Use dynamic aura slot duration in lookahead collator

cumulus/client/consensus/aura/src/collators/lookahead.rs

@@ -52,14 +52,14 @@ use polkadot_overseer::Handle as OverseerHandle;
 use polkadot_primitives::{CollatorPair, Id as ParaId, OccupiedCoreAssumption};
 
 use futures::{channel::oneshot, prelude::*};
-use sc_client_api::{backend::AuxStore, BlockBackend, BlockOf};
+use sc_client_api::{backend::AuxStore, BlockBackend, BlockOf, UsageProvider};
 use sc_consensus::BlockImport;
 use sc_consensus_aura::standalone as aura_internal;
 use sp_api::ProvideRuntimeApi;
 use sp_application_crypto::AppPublic;
 use sp_blockchain::HeaderBackend;
 use sp_consensus::SyncOracle;
-use sp_consensus_aura::{AuraApi, Slot, SlotDuration};
+use sp_consensus_aura::{AuraApi, Slot};
 use sp_core::crypto::Pair;
 use sp_inherents::CreateInherentDataProviders;
 use sp_keystore::KeystorePtr;
@@ -95,8 +95,6 @@ pub struct Params<BI, CIDP, Client, Backend, RClient, CHP, SO, Proposer, CS> {
 	pub para_id: ParaId,
 	/// A handle to the relay-chain client's "Overseer" or task orchestrator.
 	pub overseer_handle: OverseerHandle,
-	/// The length of slots in this chain.
-	pub slot_duration: SlotDuration,
 	/// The length of slots in the relay chain.
 	pub relay_chain_slot_duration: Duration,
 	/// The underlying block proposer this should call into.
@@ -120,6 +118,7 @@ where
 		+ AuxStore
 		+ HeaderBackend<Block>
 		+ BlockBackend<Block>
+		+ UsageProvider<Block>
 		+ Send
 		+ Sync
 		+ 'static,
@@ -214,26 +213,6 @@ where
 				},
 			};
 
-			let (slot_now, timestamp) = match consensus_common::relay_slot_and_timestamp(
-				&relay_parent_header,
-				params.relay_chain_slot_duration,
-			) {
-				None => continue,
-				Some((r_s, t)) => {
-					let our_slot = Slot::from_timestamp(t, params.slot_duration);
-					tracing::debug!(
-						target: crate::LOG_TARGET,
-						relay_slot = ?r_s,
-						para_slot = ?our_slot,
-						timestamp = ?t,
-						slot_duration = ?params.slot_duration,
-						relay_chain_slot_duration = ?params.relay_chain_slot_duration,
-						"Adjusted relay-chain slot to parachain slot"
-					);
-					(our_slot, t)
-				},
-			};
-
 			let parent_search_params = ParentSearchParams {
 				relay_parent,
 				para_id: params.para_id,
@@ -272,14 +251,39 @@ where
 			let para_client = &*params.para_client;
 			let keystore = &params.keystore;
 			let can_build_upon = |block_hash| {
-				can_build_upon::<_, _, P>(
+				let slot_duration = match sc_consensus_aura::standalone::slot_duration_at(
+					&*params.para_client,
+					block_hash,
+				) {
+					Ok(sd) => sd,
+					Err(err) => {
+						tracing::error!(target: crate::LOG_TARGET, ?err, "Failed to acquire parachain slot duration");
+						return None
+					},
+				};
+				tracing::debug!(target: crate::LOG_TARGET, "Parachain slot duration acquired: {:?}", slot_duration);
+				let (relay_slot, timestamp) = consensus_common::relay_slot_and_timestamp(
+					&relay_parent_header,
+					params.relay_chain_slot_duration,
+				)?;
+				let slot_now = Slot::from_timestamp(timestamp, slot_duration);
+				tracing::debug!(
+					target: crate::LOG_TARGET,
+					relay_slot = ?relay_slot,
+					para_slot = ?slot_now,
+					timestamp = ?timestamp,
+					slot_duration = ?slot_duration,
+					relay_chain_slot_duration = ?params.relay_chain_slot_duration,
+					"Adjusted relay-chain slot to parachain slot"
+				);
+				Some(can_build_upon::<_, _, P>(
 					slot_now,
 					timestamp,
 					block_hash,
 					included_block,
 					para_client,
 					&keystore,
-				)
+				))
 			};
 
 			// Sort by depth, ascending, to choose the longest chain.
@@ -301,9 +305,12 @@ where
 			// This needs to change to support elastic scaling, but for continuously
 			// scheduled chains this ensures that the backlog will grow steadily.
 			for n_built in 0..2 {
-				let slot_claim = match can_build_upon(parent_hash).await {
+				let slot_claim = match can_build_upon(parent_hash) {
+					Some(fut) => match fut.await {
+						None => break,
+						Some(c) => c,
+					},
 					None => break,
-					Some(c) => c,
 				};
 
 				tracing::debug!(

cumulus/parachains/runtimes/contracts/contracts-rococo/src/lib.rs

@@ -58,10 +58,10 @@ use frame_system::limits::{BlockLength, BlockWeights};
 pub use parachains_common as common;
 use parachains_common::{
 	impls::DealWithFees, message_queue::*, AccountId, BlockNumber, Hash, Header, Nonce, Signature,
-	AVERAGE_ON_INITIALIZE_RATIO, MINUTES, NORMAL_DISPATCH_RATIO,
+	AVERAGE_ON_INITIALIZE_RATIO, NORMAL_DISPATCH_RATIO,
 };
 pub use parachains_common::{AuraId, Balance};
-use testnet_parachains_constants::rococo::{consensus::*, currency::*, fee::WeightToFee};
+use testnet_parachains_constants::rococo::{consensus::*, currency::*, fee::WeightToFee, time::*};
 use xcm_config::CollatorSelectionUpdateOrigin;
 
 #[cfg(any(feature = "std", test))]

cumulus/parachains/runtimes/people/people-rococo/src/lib.rs

@@ -44,7 +44,7 @@ use parachains_common::{
 	impls::DealWithFees,
 	message_queue::{NarrowOriginToSibling, ParaIdToSibling},
 	AccountId, Balance, BlockNumber, Hash, Header, Nonce, Signature, AVERAGE_ON_INITIALIZE_RATIO,
-	HOURS, NORMAL_DISPATCH_RATIO,
+	NORMAL_DISPATCH_RATIO,
 };
 use polkadot_runtime_common::{identity_migrator, BlockHashCount, SlowAdjustingFeeUpdate};
 use sp_api::impl_runtime_apis;
@@ -63,7 +63,7 @@ use sp_std::prelude::*;
 #[cfg(feature = "std")]
 use sp_version::NativeVersion;
 use sp_version::RuntimeVersion;
-use testnet_parachains_constants::rococo::{consensus::*, currency::*, fee::WeightToFee};
+use testnet_parachains_constants::rococo::{consensus::*, currency::*, fee::WeightToFee, time::*};
 use weights::{BlockExecutionWeight, ExtrinsicBaseWeight, RocksDbWeight};
 use xcm::latest::prelude::BodyId;
 use xcm_config::{

cumulus/polkadot-parachain/src/service.rs

@@ -939,8 +939,6 @@ pub async fn start_rococo_parachain_node(
 		 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(),
@@ -971,7 +969,6 @@ pub async fn start_rococo_parachain_node(
 				collator_key,
 				para_id,
 				overseer_handle,
-				slot_duration,
 				relay_chain_slot_duration,
 				proposer,
 				collator_service,
@@ -1435,8 +1432,6 @@ where
 		 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(),
@@ -1467,7 +1462,6 @@ where
 				collator_key,
 				para_id,
 				overseer_handle,
-				slot_duration,
 				relay_chain_slot_duration,
 				proposer,
 				collator_service,
@@ -1737,14 +1731,6 @@ where
 				}
 
 				// Move to Aura consensus.
-				let slot_duration = match cumulus_client_consensus_aura::slot_duration(&*client) {
-					Ok(d) => d,
-					Err(e) => {
-						log::error!("Could not get Aura slot duration: {e}");
-						return
-					},
-				};
-
 				let proposer = Proposer::new(proposer_factory);
 
 				let params = AuraParams {
@@ -1761,7 +1747,6 @@ where
 					collator_key,
 					para_id,
 					overseer_handle,
-					slot_duration,
 					relay_chain_slot_duration,
 					proposer,
 					collator_service,
@@ -1832,8 +1817,6 @@ where
 		 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(),
@@ -1864,7 +1847,6 @@ where
 				collator_key,
 				para_id,
 				overseer_handle,
-				slot_duration,
 				relay_chain_slot_duration,
 				proposer,
 				collator_service,
@@ -2141,8 +2123,6 @@ pub async fn start_contracts_rococo_node(
 		 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(),
@@ -2173,7 +2153,6 @@ pub async fn start_contracts_rococo_node(
 				collator_key,
 				para_id,
 				overseer_handle,
-				slot_duration,
 				relay_chain_slot_duration,
 				proposer,
 				collator_service,