fix runtime and collator node to support async backing without activa…

…ting it.

node/src/command.rs

@@ -349,7 +349,7 @@ pub fn run() -> Result<()> {
 				#[allow(clippy::match_single_binding)]
 				match config.chain_spec.runtime()? {
 					Runtime::Default => {
-							crate::service::start_generic_aura_node(config, polkadot_config, collator_options, id, hwbench)
+							crate::service::start_generic_aura_lookahead_node(config, polkadot_config, collator_options, id, hwbench)
 								.await
 								.map(|r| r.0)
 					}

node/src/service.rs

@@ -16,9 +16,7 @@
 
 use cumulus_client_cli::CollatorOptions;
 use cumulus_client_collator::service::CollatorService;
-use cumulus_client_consensus_aura::collators::basic::{
-	self as basic_aura, Params as BasicAuraParams,
-};
+use cumulus_client_consensus_aura::collators::lookahead::{self as aura, Params as AuraParams};
 use cumulus_client_consensus_common::{
 	ParachainBlockImport as TParachainBlockImport, ParachainCandidate, ParachainConsensus,
 };
@@ -28,7 +26,7 @@ use cumulus_client_service::{
 	BuildNetworkParams, CollatorSybilResistance, DARecoveryProfile, StartRelayChainTasksParams,
 };
 use cumulus_primitives_core::{
-	relay_chain::{Hash as PHash, PersistedValidationData},
+	relay_chain::{Hash as PHash, PersistedValidationData, ValidationCode},
 	ParaId,
 };
 use cumulus_relay_chain_interface::{OverseerHandle, RelayChainInterface};
@@ -607,8 +605,10 @@ where
 	Ok(BasicQueue::new(verifier, Box::new(block_import), None, &spawner, registry))
 }
 
+/// Uses the lookahead collator to support async backing.
+///
 /// Start an aura powered parachain node. Some system chains use this.
-pub async fn start_generic_aura_node(
+pub async fn start_generic_aura_lookahead_node(
 	parachain_config: Configuration,
 	polkadot_config: Configuration,
 	collator_options: CollatorOptions,
@@ -623,69 +623,72 @@ pub async fn start_generic_aura_node(
 		para_id,
 		build_parachain_rpc_extensions::<FakeRuntimeApi>,
 		build_relay_to_aura_import_queue::<_, AuraId>,
-		|client,
-		 block_import,
-		 prometheus_registry,
-		 telemetry,
-		 task_manager,
-		 relay_chain_interface,
-		 transaction_pool,
-		 sync_oracle,
-		 keystore,
-		 relay_chain_slot_duration,
-		 para_id,
-		 collator_key,
-		 overseer_handle,
-		 announce_block,
-		 _backend| {
-			let slot_duration = cumulus_client_consensus_aura::slot_duration(&*client)?;
-
-			let proposer_factory = sc_basic_authorship::ProposerFactory::with_proof_recording(
-				task_manager.spawn_handle(),
-				client.clone(),
-				transaction_pool,
-				prometheus_registry,
-				telemetry.clone(),
-			);
-			let proposer = Proposer::new(proposer_factory);
-
-			let collator_service = CollatorService::new(
-				client.clone(),
-				Arc::new(task_manager.spawn_handle()),
-				announce_block,
-				client.clone(),
-			);
-
-			let params = BasicAuraParams {
-				create_inherent_data_providers: move |_, ()| async move { Ok(()) },
-				block_import,
-				para_client: client,
-				relay_client: relay_chain_interface,
-				sync_oracle,
-				keystore,
-				collator_key,
-				para_id,
-				overseer_handle,
-				slot_duration,
-				relay_chain_slot_duration,
-				proposer,
-				collator_service,
-				// Very limited proposal time.
-				authoring_duration: Duration::from_millis(500),
-				collation_request_receiver: None,
-			};
-
-			let fut =
-				basic_aura::run::<Block, <AuraId as AppCrypto>::Pair, _, _, _, _, _, _, _>(params);
-			task_manager.spawn_essential_handle().spawn("aura", None, fut);
-
-			Ok(())
-		},
+		start_lookahead_aura_consensus,
 		hwbench,
 	)
 	.await
 }
 
+/// Start consensus using the lookahead aura collator.
+fn start_lookahead_aura_consensus(
+	client: Arc<ParachainClient<FakeRuntimeApi>>,
+	block_import: ParachainBlockImport<FakeRuntimeApi>,
+	prometheus_registry: Option<&Registry>,
+	telemetry: Option<TelemetryHandle>,
+	task_manager: &TaskManager,
+	relay_chain_interface: Arc<dyn RelayChainInterface>,
+	transaction_pool: Arc<sc_transaction_pool::FullPool<Block, ParachainClient<FakeRuntimeApi>>>,
+	sync_oracle: Arc<SyncingService<Block>>,
+	keystore: KeystorePtr,
+	relay_chain_slot_duration: Duration,
+	para_id: ParaId,
+	collator_key: CollatorPair,
+	overseer_handle: OverseerHandle,
+	announce_block: Arc<dyn Fn(Hash, Option<Vec<u8>>) + Send + Sync>,
+	backend: Arc<ParachainBackend>,
+) -> Result<(), sc_service::Error> {
+	let proposer_factory = sc_basic_authorship::ProposerFactory::with_proof_recording(
+		task_manager.spawn_handle(),
+		client.clone(),
+		transaction_pool,
+		prometheus_registry,
+		telemetry.clone(),
+	);
+
+	let collator_service = CollatorService::new(
+		client.clone(),
+		Arc::new(task_manager.spawn_handle()),
+		announce_block,
+		client.clone(),
+	);
+
+	let params = AuraParams {
+		create_inherent_data_providers: move |_, ()| async move { Ok(()) },
+		block_import,
+		para_client: client.clone(),
+		para_backend: backend,
+		relay_client: relay_chain_interface,
+		code_hash_provider: move |block_hash| {
+			client.code_at(block_hash).ok().map(|c| ValidationCode::from(c).hash())
+		},
+		sync_oracle,
+		keystore,
+		collator_key,
+		para_id,
+		overseer_handle,
+		relay_chain_slot_duration,
+		proposer: Proposer::new(proposer_factory),
+		collator_service,
+		authoring_duration: Duration::from_millis(1500),
+		reinitialize: false,
+	};
+
+	let fut = aura::run::<Block, <AuraId as AppCrypto>::Pair, _, _, _, _, _, _, _, _, _>(params);
+	task_manager.spawn_essential_handle().spawn("aura", None, fut);
+
+	Ok(())
+}
+
 /// Checks that the hardware meets the requirements and print a warning otherwise.
 fn warn_if_slow_hardware(hwbench: &sc_sysinfo::HwBench) {
 	// Polkadot para-chains should generally use these requirements to ensure that the relay-chain

runtime/bajun/src/lib.rs

@@ -231,7 +231,6 @@ pub const VERSION: RuntimeVersion = RuntimeVersion {
 	state_version: 1,
 };
 
-/// This determines the average expected block time that we are targeting.
 /// Blocks will be produced at a minimum duration defined by `SLOT_DURATION`.
 /// `SLOT_DURATION` is picked up by `pallet_timestamp` which is in turn picked
 /// up by `pallet_aura` to implement `fn slot_duration()`.
@@ -272,14 +271,14 @@ const MAXIMUM_BLOCK_WEIGHT: Weight = Weight::from_parts(
 	cumulus_primitives_core::relay_chain::MAX_POV_SIZE as u64,
 );
 
-/// Maximum number of blocks simultaneously accepted by the Runtime, not yet included
-/// into the relay chain.
-const UNINCLUDED_SEGMENT_CAPACITY: u32 = 3;
-/// How many parachain blocks are processed by the relay chain per parent. Limits the
-/// number of blocks authored per slot.
-const BLOCK_PROCESSING_VELOCITY: u32 = 1;
+/// Maximum number of blocks simultaneously accepted by the Runtime, not yet included into the
+/// relay chain.
+pub const UNINCLUDED_SEGMENT_CAPACITY: u32 = 1;
+/// How many parachain blocks are processed by the relay chain per parent. Limits the number of
+/// blocks authored per slot.
+pub const BLOCK_PROCESSING_VELOCITY: u32 = 1;
 /// Relay chain slot duration, in milliseconds.
-const RELAY_CHAIN_SLOT_DURATION_MILLIS: u32 = 6_000;
+pub const RELAY_CHAIN_SLOT_DURATION_MILLIS: u32 = 6000;
 
 /// The version information used to identify this runtime when compiled natively.
 #[cfg(feature = "std")]
@@ -397,10 +396,7 @@ impl pallet_timestamp::Config for Runtime {
 	/// A timestamp: milliseconds since the unix epoch.
 	type Moment = u64;
 	type OnTimestampSet = Aura;
-	#[cfg(feature = "experimental")]
 	type MinimumPeriod = ConstU64<0>;
-	#[cfg(not(feature = "experimental"))]
-	type MinimumPeriod = ConstU64<{ SLOT_DURATION / 2 }>;
 	type WeightInfo = weights::pallet_timestamp::WeightInfo<Runtime>;
 }