eth/syncer: advance safe and finalized block (#33038)

Author: jsvisa

eth/syncer/syncer.go

@@ -22,6 +22,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/ethereum/go-ethereum/beacon/params"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/eth"
@@ -133,13 +134,35 @@ func (s *Syncer) run() {
 			}
 
 		case <-ticker.C:
-			if target == nil || !s.exitWhenSynced {
+			if target == nil {
 				continue
 			}
-			if block := s.backend.BlockChain().GetBlockByHash(target.Hash()); block != nil {
-				log.Info("Sync target reached", "number", block.NumberU64(), "hash", block.Hash())
-				go s.stack.Close() // async since we need to close ourselves
-				return
+
+			// Terminate the node if the target has been reached
+			if s.exitWhenSynced {
+				if block := s.backend.BlockChain().GetBlockByHash(target.Hash()); block != nil {
+					log.Info("Sync target reached", "number", block.NumberU64(), "hash", block.Hash())
+					go s.stack.Close() // async since we need to close ourselves
+					return
+				}
+			}
+
+			// Set the finalized and safe markers relative to the current head.
+			// The finalized marker is set two epochs behind the target,
+			// and the safe marker is set one epoch behind the target.
+			head := s.backend.BlockChain().CurrentHeader()
+			if head == nil {
+				continue
+			}
+			if header := s.backend.BlockChain().GetHeaderByNumber(head.Number.Uint64() - params.EpochLength*2); header != nil {
+				if final := s.backend.BlockChain().CurrentFinalBlock(); final == nil || final.Number.Cmp(header.Number) < 0 {
+					s.backend.BlockChain().SetFinalized(header)
+				}
+			}
+			if header := s.backend.BlockChain().GetHeaderByNumber(head.Number.Uint64() - params.EpochLength); header != nil {
+				if safe := s.backend.BlockChain().CurrentSafeBlock(); safe == nil || safe.Number.Cmp(header.Number) < 0 {
+					s.backend.BlockChain().SetSafe(header)
+				}
 			}
 
 		case <-s.closed: