statement-distribution: fix filtering of statements for elastic parachains

polkadot/node/collation-generation/src/error.rs

@@ -27,6 +27,8 @@ pub enum Error {
 	#[error(transparent)]
 	Util(#[from] polkadot_node_subsystem_util::Error),
 	#[error(transparent)]
+	UtilRuntime(#[from] polkadot_node_subsystem_util::runtime::Error),
+	#[error(transparent)]
 	Erasure(#[from] polkadot_erasure_coding::Error),
 	#[error("Parachain backing state not available in runtime.")]
 	MissingParaBackingState,

polkadot/node/collation-generation/src/lib.rs

@@ -38,25 +38,23 @@ use polkadot_node_primitives::{
 	SubmitCollationParams,
 };
 use polkadot_node_subsystem::{
-	messages::{CollationGenerationMessage, CollatorProtocolMessage, RuntimeApiRequest},
+	messages::{CollationGenerationMessage, CollatorProtocolMessage},
 	overseer, ActiveLeavesUpdate, FromOrchestra, OverseerSignal, RuntimeApiError, SpawnedSubsystem,
 	SubsystemContext, SubsystemError, SubsystemResult,
 };
 use polkadot_node_subsystem_util::{
-	has_required_runtime, request_async_backing_params, request_availability_cores,
-	request_claim_queue, request_para_backing_state, request_persisted_validation_data,
-	request_validation_code, request_validation_code_hash, request_validators,
+	request_async_backing_params, request_availability_cores, request_para_backing_state,
+	request_persisted_validation_data, request_validation_code, request_validation_code_hash,
+	request_validators,
+	vstaging::{fetch_claim_queue, fetch_next_scheduled_on_core},
 };
 use polkadot_primitives::{
 	collator_signature_payload, CandidateCommitments, CandidateDescriptor, CandidateReceipt,
 	CollatorPair, CoreIndex, CoreState, Hash, Id as ParaId, OccupiedCoreAssumption,
-	PersistedValidationData, ScheduledCore, ValidationCodeHash,
+	PersistedValidationData, ValidationCodeHash,
 };
 use sp_core::crypto::Pair;
-use std::{
-	collections::{BTreeMap, VecDeque},
-	sync::Arc,
-};
+use std::sync::Arc;
 
 mod error;
 
@@ -228,7 +226,9 @@ async fn handle_new_activations<Context>(
 		let availability_cores = availability_cores??;
 		let async_backing_params = async_backing_params?.ok();
 		let n_validators = validators??.len();
-		let maybe_claim_queue = fetch_claim_queue(ctx.sender(), relay_parent).await?;
+		let maybe_claim_queue = fetch_claim_queue(ctx.sender(), relay_parent)
+			.await
+			.map_err(crate::error::Error::UtilRuntime)?;
 
 		// The loop bellow will fill in cores that the para is allowed to build on.
 		let mut cores_to_build_on = Vec::new();
@@ -655,37 +655,3 @@ fn erasure_root(
 	let chunks = polkadot_erasure_coding::obtain_chunks_v1(n_validators, &available_data)?;
 	Ok(polkadot_erasure_coding::branches(&chunks).root())
 }
-
-// Checks if the runtime supports `request_claim_queue` and executes it. Returns `Ok(None)`
-// otherwise. Any [`RuntimeApiError`]s are bubbled up to the caller.
-async fn fetch_claim_queue(
-	sender: &mut impl overseer::CollationGenerationSenderTrait,
-	relay_parent: Hash,
-) -> crate::error::Result<Option<BTreeMap<CoreIndex, VecDeque<ParaId>>>> {
-	if has_required_runtime(
-		sender,
-		relay_parent,
-		RuntimeApiRequest::CLAIM_QUEUE_RUNTIME_REQUIREMENT,
-	)
-	.await
-	{
-		let res = request_claim_queue(relay_parent, sender).await.await??;
-		Ok(Some(res))
-	} else {
-		gum::trace!(target: LOG_TARGET, "Runtime doesn't support `request_claim_queue`");
-		Ok(None)
-	}
-}
-
-// Returns the next scheduled `ParaId` for a core in the claim queue, wrapped in `ScheduledCore`.
-// This function is supposed to be used in `handle_new_activations` hence the return type.
-fn fetch_next_scheduled_on_core(
-	claim_queue: &BTreeMap<CoreIndex, VecDeque<ParaId>>,
-	core_idx: CoreIndex,
-) -> Option<ScheduledCore> {
-	claim_queue
-		.get(&core_idx)?
-		.front()
-		.cloned()
-		.map(|para_id| ScheduledCore { para_id, collator: None })
-}

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

@@ -81,6 +81,9 @@ pub enum Error {
 	#[error("Fetching validator groups failed {0:?}")]
 	FetchValidatorGroups(RuntimeApiError),
 
+	#[error("Fetching claim queue failed {0:?}")]
+	FetchClaimQueue(runtime::Error),
+
 	#[error("Attempted to share statement when not a validator or not assigned")]
 	InvalidShare,
 

polkadot/node/network/statement-distribution/src/v2/mod.rs

@@ -46,6 +46,7 @@ use polkadot_node_subsystem_util::{
 	backing_implicit_view::View as ImplicitView,
 	reputation::ReputationAggregator,
 	runtime::{request_min_backing_votes, ProspectiveParachainsMode},
+	vstaging::{fetch_claim_queue, fetch_next_scheduled_on_core, ClaimQueueSnapshot},
 };
 use polkadot_primitives::{
 	AuthorityDiscoveryId, CandidateHash, CompactStatement, CoreIndex, CoreState, GroupIndex,
@@ -149,10 +150,9 @@ pub(crate) const REQUEST_RETRY_DELAY: Duration = Duration::from_secs(1);
 struct PerRelayParentState {
 	local_validator: Option<LocalValidatorState>,
 	statement_store: StatementStore,
-	availability_cores: Vec<CoreState>,
-	group_rotation_info: GroupRotationInfo,
 	seconding_limit: usize,
 	session: SessionIndex,
+	groups_per_para: HashMap<ParaId, Vec<GroupIndex>>,
 }
 
 impl PerRelayParentState {
@@ -693,15 +693,24 @@ pub(crate) async fn handle_active_leaves_update<Context>(
 			}
 		});
 
+		let maybe_claim_queue = fetch_claim_queue(ctx.sender(), new_relay_parent)
+			.await
+			.map_err(JfyiError::FetchClaimQueue)?;
+
+		let groups_per_para = determine_groups_per_para(
+			&availability_cores,
+			&group_rotation_info,
+			&maybe_claim_queue,
+			seconding_limit - 1,
+		);
 		state.per_relay_parent.insert(
 			new_relay_parent,
 			PerRelayParentState {
 				local_validator,
 				statement_store: StatementStore::new(&per_session.groups),
-				availability_cores,
-				group_rotation_info,
 				seconding_limit,
 				session: session_index,
+				groups_per_para,
 			},
 		);
 	}
@@ -2126,17 +2135,54 @@ async fn provide_candidate_to_grid<Context>(
 	}
 }
 
-fn group_for_para(
+// Utility function to populate per relay parent `ParaId` to `GroupIndex` mappings.
+fn determine_groups_per_para(
 	availability_cores: &[CoreState],
 	group_rotation_info: &GroupRotationInfo,
-	para_id: ParaId,
-) -> Option<GroupIndex> {
-	// Note: this won't work well for on-demand parachains as it assumes that core assignments are
-	// fixed across blocks.
-	let core_index = availability_cores.iter().position(|c| c.para_id() == Some(para_id));
+	maybe_claim_queue: &Option<ClaimQueueSnapshot>,
+	max_candidate_depth: usize,
+) -> HashMap<ParaId, Vec<GroupIndex>> {
+	// Determine the core indices occupied by each para at the current relay parent. To support
+	// on-demand parachains we also consider the core indices at next block if core has a candidate
+	// pending availability.
+	let para_core_indices = availability_cores.iter().enumerate().filter_map(|(index, core)| {
+		match core {
+			CoreState::Scheduled(scheduled_core) =>
+				Some((scheduled_core.para_id, CoreIndex(index as u32))),
+			CoreState::Occupied(occupied_core) => {
+				if max_candidate_depth >= 1 {
+					// Use claim queue if available, or fallback to `next_up_on_available`
+					let maybe_scheduled_core = match maybe_claim_queue {
+						Some(claim_queue) => {
+							// What's up next on this core ?
+							fetch_next_scheduled_on_core(claim_queue, CoreIndex(index as u32))
+						},
+						None => {
+							// Runtime doesn't support claim queue runtime api. Fallback to
+							// `next_up_on_available`
+							occupied_core.next_up_on_available.clone()
+						},
+					};
+
+					maybe_scheduled_core
+						.filter(|scheduled_core| scheduled_core.para_id == occupied_core.para_id())
+						.map(|scheduled_core| (scheduled_core.para_id, CoreIndex(index as u32)))
+				} else {
+					None
+				}
+			},
+			CoreState::Free => None,
+		}
+	});
 
-	core_index
-		.map(|c| group_rotation_info.group_for_core(CoreIndex(c as _), availability_cores.len()))
+	let mut groups_per_para = HashMap::new();
+	// Map from `CoreIndex` to `GroupIndex` and collect as `HashMap`.
+	for (para, core_index) in para_core_indices {
+		let group_index = group_rotation_info.group_for_core(core_index, availability_cores.len());
+		groups_per_para.entry(para).or_insert_with(Vec::new).push(group_index)
+	}
+
+	groups_per_para
 }
 
 #[overseer::contextbounds(StatementDistribution, prefix=self::overseer)]
@@ -2192,18 +2238,14 @@ async fn fragment_tree_update_inner<Context>(
 			let confirmed_candidate = state.candidates.get_confirmed(&candidate_hash);
 			let prs = state.per_relay_parent.get_mut(&receipt.descriptor().relay_parent);
 			if let (Some(confirmed), Some(prs)) = (confirmed_candidate, prs) {
-				let group_index = group_for_para(
-					&prs.availability_cores,
-					&prs.group_rotation_info,
-					receipt.descriptor().para_id,
-				);
-
 				let per_session = state.per_session.get(&prs.session);
-				if let (Some(per_session), Some(group_index)) = (per_session, group_index) {
+				// TODO(maybe for sanity): perform an extra check on the candidate backing group
+				// index all allowed
+				if let Some(per_session) = per_session {
 					send_backing_fresh_statements(
 						ctx,
 						candidate_hash,
-						group_index,
+						confirmed.group_index(),
 						&receipt.descriptor().relay_parent,
 						prs,
 						confirmed,
@@ -2311,13 +2353,14 @@ async fn handle_incoming_manifest_common<'a, Context>(
 		Some(x) => x,
 	};
 
-	let expected_group = group_for_para(
-		&relay_parent_state.availability_cores,
-		&relay_parent_state.group_rotation_info,
-		para_id,
-	);
+	let expected_groups = relay_parent_state.groups_per_para.get(&para_id);
 
-	if expected_group != Some(manifest_summary.claimed_group_index) {
+	if expected_groups.is_none() ||
+		!expected_groups
+			.expect("checked is_some(); qed")
+			.iter()
+			.any(|g| g == &manifest_summary.claimed_group_index)
+	{
 		modify_reputation(reputation, ctx.sender(), peer, COST_MALFORMED_MANIFEST).await;
 		return None
 	}
@@ -3037,13 +3080,13 @@ pub(crate) async fn handle_response<Context>(
 			relay_parent_state.session,
 			|v| per_session.session_info.validators.get(v).map(|x| x.clone()),
 			|para, g_index| {
-				let expected_group = group_for_para(
-					&relay_parent_state.availability_cores,
-					&relay_parent_state.group_rotation_info,
-					para,
-				);
+				let expected_groups = relay_parent_state.groups_per_para.get(&para);
 
-				Some(g_index) == expected_group
+				expected_groups.is_some() &&
+					expected_groups
+						.expect("checked is_some(); qed")
+						.iter()
+						.any(|g| g == &g_index)
 			},
 			disabled_mask,
 		);

polkadot/node/subsystem-util/src/vstaging.rs

@@ -19,14 +19,19 @@
 //! This module is intended to contain common boiler plate code handling unreleased runtime API
 //! calls.
 
+use std::collections::{BTreeMap, VecDeque};
+
 use polkadot_node_subsystem_types::messages::{RuntimeApiMessage, RuntimeApiRequest};
 use polkadot_overseer::SubsystemSender;
-use polkadot_primitives::{Hash, ValidatorIndex};
+use polkadot_primitives::{CoreIndex, Hash, Id as ParaId, ScheduledCore, ValidatorIndex};
 
-use crate::{has_required_runtime, request_disabled_validators, runtime};
+use crate::{has_required_runtime, request_claim_queue, request_disabled_validators, runtime};
 
 const LOG_TARGET: &'static str = "parachain::subsystem-util-vstaging";
 
+/// A snapshot of the runtime claim queue at an arbitrare relay chain block.
+pub type ClaimQueueSnapshot = BTreeMap<CoreIndex, VecDeque<ParaId>>;
+
 // TODO: https://github.com/paritytech/polkadot-sdk/issues/1940
 /// Returns disabled validators list if the runtime supports it. Otherwise logs a debug messages and
 /// returns an empty vec.
@@ -54,3 +59,40 @@ pub async fn get_disabled_validators_with_fallback<Sender: SubsystemSender<Runti
 
 	Ok(disabled_validators)
 }
+
+/// Checks if the runtime supports `request_claim_queue` and attempts to fetch the claim queue.
+/// Returns `ClaimQueueSnapshot` or `None` if claim queue API is not supported by runtime.
+/// Any specific [`RuntimeApiError`]s are bubbled up to the caller.
+pub async fn fetch_claim_queue(
+	sender: &mut impl SubsystemSender<RuntimeApiMessage>,
+	relay_parent: Hash,
+) -> Result<Option<ClaimQueueSnapshot>, runtime::Error> {
+	if has_required_runtime(
+		sender,
+		relay_parent,
+		RuntimeApiRequest::CLAIM_QUEUE_RUNTIME_REQUIREMENT,
+	)
+	.await
+	{
+		let res = request_claim_queue(relay_parent, sender)
+			.await
+			.await
+			.map_err(runtime::Error::RuntimeRequestCanceled)??;
+		Ok(Some(res))
+	} else {
+		gum::trace!(target: LOG_TARGET, "Runtime doesn't support `request_claim_queue`");
+		Ok(None)
+	}
+}
+
+/// Returns the next scheduled `ParaId` for a core in the claim queue, wrapped in `ScheduledCore`.
+pub fn fetch_next_scheduled_on_core(
+	claim_queue: &ClaimQueueSnapshot,
+	core_idx: CoreIndex,
+) -> Option<ScheduledCore> {
+	claim_queue
+		.get(&core_idx)?
+		.front()
+		.cloned()
+		.map(|para_id| ScheduledCore { para_id, collator: None })
+}