Migrate parachain swaps to Coretime

polkadot/runtime/common/src/crowdloan/mod.rs

@@ -834,7 +834,7 @@ impl<T: Config> Pallet<T> {
 	}
 }
 
-impl<T: Config> crate::traits::OnSwap for Pallet<T> {
+impl<T: Config> runtime_parachains::OnSwap for Pallet<T> {
 	fn on_swap(one: ParaId, other: ParaId) {
 		Funds::<T>::mutate(one, |x| Funds::<T>::mutate(other, |y| sp_std::mem::swap(x, y)))
 	}

polkadot/runtime/common/src/paras_registrar/mod.rs

@@ -34,10 +34,13 @@ use runtime_parachains::{
 };
 use sp_std::{prelude::*, result};
 
-use crate::traits::{OnSwap, Registrar};
+use crate::traits::Registrar;
 pub use pallet::*;
 use parity_scale_codec::{Decode, Encode};
-use runtime_parachains::paras::{OnNewHead, ParaKind};
+use runtime_parachains::{
+	paras::{OnNewHead, ParaKind},
+	OnSwap,
+};
 use scale_info::TypeInfo;
 use sp_runtime::{
 	traits::{CheckedSub, Saturating},
@@ -131,7 +134,7 @@ pub mod pallet {
 		type Currency: ReservableCurrency<Self::AccountId>;
 
 		/// Runtime hook for when a lease holding parachain and on-demand parachain swap.
-		type OnSwap: crate::traits::OnSwap;
+		type OnSwap: runtime_parachains::OnSwap;
 
 		/// The deposit to be paid to run a on-demand parachain.
 		/// This should include the cost for storing the genesis head and validation code.

polkadot/runtime/common/src/slots/mod.rs

@@ -328,7 +328,7 @@ impl<T: Config> Pallet<T> {
 	}
 }
 
-impl<T: Config> crate::traits::OnSwap for Pallet<T> {
+impl<T: Config> runtime_parachains::OnSwap for Pallet<T> {
 	fn on_swap(one: ParaId, other: ParaId) {
 		Leases::<T>::mutate(one, |x| Leases::<T>::mutate(other, |y| sp_std::mem::swap(x, y)))
 	}

polkadot/runtime/common/src/traits.rs

@@ -254,12 +254,3 @@ pub trait Auctioneer<BlockNumber> {
 	/// Check if the para and user combination has won an auction in the past.
 	fn has_won_an_auction(para: ParaId, bidder: &Self::AccountId) -> bool;
 }
-
-/// Runtime hook for when we swap a lease holding parachain and an on-demand parachain.
-#[impl_trait_for_tuples::impl_for_tuples(30)]
-pub trait OnSwap {
-	/// Updates any needed state/references to enact a logical swap of two parachains. Identity,
-	/// code and `head_data` remain equivalent for all parachains/threads, however other properties
-	/// such as leases, deposits held and thread/chain nature are swapped.
-	fn on_swap(one: ParaId, other: ParaId);
-}

polkadot/runtime/parachains/src/coretime/mod.rs

@@ -32,6 +32,7 @@ use crate::{
 	assigner_coretime::{self, PartsOf57600},
 	initializer::{OnNewSession, SessionChangeNotification},
 	origin::{ensure_parachain, Origin},
+	OnSwap,
 };
 
 mod benchmarking;
@@ -83,6 +84,8 @@ enum CoretimeCalls {
 	SetLease(pallet_broker::TaskId, pallet_broker::Timeslice),
 	#[codec(index = 19)]
 	NotifyCoreCount(u16),
+	#[codec(index = 20)]
+	SwapLeases(ParaId, ParaId),
 }
 
 #[frame_support::pallet]
@@ -241,6 +244,24 @@ impl<T: Config> OnNewSession<BlockNumberFor<T>> for Pallet<T> {
 	}
 }
 
+impl<T: Config> OnSwap for Pallet<T> {
+	fn on_swap(one: ParaId, other: ParaId) {
+		let message = Xcm(vec![
+			Instruction::UnpaidExecution {
+				weight_limit: WeightLimit::Unlimited,
+				check_origin: None,
+			},
+			mk_coretime_call(crate::coretime::CoretimeCalls::SwapLeases(one, other)),
+		]);
+		if let Err(err) = send_xcm::<T::SendXcm>(
+			Location::new(0, [Junction::Parachain(T::BrokerId::get())]),
+			message,
+		) {
+			log::error!("Sending `SwapLeases` to coretime chain failed: {:?}", err);
+		}
+	}
+}
+
 fn mk_coretime_call(call: crate::coretime::CoretimeCalls) -> Instruction<()> {
 	Instruction::Transact {
 		origin_kind: OriginKind::Superuser,

polkadot/runtime/parachains/src/lib.rs

@@ -113,3 +113,12 @@ pub fn schedule_code_upgrade<T: paras::Config>(
 pub fn set_current_head<T: paras::Config>(id: ParaId, new_head: HeadData) {
 	paras::Pallet::<T>::set_current_head(id, new_head)
 }
+
+/// Runtime hook for when we swap a lease holding parachain and an on-demand parachain.
+#[impl_trait_for_tuples::impl_for_tuples(30)]
+pub trait OnSwap {
+	/// Updates any needed state/references to enact a logical swap of two parachains. Identity,
+	/// code and `head_data` remain equivalent for all parachains/threads, however other properties
+	/// such as leases, deposits held and thread/chain nature are swapped.
+	fn on_swap(one: ParaId, other: ParaId);
+}

substrate/frame/broker/src/benchmarking.rs

@@ -918,6 +918,20 @@ mod benches {
 		Ok(())
 	}
 
+	#[benchmark]
+	fn swap_leases() -> Result<(), BenchmarkError> {
+		let admin_origin =
+			T::AdminOrigin::try_successful_origin().map_err(|_| BenchmarkError::Weightless)?;
+
+		setup_leases::<T>(T::MaxLeasedCores::get(), 1, 10);
+		setup_leases::<T>(T::MaxLeasedCores::get(), 2, 10);
+
+		#[extrinsic_call]
+		_(admin_origin as T::RuntimeOrigin, 1, 2);
+
+		Ok(())
+	}
+
 	// Implements a test for each benchmark. Execute with:
 	// `cargo test -p pallet-broker --features runtime-benchmarks`.
 	impl_benchmark_test_suite!(Pallet, crate::mock::new_test_ext(), crate::mock::Test);

substrate/frame/broker/src/dispatchable_impls.rs

@@ -437,4 +437,36 @@ impl<T: Config> Pallet<T> {
 		Self::deposit_event(Event::AllowedRenewalDropped { core, when });
 		Ok(())
 	}
+
+	pub(crate) fn do_swap_leases(id: TaskId, other: TaskId) -> DispatchResult {
+		let mut id_exists = false;
+		let mut other_exists = false;
+		let leases = Leases::<T>::get()
+			.into_inner()
+			.into_iter()
+			.map(|mut lease| {
+				if lease.task == id {
+					lease.task = other;
+					id_exists = true;
+				} else if lease.task == other {
+					lease.task = id;
+					other_exists = true;
+				}
+				lease
+			})
+			.collect::<Vec<_>>();
+
+		ensure!(id_exists && other_exists, Error::<T>::UnknownReservation);
+
+		let leases = if let Ok(leases) = BoundedVec::try_from(leases) {
+			leases
+		} else {
+			defensive!("leases is extracted from a `BoundedVec` without adding new elements so the conversation should always succeed");
+			return Err(DispatchError::Other("Failed to convert leases to BoundedVec"));
+		};
+
+		Leases::<T>::set(leases);
+
+		Ok(())
+	}
 }

substrate/frame/broker/src/lib.rs

@@ -786,5 +786,13 @@ pub mod pallet {
 			Self::do_notify_core_count(core_count)?;
 			Ok(())
 		}
+
+		#[pallet::call_index(20)]
+		#[pallet::weight(T::WeightInfo::swap_leases())]
+		pub fn swap_leases(origin: OriginFor<T>, id: TaskId, other: TaskId) -> DispatchResult {
+			T::AdminOrigin::ensure_origin_or_root(origin)?;
+			Self::do_swap_leases(id, other)?;
+			Ok(())
+		}
 	}
 }