statedb: get rid of activestate, stopPrefetcher manually (bnb-chain#1006

)

core/blockchain.go

@@ -1451,6 +1451,7 @@ func (bc *BlockChain) writeBlockWithState(block *types.Block, receipts []*types.
 	// Calculate the total difficulty of the block
 	ptd := bc.GetTd(block.ParentHash(), block.NumberU64()-1)
 	if ptd == nil {
+		state.StopPrefetcher()
 		return consensus.ErrUnknownAncestor
 	}
 	// Make sure no inconsistent state is leaked during insertion
@@ -1809,17 +1810,6 @@ func (bc *BlockChain) insertChain(chain types.Blocks, verifySeals, setHead bool)
 		bc.reportBlock(block, nil, err)
 		return it.index, err
 	}
-	// No validation errors for the first block (or chain prefix skipped)
-	var activeState *state.StateDB
-	defer func() {
-		// The chain importer is starting and stopping trie prefetchers. If a bad
-		// block or other error is hit however, an early return may not properly
-		// terminate the background threads. This defer ensures that we clean up
-		// and dangling prefetcher, without defering each and holding on live refs.
-		if activeState != nil {
-			activeState.StopPrefetcher()
-		}
-	}()
 
 	for ; block != nil && err == nil || errors.Is(err, ErrKnownBlock); block, err = it.next() {
 		// If the chain is terminating, stop processing blocks
@@ -1909,9 +1899,9 @@ func (bc *BlockChain) insertChain(chain types.Blocks, verifySeals, setHead bool)
 		statedb.SetExpectedStateRoot(block.Root())
 		statedb, receipts, logs, usedGas, err := bc.processor.Process(block, statedb, bc.vmConfig)
 		close(interruptCh) // state prefetch can be stopped
-		activeState = statedb
 		if err != nil {
 			bc.reportBlock(block, receipts, err)
+			statedb.StopPrefetcher()
 			return it.index, err
 		}
 		// Update the metrics touched during block processing
@@ -1930,6 +1920,7 @@ func (bc *BlockChain) insertChain(chain types.Blocks, verifySeals, setHead bool)
 			if err := bc.validator.ValidateState(block, statedb, receipts, usedGas); err != nil {
 				log.Error("validate state failed", "error", err)
 				bc.reportBlock(block, receipts, err)
+				statedb.StopPrefetcher()
 				return it.index, err
 			}
 		}

core/state/statedb.go

@@ -230,11 +230,10 @@ func (s *StateDB) StopPrefetcher() {
 		return
 	}
 	s.prefetcherLock.Lock()
-	defer s.prefetcherLock.Unlock()
 	if s.prefetcher != nil {
 		s.prefetcher.close()
-		s.prefetcher = nil
 	}
+	s.prefetcherLock.Unlock()
 }
 
 func (s *StateDB) TriePrefetchInAdvance(block *types.Block, signer types.Signer) {
@@ -1155,15 +1154,7 @@ func (s *StateDB) StateIntermediateRoot() common.Hash {
 	// the remainder without, but pre-byzantium even the initial prefetcher is
 	// useless, so no sleep lost.
 	prefetcher := s.prefetcher
-	defer func() {
-		s.prefetcherLock.Lock()
-		if s.prefetcher != nil {
-			s.prefetcher.close()
-			s.prefetcher = nil
-		}
-		// try not use defer inside defer
-		s.prefetcherLock.Unlock()
-	}()
+	defer s.StopPrefetcher()
 
 	// Now we're about to start to write changes to the trie. The trie is so far
 	// _untouched_. We can check with the prefetcher, if it can give us a trie
@@ -1356,10 +1347,12 @@ func (s *StateDB) LightCommit() (common.Hash, *types.DiffLayer, error) {
 // Commit writes the state to the underlying in-memory trie database.
 func (s *StateDB) Commit(failPostCommitFunc func(), postCommitFuncs ...func() error) (common.Hash, *types.DiffLayer, error) {
 	if s.dbErr != nil {
+		s.StopPrefetcher()
 		return common.Hash{}, nil, fmt.Errorf("commit aborted due to earlier error: %v", s.dbErr)
 	}
 	// Finalize any pending changes and merge everything into the tries
 	if s.lightProcessed {
+		defer s.StopPrefetcher()
 		root, diff, err := s.LightCommit()
 		if err != nil {
 			return root, diff, err
@@ -1568,6 +1561,7 @@ func (s *StateDB) Commit(failPostCommitFunc func(), postCommitFuncs ...func() er
 	if s.pipeCommit {
 		go commmitTrie()
 	} else {
+		defer s.StopPrefetcher()
 		commitFuncs = append(commitFuncs, commmitTrie)
 	}
 	commitRes := make(chan error, len(commitFuncs))