eth, core: interupt the chain processing on stop

Added an additional channel which is used to interupt the chain manager
when it's processing blocks.

core/chain_manager.go

@@ -101,6 +101,7 @@ type ChainManager struct {
 	futureBlocks *BlockCache
 
 	quit         chan struct{}
+	procInterupt chan struct{} // interupt signaler for block processing
 	wg           sync.WaitGroup
 
 	pow pow.PoW
@@ -113,6 +114,7 @@ func NewChainManager(genesis *types.Block, blockDb, stateDb common.Database, pow
 		genesisBlock: GenesisBlock(42, stateDb),
 		eventMux:     mux,
 		quit:         make(chan struct{}),
+		procInterupt: make(chan struct{}),
 		cache:        NewBlockCache(blockCacheLimit),
 		pow:          pow,
 	}
@@ -516,6 +518,7 @@ func (self *ChainManager) CalcTotalDiff(block *types.Block) (*big.Int, error) {
 
 func (bc *ChainManager) Stop() {
 	close(bc.quit)
+	close(bc.procInterupt)
 
 	bc.wg.Wait()
 
@@ -568,7 +571,13 @@ func (self *ChainManager) InsertChain(chain types.Blocks) (int, error) {
 	defer close(nonceQuit)
 
 	txcount := 0
+done:
 	for i, block := range chain {
+		select {
+		case <-self.procInterupt:
+			glog.V(logger.Debug).Infoln("Premature abort during chain processing")
+			break done
+		default:
 			bstart := time.Now()
 			// Wait for block i's nonce to be verified before processing
 			// its state transition.
@@ -682,6 +691,7 @@ func (self *ChainManager) InsertChain(chain types.Blocks) (int, error) {
 			stats.processed++
 
 		}
+	}
 
 	if (stats.queued > 0 || stats.processed > 0 || stats.ignored > 0) && bool(glog.V(logger.Info)) {
 		tend := time.Since(tstart)

eth/backend.go

@@ -527,8 +527,8 @@ func (self *Ethereum) AddPeer(nodeURL string) error {
 
 func (s *Ethereum) Stop() {
 	s.net.Stop()
-	s.protocolManager.Stop()
 	s.chainManager.Stop()
+	s.protocolManager.Stop()
 	s.txPool.Stop()
 	s.eventMux.Stop()
 	if s.whisper != nil {