fix: add shared lock for unsealed block state

core/blockchain.go

@@ -244,12 +244,14 @@ type BlockChain struct {
 	// Readers don't need to take it, they can just read the database.
 	chainmu *syncx.ClosableMutex
 
-	currentBlock         atomic.Pointer[types.Header] // Current head of the chain
-	currentSnapBlock     atomic.Pointer[types.Header] // Current head of snap-sync
-	currentFinalBlock    atomic.Pointer[types.Header] // Latest (consensus) finalized block
-	currentSafeBlock     atomic.Pointer[types.Header] // Latest (consensus) safe block
-	currentUnsealedBlock *types.UnsealedBlock         // Current unsealed block
-	unsealedBlockDbState *state.StateDB               // StateDB for the current unsealed block
+	currentBlock      atomic.Pointer[types.Header] // Current head of the chain
+	currentSnapBlock  atomic.Pointer[types.Header] // Current head of snap-sync
+	currentFinalBlock atomic.Pointer[types.Header] // Latest (consensus) finalized block
+	currentSafeBlock  atomic.Pointer[types.Header] // Latest (consensus) safe block
+
+	currentUnsealedBlock *types.UnsealedBlock // Current unsealed block
+	unsealedBlockDbState *state.StateDB       // StateDB for the current unsealed block
+	unsealedBlockLock    sync.Mutex           // Lock for the unsealedBlock
 
 	bodyCache     *lru.Cache[common.Hash, *types.Body]
 	bodyRLPCache  *lru.Cache[common.Hash, rlp.RawValue]
@@ -2551,3 +2553,8 @@ func (bc *BlockChain) SetTrieFlushInterval(interval time.Duration) {
 func (bc *BlockChain) GetTrieFlushInterval() time.Duration {
 	return time.Duration(bc.flushInterval.Load())
 }
+
+// UnsealedBlockLock returns a pointer to the unsealed block lock
+func (bc *BlockChain) UnsealedBlockLock() *sync.Mutex {
+	return &bc.unsealedBlockLock
+}

eth/api_backend.go

@@ -203,9 +203,16 @@ func (b *EthAPIBackend) StateAndHeaderByNumber(ctx context.Context, number rpc.B
 
 	// Latest state is the current open unselaed block
 	if number == rpc.LatestBlockNumber {
-		stateDb := b.eth.BlockChain().CurrentUnsealedBlockState()
-		if stateDb != nil {
-			return stateDb, b.eth.BlockChain().CurrentUnsealedBlock().TempHeader(), nil
+		// if the lock is held, we can't access the unsealed block
+		if b.eth.BlockChain().UnsealedBlockLock().TryLock() {
+			defer b.eth.BlockChain().UnsealedBlockLock().Unlock()
+
+			stateDb := b.eth.BlockChain().CurrentUnsealedBlockState()
+			if stateDb != nil {
+				return stateDb.Copy(), b.eth.BlockChain().CurrentUnsealedBlock().TempHeader(), nil
+			}
+		} else {
+			log.Warn("unsealed block lock is held, falling back to latest state")
 		}
 	}
 

eth/catalyst/api.go

@@ -160,7 +160,6 @@ type ConsensusAPI struct {
 	forkchoiceLock sync.Mutex // Lock for the forkChoiceUpdated method
 	newPayloadLock sync.Mutex // Lock for the NewPayload method
 
-	unsealedBlockLock sync.Mutex // Lock for the unsealedBlock
 }
 
 // NewConsensusAPI creates a new consensus api for the given backend.
@@ -1357,13 +1356,13 @@ func validateRequests(requests [][]byte) error {
 func (api *ConsensusAPI) NewFragV0(frag engine.SignedNewFrag) (string, error) {
 	log.Info("new frag received", "forBlock", frag.Frag.BlockNumber, "current", api.eth.BlockChain().CurrentBlock().Number)
 
-	api.unsealedBlockLock.Lock()
+	api.eth.BlockChain().UnsealedBlockLock().Lock()
 	res, err := api.newFragV0(frag)
 	if err != nil {
 		log.Error("failed to insert new frag, discarding unsealed block", "error", err)
 		api.eth.BlockChain().ResetCurrentUnsealedBlock()
 	}
-	api.unsealedBlockLock.Unlock()
+	api.eth.BlockChain().UnsealedBlockLock().Unlock()
 
 	log.Info("new frag handled successfully")
 
@@ -1445,13 +1444,13 @@ func (api *ConsensusAPI) SealFragV0(seal engine.SignedSeal) (string, error) {
 		return engine.VALID, nil
 	}
 
-	api.unsealedBlockLock.Lock()
+	api.eth.BlockChain().UnsealedBlockLock().Lock()
 	res, err := api.sealFragV0(seal)
 	if err != nil {
 		log.Error("failed to seal block, discarding unsealed block", "error", err)
 		api.eth.BlockChain().ResetCurrentUnsealedBlock()
 	}
-	api.unsealedBlockLock.Unlock()
+	api.eth.BlockChain().UnsealedBlockLock().Unlock()
 
 	return res, err
 }
@@ -1521,14 +1520,14 @@ func (api *ConsensusAPI) ValidateSealFragV0(preSealedBlock *types.Block, seal en
 func (api *ConsensusAPI) EnvV0(env engine.SignedEnv) (string, error) {
 	log.Info("env received", "forBlock", env.Env.Number, "current", api.eth.BlockChain().CurrentBlock().Number, "env", env.Env)
 
-	api.unsealedBlockLock.Lock()
+	api.eth.BlockChain().UnsealedBlockLock().Lock()
 	res, err := api.envV0(env)
 	if err != nil {
 		log.Error("failed to open unsealed block, discarding unsealed block", "error", err)
 		api.eth.BlockChain().ResetCurrentUnsealedBlock()
 		log.Error("EnvV0 failed", "error", err)
 	}
-	api.unsealedBlockLock.Unlock()
+	api.eth.BlockChain().UnsealedBlockLock().Unlock()
 
 	log.Info("env handled successfully")