pallet_broker: Support renewing leases expired in a previous period (#4089)

Part of: https://github.com/paritytech/polkadot-sdk/issues/4107

Cargo.lock

@@ -9937,6 +9937,7 @@ dependencies = [
  "frame-support",
  "frame-system",
  "parity-scale-codec",
+ "pretty_assertions",
  "scale-info",
  "sp-api",
  "sp-arithmetic",

prdoc/pr_4089.prdoc

@@ -0,0 +1,11 @@
+title: "pallet_broker: Support renewing leases expired in a previous period"
+
+doc:
+  - audience: Runtime User
+    description: |
+      Allow renewals of leases that ended before `start_sales` or in the first period after calling `start_sales`.
+      This ensures that everyone has a smooth experience when migrating to coretime and the timing of
+      `start_sales` isn't that important.
+
+crates:
+  - name: pallet-broker

substrate/frame/broker/Cargo.toml

@@ -29,6 +29,7 @@ frame-system = { path = "../system", default-features = false }
 
 [dev-dependencies]
 sp-io = { path = "../../primitives/io" }
+pretty_assertions = "1.3.0"
 
 [features]
 default = ["std"]

substrate/frame/broker/src/mock.rs

@@ -29,7 +29,7 @@ use frame_support::{
 };
 use frame_system::{EnsureRoot, EnsureSignedBy};
 use sp_arithmetic::Perbill;
-use sp_core::{ConstU32, ConstU64};
+use sp_core::{ConstU32, ConstU64, Get};
 use sp_runtime::{
 	traits::{BlockNumberProvider, Identity},
 	BuildStorage, Saturating,
@@ -210,6 +210,15 @@ pub fn advance_to(b: u64) {
 	}
 }
 
+pub fn advance_sale_period() {
+	let sale = SaleInfo::<Test>::get().unwrap();
+
+	let target_block_number =
+		sale.region_begin as u64 * <<Test as crate::Config>::TimeslicePeriod as Get<u64>>::get();
+
+	advance_to(target_block_number)
+}
+
 pub fn pot() -> u64 {
 	balance(Broker::account_id())
 }

substrate/frame/broker/src/tests.rs

@@ -24,6 +24,7 @@ use frame_support::{
 	BoundedVec,
 };
 use frame_system::RawOrigin::Root;
+use pretty_assertions::assert_eq;
 use sp_runtime::{traits::Get, TokenError};
 use CoreAssignment::*;
 use CoretimeTraceItem::*;
@@ -1092,3 +1093,141 @@ fn config_works() {
 		assert_noop!(Broker::configure(Root.into(), cfg), Error::<Test>::InvalidConfig);
 	});
 }
+
+/// Ensure that a lease that ended before `start_sales` was called can be renewed.
+#[test]
+fn renewal_works_leases_ended_before_start_sales() {
+	TestExt::new().endow(1, 1000).execute_with(|| {
+		let config = Configuration::<Test>::get().unwrap();
+
+		// This lease is ended before `start_stales` was called.
+		assert_ok!(Broker::do_set_lease(1, 1));
+
+		// Go to some block to ensure that the lease of task 1 already ended.
+		advance_to(5);
+
+		// This lease will end three sale periods in.
+		assert_ok!(Broker::do_set_lease(
+			2,
+			Broker::latest_timeslice_ready_to_commit(&config) + config.region_length * 3
+		));
+
+		// This intializes the first sale and the period 0.
+		assert_ok!(Broker::do_start_sales(100, 2));
+		assert_noop!(Broker::do_renew(1, 1), Error::<Test>::Unavailable);
+		assert_noop!(Broker::do_renew(1, 0), Error::<Test>::Unavailable);
+
+		// Lease for task 1 should have been dropped.
+		assert!(Leases::<Test>::get().iter().any(|l| l.task == 2));
+
+		// This intializes the second and the period 1.
+		advance_sale_period();
+
+		// Now we can finally renew the core 0 of task 1.
+		let new_core = Broker::do_renew(1, 0).unwrap();
+		// Renewing the active lease doesn't work.
+		assert_noop!(Broker::do_renew(1, 1), Error::<Test>::SoldOut);
+		assert_eq!(balance(1), 900);
+
+		// This intializes the third sale and the period 2.
+		advance_sale_period();
+		let new_core = Broker::do_renew(1, new_core).unwrap();
+
+		// Renewing the active lease doesn't work.
+		assert_noop!(Broker::do_renew(1, 0), Error::<Test>::SoldOut);
+		assert_eq!(balance(1), 800);
+
+		// All leases should have ended
+		assert!(Leases::<Test>::get().is_empty());
+
+		// This intializes the fourth sale and the period 3.
+		advance_sale_period();
+
+		// Renew again
+		assert_eq!(0, Broker::do_renew(1, new_core).unwrap());
+		// Renew the task 2.
+		assert_eq!(1, Broker::do_renew(1, 0).unwrap());
+		assert_eq!(balance(1), 600);
+
+		// This intializes the fifth sale and the period 4.
+		advance_sale_period();
+
+		assert_eq!(
+			CoretimeTrace::get(),
+			vec![
+				(
+					10,
+					AssignCore {
+						core: 0,
+						begin: 12,
+						assignment: vec![(Task(1), 57600)],
+						end_hint: None
+					}
+				),
+				(
+					10,
+					AssignCore {
+						core: 1,
+						begin: 12,
+						assignment: vec![(Task(2), 57600)],
+						end_hint: None
+					}
+				),
+				(
+					16,
+					AssignCore {
+						core: 0,
+						begin: 18,
+						assignment: vec![(Task(2), 57600)],
+						end_hint: None
+					}
+				),
+				(
+					16,
+					AssignCore {
+						core: 1,
+						begin: 18,
+						assignment: vec![(Task(1), 57600)],
+						end_hint: None
+					}
+				),
+				(
+					22,
+					AssignCore {
+						core: 0,
+						begin: 24,
+						assignment: vec![(Task(2), 57600)],
+						end_hint: None,
+					},
+				),
+				(
+					22,
+					AssignCore {
+						core: 1,
+						begin: 24,
+						assignment: vec![(Task(1), 57600)],
+						end_hint: None,
+					},
+				),
+				(
+					28,
+					AssignCore {
+						core: 0,
+						begin: 30,
+						assignment: vec![(Task(1), 57600)],
+						end_hint: None,
+					},
+				),
+				(
+					28,
+					AssignCore {
+						core: 1,
+						begin: 30,
+						assignment: vec![(Task(2), 57600)],
+						end_hint: None,
+					},
+				),
+			]
+		);
+	});
+}

substrate/frame/broker/src/tick_impls.rs

@@ -216,11 +216,10 @@ impl<T: Config> Pallet<T> {
 			let assignment = CoreAssignment::Task(task);
 			let schedule = BoundedVec::truncate_from(vec![ScheduleItem { mask, assignment }]);
 			Workplan::<T>::insert((region_begin, first_core), &schedule);
-			// Separate these to avoid missed expired leases hanging around forever.
-			let expired = until < region_end;
-			let expiring = until >= region_begin && expired;
-			if expiring {
-				// last time for this one - make it renewable.
+			// Will the lease expire at the end of the period?
+			let expire = until < region_end;
+			if expire {
+				// last time for this one - make it renewable in the next sale.
 				let renewal_id = AllowedRenewalId { core: first_core, when: region_end };
 				let record = AllowedRenewalRecord { price, completion: Complete(schedule) };
 				AllowedRenewals::<T>::insert(renewal_id, &record);
@@ -232,8 +231,10 @@ impl<T: Config> Pallet<T> {
 				});
 				Self::deposit_event(Event::LeaseEnding { when: region_end, task });
 			}
+
 			first_core.saturating_inc();
-			!expired
+
+			!expire
 		});
 		Leases::<T>::put(&leases);