# beacon_chain # Copyright (c) 2018-2020 Status Research & Development GmbH # Licensed and distributed under either of # * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT). # * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0). # at your option. This file may not be copied, modified, or distributed except according to those terms. # State transition - epoch processing, as described in # https://github.com/ethereum/eth2.0-specs/blob/master/specs/core/0_beacon-chain.md#beacon-chain-state-transition-function # # The entry point is `process_epoch`, which is at the bottom of this file. # # General notes about the code: # * Weird styling - the sections taken from the spec use python styling while # the others use NEP-1 - helps grepping identifiers in spec # * When updating the code, add TODO sections to mark where there are clear # improvements to be made - other than that, keep things similar to spec unless # motivated by security or performance considerations {.push raises: [Defect].} import std/[math, sequtils, tables, algorithm], stew/[bitops2], chronicles, metrics, ../extras, ../ssz/merkleization, ./beaconstate, ./crypto, ./datatypes, ./digest, ./helpers, ./validator, ../../nbench/bench_lab # Logging utilities # -------------------------------------------------------- logScope: topics = "consens" # https://github.com/ethereum/eth2.0-metrics/blob/master/metrics.md#interop-metrics declareGauge beacon_finalized_epoch, "Current finalized epoch" # On epoch transition declareGauge beacon_finalized_root, "Current finalized root" # On epoch transition declareGauge beacon_current_justified_epoch, "Current justified epoch" # On epoch transition declareGauge beacon_current_justified_root, "Current justified root" # On epoch transition declareGauge beacon_previous_justified_epoch, "Current previously justified epoch" # On epoch transition declareGauge beacon_previous_justified_root, "Current previously justified root" # On epoch transition # Non-spec declareGauge epoch_transition_justification_and_finalization, "Epoch transition justification and finalization time" declareGauge epoch_transition_times_rewards_and_penalties, "Epoch transition reward and penalty time" declareGauge epoch_transition_registry_updates, "Epoch transition registry updates time" declareGauge epoch_transition_slashings, "Epoch transition slashings time" declareGauge epoch_transition_final_updates, "Epoch transition final updates time" declareGauge beacon_current_epoch, "Current epoch" type # Caches for computing justificiation, rewards and penalties - based on # implementation in Lighthouse: # https://github.com/sigp/lighthouse/blob/master/consensus/state_processing/src/per_epoch_processing/validator_statuses.rs Delta* = object rewards*: Gwei penalties*: Gwei InclusionInfo = object # The distance between the attestation slot and the slot that attestation # was included in block. delay: uint64 # The index of the proposer at the slot where the attestation was included. proposer_index: uint64 ValidatorStatus = object # True if the validator has been slashed, ever. is_slashed: bool # True if the validator can withdraw in the current epoch. is_withdrawable_in_current_epoch: bool # True if the validator was active in the state's _current_ epoch. is_active_in_current_epoch: bool # True if the validator was active in the state's _previous_ epoch. is_active_in_previous_epoch: bool # The validator's effective balance in the _current_ epoch. current_epoch_effective_balance: uint64 # True if the validator had an attestation included in the _current_ epoch. is_current_epoch_attester: bool # True if the validator's beacon block root attestation for the first slot # of the _current_ epoch matches the block root known to the state. is_current_epoch_target_attester: bool # True if the validator had an attestation included in the _previous_ epoch. is_previous_epoch_attester: Option[InclusionInfo] # Set if the validator's beacon block root attestation for the first slot of # the _previous_ epoch matches the block root known to the state. # Information used to reward the block producer of this validators # earliest-included attestation. is_previous_epoch_target_attester: bool # True if the validator's beacon block root attestation in the _previous_ # epoch at the attestation's slot (`attestation_data.slot`) matches the # block root known to the state. is_previous_epoch_head_attester: bool inclusion_info: Option[InclusionInfo] # Total rewards and penalties for this validator delta: Delta # https://github.com/ethereum/eth2.0-specs/blob/v1.0.0-rc.0/specs/phase0/beacon-chain.md#get_total_balance TotalBalances = object # The total effective balance of all active validators during the _current_ # epoch. current_epoch_raw: Gwei # The total effective balance of all active validators during the _previous_ # epoch. previous_epoch_raw: Gwei # The total effective balance of all validators who attested during the # _current_ epoch. current_epoch_attesters_raw: Gwei # The total effective balance of all validators who attested during the # _current_ epoch and agreed with the state about the beacon block at the # first slot of the _current_ epoch. current_epoch_target_attesters_raw: Gwei # The total effective balance of all validators who attested during the # _previous_ epoch. previous_epoch_attesters_raw: Gwei # The total effective balance of all validators who attested during the # _previous_ epoch and agreed with the state about the beacon block at the # first slot of the _previous_ epoch. previous_epoch_target_attesters_raw: Gwei # The total effective balance of all validators who attested during the # _previous_ epoch and agreed with the state about the beacon block at the # time of attestation. previous_epoch_head_attesters_raw: Gwei ValidatorStatuses* = object statuses*: seq[ValidatorStatus] total_balances*: TotalBalances # Accessors that implement the max condition in `get_total_balance`: # https://github.com/ethereum/eth2.0-specs/blob/v1.0.0-rc.0/specs/phase0/beacon-chain.md#get_total_balance template current_epoch*(v: TotalBalances): Gwei = max(EFFECTIVE_BALANCE_INCREMENT, v.current_epoch_raw) template previous_epoch*(v: TotalBalances): Gwei = max(EFFECTIVE_BALANCE_INCREMENT, v.previous_epoch_raw) template current_epoch_attesters*(v: TotalBalances): Gwei = max(EFFECTIVE_BALANCE_INCREMENT, v.current_epoch_attesters_raw) template current_epoch_target_attesters*(v: TotalBalances): Gwei = max(EFFECTIVE_BALANCE_INCREMENT, v.current_epoch_target_attesters_raw) template previous_epoch_attesters*(v: TotalBalances): Gwei = max(EFFECTIVE_BALANCE_INCREMENT, v.previous_epoch_attesters_raw) template previous_epoch_target_attesters*(v: TotalBalances): Gwei = max(EFFECTIVE_BALANCE_INCREMENT, v.previous_epoch_target_attesters_raw) template previous_epoch_head_attesters*(v: TotalBalances): Gwei = max(EFFECTIVE_BALANCE_INCREMENT, v.previous_epoch_head_attesters_raw) func init*(T: type ValidatorStatuses, state: BeaconState): T = result.statuses = newSeq[ValidatorStatus](state.validators.len) for i, v in state.validators: result.statuses[i].is_slashed = v.slashed result.statuses[i].is_withdrawable_in_current_epoch = state.get_current_epoch() >= v.withdrawable_epoch result.statuses[i].current_epoch_effective_balance = v.effective_balance if v.is_active_validator(state.get_current_epoch()): result.statuses[i].is_active_in_current_epoch = true result.total_balances.current_epoch_raw += v.effective_balance if v.is_active_validator(state.get_previous_epoch()): result.statuses[i].is_active_in_previous_epoch = true result.total_balances.previous_epoch_raw += v.effective_balance func add(a: var Delta, b: Delta) = a.rewards += b.rewards a.penalties += b.penalties func process_attestation( self: var ValidatorStatuses, state: BeaconState, a: PendingAttestation, cache: var StateCache) = # Collect information about the attestation var is_current_epoch_attester, is_current_epoch_target_attester: bool is_previous_epoch_target_attester: bool is_previous_epoch_head_attester: bool is_previous_epoch_attester: Option[InclusionInfo] if a.data.target.epoch == state.get_current_epoch(): is_current_epoch_attester = true if a.data.target.root == get_block_root(state, state.get_current_epoch()): is_current_epoch_target_attester = true; elif a.data.target.epoch == state.get_previous_epoch(): is_previous_epoch_attester = some(InclusionInfo( delay: a.inclusion_delay, proposer_index: a.proposer_index, )) if a.data.target.root == get_block_root(state, state.get_previous_epoch()): is_previous_epoch_target_attester = true; if a.data.beacon_block_root == get_block_root_at_slot(state, a.data.slot): is_previous_epoch_head_attester = true # Update the cache for all participants for validator_index in get_attesting_indices( state, a.data, a.aggregation_bits, cache): template v(): untyped = self.statuses[validator_index] if is_current_epoch_attester: v.is_current_epoch_attester = true if is_current_epoch_target_attester: v.is_current_epoch_target_attester = true if is_previous_epoch_attester.isSome: if v.is_previous_epoch_attester.isSome: if is_previous_epoch_attester.get().delay < v.is_previous_epoch_attester.get().delay: v.is_previous_epoch_attester = is_previous_epoch_attester else: v.is_previous_epoch_attester = is_previous_epoch_attester if is_previous_epoch_target_attester: v.is_previous_epoch_target_attester = true if is_previous_epoch_head_attester: v.is_previous_epoch_head_attester = true func process_attestations*( self: var ValidatorStatuses, state: BeaconState, cache: var StateCache) = # Walk state attestations and update the status information for a in state.previous_epoch_attestations: process_attestation(self, state, a, cache) for a in state.current_epoch_attestations: process_attestation(self, state, a, cache) for idx, v in self.statuses: if v.is_slashed: continue let validator_balance = state.validators[idx].effective_balance if v.is_current_epoch_attester: self.total_balances.current_epoch_attesters_raw += validator_balance if v.is_current_epoch_target_attester: self.total_balances.current_epoch_target_attesters_raw += validator_balance if v.is_previous_epoch_attester.isSome(): self.total_balances.previous_epoch_attesters_raw += validator_balance if v.is_previous_epoch_target_attester: self.total_balances.previous_epoch_target_attesters_raw += validator_balance if v.is_previous_epoch_head_attester: self.total_balances.previous_epoch_head_attesters_raw += validator_balance func is_eligible_validator*(validator: ValidatorStatus): bool = validator.is_active_in_previous_epoch or (validator.is_slashed and (not validator.is_withdrawable_in_current_epoch)) # Spec # -------------------------------------------------------- # https://github.com/ethereum/eth2.0-specs/blob/v1.0.0-rc.0/specs/phase0/beacon-chain.md#get_total_active_balance func get_total_active_balance*(state: BeaconState, cache: var StateCache): Gwei = ## Return the combined effective balance of the active validators. # Note: ``get_total_balance`` returns ``EFFECTIVE_BALANCE_INCREMENT`` Gwei # minimum to avoid divisions by zero. let epoch = state.get_current_epoch() get_total_balance( state, cache.get_shuffled_active_validator_indices(state, epoch)) # https://github.com/ethereum/eth2.0-specs/blob/v1.0.0-rc.0/specs/phase0/beacon-chain.md#justification-and-finalization proc process_justification_and_finalization*(state: var BeaconState, total_balances: TotalBalances, updateFlags: UpdateFlags = {}) {.nbench.} = # Initial FFG checkpoint values have a `0x00` stub for `root`. # Skip FFG updates in the first two epochs to avoid corner cases that might # result in modifying this stub. if get_current_epoch(state) <= GENESIS_EPOCH + 1: return let previous_epoch = get_previous_epoch(state) current_epoch = get_current_epoch(state) old_previous_justified_checkpoint = state.previous_justified_checkpoint old_current_justified_checkpoint = state.current_justified_checkpoint # Process justifications state.previous_justified_checkpoint = state.current_justified_checkpoint ## Spec: ## state.justification_bits[1:] = state.justification_bits[:-1] ## state.justification_bits[0] = 0b0 # TODO JUSTIFICATION_BITS_LENGTH is a constant in spec, move there or fix # BitVector serialization in SSZ layer const JUSTIFICATION_BITS_LENGTH = 4 state.justification_bits = (state.justification_bits shl 1) and cast[uint8]((2^JUSTIFICATION_BITS_LENGTH) - 1) let total_active_balance = total_balances.current_epoch if total_balances.previous_epoch_target_attesters * 3 >= total_active_balance * 2: state.current_justified_checkpoint = Checkpoint(epoch: previous_epoch, root: get_block_root(state, previous_epoch)) state.justification_bits.setBit 1 trace "Justified with previous epoch", current_epoch = current_epoch, checkpoint = shortLog(state.current_justified_checkpoint) elif verifyFinalization in updateFlags: warn "Low attestation participation in previous epoch", total_balances, epoch = get_current_epoch(state) if total_balances.current_epoch_target_attesters * 3 >= total_active_balance * 2: state.current_justified_checkpoint = Checkpoint(epoch: current_epoch, root: get_block_root(state, current_epoch)) state.justification_bits.setBit 0 trace "Justified with current epoch", current_epoch = current_epoch, checkpoint = shortLog(state.current_justified_checkpoint) # Process finalizations let bitfield = state.justification_bits ## The 2nd/3rd/4th most recent epochs are justified, the 2nd using the 4th ## as source if (bitfield and 0b1110) == 0b1110 and old_previous_justified_checkpoint.epoch + 3 == current_epoch: state.finalized_checkpoint = old_previous_justified_checkpoint trace "Finalized with rule 234", current_epoch = current_epoch, checkpoint = shortLog(state.finalized_checkpoint) ## The 2nd/3rd most recent epochs are justified, the 2nd using the 3rd as ## source if (bitfield and 0b110) == 0b110 and old_previous_justified_checkpoint.epoch + 2 == current_epoch: state.finalized_checkpoint = old_previous_justified_checkpoint trace "Finalized with rule 23", current_epoch = current_epoch, checkpoint = shortLog(state.finalized_checkpoint) ## The 1st/2nd/3rd most recent epochs are justified, the 1st using the 3rd as ## source if (bitfield and 0b111) == 0b111 and old_current_justified_checkpoint.epoch + 2 == current_epoch: state.finalized_checkpoint = old_current_justified_checkpoint trace "Finalized with rule 123", current_epoch = current_epoch, checkpoint = shortLog(state.finalized_checkpoint) ## The 1st/2nd most recent epochs are justified, the 1st using the 2nd as ## source if (bitfield and 0b11) == 0b11 and old_current_justified_checkpoint.epoch + 1 == current_epoch: state.finalized_checkpoint = old_current_justified_checkpoint trace "Finalized with rule 12", current_epoch = current_epoch, checkpoint = shortLog(state.finalized_checkpoint) # https://github.com/ethereum/eth2.0-specs/blob/v1.0.0-rc.0/specs/phase0/beacon-chain.md#helpers func get_base_reward_sqrt*(state: BeaconState, index: ValidatorIndex, total_balance_sqrt: auto): Gwei = # Spec function recalculates total_balance every time, which creates an # O(n^2) situation. let effective_balance = state.validators[index].effective_balance effective_balance * BASE_REWARD_FACTOR div total_balance_sqrt div BASE_REWARDS_PER_EPOCH func get_proposer_reward(base_reward: Gwei): Gwei = # Spec version recalculates get_total_active_balance(state) quadratically base_reward div PROPOSER_REWARD_QUOTIENT func is_in_inactivity_leak(finality_delay: uint64): bool = finality_delay > MIN_EPOCHS_TO_INACTIVITY_PENALTY func get_finality_delay(state: BeaconState): uint64 = get_previous_epoch(state) - state.finalized_checkpoint.epoch func get_attestation_component_delta(is_unslashed_attester: bool, attesting_balance: Gwei, total_balance: Gwei, base_reward: uint64, finality_delay: uint64): Delta = # Helper with shared logic for use by get source, target, and head deltas # functions if is_unslashed_attester: if is_in_inactivity_leak(finality_delay): # Since full base reward will be canceled out by inactivity penalty deltas, # optimal participation receives full base reward compensation here. Delta(rewards: base_reward) else: let reward_numerator = base_reward * (attesting_balance div EFFECTIVE_BALANCE_INCREMENT) Delta(rewards: reward_numerator div (total_balance div EFFECTIVE_BALANCE_INCREMENT)) else: Delta(penalties: base_reward) # https://github.com/ethereum/eth2.0-specs/blob/v1.0.0-rc.0/specs/phase0/beacon-chain.md#components-of-attestation-deltas func get_source_delta*(validator: ValidatorStatus, base_reward: uint64, total_balances: TotalBalances, finality_delay: uint64): Delta = ## Return attester micro-rewards/penalties for source-vote for each validator. get_attestation_component_delta( validator.is_previous_epoch_attester.isSome() and (not validator.is_slashed), total_balances.previous_epoch_attesters, total_balances.current_epoch, base_reward, finality_delay) func get_target_delta*(validator: ValidatorStatus, base_reward: uint64, total_balances: TotalBalances, finality_delay: uint64): Delta = ## Return attester micro-rewards/penalties for target-vote for each validator. get_attestation_component_delta( validator.is_previous_epoch_target_attester and (not validator.is_slashed), total_balances.previous_epoch_target_attesters, total_balances.current_epoch, base_reward, finality_delay) func get_head_delta*(validator: ValidatorStatus, base_reward: uint64, total_balances: TotalBalances, finality_delay: uint64): Delta = ## Return attester micro-rewards/penalties for head-vote for each validator. get_attestation_component_delta( validator.is_previous_epoch_head_attester and (not validator.is_slashed), total_balances.previous_epoch_head_attesters, total_balances.current_epoch, base_reward, finality_delay) func get_inclusion_delay_delta*(validator: ValidatorStatus, base_reward: uint64): (Delta, Option[(uint64, Delta)]) = ## Return proposer and inclusion delay micro-rewards/penalties for each validator. if validator.is_previous_epoch_attester.isSome() and (not validator.is_slashed): let inclusion_info = validator.is_previous_epoch_attester.get() proposer_reward = get_proposer_reward(base_reward) proposer_delta = Delta(rewards: proposer_reward) let max_attester_reward = base_reward - proposer_reward delta = Delta(rewards: max_attester_reward div inclusion_info.delay) proposer_index = inclusion_info.proposer_index; return (delta, some((proposer_index, proposer_delta))) func get_inactivity_penalty_delta*(validator: ValidatorStatus, base_reward: Gwei, finality_delay: uint64): Delta = ## Return inactivity reward/penalty deltas for each validator. var delta: Delta if is_in_inactivity_leak(finality_delay): # If validator is performing optimally this cancels all rewards for a neutral balance delta.penalties += BASE_REWARDS_PER_EPOCH * base_reward - get_proposer_reward(base_reward) # Additionally, all validators whose FFG target didn't match are penalized extra # This condition is equivalent to this condition from the spec: # `index not in get_unslashed_attesting_indices(state, matching_target_attestations)` if validator.is_slashed or (not validator.is_previous_epoch_target_attester): delta.penalties += validator.current_epoch_effective_balance * finality_delay div INACTIVITY_PENALTY_QUOTIENT delta # https://github.com/ethereum/eth2.0-specs/blob/v1.0.0-rc.0/specs/phase0/beacon-chain.md#get_attestation_deltas func get_attestation_deltas( state: BeaconState, validator_statuses: var ValidatorStatuses) = ## Update validator_statuses with attestation reward/penalty deltas for each validator. let finality_delay = get_finality_delay(state) total_balance = validator_statuses.total_balances.current_epoch total_balance_sqrt = integer_squareroot(total_balance) # Filter out ineligible validators. All sub-functions of the spec do this # except for `get_inclusion_delay_deltas`. It's safe to do so here because # any validator that is in the unslashed indices of the matching source # attestations is active, and therefore eligible. for index, validator in validator_statuses.statuses.mpairs(): if not is_eligible_validator(validator): continue let base_reward = get_base_reward_sqrt( state, index.ValidatorIndex, total_balance_sqrt) let source_delta = get_source_delta( validator, base_reward, validator_statuses.total_balances, finality_delay) target_delta = get_target_delta( validator, base_reward, validator_statuses.total_balances, finality_delay) head_delta = get_head_delta( validator, base_reward, validator_statuses.total_balances, finality_delay) (inclusion_delay_delta, proposer_delta) = get_inclusion_delay_delta(validator, base_reward) inactivity_delta = get_inactivity_penalty_delta( validator, base_reward, finality_delay) validator.delta.add source_delta validator.delta.add target_delta validator.delta.add head_delta validator.delta.add inclusion_delay_delta validator.delta.add inactivity_delta if proposer_delta.isSome: let proposer_index = proposer_delta.get()[0] if proposer_index < validator_statuses.statuses.lenu64: validator_statuses.statuses[proposer_index].delta.add( proposer_delta.get()[1]) # https://github.com/ethereum/eth2.0-specs/blob/v1.0.0-rc.0/specs/phase0/beacon-chain.md#process_rewards_and_penalties func process_rewards_and_penalties( state: var BeaconState, validator_statuses: var ValidatorStatuses) {.nbench.} = # No rewards are applied at the end of `GENESIS_EPOCH` because rewards are # for work done in the previous epoch doAssert validator_statuses.statuses.len == state.validators.len if get_current_epoch(state) == GENESIS_EPOCH: return get_attestation_deltas(state, validator_statuses) for idx, v in validator_statuses.statuses: increase_balance(state, idx.ValidatorIndex, v.delta.rewards) decrease_balance(state, idx.ValidatorIndex, v.delta.penalties) # https://github.com/ethereum/eth2.0-specs/blob/v1.0.0-rc.0/specs/phase0/beacon-chain.md#slashings func process_slashings*(state: var BeaconState, total_balance: Gwei) {.nbench.}= let epoch = get_current_epoch(state) adjusted_total_slashing_balance = min(sum(state.slashings) * PROPORTIONAL_SLASHING_MULTIPLIER, total_balance) for index, validator in state.validators: if validator.slashed and epoch + EPOCHS_PER_SLASHINGS_VECTOR div 2 == validator.withdrawable_epoch: let increment = EFFECTIVE_BALANCE_INCREMENT # Factored out from penalty # numerator to avoid uint64 overflow let penalty_numerator = validator.effective_balance div increment * adjusted_total_slashing_balance let penalty = penalty_numerator div total_balance * increment decrease_balance(state, index.ValidatorIndex, penalty) # https://github.com/ethereum/eth2.0-specs/blob/v1.0.0-rc.0/specs/phase0/beacon-chain.md#final-updates func process_final_updates*(state: var BeaconState) {.nbench.}= let current_epoch = get_current_epoch(state) next_epoch = current_epoch + 1 # Reset eth1 data votes if next_epoch mod EPOCHS_PER_ETH1_VOTING_PERIOD == 0: state.eth1_data_votes = default(type state.eth1_data_votes) # Update effective balances with hysteresis for index, validator in state.validators: let balance = state.balances[index] const HYSTERESIS_INCREMENT = EFFECTIVE_BALANCE_INCREMENT div HYSTERESIS_QUOTIENT DOWNWARD_THRESHOLD = HYSTERESIS_INCREMENT * HYSTERESIS_DOWNWARD_MULTIPLIER UPWARD_THRESHOLD = HYSTERESIS_INCREMENT * HYSTERESIS_UPWARD_MULTIPLIER if balance + DOWNWARD_THRESHOLD < validator.effective_balance or validator.effective_balance + UPWARD_THRESHOLD < balance: state.validators[index].effective_balance = min( balance - balance mod EFFECTIVE_BALANCE_INCREMENT, MAX_EFFECTIVE_BALANCE) # Reset slashings state.slashings[int(next_epoch mod EPOCHS_PER_SLASHINGS_VECTOR)] = 0.Gwei # Set randao mix state.randao_mixes[next_epoch mod EPOCHS_PER_HISTORICAL_VECTOR] = get_randao_mix(state, current_epoch) # Set historical root accumulator if next_epoch mod (SLOTS_PER_HISTORICAL_ROOT div SLOTS_PER_EPOCH) == 0: # Equivalent to hash_tree_root(foo: HistoricalBatch), but without using # significant additional stack or heap. # https://github.com/ethereum/eth2.0-specs/blob/v1.0.0-rc.0/specs/phase0/beacon-chain.md#historicalbatch # In response to https://github.com/status-im/nimbus-eth2/issues/921 state.historical_roots.add hash_tree_root( [hash_tree_root(state.block_roots), hash_tree_root(state.state_roots)]) # Rotate current/previous epoch attestations state.previous_epoch_attestations = state.current_epoch_attestations state.current_epoch_attestations = default(type state.current_epoch_attestations) # https://github.com/ethereum/eth2.0-specs/blob/v1.0.0-rc.0/specs/phase0/beacon-chain.md#epoch-processing proc process_epoch*(state: var BeaconState, updateFlags: UpdateFlags, cache: var StateCache) {.nbench.} = let currentEpoch = get_current_epoch(state) trace "process_epoch", current_epoch = currentEpoch var validator_statuses = ValidatorStatuses.init(state) validator_statuses.process_attestations(state, cache) # https://github.com/ethereum/eth2.0-specs/blob/v1.0.0-rc.0/specs/phase0/beacon-chain.md#justification-and-finalization process_justification_and_finalization( state, validator_statuses.total_balances, updateFlags) # state.slot hasn't been incremented yet. if verifyFinalization in updateFlags and currentEpoch >= 2: doAssert state.current_justified_checkpoint.epoch + 2 >= currentEpoch if verifyFinalization in updateFlags and currentEpoch >= 3: # Rule 2/3/4 finalization results in the most pessimal case. The other # three finalization rules finalize more quickly as long as the any of # the finalization rules triggered. doAssert state.finalized_checkpoint.epoch + 3 >= currentEpoch # https://github.com/ethereum/eth2.0-specs/blob/v1.0.0-rc.0/specs/phase0/beacon-chain.md#rewards-and-penalties-1 process_rewards_and_penalties(state, validator_statuses) # https://github.com/ethereum/eth2.0-specs/blob/v1.0.0-rc.0/specs/phase0/beacon-chain.md#registry-updates process_registry_updates(state, cache) # https://github.com/ethereum/eth2.0-specs/blob/v1.0.0-rc.0/specs/phase0/beacon-chain.md#slashings process_slashings(state, validator_statuses.total_balances.current_epoch) # https://github.com/ethereum/eth2.0-specs/blob/v1.0.0-rc.0/specs/phase0/beacon-chain.md#final-updates process_final_updates(state) # Once per epoch metrics beacon_current_epoch.set(currentEpoch.int64) beacon_finalized_epoch.set(state.finalized_checkpoint.epoch.int64) beacon_finalized_root.set(state.finalized_checkpoint.root.toGaugeValue) beacon_current_justified_epoch.set( state.current_justified_checkpoint.epoch.int64) beacon_current_justified_root.set( state.current_justified_checkpoint.root.toGaugeValue) beacon_previous_justified_epoch.set( state.previous_justified_checkpoint.epoch.int64) beacon_previous_justified_root.set( state.previous_justified_checkpoint.root.toGaugeValue)