ AS, &'_ NB, &'_ CA, &'_ CG, &'_ CP, &'_ ApD, &'_ ApV, &'_ GS> {
+	pub fn as_ref(&self) -> AllSubsystems<&'_ CV, &'_ CB, &'_ SD, &'_ AD, &'_ AR, &'_ BS, &'_ BD, &'_ P, &'_ RA, &'_ AS, &'_ NB, &'_ CA, &'_ CG, &'_ CP, &'_ ApD, &'_ ApV, &'_ GS, &'_ DC, &'_ DP, &'_ DD, &'_ CS> {
 		AllSubsystems {
 			candidate_validation: &self.candidate_validation,
 			candidate_backing: &self.candidate_backing,
@@ -190,6 +206,10 @@ impl<CV, CB, SD, AD, AR, BS, BD, P, RA, AS, NB, CA, CG, CP, ApD, ApV, GS>
 			approval_distribution: &self.approval_distribution,
 			approval_voting: &self.approval_voting,
 			gossip_support: &self.gossip_support,
+			dispute_coordinator: &self.dispute_coordinator,
+			dispute_participation: &self.dispute_participation,
+			dispute_distribution: &self.dispute_distribution,
+			chain_selection: &self.chain_selection,
 		}
 	}
 
@@ -213,6 +233,10 @@ impl<CV, CB, SD, AD, AR, BS, BD, P, RA, AS, NB, CA, CG, CP, ApD, ApV, GS>
 			<Mapper as MapSubsystem<ApD>>::Output,
 			<Mapper as MapSubsystem<ApV>>::Output,
 			<Mapper as MapSubsystem<GS>>::Output,
+			<Mapper as MapSubsystem<DC>>::Output,
+			<Mapper as MapSubsystem<DP>>::Output,
+			<Mapper as MapSubsystem<DD>>::Output,
+			<Mapper as MapSubsystem<CS>>::Output,
 		>
 	where
 		Mapper: MapSubsystem<CV>,
@@ -232,6 +256,10 @@ impl<CV, CB, SD, AD, AR, BS, BD, P, RA, AS, NB, CA, CG, CP, ApD, ApV, GS>
 		Mapper: MapSubsystem<ApD>,
 		Mapper: MapSubsystem<ApV>,
 		Mapper: MapSubsystem<GS>,
+		Mapper: MapSubsystem<DC>,
+		Mapper: MapSubsystem<DP>,
+		Mapper: MapSubsystem<DD>,
+		Mapper: MapSubsystem<CS>,
 	{
 		AllSubsystems {
 			candidate_validation: <Mapper as MapSubsystem<CV>>::map_subsystem(&mapper, self.candidate_validation),
@@ -251,6 +279,10 @@ impl<CV, CB, SD, AD, AR, BS, BD, P, RA, AS, NB, CA, CG, CP, ApD, ApV, GS>
 			approval_distribution: <Mapper as MapSubsystem<ApD>>::map_subsystem(&mapper, self.approval_distribution),
 			approval_voting: <Mapper as MapSubsystem<ApV>>::map_subsystem(&mapper, self.approval_voting),
 			gossip_support: <Mapper as MapSubsystem<GS>>::map_subsystem(&mapper, self.gossip_support),
+			dispute_coordinator: <Mapper as MapSubsystem<DC>>::map_subsystem(&mapper, self.dispute_coordinator),
+			dispute_participation: <Mapper as MapSubsystem<DP>>::map_subsystem(&mapper, self.dispute_participation),
+			dispute_distribution: <Mapper as MapSubsystem<DD>>::map_subsystem(&mapper, self.dispute_distribution),
+			chain_selection: <Mapper as MapSubsystem<CS>>::map_subsystem(&mapper, self.chain_selection),
 		}
 	}
 }

polkadot/node/overseer/src/tests.rs

@@ -18,6 +18,7 @@ use std::sync::atomic;
 use std::collections::HashMap;
 use std::task::{Poll};
 use futures::{executor, pin_mut, select, FutureExt, pending, poll, stream};
+use futures::channel::mpsc;
 
 use polkadot_primitives::v1::{CollatorPair, CandidateHash};
 use polkadot_node_primitives::{CollationResult, CollationGenerationConfig, PoV, BlockData};
@@ -166,13 +167,14 @@ fn overseer_works() {
 			.replace_candidate_validation(TestSubsystem1(s1_tx))
 			.replace_candidate_backing(TestSubsystem2(s2_tx));
 
-		let (overseer, mut handler) = Overseer::new(
+		let (overseer, handle) = Overseer::new(
 			vec![],
 			all_subsystems,
 			None,
 			MockSupportsParachains,
 			spawner,
 		).unwrap();
+		let mut handle = Handle::Connected(handle);
 		let overseer_fut = overseer.run().fuse();
 
 		pin_mut!(overseer_fut);
@@ -188,7 +190,7 @@ fn overseer_works() {
 						Some(msg) => {
 							s1_results.push(msg);
 							if s1_results.len() == 10 {
-								handler.stop().await;
+								handle.stop().await;
 							}
 						}
 						None => break,
@@ -236,21 +238,22 @@ fn overseer_metrics_work() {
 
 		let all_subsystems = AllSubsystems::<()>::dummy();
 		let registry = prometheus::Registry::new();
-		let (overseer, mut handler) = Overseer::new(
+		let (overseer, handle) = Overseer::new(
 			vec![first_block],
 			all_subsystems,
 			Some(&registry),
 			MockSupportsParachains,
 			spawner,
 		).unwrap();
+		let mut handle = Handle::Connected(handle);
 		let overseer_fut = overseer.run().fuse();
 
 		pin_mut!(overseer_fut);
 
-		handler.block_imported(second_block).await;
-		handler.block_imported(third_block).await;
-		handler.send_msg_anon(AllMessages::CandidateValidation(test_candidate_validation_msg())).await;
-		handler.stop().await;
+		handle.block_imported(second_block).await;
+		handle.block_imported(third_block).await;
+		handle.send_msg_anon(AllMessages::CandidateValidation(test_candidate_validation_msg())).await;
+		handle.stop().await;
 
 		select! {
 			res = overseer_fut => {
@@ -398,13 +401,14 @@ fn overseer_start_stop_works() {
 		let all_subsystems = AllSubsystems::<()>::dummy()
 			.replace_candidate_validation(TestSubsystem5(tx_5))
 			.replace_candidate_backing(TestSubsystem6(tx_6));
-		let (overseer, mut handler) = Overseer::new(
+		let (overseer, handle) = Overseer::new(
 			vec![first_block],
 			all_subsystems,
 			None,
 			MockSupportsParachains,
 			spawner,
 		).unwrap();
+		let mut handle = Handle::Connected(handle);
 
 		let overseer_fut = overseer.run().fuse();
 		pin_mut!(overseer_fut);
@@ -412,8 +416,8 @@ fn overseer_start_stop_works() {
 		let mut ss5_results = Vec::new();
 		let mut ss6_results = Vec::new();
 
-		handler.block_imported(second_block).await;
-		handler.block_imported(third_block).await;
+		handle.block_imported(second_block).await;
+		handle.block_imported(third_block).await;
 
 		let expected_heartbeats = vec![
 			OverseerSignal::ActiveLeaves(ActiveLeavesUpdate::start_work(ActivatedLeaf {
@@ -463,7 +467,7 @@ fn overseer_start_stop_works() {
 
 			if ss5_results.len() == expected_heartbeats.len() &&
 				ss6_results.len() == expected_heartbeats.len() {
-					handler.stop().await;
+					handle.stop().await;
 			}
 		}
 
@@ -507,13 +511,14 @@ fn overseer_finalize_works() {
 			.replace_candidate_backing(TestSubsystem6(tx_6));
 
 		// start with two forks of different height.
-		let (overseer, mut handler) = Overseer::new(
+		let (overseer, handle) = Overseer::new(
 			vec![first_block, second_block],
 			all_subsystems,
 			None,
 			MockSupportsParachains,
 			spawner,
 		).unwrap();
+		let mut handle = Handle::Connected(handle);
 
 		let overseer_fut = overseer.run().fuse();
 		pin_mut!(overseer_fut);
@@ -522,7 +527,7 @@ fn overseer_finalize_works() {
 		let mut ss6_results = Vec::new();
 
 		// this should stop work on both forks we started with earlier.
-		handler.block_finalized(third_block).await;
+		handle.block_finalized(third_block).await;
 
 		let expected_heartbeats = vec![
 			OverseerSignal::ActiveLeaves(ActiveLeavesUpdate {
@@ -569,7 +574,7 @@ fn overseer_finalize_works() {
 			}
 
 			if ss5_results.len() == expected_heartbeats.len() && ss6_results.len() == expected_heartbeats.len() {
-				handler.stop().await;
+				handle.stop().await;
 			}
 		}
 
@@ -607,21 +612,22 @@ fn do_not_send_empty_leaves_update_on_block_finalization() {
 		let all_subsystems = AllSubsystems::<()>::dummy()
 			.replace_candidate_backing(TestSubsystem6(tx_5));
 
-		let (overseer, mut handler) = Overseer::new(
+		let (overseer, handle) = Overseer::new(
 			Vec::new(),
 			all_subsystems,
 			None,
 			MockSupportsParachains,
 			spawner,
 		).unwrap();
+		let mut handle = Handle::Connected(handle);
 
 		let overseer_fut = overseer.run().fuse();
 		pin_mut!(overseer_fut);
 
 		let mut ss5_results = Vec::new();
 
-		handler.block_finalized(finalized_block.clone()).await;
-		handler.block_imported(imported_block.clone()).await;
+		handle.block_finalized(finalized_block.clone()).await;
+		handle.block_imported(imported_block.clone()).await;
 
 		let expected_heartbeats = vec![
 			OverseerSignal::ActiveLeaves(ActiveLeavesUpdate {
@@ -652,7 +658,7 @@ fn do_not_send_empty_leaves_update_on_block_finalization() {
 			}
 
 			if ss5_results.len() == expected_heartbeats.len() {
-				handler.stop().await;
+				handle.stop().await;
 			}
 		}
 
@@ -809,10 +815,35 @@ fn test_approval_voting_msg() -> ApprovalVotingMessage {
 	ApprovalVotingMessage::ApprovedAncestor(Default::default(), 0, sender)
 }
 
+fn test_dispute_coordinator_msg() -> DisputeCoordinatorMessage {
+	let (sender, _) = oneshot::channel();
+	DisputeCoordinatorMessage::RecentDisputes(sender)
+}
+
+fn test_dispute_participation_msg() -> DisputeParticipationMessage {
+	let (sender, _) = oneshot::channel();
+	DisputeParticipationMessage::Participate {
+		candidate_hash: Default::default(),
+		candidate_receipt: Default::default(),
+		session: 0,
+		n_validators: 0,
+		report_availability: sender,
+	}
+}
+
+fn test_dispute_distribution_msg() -> DisputeDistributionMessage {
+	let (_, receiver) = mpsc::channel(1);
+	DisputeDistributionMessage::DisputeSendingReceiver(receiver)
+}
+
+fn test_chain_selection_msg() -> ChainSelectionMessage {
+	ChainSelectionMessage::Approved(Default::default())
+}
+
 // Checks that `stop`, `broadcast_signal` and `broadcast_message` are implemented correctly.
 #[test]
 fn overseer_all_subsystems_receive_signals_and_messages() {
-	const NUM_SUBSYSTEMS: usize = 17;
+	const NUM_SUBSYSTEMS: usize = 21;
 	// -3 for BitfieldSigning, GossipSupport and AvailabilityDistribution
 	const NUM_SUBSYSTEMS_MESSAGED: usize = NUM_SUBSYSTEMS - 3;
 
@@ -846,20 +877,25 @@ fn overseer_all_subsystems_receive_signals_and_messages() {
 			approval_distribution: subsystem.clone(),
 			approval_voting: subsystem.clone(),
 			gossip_support: subsystem.clone(),
+			dispute_coordinator: subsystem.clone(),
+			dispute_participation: subsystem.clone(),
+			dispute_distribution: subsystem.clone(),
+			chain_selection: subsystem.clone(),
 		};
-		let (overseer, mut handler) = Overseer::new(
+		let (overseer, handle) = Overseer::new(
 			vec![],
 			all_subsystems,
 			None,
 			MockSupportsParachains,
 			spawner,
 		).unwrap();
+		let mut handle = Handle::Connected(handle);
 		let overseer_fut = overseer.run().fuse();
 
 		pin_mut!(overseer_fut);
 
 		// send a signal to each subsystem
-		handler.block_imported(BlockInfo {
+		handle.block_imported(BlockInfo {
 			hash: Default::default(),
 			parent_hash: Default::default(),
 			number: Default::default(),
@@ -867,22 +903,26 @@ fn overseer_all_subsystems_receive_signals_and_messages() {
 
 		// send a msg to each subsystem
 		// except for BitfieldSigning and GossipSupport as the messages are not instantiable
-		handler.send_msg_anon(AllMessages::CandidateValidation(test_candidate_validation_msg())).await;
-		handler.send_msg_anon(AllMessages::CandidateBacking(test_candidate_backing_msg())).await;
-		handler.send_msg_anon(AllMessages::CollationGeneration(test_collator_generation_msg())).await;
-		handler.send_msg_anon(AllMessages::CollatorProtocol(test_collator_protocol_msg())).await;
-		handler.send_msg_anon(AllMessages::StatementDistribution(test_statement_distribution_msg())).await;
-		handler.send_msg_anon(AllMessages::AvailabilityRecovery(test_availability_recovery_msg())).await;
-		// handler.send_msg_anon(AllMessages::BitfieldSigning(test_bitfield_signing_msg())).await;
-		// handler.send_msg_anon(AllMessages::GossipSupport(test_bitfield_signing_msg())).await;
-		handler.send_msg_anon(AllMessages::BitfieldDistribution(test_bitfield_distribution_msg())).await;
-		handler.send_msg_anon(AllMessages::Provisioner(test_provisioner_msg())).await;
-		handler.send_msg_anon(AllMessages::RuntimeApi(test_runtime_api_msg())).await;
-		handler.send_msg_anon(AllMessages::AvailabilityStore(test_availability_store_msg())).await;
-		handler.send_msg_anon(AllMessages::NetworkBridge(test_network_bridge_msg())).await;
-		handler.send_msg_anon(AllMessages::ChainApi(test_chain_api_msg())).await;
-		handler.send_msg_anon(AllMessages::ApprovalDistribution(test_approval_distribution_msg())).await;
-		handler.send_msg_anon(AllMessages::ApprovalVoting(test_approval_voting_msg())).await;
+		handle.send_msg_anon(AllMessages::CandidateValidation(test_candidate_validation_msg())).await;
+		handle.send_msg_anon(AllMessages::CandidateBacking(test_candidate_backing_msg())).await;
+		handle.send_msg_anon(AllMessages::CollationGeneration(test_collator_generation_msg())).await;
+		handle.send_msg_anon(AllMessages::CollatorProtocol(test_collator_protocol_msg())).await;
+		handle.send_msg_anon(AllMessages::StatementDistribution(test_statement_distribution_msg())).await;
+		handle.send_msg_anon(AllMessages::AvailabilityRecovery(test_availability_recovery_msg())).await;
+		// handle.send_msg_anon(AllMessages::BitfieldSigning(test_bitfield_signing_msg())).await;
+		// handle.send_msg_anon(AllMessages::GossipSupport(test_bitfield_signing_msg())).await;
+		handle.send_msg_anon(AllMessages::BitfieldDistribution(test_bitfield_distribution_msg())).await;
+		handle.send_msg_anon(AllMessages::Provisioner(test_provisioner_msg())).await;
+		handle.send_msg_anon(AllMessages::RuntimeApi(test_runtime_api_msg())).await;
+		handle.send_msg_anon(AllMessages::AvailabilityStore(test_availability_store_msg())).await;
+		handle.send_msg_anon(AllMessages::NetworkBridge(test_network_bridge_msg())).await;
+		handle.send_msg_anon(AllMessages::ChainApi(test_chain_api_msg())).await;
+		handle.send_msg_anon(AllMessages::ApprovalDistribution(test_approval_distribution_msg())).await;
+		handle.send_msg_anon(AllMessages::ApprovalVoting(test_approval_voting_msg())).await;
+		handle.send_msg_anon(AllMessages::DisputeCoordinator(test_dispute_coordinator_msg())).await;
+		handle.send_msg_anon(AllMessages::DisputeParticipation(test_dispute_participation_msg())).await;
+		handle.send_msg_anon(AllMessages::DisputeDistribution(test_dispute_distribution_msg())).await;
+		handle.send_msg_anon(AllMessages::ChainSelection(test_chain_selection_msg())).await;
 
 		// Wait until all subsystems have received. Otherwise the messages might race against
 		// the conclude signal.
@@ -903,7 +943,7 @@ fn overseer_all_subsystems_receive_signals_and_messages() {
 		}
 
 		// send a stop signal to each subsystems
-		handler.stop().await;
+		handle.stop().await;
 
 		let res = overseer_fut.await;
 		assert_eq!(stop_signals_received.load(atomic::Ordering::SeqCst), NUM_SUBSYSTEMS);
@@ -933,6 +973,10 @@ fn context_holds_onto_message_until_enough_signals_received() {
 	let (approval_distribution_bounded_tx, _) = metered::channel(CHANNEL_CAPACITY);
 	let (approval_voting_bounded_tx, _) = metered::channel(CHANNEL_CAPACITY);
 	let (gossip_support_bounded_tx, _) = metered::channel(CHANNEL_CAPACITY);
+	let (dispute_coordinator_bounded_tx, _) = metered::channel(CHANNEL_CAPACITY);
+	let (dispute_participation_bounded_tx, _) = metered::channel(CHANNEL_CAPACITY);
+	let (dispute_distribution_bounded_tx, _) = metered::channel(CHANNEL_CAPACITY);
+	let (chain_selection_bounded_tx, _) = metered::channel(CHANNEL_CAPACITY);
 
 	let (candidate_validation_unbounded_tx, _) = metered::unbounded();
 	let (candidate_backing_unbounded_tx, _) = metered::unbounded();
@@ -951,6 +995,10 @@ fn context_holds_onto_message_until_enough_signals_received() {
 	let (approval_distribution_unbounded_tx, _) = metered::unbounded();
 	let (approval_voting_unbounded_tx, _) = metered::unbounded();
 	let (gossip_support_unbounded_tx, _) = metered::unbounded();
+	let (dispute_coordinator_unbounded_tx, _) = metered::unbounded();
+	let (dispute_participation_unbounded_tx, _) = metered::unbounded();
+	let (dispute_distribution_unbounded_tx, _) = metered::unbounded();
+	let (chain_selection_unbounded_tx, _) = metered::unbounded();
 
 	let channels_out = ChannelsOut {
 		candidate_validation: candidate_validation_bounded_tx.clone(),
@@ -970,6 +1018,10 @@ fn context_holds_onto_message_until_enough_signals_received() {
 		approval_distribution: approval_distribution_bounded_tx.clone(),
 		approval_voting: approval_voting_bounded_tx.clone(),
 		gossip_support: gossip_support_bounded_tx.clone(),
+		dispute_coordinator: dispute_coordinator_bounded_tx.clone(),
+		dispute_participation: dispute_participation_bounded_tx.clone(),
+		dispute_distribution: dispute_distribution_bounded_tx.clone(),
+		chain_selection: chain_selection_bounded_tx.clone(),
 
 		candidate_validation_unbounded: candidate_validation_unbounded_tx.clone(),
 		candidate_backing_unbounded: candidate_backing_unbounded_tx.clone(),
@@ -988,6 +1040,10 @@ fn context_holds_onto_message_until_enough_signals_received() {
 		approval_distribution_unbounded: approval_distribution_unbounded_tx.clone(),
 		approval_voting_unbounded: approval_voting_unbounded_tx.clone(),
 		gossip_support_unbounded: gossip_support_unbounded_tx.clone(),
+		dispute_coordinator_unbounded: dispute_coordinator_unbounded_tx.clone(),
+		dispute_participation_unbounded: dispute_participation_unbounded_tx.clone(),
+		dispute_distribution_unbounded: dispute_distribution_unbounded_tx.clone(),
+		chain_selection_unbounded: chain_selection_unbounded_tx.clone(),
 	};
 
 	let (mut signal_tx, signal_rx) = metered::channel(CHANNEL_CAPACITY);

polkadot/node/service/Cargo.toml

@@ -103,6 +103,9 @@ polkadot-node-core-backing = { path = "../core/backing", optional = true }
 polkadot-node-core-bitfield-signing = { path = "../core/bitfield-signing", optional = true }
 polkadot-node-core-candidate-validation = { path = "../core/candidate-validation", optional = true }
 polkadot-node-core-chain-api = { path = "../core/chain-api", optional = true }
+polkadot-node-core-chain-selection = { path = "../core/chain-selection", optional = true }
+polkadot-node-core-dispute-coordinator = { path = "../core/dispute-coordinator", optional = true }
+polkadot-node-core-dispute-participation = { path = "../core/dispute-participation", optional = true }
 polkadot-node-core-provisioner = { path = "../core/provisioner", optional = true }
 polkadot-node-core-runtime-api = { path = "../core/runtime-api", optional = true }
 polkadot-statement-distribution = { path = "../network/statement-distribution", optional = true }
@@ -133,6 +136,9 @@ full-node = [
 	"polkadot-node-core-bitfield-signing",
 	"polkadot-node-core-candidate-validation",
 	"polkadot-node-core-chain-api",
+	"polkadot-node-core-chain-selection",
+	"polkadot-node-core-dispute-coordinator",
+	"polkadot-node-core-dispute-participation",
 	"polkadot-node-core-provisioner",
 	"polkadot-node-core-runtime-api",
 	"polkadot-statement-distribution",

polkadot/node/service/src/grandpa_support.rs

@@ -23,179 +23,7 @@ use sp_runtime::generic::BlockId;
 use sp_runtime::traits::Header as _;
 
 #[cfg(feature = "full-node")]
-use {
-	polkadot_primitives::v1::{Hash, Block as PolkadotBlock, Header as PolkadotHeader},
-	polkadot_subsystem::messages::ApprovalVotingMessage,
-	prometheus_endpoint::{self, Registry},
-	polkadot_overseer::Handle,
-	futures::channel::oneshot,
-};
-
-/// A custom GRANDPA voting rule that acts as a diagnostic for the approval
-/// voting subsystem's desired votes.
-///
-/// The practical effect of this voting rule is to implement a fixed delay of
-/// blocks and to issue a prometheus metric on the lag behind the head that
-/// approval checking would indicate.
-#[cfg(feature = "full-node")]
-#[derive(Clone)]
-pub(crate) struct ApprovalCheckingVotingRule {
-	checking_lag: Option<prometheus_endpoint::Gauge<prometheus_endpoint::U64>>,
-	overseer: Handle,
-}
-
-#[cfg(feature = "full-node")]
-impl ApprovalCheckingVotingRule {
-	/// Create a new approval checking diagnostic voting rule.
-	pub fn new(overseer: Handle, registry: Option<&Registry>)
-		-> Result<Self, prometheus_endpoint::PrometheusError>
-	{
-		Ok(ApprovalCheckingVotingRule {
-			checking_lag: if let Some(registry) = registry {
-				Some(prometheus_endpoint::register(
-					prometheus_endpoint::Gauge::with_opts(
-						prometheus_endpoint::Opts::new(
-							"parachain_approval_checking_finality_lag",
-							"How far behind the head of the chain the Approval Checking protocol wants to vote",
-						)
-					)?,
-					registry,
-				)?)
-			} else {
-				None
-			},
-			overseer,
-		})
-	}
-}
-
-#[cfg(feature = "full-node")]
-#[derive(Debug, PartialEq)]
-/// Vote explicitly on the given hash.
-enum ParachainVotingRuleTarget<H, N> {
-	Explicit((H, N)),
-	/// Vote on the current target.
-	Current,
-	/// Vote on the base target - the minimal possible vote.
-	Base,
-}
-
-#[cfg(feature = "full-node")]
-fn approval_checking_vote_to_grandpa_vote<H, N: PartialOrd>(
-	approval_checking_vote: Option<(H, N)>,
-	current_number: N,
-) -> ParachainVotingRuleTarget<H, N> {
-	match approval_checking_vote {
-		Some((hash, number)) => if number > current_number {
-			// respect other voting rule.
-			ParachainVotingRuleTarget::Current
-		} else {
-			ParachainVotingRuleTarget::Explicit((hash, number))
-		},
-		// If approval-voting chooses 'None', that means we should vote on the base (last round estimate).
-		None => ParachainVotingRuleTarget::Base,
-	}
-}
-
-/// The maximum amount of unfinalized blocks we are willing to allow due to approval checking lag.
-/// This is a safety net that should be removed at some point in the future.
-#[cfg(feature = "full-node")]
-const MAX_APPROVAL_CHECKING_FINALITY_LAG: polkadot_primitives::v1::BlockNumber = 50;
-
-#[cfg(feature = "full-node")]
-impl<B> grandpa::VotingRule<PolkadotBlock, B> for ApprovalCheckingVotingRule
-	where B: sp_blockchain::HeaderBackend<PolkadotBlock> + 'static
-{
-	fn restrict_vote(
-		&self,
-		backend: Arc<B>,
-		base: &PolkadotHeader,
-		best_target: &PolkadotHeader,
-		current_target: &PolkadotHeader,
-	) -> grandpa::VotingRuleResult<PolkadotBlock> {
-		// Query approval checking and issue metrics.
-		let mut overseer = self.overseer.clone();
-		let checking_lag = self.checking_lag.clone();
-
-		let best_hash = best_target.hash();
-		let best_number = best_target.number.clone();
-		let best_header = best_target.clone();
-
-		let current_hash = current_target.hash();
-		let current_number = current_target.number.clone();
-
-		let base_hash = base.hash();
-		let base_number = base.number;
-
-		Box::pin(async move {
-			let (tx, rx) = oneshot::channel();
-			let approval_checking_subsystem_vote = {
-				overseer.send_msg(
-					ApprovalVotingMessage::ApprovedAncestor(
-						best_hash,
-						base_number,
-						tx,
-					),
-					std::any::type_name::<Self>(),
-				).await;
-
-				rx.await.ok().and_then(|v| v)
-			};
-
-			let approval_checking_subsystem_lag = approval_checking_subsystem_vote.map_or(
-				best_number - base_number,
-				|(_h, n)| best_number - n,
-			);
-
-			if let Some(ref checking_lag) = checking_lag {
-				checking_lag.set(approval_checking_subsystem_lag as _);
-			}
-
-			let min_vote = {
-				let diff = best_number.saturating_sub(base_number);
-				if diff >= MAX_APPROVAL_CHECKING_FINALITY_LAG {
-					// Catch up to the best, with some extra lag.
-					let target_number = best_number - MAX_APPROVAL_CHECKING_FINALITY_LAG;
-					if target_number >= current_number {
-						Some((current_hash, current_number))
-					} else {
-						walk_backwards_to_target_block(&*backend, target_number, &best_header).ok()
-					}
-				} else {
-					Some((base_hash, base_number))
-				}
-			};
-
-			let vote = match approval_checking_vote_to_grandpa_vote(
-				approval_checking_subsystem_vote,
-				current_number,
-			) {
-				ParachainVotingRuleTarget::Explicit(vote) => {
-					if min_vote.as_ref().map_or(false, |min| min.1 > vote.1) {
-						min_vote
-					} else {
-						Some(vote)
-					}
-				}
-				ParachainVotingRuleTarget::Current => Some((current_hash, current_number)),
-				ParachainVotingRuleTarget::Base => min_vote.or(Some((base_hash, base_number))),
-			};
-
-			tracing::trace!(
-				target: "parachain::approval-voting",
-				?vote,
-				?approval_checking_subsystem_vote,
-				approval_checking_subsystem_lag,
-				current_number,
-				best_number,
-				base_number,
-				"GRANDPA: voting based on approved ancestor.",
-			);
-
-			vote
-		})
-	}
-}
+use polkadot_primitives::v1::Hash;
 
 /// Returns the block hash of the block at the given `target_number` by walking
 /// backwards from the given `current_header`.
@@ -433,7 +261,6 @@ mod tests {
 	use sp_runtime::{generic::BlockId, traits::Header};
 	use consensus_common::BlockOrigin;
 	use std::sync::Arc;
-	use super::{approval_checking_vote_to_grandpa_vote, ParachainVotingRuleTarget};
 
 	#[test]
 	fn grandpa_pause_voting_rule_works() {
@@ -545,27 +372,4 @@ mod tests {
 			None,
 		);
 	}
-
-	#[test]
-	fn approval_checking_to_grandpa_rules() {
-		assert_eq!(
-			approval_checking_vote_to_grandpa_vote::<(), _>(None, 5),
-			ParachainVotingRuleTarget::Base,
-		);
-
-		assert_eq!(
-			approval_checking_vote_to_grandpa_vote(Some(("2", 2)), 3),
-			ParachainVotingRuleTarget::Explicit(("2", 2)),
-		);
-
-		assert_eq!(
-			approval_checking_vote_to_grandpa_vote(Some(("2", 2)), 2),
-			ParachainVotingRuleTarget::Explicit(("2", 2)),
-		);
-
-		assert_eq!(
-			approval_checking_vote_to_grandpa_vote(Some(("2", 2)), 1),
-			ParachainVotingRuleTarget::Current,
-		);
-	}
 }

polkadot/node/service/src/lib.rs

@@ -42,6 +42,11 @@ use {
 	polkadot_node_core_av_store::Error as AvailabilityError,
 	polkadot_node_core_approval_voting::Config as ApprovalVotingConfig,
 	polkadot_node_core_candidate_validation::Config as CandidateValidationConfig,
+	polkadot_node_core_chain_selection::{
+		self as chain_selection_subsystem,
+		Config as ChainSelectionConfig,
+	},
+	polkadot_node_core_dispute_coordinator::Config as DisputeCoordinatorConfig,
 	polkadot_overseer::BlockInfo,
 	sp_trie::PrefixedMemoryDB,
 	sc_client_api::ExecutorProvider,
@@ -56,7 +61,7 @@ pub use {
 	sp_authority_discovery::AuthorityDiscoveryApi,
 	sc_client_api::AuxStore,
 	polkadot_primitives::v1::ParachainHost,
-	polkadot_overseer::{Overseer, Handle},
+	polkadot_overseer::{Overseer, Handle, OverseerHandle},
 };
 pub use sp_core::traits::SpawnNamed;
 
@@ -214,7 +219,7 @@ fn jaeger_launch_collector_with_agent(spawner: impl SpawnNamed, config: &Configu
 }
 
 #[cfg(feature = "full-node")]
-type FullSelectChain = sc_consensus::LongestChain<FullBackend, Block>;
+type FullSelectChain = relay_chain_selection::SelectRelayChain<FullBackend>;
 #[cfg(feature = "full-node")]
 type FullGrandpaBlockImport<RuntimeApi, Executor> = grandpa::GrandpaBlockImport<
 	FullBackend, Block, FullClient<RuntimeApi, Executor>, FullSelectChain
@@ -298,7 +303,11 @@ fn new_partial<RuntimeApi, Executor>(
 
 	jaeger_launch_collector_with_agent(task_manager.spawn_handle(), &*config, jaeger_agent)?;
 
-	let select_chain = sc_consensus::LongestChain::new(backend.clone());
+	let select_chain = relay_chain_selection::SelectRelayChain::new(
+		backend.clone(),
+		Handle::new_disconnected(),
+		polkadot_node_subsystem_util::metrics::Metrics::register(config.prometheus_registry())?,
+	);
 
 	let transaction_pool = sc_transaction_pool::BasicPool::new_full(
 		config.transaction_pool.clone(),
@@ -427,7 +436,7 @@ fn new_partial<RuntimeApi, Executor>(
 pub struct NewFull<C> {
 	pub task_manager: TaskManager,
 	pub client: C,
-	pub overseer_handler: Option<Handle>,
+	pub overseer_handle: Option<Handle>,
 	pub network: Arc<sc_network::NetworkService<Block, <Block as BlockT>::Hash>>,
 	pub rpc_handlers: RpcHandlers,
 	pub backend: Arc<FullBackend>,
@@ -440,7 +449,7 @@ impl<C> NewFull<C> {
 		NewFull {
 			client: func(self.client),
 			task_manager: self.task_manager,
-			overseer_handler: self.overseer_handler,
+			overseer_handle: self.overseer_handle,
 			network: self.network,
 			rpc_handlers: self.rpc_handlers,
 			backend: self.backend,
@@ -480,7 +489,7 @@ impl IsCollator {
 /// Returns the active leaves the overseer should start with.
 #[cfg(feature = "full-node")]
 async fn active_leaves<RuntimeApi, Executor>(
-	select_chain: &sc_consensus::LongestChain<FullBackend, Block>,
+	select_chain: &impl SelectChain<Block>,
 	client: &FullClient<RuntimeApi, Executor>,
 ) -> Result<Vec<BlockInfo>, Error>
 where
@@ -573,7 +582,7 @@ pub fn new_full<RuntimeApi, Executor, OverseerGenerator>(
 		backend,
 		mut task_manager,
 		keystore_container,
-		select_chain,
+		mut select_chain,
 		import_queue,
 		transaction_pool,
 		other: (rpc_extensions_builder, import_setup, rpc_setup, slot_duration, mut telemetry)
@@ -655,6 +664,15 @@ pub fn new_full<RuntimeApi, Executor, OverseerGenerator>(
 		},
 	};
 
+	let chain_selection_config = ChainSelectionConfig {
+		col_data: crate::parachains_db::REAL_COLUMNS.col_chain_selection_data,
+		stagnant_check_interval: chain_selection_subsystem::StagnantCheckInterval::never(),
+	};
+
+	let dispute_coordinator_config = DisputeCoordinatorConfig {
+		col_data: crate::parachains_db::REAL_COLUMNS.col_dispute_coordinator_data,
+	};
+
 	let chain_spec = config.chain_spec.cloned_box();
 	let rpc_handlers = service::spawn_tasks(service::SpawnTasksParams {
 		config,
@@ -714,8 +732,6 @@ pub fn new_full<RuntimeApi, Executor, OverseerGenerator>(
 		None
 	};
 
-	// we'd say let overseer_handler = authority_discovery_service.map(|authority_discovery_service|, ...),
-	// but in that case we couldn't use ? to propagate errors
 	let local_keystore = keystore_container.local_keystore();
 	if local_keystore.is_none() {
 		tracing::info!("Cannot run as validator without local keystore.");
@@ -724,8 +740,8 @@ pub fn new_full<RuntimeApi, Executor, OverseerGenerator>(
 	let maybe_params = local_keystore
 		.and_then(move |k| authority_discovery_service.map(|a| (a, k)));
 
-	let overseer_handler = if let Some((authority_discovery_service, keystore)) = maybe_params {
-		let (overseer, overseer_handler) = overseer_gen.generate::<
+	let overseer_handle = if let Some((authority_discovery_service, keystore)) = maybe_params {
+		let (overseer, overseer_handle) = overseer_gen.generate::<
 			service::SpawnTaskHandle,
 			FullClient<RuntimeApi, Executor>,
 		>(
@@ -734,23 +750,26 @@ pub fn new_full<RuntimeApi, Executor, OverseerGenerator>(
 				keystore,
 				runtime_client: overseer_client.clone(),
 				parachains_db,
-				availability_config,
-				approval_voting_config,
 				network_service: network.clone(),
 				authority_discovery_service,
 				request_multiplexer,
 				registry: prometheus_registry.as_ref(),
 				spawner,
 				is_collator,
+				approval_voting_config,
+				availability_config,
 				candidate_validation_config,
+				chain_selection_config,
+				dispute_coordinator_config,
 			}
 		)?;
-		let overseer_handler_clone = overseer_handler.clone();
+		let handle = Handle::Connected(overseer_handle.clone());
+		let handle_clone = handle.clone();
 
 		task_manager.spawn_essential_handle().spawn_blocking("overseer", Box::pin(async move {
 			use futures::{pin_mut, select, FutureExt};
 
-			let forward = polkadot_overseer::forward_events(overseer_client, overseer_handler_clone);
+			let forward = polkadot_overseer::forward_events(overseer_client, handle_clone);
 
 			let forward = forward.fuse();
 			let overseer_fut = overseer.run().fuse();
@@ -764,8 +783,19 @@ pub fn new_full<RuntimeApi, Executor, OverseerGenerator>(
 				complete => (),
 			}
 		}));
+		// we should remove this check before we deploy parachains on polkadot
+		// TODO: https://github.com/paritytech/polkadot/issues/3326
+		let should_connect_overseer = chain_spec.is_kusama()
+			|| chain_spec.is_westend()
+			|| chain_spec.is_rococo()
+			|| chain_spec.is_wococo();
 
-		Some(overseer_handler)
+		if should_connect_overseer {
+			select_chain.connect_to_overseer(overseer_handle.clone());
+		} else {
+			tracing::info!("Overseer is running in the disconnected state");
+		}
+		Some(handle)
 	} else {
 		None
 	};
@@ -783,7 +813,7 @@ pub fn new_full<RuntimeApi, Executor, OverseerGenerator>(
 		);
 
 		let client_clone = client.clone();
-		let overseer_handler = overseer_handler.as_ref().ok_or(Error::AuthoritiesRequireRealOverseer)?.clone();
+		let overseer_handle = overseer_handle.as_ref().ok_or(Error::AuthoritiesRequireRealOverseer)?.clone();
 		let slot_duration = babe_link.config().slot_duration();
 		let babe_config = babe::BabeParams {
 			keystore: keystore_container.sync_keystore(),
@@ -795,11 +825,11 @@ pub fn new_full<RuntimeApi, Executor, OverseerGenerator>(
 			justification_sync_link: network.clone(),
 			create_inherent_data_providers: move |parent, ()| {
 				let client_clone = client_clone.clone();
-				let overseer_handler = overseer_handler.clone();
+				let overseer_handle = overseer_handle.clone();
 				async move {
 					let parachain = polkadot_node_core_parachains_inherent::ParachainsInherentDataProvider::create(
 						&*client_clone,
-						overseer_handler,
+						overseer_handle,
 						parent,
 					).await.map_err(|e| Box::new(e))?;
 
@@ -889,24 +919,6 @@ pub fn new_full<RuntimeApi, Executor, OverseerGenerator>(
 		// after the given pause block is finalized and restarting after the
 		// given delay.
 		let builder = grandpa::VotingRulesBuilder::default();
-		// we should enable approval checking voting rule before we deploy parachains on polkadot
-		let enable_approval_checking_voting_rule = chain_spec.is_kusama()
-			|| chain_spec.is_westend()
-			|| chain_spec.is_rococo()
-			|| chain_spec.is_wococo();
-
-		let builder = if let Some(ref overseer) = overseer_handler {
-			if enable_approval_checking_voting_rule {
-				builder.add(grandpa_support::ApprovalCheckingVotingRule::new(
-					overseer.clone(),
-					prometheus_registry.as_ref(),
-				)?)
-			} else {
-				builder
-			}
-		} else {
-			builder
-		};
 
 		let voting_rule = match grandpa_pause {
 			Some((block, delay)) => {
@@ -946,7 +958,7 @@ pub fn new_full<RuntimeApi, Executor, OverseerGenerator>(
 	Ok(NewFull {
 		task_manager,
 		client,
-		overseer_handler,
+		overseer_handle,
 		network,
 		rpc_handlers,
 		backend,

polkadot/node/service/src/overseer.rs

@@ -28,7 +28,9 @@ use polkadot_network_bridge::RequestMultiplexer;
 use polkadot_node_core_av_store::Config as AvailabilityConfig;
 use polkadot_node_core_approval_voting::Config as ApprovalVotingConfig;
 use polkadot_node_core_candidate_validation::Config as CandidateValidationConfig;
-use polkadot_overseer::{AllSubsystems, BlockInfo, Overseer, Handle};
+use polkadot_node_core_chain_selection::Config as ChainSelectionConfig;
+use polkadot_node_core_dispute_coordinator::Config as DisputeCoordinatorConfig;
+use polkadot_overseer::{AllSubsystems, BlockInfo, Overseer, OverseerHandle};
 use polkadot_primitives::v1::ParachainHost;
 use sc_authority_discovery::Service as AuthorityDiscoveryService;
 use sp_api::ProvideRuntimeApi;
@@ -54,6 +56,10 @@ pub use polkadot_availability_recovery::AvailabilityRecoverySubsystem;
 pub use polkadot_approval_distribution::ApprovalDistribution as ApprovalDistributionSubsystem;
 pub use polkadot_node_core_approval_voting::ApprovalVotingSubsystem;
 pub use polkadot_gossip_support::GossipSupport as GossipSupportSubsystem;
+pub use polkadot_node_core_dispute_coordinator::DisputeCoordinatorSubsystem;
+pub use polkadot_node_core_dispute_participation::DisputeParticipationSubsystem;
+pub use polkadot_dispute_distribution::DisputeDistributionSubsystem;
+pub use polkadot_node_core_chain_selection::ChainSelectionSubsystem;
 
 /// Arguments passed for overseer construction.
 pub struct OverseerGenArgs<'a, Spawner, RuntimeClient> where
@@ -69,10 +75,6 @@ pub struct OverseerGenArgs<'a, Spawner, RuntimeClient> where
 	pub runtime_client: Arc<RuntimeClient>,
 	/// The underlying key value store for the parachains.
 	pub parachains_db: Arc<dyn kvdb::KeyValueDB>,
-	/// Configuration for the availability store subsystem.
-	pub availability_config: AvailabilityConfig,
-	/// Configuration for the approval voting subsystem.
-	pub approval_voting_config: ApprovalVotingConfig,
 	/// Underlying network service implementation.
 	pub network_service: Arc<sc_network::NetworkService<Block, Hash>>,
 	/// Underlying authority discovery service.
@@ -85,8 +87,16 @@ pub struct OverseerGenArgs<'a, Spawner, RuntimeClient> where
 	pub spawner: Spawner,
 	/// Determines the behavior of the collator.
 	pub is_collator: IsCollator,
+	/// Configuration for the approval voting subsystem.
+	pub approval_voting_config: ApprovalVotingConfig,
+	/// Configuration for the availability store subsystem.
+	pub availability_config: AvailabilityConfig,
 	/// Configuration for the candidate validation subsystem.
 	pub candidate_validation_config: CandidateValidationConfig,
+	/// Configuration for the chain selection subsystem.
+	pub chain_selection_config: ChainSelectionConfig,
+	/// Configuration for the dispute coordinator subsystem.
+	pub dispute_coordinator_config: DisputeCoordinatorConfig,
 }
 
 /// Create a default, unaltered set of subsystems.
@@ -99,15 +109,17 @@ pub fn create_default_subsystems<'a, Spawner, RuntimeClient>
 		keystore,
 		runtime_client,
 		parachains_db,
-		availability_config,
-		approval_voting_config,
 		network_service,
 		authority_discovery_service,
 		request_multiplexer,
 		registry,
 		spawner,
 		is_collator,
+		approval_voting_config,
+		availability_config,
 		candidate_validation_config,
+		chain_selection_config,
+		dispute_coordinator_config,
 		..
 	} : OverseerGenArgs<'a, Spawner, RuntimeClient>
 ) -> Result<
@@ -129,6 +141,10 @@ pub fn create_default_subsystems<'a, Spawner, RuntimeClient>
 	ApprovalDistributionSubsystem,
 	ApprovalVotingSubsystem,
 	GossipSupportSubsystem,
+	DisputeCoordinatorSubsystem,
+	DisputeParticipationSubsystem,
+	DisputeDistributionSubsystem<AuthorityDiscoveryService>,
+	ChainSelectionSubsystem,
 >,
 	Error
 >
@@ -218,7 +234,7 @@ where
 		),
 		approval_voting: ApprovalVotingSubsystem::with_config(
 			approval_voting_config,
-			parachains_db,
+			parachains_db.clone(),
 			keystore.clone(),
 			Box::new(network_service.clone()),
 			Metrics::register(registry)?,
@@ -226,6 +242,21 @@ where
 		gossip_support: GossipSupportSubsystem::new(
 			keystore.clone(),
 		),
+		dispute_coordinator: DisputeCoordinatorSubsystem::new(
+			parachains_db.clone(),
+			dispute_coordinator_config,
+			keystore.clone(),
+		),
+		dispute_participation: DisputeParticipationSubsystem::new(),
+		dispute_distribution: DisputeDistributionSubsystem::new(
+			keystore.clone(),
+			authority_discovery_service.clone(),
+			Metrics::register(registry)?,
+		),
+		chain_selection: ChainSelectionSubsystem::new(
+			chain_selection_config,
+			parachains_db,
+		),
 	};
 	Ok(all_subsystems)
 }
@@ -237,7 +268,7 @@ where
 /// would do.
 pub trait OverseerGen {
 	/// Overwrite the full generation of the overseer, including the subsystems.
-	fn generate<'a, Spawner, RuntimeClient>(&self, args: OverseerGenArgs<'a, Spawner, RuntimeClient>) -> Result<(Overseer<Spawner, Arc<RuntimeClient>>, Handle), Error>
+	fn generate<'a, Spawner, RuntimeClient>(&self, args: OverseerGenArgs<'a, Spawner, RuntimeClient>) -> Result<(Overseer<Spawner, Arc<RuntimeClient>>, OverseerHandle), Error>
 	where
 		RuntimeClient: 'static + ProvideRuntimeApi<Block> + HeaderBackend<Block> + AuxStore,
 		RuntimeClient::Api: ParachainHost<Block> + BabeApi<Block> + AuthorityDiscoveryApi<Block>,
@@ -256,7 +287,7 @@ pub struct RealOverseerGen;
 impl OverseerGen for RealOverseerGen {
 	fn generate<'a, Spawner, RuntimeClient>(&self,
 		args : OverseerGenArgs<'a, Spawner, RuntimeClient>
-	) -> Result<(Overseer<Spawner, Arc<RuntimeClient>>, Handle), Error>
+	) -> Result<(Overseer<Spawner, Arc<RuntimeClient>>, OverseerHandle), Error>
 	where
 		RuntimeClient: 'static + ProvideRuntimeApi<Block> + HeaderBackend<Block> + AuxStore,
 		RuntimeClient::Api: ParachainHost<Block> + BabeApi<Block> + AuthorityDiscoveryApi<Block>,

polkadot/node/service/src/parachains_db/mod.rs

@@ -22,16 +22,21 @@ use {
 	kvdb::KeyValueDB,
 };
 
+#[cfg(feature = "full-node")]
 mod upgrade;
 
 #[cfg(any(test,feature = "full-node"))]
-mod columns {
-	pub const NUM_COLUMNS: u32 = 3;
-
+pub(crate) mod columns {
+	pub mod v0 {
+		pub const NUM_COLUMNS: u32 = 3;
+	}
+	pub const NUM_COLUMNS: u32 = 5;
 
 	pub const COL_AVAILABILITY_DATA: u32 = 0;
 	pub const COL_AVAILABILITY_META: u32 = 1;
 	pub const COL_APPROVAL_DATA: u32 = 2;
+	pub const COL_CHAIN_SELECTION_DATA: u32 = 3;
+	pub const COL_DISPUTE_COORDINATOR_DATA: u32 = 4;
 }
 
 /// Columns used by different subsystems.
@@ -44,6 +49,10 @@ pub struct ColumnsConfig {
 	pub col_availability_meta: u32,
 	/// The column used by approval voting for data.
 	pub col_approval_data: u32,
+	/// The column used by chain selection for data.
+	pub col_chain_selection_data: u32,
+	/// The column used by dispute coordinator for data.
+	pub col_dispute_coordinator_data: u32,
 }
 
 /// The real columns used by the parachains DB.
@@ -52,6 +61,8 @@ pub const REAL_COLUMNS: ColumnsConfig = ColumnsConfig {
 	col_availability_data: columns::COL_AVAILABILITY_DATA,
 	col_availability_meta: columns::COL_AVAILABILITY_META,
 	col_approval_data: columns::COL_APPROVAL_DATA,
+	col_chain_selection_data: columns::COL_CHAIN_SELECTION_DATA,
+	col_dispute_coordinator_data: columns::COL_DISPUTE_COORDINATOR_DATA,
 };
 
 /// The cache size for each column, in megabytes.
@@ -76,7 +87,7 @@ impl Default for CacheSizes {
 }
 
 #[cfg(feature = "full-node")]
-fn other_io_error(err: String) -> io::Error {
+pub(crate) fn other_io_error(err: String) -> io::Error {
 	io::Error::new(io::ErrorKind::Other, err)
 }
 

polkadot/node/service/src/parachains_db/upgrade.rs

@@ -27,7 +27,7 @@ type Version = u32;
 const VERSION_FILE_NAME: &'static str = "parachain_db_version";
 
 /// Current db version.
-const CURRENT_VERSION: Version = 0;
+const CURRENT_VERSION: Version = 1;
 
 #[derive(thiserror::Error, Debug)]
 pub enum Error {
@@ -56,6 +56,7 @@ pub fn try_upgrade_db(db_path: &Path) -> Result<(), Error> {
 	let is_empty = db_path.read_dir().map_or(true, |mut d| d.next().is_none());
 	if !is_empty {
 		match current_version(db_path)? {
+			0 => migrate_from_version_0_to_1(db_path)?,
 			CURRENT_VERSION => (),
 			v => return Err(Error::FutureVersion {
 				current: CURRENT_VERSION,
@@ -68,10 +69,10 @@ pub fn try_upgrade_db(db_path: &Path) -> Result<(), Error> {
 }
 
 /// Reads current database version from the file at given path.
-/// If the file does not exist, assumes version 0.
+/// If the file does not exist, assumes the current version.
 fn current_version(path: &Path) -> Result<Version, Error> {
 	match fs::read_to_string(version_file_path(path)) {
-		Err(ref err) if err.kind() == io::ErrorKind::NotFound => Ok(0),
+		Err(ref err) if err.kind() == io::ErrorKind::NotFound => Ok(CURRENT_VERSION),
 		Err(err) => Err(err.into()),
 		Ok(content) => u32::from_str(&content).map_err(|_| Error::CorruptedVersionFile),
 	}
@@ -90,3 +91,20 @@ fn version_file_path(path: &Path) -> PathBuf {
 	file_path.push(VERSION_FILE_NAME);
 	file_path
 }
+
+
+/// Migration from version 0 to version 1:
+/// * the number of columns has changed from 3 to 5;
+fn migrate_from_version_0_to_1(path: &Path) -> Result<(), Error> {
+	use kvdb_rocksdb::{Database, DatabaseConfig};
+
+	let db_path = path.to_str()
+		.ok_or_else(|| super::other_io_error("Invalid database path".into()))?;
+	let db_cfg = DatabaseConfig::with_columns(super::columns::v0::NUM_COLUMNS);
+	let db = Database::open(&db_cfg, db_path)?;
+
+	db.add_column()?;
+	db.add_column()?;
+
+	Ok(())
+}

polkadot/node/service/src/relay_chain_selection.rs

@@ -41,7 +41,7 @@ use {
 	},
 	polkadot_subsystem::messages::{ApprovalVotingMessage, ChainSelectionMessage},
 	polkadot_node_subsystem_util::metrics::{self, prometheus},
-	polkadot_overseer::Handle,
+	polkadot_overseer::{Handle, OverseerHandle},
 	futures::channel::oneshot,
 	consensus_common::{Error as ConsensusError, SelectChain},
 	sp_blockchain::HeaderBackend,
@@ -125,7 +125,6 @@ impl<B> SelectRelayChain<B>
 {
 	/// Create a new [`SelectRelayChain`] wrapping the given chain backend
 	/// and a handle to the overseer.
-	#[allow(unused)]
 	pub fn new(backend: Arc<B>, overseer: Handle, metrics: Metrics) -> Self {
 		SelectRelayChain {
 			fallback: sc_consensus::LongestChain::new(backend.clone()),
@@ -167,14 +166,13 @@ impl<B> SelectRelayChain<B>
 }
 
 impl<B> SelectRelayChain<B> {
-	/// Given an overseer handler, this connects the [`SelectRelayChain`]'s
-	/// internal handler to the same overseer.
-	#[allow(unused)]
-	pub fn connect_overseer_handler(
+	/// Given an overseer handle, connects the [`SelectRelayChain`]'s
+	/// internal handle and its clones to the same overseer.
+	pub fn connect_to_overseer(
 		&mut self,
-		other_handler: &Handle,
+		handle: OverseerHandle,
 	) {
-		other_handler.connect_other(&mut self.overseer);
+		self.overseer.connect_to_overseer(handle);
 	}
 }
 

polkadot/node/subsystem-test-helpers/src/lib.rs

@@ -375,7 +375,7 @@ where
 #[cfg(test)]
 mod tests {
 	use super::*;
-	use polkadot_overseer::{Overseer, HeadSupportsParachains, AllSubsystems};
+	use polkadot_overseer::{Overseer, Handle, HeadSupportsParachains, AllSubsystems};
 	use futures::executor::block_on;
 	use polkadot_primitives::v1::Hash;
 	use polkadot_node_subsystem::messages::CollatorProtocolMessage;
@@ -390,17 +390,18 @@ mod tests {
 		let spawner = sp_core::testing::TaskExecutor::new();
 		let (tx, rx) = mpsc::channel(2);
 		let all_subsystems = AllSubsystems::<()>::dummy().replace_collator_protocol(ForwardSubsystem(tx));
-		let (overseer, mut handler) = Overseer::new(
+		let (overseer, handle) = Overseer::new(
 			Vec::new(),
 			all_subsystems,
 			None,
 			AlwaysSupportsParachains,
 			spawner.clone(),
 		).unwrap();
+		let mut handle = Handle::Connected(handle);
 
 		spawner.spawn("overseer", overseer.run().then(|_| async { () }).boxed());
 
-		block_on(handler.send_msg_anon(CollatorProtocolMessage::CollateOn(Default::default())));
+		block_on(handle.send_msg_anon(CollatorProtocolMessage::CollateOn(Default::default())));
 		assert!(matches!(block_on(rx.into_future()).0.unwrap(), CollatorProtocolMessage::CollateOn(_)));
 	}
 }

polkadot/node/test/service/src/lib.rs

@@ -223,17 +223,17 @@ pub fn run_validator_node(
 ) -> PolkadotTestNode {
 	let config = node_config(storage_update_func, task_executor, key, boot_nodes, true);
 	let multiaddr = config.network.listen_addresses[0].clone();
-	let NewFull { task_manager, client, network, rpc_handlers, overseer_handler, .. } =
+	let NewFull { task_manager, client, network, rpc_handlers, overseer_handle, .. } =
 		new_full(config, IsCollator::No, worker_program_path).expect("could not create Polkadot test service");
 
-	let overseer_handler = overseer_handler.expect("test node must have an overseer handler");
+	let overseer_handle = overseer_handle.expect("test node must have an overseer handle");
 	let peer_id = network.local_peer_id().clone();
 	let addr = MultiaddrWithPeerId { multiaddr, peer_id };
 
 	PolkadotTestNode {
 		task_manager,
 		client,
-		overseer_handler,
+		overseer_handle,
 		addr,
 		rpc_handlers,
 	}
@@ -265,19 +265,19 @@ pub fn run_collator_node(
 		client,
 		network,
 		rpc_handlers,
-		overseer_handler,
+		overseer_handle,
 		..
 	} = new_full(config, IsCollator::Yes(collator_pair), None)
 		.expect("could not create Polkadot test service");
 
-	let overseer_handler = overseer_handler.expect("test node must have an overseer handler");
+	let overseer_handle = overseer_handle.expect("test node must have an overseer handle");
 	let peer_id = network.local_peer_id().clone();
 	let addr = MultiaddrWithPeerId { multiaddr, peer_id };
 
 	PolkadotTestNode {
 		task_manager,
 		client,
-		overseer_handler,
+		overseer_handle,
 		addr,
 		rpc_handlers,
 	}
@@ -289,8 +289,8 @@ pub struct PolkadotTestNode {
 	pub task_manager: TaskManager,
 	/// Client's instance.
 	pub client: Arc<Client>,
-	/// The overseer handler.
-	pub overseer_handler: Handle,
+	/// A handle to Overseer.
+	pub overseer_handle: Handle,
 	/// The `MultiaddrWithPeerId` to this node. This is useful if you want to pass it as "boot node" to other nodes.
 	pub addr: MultiaddrWithPeerId,
 	/// `RPCHandlers` to make RPC queries.
@@ -347,11 +347,11 @@ impl PolkadotTestNode {
 			para_id,
 		};
 
-		self.overseer_handler
+		self.overseer_handle
 			.send_msg(CollationGenerationMessage::Initialize(config), "Collator")
 			.await;
 
-		self.overseer_handler
+		self.overseer_handle
 			.send_msg(CollatorProtocolMessage::CollateOn(para_id), "Collator")
 			.await;
 	}

polkadot/parachain/test-parachains/adder/collator/src/main.rs

@@ -67,9 +67,9 @@ fn main() -> Result<()> {
 							None,
 							polkadot_service::RealOverseerGen,
 						).map_err(|e| e.to_string())?;
-						let mut overseer_handler = full_node
-							.overseer_handler
-							.expect("Overseer handler should be initialized for collators");
+						let mut overseer_handle = full_node
+							.overseer_handle
+							.expect("Overseer handle should be initialized for collators");
 
 						let genesis_head_hex =
 							format!("0x{:?}", HexDisplay::from(&collator.genesis_head()));
@@ -87,11 +87,11 @@ fn main() -> Result<()> {
 							collator: collator.create_collation_function(full_node.task_manager.spawn_handle()),
 							para_id,
 						};
-						overseer_handler
+						overseer_handle
 							.send_msg(CollationGenerationMessage::Initialize(config), "Collator")
 							.await;
 
-						overseer_handler
+						overseer_handle
 							.send_msg(CollatorProtocolMessage::CollateOn(para_id), "Collator")
 							.await;