feat: implement eip7514 to limit the validatior activation limit dene…

…b onwards
ChainSafe · Sep 18, 2023 · 7903820 · 7903820
1 parent 8794025
commit 7903820
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Showing 7 changed files with 27 additions and 2 deletions.
diff --git a/packages/config/src/chainConfig/presets/mainnet.ts b/packages/config/src/chainConfig/presets/mainnet.ts
@@ -70,6 +70,7 @@ export const chainConfig: ChainConfig = {
   MIN_PER_EPOCH_CHURN_LIMIT: 4,
   // 2**16 (= 65,536)
   CHURN_LIMIT_QUOTIENT: 65536,
+  MAX_PER_EPOCH_ACTIVATION_CHURN_LIMIT: 8,
   PROPOSER_SCORE_BOOST: 40,
 
   // Deposit contract

diff --git a/packages/config/src/chainConfig/presets/minimal.ts b/packages/config/src/chainConfig/presets/minimal.ts
@@ -68,6 +68,7 @@ export const chainConfig: ChainConfig = {
   MIN_PER_EPOCH_CHURN_LIMIT: 4,
   // [customized] scale queue churn at much lower validator counts for testing
   CHURN_LIMIT_QUOTIENT: 32,
+  MAX_PER_EPOCH_ACTIVATION_CHURN_LIMIT: 8,
   PROPOSER_SCORE_BOOST: 40,
 
   // Deposit contract

diff --git a/packages/config/src/chainConfig/types.ts b/packages/config/src/chainConfig/types.ts
@@ -54,6 +54,7 @@ export type ChainConfig = {
   EJECTION_BALANCE: number;
   MIN_PER_EPOCH_CHURN_LIMIT: number;
   CHURN_LIMIT_QUOTIENT: number;
+  MAX_PER_EPOCH_ACTIVATION_CHURN_LIMIT: number;
 
   // Proposer boost
   PROPOSER_SCORE_BOOST: number;
@@ -106,6 +107,7 @@ export const chainConfigTypes: SpecTypes<ChainConfig> = {
   EJECTION_BALANCE: "number",
   MIN_PER_EPOCH_CHURN_LIMIT: "number",
   CHURN_LIMIT_QUOTIENT: "number",
+  MAX_PER_EPOCH_ACTIVATION_CHURN_LIMIT: "number",
 
   // Proposer boost
   PROPOSER_SCORE_BOOST: "number",

diff --git a/packages/state-transition/src/cache/epochCache.ts b/packages/state-transition/src/cache/epochCache.ts
@@ -145,6 +145,10 @@ export class EpochCache {
    * change through the epoch. It's used in initiateValidatorExit(). Must be update after changing active indexes.
    */
   churnLimit: number;
+  /**
+   * Modified ("limited") churn limit as per the fork dependent activation of EIP-7514
+   */
+  activationChurnLimit: number;
   /**
    * Closest epoch with available churn for validators to exit at. May be updated every block as validators are
    * initiateValidatorExit(). This value may vary on each fork of the state.
@@ -213,6 +217,7 @@ export class EpochCache {
     epoch: Epoch;
     syncPeriod: SyncPeriod;
   }) {
+    this.epoch = data.epoch;
     this.config = data.config;
     this.pubkey2index = data.pubkey2index;
     this.index2pubkey = data.index2pubkey;
@@ -227,14 +232,19 @@ export class EpochCache {
     this.syncProposerReward = data.syncProposerReward;
     this.baseRewardPerIncrement = data.baseRewardPerIncrement;
     this.totalActiveBalanceIncrements = data.totalActiveBalanceIncrements;
+
     this.churnLimit = data.churnLimit;
+    this.activationChurnLimit =
+      this.epoch >= this.config.DENEB_FORK_EPOCH
+        ? Math.min(this.config.MAX_PER_EPOCH_ACTIVATION_CHURN_LIMIT, this.churnLimit)
+        : this.churnLimit;
+
     this.exitQueueEpoch = data.exitQueueEpoch;
     this.exitQueueChurn = data.exitQueueChurn;
     this.currentTargetUnslashedBalanceIncrements = data.currentTargetUnslashedBalanceIncrements;
     this.previousTargetUnslashedBalanceIncrements = data.previousTargetUnslashedBalanceIncrements;
     this.currentSyncCommitteeIndexed = data.currentSyncCommitteeIndexed;
     this.nextSyncCommitteeIndexed = data.nextSyncCommitteeIndexed;
-    this.epoch = data.epoch;
     this.syncPeriod = data.syncPeriod;
   }
 
@@ -503,6 +513,10 @@ export class EpochCache {
     // the first block of the epoch process_block() call. So churnLimit must be computed at the end of the before epoch
     // transition and the result is valid until the end of the next epoch transition
     this.churnLimit = getChurnLimit(this.config, this.currentShuffling.activeIndices.length);
+    this.activationChurnLimit =
+      this.config.DENEB_FORK_EPOCH >= this.epoch
+        ? Math.min(this.config.MAX_PER_EPOCH_ACTIVATION_CHURN_LIMIT, this.churnLimit)
+        : this.churnLimit;
 
     // Maybe advance exitQueueEpoch at the end of the epoch if there haven't been any exists for a while
     const exitQueueEpoch = computeActivationExitEpoch(currEpoch);

diff --git a/packages/state-transition/src/epoch/processRegistryUpdates.ts b/packages/state-transition/src/epoch/processRegistryUpdates.ts
@@ -38,7 +38,8 @@ export function processRegistryUpdates(state: CachedBeaconStateAllForks, cache:
 
   const finalityEpoch = state.finalizedCheckpoint.epoch;
   // dequeue validators for activation up to churn limit
-  for (const index of cache.indicesEligibleForActivation.slice(0, epochCtx.churnLimit)) {
+  //  - use fork dependent churn limit for activation (EIP-7514)
+  for (const index of cache.indicesEligibleForActivation.slice(0, epochCtx.activationChurnLimit)) {
     const validator = validators.get(index);
     // placement in queue is finalized
     if (validator.activationEligibilityEpoch > finalityEpoch) {

diff --git a/packages/state-transition/src/util/validator.ts b/packages/state-transition/src/util/validator.ts
@@ -38,3 +38,8 @@ export function getActiveValidatorIndices(state: BeaconStateAllForks, epoch: Epo
 export function getChurnLimit(config: ChainForkConfig, activeValidatorCount: number): number {
   return Math.max(config.MIN_PER_EPOCH_CHURN_LIMIT, intDiv(activeValidatorCount, config.CHURN_LIMIT_QUOTIENT));
 }
+
+// Just for completeness sake, epochCtx directly uses churnLimit to get the final churn limit
+export function getctivationChurnLimit(config: ChainForkConfig, activeValidatorCount: number): number {
+  return Math.min(config.MAX_PER_EPOCH_ACTIVATION_CHURN_LIMIT, getChurnLimit(config, activeValidatorCount));
+}
diff --git a/packages/validator/src/util/params.ts b/packages/validator/src/util/params.ts
@@ -119,6 +119,7 @@ function getSpecCriticalParams(localConfig: ChainConfig): Record<keyof ConfigWit
     EJECTION_BALANCE: true,
     MIN_PER_EPOCH_CHURN_LIMIT: true,
     CHURN_LIMIT_QUOTIENT: true,
+    MAX_PER_EPOCH_ACTIVATION_CHURN_LIMIT: denebForkRelevant,
 
     // Proposer boost
     PROPOSER_SCORE_BOOST: false, // Ignored as it's changing https://github.com/ethereum/consensus-specs/pull/2895