Update Scheduler to have a configurable block provider #7434

cumulus/parachains/runtimes/collectives/collectives-westend/src/lib.rs

@@ -628,6 +628,7 @@ impl pallet_scheduler::Config for Runtime {
 	type WeightInfo = weights::pallet_scheduler::WeightInfo<Runtime>;
 	type OriginPrivilegeCmp = EqualOrGreatestRootCmp;
 	type Preimages = Preimage;
+	type BlockNumberProvider = frame_system::Pallet<Runtime>;
 }
 
 parameter_types! {

polkadot/runtime/rococo/src/lib.rs

@@ -344,6 +344,7 @@ impl pallet_scheduler::Config for Runtime {
 	type WeightInfo = weights::pallet_scheduler::WeightInfo<Runtime>;
 	type OriginPrivilegeCmp = OriginPrivilegeCmp;
 	type Preimages = Preimage;
+	type BlockNumberProvider = frame_system::Pallet<Runtime>;
 }
 
 parameter_types! {

polkadot/runtime/westend/src/lib.rs

@@ -250,6 +250,7 @@ impl pallet_scheduler::Config for Runtime {
 	type WeightInfo = weights::pallet_scheduler::WeightInfo<Runtime>;
 	type OriginPrivilegeCmp = frame_support::traits::EqualPrivilegeOnly;
 	type Preimages = Preimage;
+	type BlockNumberProvider = frame_system::Pallet<Runtime>;
 }
 
 parameter_types! {

prdoc/pr_7441.prdoc

@@ -0,0 +1,21 @@
+title: 'Update Scheduler to have a configurable block provider #7434'
+doc:
+- audience: Runtime Dev
+  description: |-
+    Follow up from https://github.com/paritytech/polkadot-sdk/pull/6362#issuecomment-2629744365
+
+        This PR modifies the pallet_scheduler to support parachains that do not produce blocks on a regular schedule. Since block numbers may not increase monotonically in such environments, the scheduler cannot rely on frame_system::Pallet::<T>::block_number(). Instead, this update introduces BlockNumberProvider = frame_system::Pallet<Runtime> in pallet_scheduler::Config, allowing the scheduler to use an external provider, such as the relay chain, for block numbers.
+
+crates:
+- name: collectives-westend-runtime
+  bump: minor
+- name: rococo-runtime
+  bump: minor
+- name: westend-runtime
+  bump: minor
+- name: pallet-democracy
+  bump: minor
+- name: pallet-referenda
+  bump: minor
+- name: pallet-scheduler
+  bump: major

substrate/bin/node/runtime/src/lib.rs

@@ -504,6 +504,7 @@ impl pallet_scheduler::Config for Runtime {
 	type WeightInfo = pallet_scheduler::weights::SubstrateWeight<Runtime>;
 	type OriginPrivilegeCmp = EqualPrivilegeOnly;
 	type Preimages = Preimage;
+	type BlockNumberProvider = frame_system::Pallet<Runtime>;
 }
 
 impl pallet_glutton::Config for Runtime {

substrate/frame/democracy/src/tests.rs

@@ -106,6 +106,7 @@ impl pallet_scheduler::Config for Test {
 	type WeightInfo = ();
 	type OriginPrivilegeCmp = EqualPrivilegeOnly;
 	type Preimages = ();
+	type BlockNumberProvider = frame_system::Pallet<Test>;
 }
 
 #[derive_impl(pallet_balances::config_preludes::TestDefaultConfig)]

substrate/frame/referenda/src/mock.rs

@@ -81,6 +81,7 @@ impl pallet_scheduler::Config for Test {
 	type WeightInfo = ();
 	type OriginPrivilegeCmp = EqualPrivilegeOnly;
 	type Preimages = Preimage;
+	type BlockNumberProvider = frame_system::Pallet<Test>;
 }
 #[derive_impl(pallet_balances::config_preludes::TestDefaultConfig)]
 impl pallet_balances::Config for Test {

substrate/frame/scheduler/src/benchmarking.rs

@@ -49,10 +49,7 @@ fn assert_last_event<T: Config>(generic_event: <T as Config>::RuntimeEvent) {
 /// - `None`: aborted (hash without preimage)
 /// - `Some(true)`: hash resolves into call if possible, plain call otherwise
 /// - `Some(false)`: plain call
-fn fill_schedule<T: Config>(
-	when: frame_system::pallet_prelude::BlockNumberFor<T>,
-	n: u32,
-) -> Result<(), &'static str> {
+fn fill_schedule<T: Config>(when: BlockNumberFor<T>, n: u32) -> Result<(), &'static str> {
 	let t = DispatchTime::At(when);
 	let origin: <T as Config>::PalletsOrigin = frame_system::RawOrigin::Root.into();
 	for i in 0..n {

substrate/frame/scheduler/src/lib.rs

@@ -100,17 +100,16 @@ use frame_support::{
 	},
 	weights::{Weight, WeightMeter},
 };
-use frame_system::{
-	pallet_prelude::BlockNumberFor,
-	{self as system},
-};
+use frame_system::{self as system};
 use scale_info::TypeInfo;
 use sp_io::hashing::blake2_256;
 use sp_runtime::{
 	traits::{BadOrigin, Dispatchable, One, Saturating, Zero},
 	BoundedVec, DispatchError, RuntimeDebug,
 };
 
+use sp_runtime::traits::BlockNumberProvider;
+
 pub use pallet::*;
 pub use weights::WeightInfo;
 
@@ -125,6 +124,9 @@ pub type CallOrHashOf<T> =
 pub type BoundedCallOf<T> =
 	Bounded<<T as Config>::RuntimeCall, <T as frame_system::Config>::Hashing>;
 
+pub type BlockNumberFor<T> =
+	<<T as Config>::BlockNumberProvider as BlockNumberProvider>::BlockNumber;
+
 /// The configuration of the retry mechanism for a given task along with its current state.
 #[derive(Clone, Copy, RuntimeDebug, PartialEq, Eq, Encode, Decode, MaxEncodedLen, TypeInfo)]
 pub struct RetryConfig<Period> {
@@ -230,7 +232,7 @@ impl<T: WeightInfo> MarginalWeightInfo for T {}
 pub mod pallet {
 	use super::*;
 	use frame_support::{dispatch::PostDispatchInfo, pallet_prelude::*};
-	use frame_system::pallet_prelude::*;
+	use frame_system::pallet_prelude::{BlockNumberFor as SystemBlockNumberFor, OriginFor};
 
 	/// The in-code storage version.
 	const STORAGE_VERSION: StorageVersion = StorageVersion::new(4);
@@ -292,6 +294,12 @@ pub mod pallet {
 
 		/// The preimage provider with which we look up call hashes to get the call.
 		type Preimages: QueryPreimage<H = Self::Hashing> + StorePreimage;
+
+		/// Suggested value: Use the system block number or if you expect the parachain to execute
+		/// very regularly you can use the relay chain block number. Warning: This value must not
+		/// be too much out of sync with the local block number. Between every block the increment of
+		/// this number should be reasonably small to avoid performance degradation and added latency
+		type BlockNumberProvider: BlockNumberProvider;
 	}
 
 	#[pallet::storage]
@@ -374,9 +382,10 @@ pub mod pallet {
 	}
 
 	#[pallet::hooks]
-	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {
+	impl<T: Config> Hooks<SystemBlockNumberFor<T>> for Pallet<T> {
 		/// Execute the scheduled calls
-		fn on_initialize(now: BlockNumberFor<T>) -> Weight {
+		fn on_initialize(_do_not_use_local_block_number: SystemBlockNumberFor<T>) -> Weight {
+			let now = T::BlockNumberProvider::current_block_number();
 			let mut weight_counter = WeightMeter::with_limit(T::MaximumWeight::get());
 			Self::service_agendas(&mut weight_counter, now, u32::max_value());
 			weight_counter.consumed()
@@ -889,8 +898,7 @@ impl<T: Config> Pallet<T> {
 	fn resolve_time(
 		when: DispatchTime<BlockNumberFor<T>>,
 	) -> Result<BlockNumberFor<T>, DispatchError> {
-		let now = frame_system::Pallet::<T>::block_number();
-
+		let now = T::BlockNumberProvider::current_block_number();
 		let when = match when {
 			DispatchTime::At(x) => x,
 			// The current block has already completed it's scheduled tasks, so
@@ -926,11 +934,11 @@ impl<T: Config> Pallet<T> {
 		let mut agenda = Agenda::<T>::get(when);
 		let index = if (agenda.len() as u32) < T::MaxScheduledPerBlock::get() {
 			// will always succeed due to the above check.
-			let _ = agenda.try_push(Some(what));
+			let _ = agenda.try_push(Some(what.clone()));
 			agenda.len() as u32 - 1
 		} else {
 			if let Some(hole_index) = agenda.iter().position(|i| i.is_none()) {
-				agenda[hole_index] = Some(what);
+				agenda[hole_index] = Some(what.clone());
 				hole_index as u32
 			} else {
 				return Err((DispatchError::Exhausted, what))

substrate/frame/scheduler/src/migration.rs

@@ -19,7 +19,6 @@
 
 use super::*;
 use frame_support::traits::OnRuntimeUpgrade;
-use frame_system::pallet_prelude::BlockNumberFor;
 
 #[cfg(feature = "try-runtime")]
 use sp_runtime::TryRuntimeError;

substrate/frame/scheduler/src/mock.rs

@@ -223,10 +223,11 @@ impl Config for Test {
 	type RuntimeCall = RuntimeCall;
 	type MaximumWeight = MaximumSchedulerWeight;
 	type ScheduleOrigin = EitherOfDiverse<EnsureRoot<u64>, EnsureSignedBy<One, u64>>;
+	type OriginPrivilegeCmp = EqualPrivilegeOnly;
 	type MaxScheduledPerBlock = ConstU32<10>;
 	type WeightInfo = TestWeightInfo;
-	type OriginPrivilegeCmp = EqualPrivilegeOnly;
 	type Preimages = Preimage;
+	type BlockNumberProvider = frame_system::Pallet<Self>;
 }
 
 pub type LoggerCall = logger::Call<Test>;

substrate/frame/scheduler/src/tests.rs

@@ -1636,6 +1636,7 @@ fn on_initialize_weight_is_correct() {
 		));
 
 		// Will include the named periodic only
+		System::set_block_number(1);
 		assert_eq!(
 			Scheduler::on_initialize(1),
 			TestWeightInfo::service_agendas_base() +
@@ -1648,6 +1649,7 @@ fn on_initialize_weight_is_correct() {
 		assert_eq!(logger::log(), vec![(root(), 2600u32)]);
 
 		// Will include anon and anon periodic
+		System::set_block_number(2);
 		assert_eq!(
 			Scheduler::on_initialize(2),
 			TestWeightInfo::service_agendas_base() +
@@ -1663,6 +1665,7 @@ fn on_initialize_weight_is_correct() {
 		assert_eq!(logger::log(), vec![(root(), 2600u32), (root(), 69u32), (root(), 42u32)]);
 
 		// Will include named only
+		System::set_block_number(3);
 		assert_eq!(
 			Scheduler::on_initialize(3),
 			TestWeightInfo::service_agendas_base() +
@@ -1678,6 +1681,7 @@ fn on_initialize_weight_is_correct() {
 		);
 
 		// Will contain none
+		System::set_block_number(4);
 		let actual_weight = Scheduler::on_initialize(4);
 		assert_eq!(
 			actual_weight,