eip-7251: process_registry_updates (#14005)

* eip-7251: registry_updates

* Fix spectest violation

* More unit tests for process_registry_updates

* Update tests for ProcessRegistryUpdates

* Minor refactorings and benchmark

* Update beacon-chain/core/electra/registry_updates.go

Co-authored-by: Sammy Rosso <15244892+saolyn@users.noreply.github.com>

* Wrap errors from process_registry_updates for easier debugging

* Rewrite process_registry_updates not to use st.Validators()

---------

Co-authored-by: Sammy Rosso <15244892+saolyn@users.noreply.github.com>

beacon-chain/core/electra/BUILD.bazel

@@ -52,6 +52,7 @@ go_test(
         "deposit_fuzz_test.go",
         "deposits_test.go",
         "effective_balance_updates_test.go",
+        "registry_updates_test.go",
         "transition_test.go",
         "upgrade_test.go",
         "validator_test.go",

beacon-chain/core/electra/registry_updates.go

@@ -2,12 +2,18 @@ package electra
 
 import (
 	"context"
+	"fmt"
 
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/time"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/validators"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 )
 
-// ProcessRegistryUpdates rotates validators in and out of active pool.
-// the amount to rotate is determined churn limit.
+// ProcessRegistryUpdates processes all validators eligible for the activation queue, all validators
+// which should be ejected, and all validators which are eligible for activation from the queue.
 //
 // Spec pseudocode definition:
 //
@@ -28,7 +34,72 @@ import (
 //	         for validator in state.validators:
 //	             if is_eligible_for_activation(state, validator):
 //	                 validator.activation_epoch = activation_epoch
-func ProcessRegistryUpdates(ctx context.Context, state state.BeaconState) (state.BeaconState, error) {
-	// TODO: replace with real implementation
-	return state, nil
+func ProcessRegistryUpdates(ctx context.Context, st state.BeaconState) error {
+	currentEpoch := time.CurrentEpoch(st)
+	ejectionBal := params.BeaconConfig().EjectionBalance
+	activationEpoch := helpers.ActivationExitEpoch(currentEpoch)
+
+	// To avoid copying the state validator set via st.Validators(), we will perform a read only pass
+	// over the validator set while collecting validator indices where the validator copy is actually
+	// necessary, then we will process these operations.
+	eligibleForActivationQ := make([]primitives.ValidatorIndex, 0)
+	eligibleForEjection := make([]primitives.ValidatorIndex, 0)
+	eligibleForActivation := make([]primitives.ValidatorIndex, 0)
+
+	if err := st.ReadFromEveryValidator(func(idx int, val state.ReadOnlyValidator) error {
+		// Collect validators eligible to enter the activation queue.
+		if helpers.IsEligibleForActivationQueue(val, currentEpoch) {
+			eligibleForActivationQ = append(eligibleForActivationQ, primitives.ValidatorIndex(idx))
+		}
+
+		// Collect validators to eject.
+		if val.EffectiveBalance() <= ejectionBal && helpers.IsActiveValidatorUsingTrie(val, currentEpoch) {
+			eligibleForEjection = append(eligibleForEjection, primitives.ValidatorIndex(idx))
+		}
+
+		// Collect validators eligible for activation and not yet dequeued for activation.
+		if helpers.IsEligibleForActivationUsingTrie(st, val) {
+			eligibleForActivation = append(eligibleForActivation, primitives.ValidatorIndex(idx))
+		}
+
+		return nil
+	}); err != nil {
+		return fmt.Errorf("failed to read validators: %w", err)
+	}
+
+	// Handle validators eligible to join the activation queue.
+	for _, idx := range eligibleForActivationQ {
+		v, err := st.ValidatorAtIndex(idx)
+		if err != nil {
+			return err
+		}
+		v.ActivationEligibilityEpoch = currentEpoch + 1
+		if err := st.UpdateValidatorAtIndex(idx, v); err != nil {
+			return fmt.Errorf("failed to updated eligible validator at index %d: %w", idx, err)
+		}
+	}
+
+	// Handle validator ejections.
+	for _, idx := range eligibleForEjection {
+		var err error
+		// exitQueueEpoch and churn arguments are not used in electra.
+		st, _, err = validators.InitiateValidatorExit(ctx, st, idx, 0 /*exitQueueEpoch*/, 0 /*churn*/)
+		if err != nil {
+			return fmt.Errorf("failed to initiate validator exit at index %d: %w", idx, err)
+		}
+	}
+
+	for _, idx := range eligibleForActivation {
+		// Activate all eligible validators.
+		v, err := st.ValidatorAtIndex(idx)
+		if err != nil {
+			return err
+		}
+		v.ActivationEpoch = activationEpoch
+		if err := st.UpdateValidatorAtIndex(idx, v); err != nil {
+			return fmt.Errorf("failed to activate validator at index %d: %w", idx, err)
+		}
+	}
+
+	return nil
 }

beacon-chain/core/electra/registry_updates_test.go

@@ -0,0 +1,145 @@
+package electra_test
+
+import (
+	"context"
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/electra"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
+	state_native "github.com/prysmaticlabs/prysm/v5/beacon-chain/state/state-native"
+	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	eth "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v5/testing/util"
+)
+
+func TestProcessRegistryUpdates(t *testing.T) {
+	finalizedEpoch := primitives.Epoch(4)
+
+	tests := []struct {
+		name  string
+		state state.BeaconState
+		check func(*testing.T, state.BeaconState)
+	}{
+		{
+			name: "No rotation",
+			state: func() state.BeaconState {
+				base := &eth.BeaconStateElectra{
+					Slot: 5 * params.BeaconConfig().SlotsPerEpoch,
+					Validators: []*eth.Validator{
+						{ExitEpoch: params.BeaconConfig().MaxSeedLookahead},
+						{ExitEpoch: params.BeaconConfig().MaxSeedLookahead},
+					},
+					Balances: []uint64{
+						params.BeaconConfig().MaxEffectiveBalance,
+						params.BeaconConfig().MaxEffectiveBalance,
+					},
+					FinalizedCheckpoint: &eth.Checkpoint{Root: make([]byte, fieldparams.RootLength)},
+				}
+				st, err := state_native.InitializeFromProtoElectra(base)
+				require.NoError(t, err)
+				return st
+			}(),
+			check: func(t *testing.T, st state.BeaconState) {
+				for i, val := range st.Validators() {
+					require.Equal(t, params.BeaconConfig().MaxSeedLookahead, val.ExitEpoch, "validator updated unexpectedly at index %d", i)
+				}
+			},
+		},
+		{
+			name: "Validators are activated",
+			state: func() state.BeaconState {
+				base := &eth.BeaconStateElectra{
+					Slot:                5 * params.BeaconConfig().SlotsPerEpoch,
+					FinalizedCheckpoint: &eth.Checkpoint{Epoch: finalizedEpoch, Root: make([]byte, fieldparams.RootLength)},
+				}
+				for i := uint64(0); i < 10; i++ {
+					base.Validators = append(base.Validators, &eth.Validator{
+						ActivationEligibilityEpoch: finalizedEpoch,
+						EffectiveBalance:           params.BeaconConfig().MaxEffectiveBalance,
+						ActivationEpoch:            params.BeaconConfig().FarFutureEpoch,
+					})
+				}
+				st, err := state_native.InitializeFromProtoElectra(base)
+				require.NoError(t, err)
+				return st
+			}(),
+			check: func(t *testing.T, st state.BeaconState) {
+				activationEpoch := helpers.ActivationExitEpoch(5)
+				// All validators should be activated.
+				for i, val := range st.Validators() {
+					require.Equal(t, activationEpoch, val.ActivationEpoch, "failed to update validator at index %d", i)
+				}
+			},
+		},
+		{
+			name: "Validators are exited",
+			state: func() state.BeaconState {
+				base := &eth.BeaconStateElectra{
+					Slot:                5 * params.BeaconConfig().SlotsPerEpoch,
+					FinalizedCheckpoint: &eth.Checkpoint{Epoch: finalizedEpoch, Root: make([]byte, fieldparams.RootLength)},
+				}
+				for i := uint64(0); i < 10; i++ {
+					base.Validators = append(base.Validators, &eth.Validator{
+						EffectiveBalance:  params.BeaconConfig().EjectionBalance - 1,
+						ExitEpoch:         params.BeaconConfig().FarFutureEpoch,
+						WithdrawableEpoch: params.BeaconConfig().FarFutureEpoch,
+					})
+				}
+				st, err := state_native.InitializeFromProtoElectra(base)
+				require.NoError(t, err)
+				return st
+			}(),
+			check: func(t *testing.T, st state.BeaconState) {
+				// All validators should be exited
+				for i, val := range st.Validators() {
+					require.NotEqual(t, params.BeaconConfig().FarFutureEpoch, val.ExitEpoch, "failed to update exit epoch on validator %d", i)
+					require.NotEqual(t, params.BeaconConfig().FarFutureEpoch, val.WithdrawableEpoch, "failed to update withdrawable epoch on validator %d", i)
+				}
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := electra.ProcessRegistryUpdates(context.TODO(), tt.state)
+			require.NoError(t, err)
+			if tt.check != nil {
+				tt.check(t, tt.state)
+			}
+		})
+	}
+}
+
+func Benchmark_ProcessRegistryUpdates_MassEjection(b *testing.B) {
+	bal := params.BeaconConfig().EjectionBalance - 1
+	ffe := params.BeaconConfig().FarFutureEpoch
+	genValidators := func(num uint64) []*eth.Validator {
+		vals := make([]*eth.Validator, num)
+		for i := range vals {
+			vals[i] = &eth.Validator{
+				EffectiveBalance: bal,
+				ExitEpoch:        ffe,
+			}
+		}
+		return vals
+	}
+
+	st, err := util.NewBeaconStateElectra()
+	require.NoError(b, err)
+
+	for i := 0; i < b.N; i++ {
+		b.StopTimer()
+		if err := st.SetValidators(genValidators(100000)); err != nil {
+			panic(err)
+		}
+		b.StartTimer()
+
+		if err := electra.ProcessRegistryUpdates(context.TODO(), st); err != nil {
+			panic(err)
+		}
+	}
+}

beacon-chain/core/electra/transition.go

@@ -77,8 +77,7 @@ func ProcessEpoch(ctx context.Context, state state.BeaconState) error {
 		return errors.Wrap(err, "could not process rewards and penalties")
 	}
 
-	state, err = ProcessRegistryUpdates(ctx, state)
-	if err != nil {
+	if err := ProcessRegistryUpdates(ctx, state); err != nil {
 		return errors.Wrap(err, "could not process registry updates")
 	}
 

testing/spectest/mainnet/electra/epoch_processing/BUILD.bazel

@@ -12,6 +12,7 @@ go_test(
         "pending_balance_updates_test.go",
         "pending_consolidations_test.go",
         "randao_mixes_reset_test.go",
+        "registry_updates_test.go",
         "rewards_and_penalties_test.go",
         "slashings_reset_test.go",
         "slashings_test.go",

testing/spectest/mainnet/electra/epoch_processing/registry_updates_test.go

@@ -0,0 +1,11 @@
+package epoch_processing
+
+import (
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/v5/testing/spectest/shared/electra/epoch_processing"
+)
+
+func TestMainnet_Electra_EpochProcessing_RegistryUpdates(t *testing.T) {
+	epoch_processing.RunRegistryUpdatesTests(t, "mainnet")
+}

testing/spectest/minimal/electra/epoch_processing/BUILD.bazel

@@ -12,6 +12,7 @@ go_test(
         "pending_balance_updates_test.go",
         "pending_consolidations_test.go",
         "randao_mixes_reset_test.go",
+        "registry_updates_test.go",
         "rewards_and_penalties_test.go",
         "slashings_reset_test.go",
         "slashings_test.go",

testing/spectest/minimal/electra/epoch_processing/registry_updates_test.go

@@ -0,0 +1,11 @@
+package epoch_processing
+
+import (
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/v5/testing/spectest/shared/electra/epoch_processing"
+)
+
+func TestMinimal_Electra_EpochProcessing_RegistryUpdates(t *testing.T) {
+	epoch_processing.RunRegistryUpdatesTests(t, "minimal")
+}

testing/spectest/shared/electra/epoch_processing/BUILD.bazel

@@ -14,6 +14,7 @@ go_library(
         "pending_balance_updates.go",
         "pending_consolidations.go",
         "randao_mixes_reset.go",
+        "registry_updates.go",
         "rewards_and_penalties.go",
         "slashings.go",
         "slashings_reset.go",

testing/spectest/shared/electra/epoch_processing/registry_updates.go

@@ -0,0 +1,32 @@
+package epoch_processing
+
+import (
+	"context"
+	"path"
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/electra"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v5/testing/spectest/utils"
+)
+
+// RunRegistryUpdatesTests executes "epoch_processing/registry_updates" tests.
+func RunRegistryUpdatesTests(t *testing.T, config string) {
+	require.NoError(t, utils.SetConfig(t, config))
+
+	testFolders, testsFolderPath := utils.TestFolders(t, config, "electra", "epoch_processing/registry_updates/pyspec_tests")
+	for _, folder := range testFolders {
+		t.Run(folder.Name(), func(t *testing.T) {
+			// Important to clear cache for every test or else the old value of active validator count gets reused.
+			helpers.ClearCache()
+			folderPath := path.Join(testsFolderPath, folder.Name())
+			RunEpochOperationTest(t, folderPath, processRegistryUpdatesWrapper)
+		})
+	}
+}
+
+func processRegistryUpdatesWrapper(_ *testing.T, state state.BeaconState) (state.BeaconState, error) {
+	return state, electra.ProcessRegistryUpdates(context.Background(), state)
+}