fix bug

node/node.go

@@ -212,41 +212,37 @@ TASK_LOOP:
 	bc := &blockchain.Blockchain{
 		Blocks: make([]*blockchain.Block, blockSize),
 	}
-	// loop to do syncing.
-	for {
-		var wg sync.WaitGroup
-		wg.Add(activePeerNumber)
 
-		for _, configPeer := range syncConfig.peers {
-			if configPeer.err != nil {
-				continue
-			}
-			go func(peerConfig *SyncPeerConfig, taskSyncQueue *queue.Queue, bc *blockchain.Blockchain) {
-				defer wg.Done()
-				for !taskSyncQueue.Empty() {
-					task, err := taskSyncQueue.Poll(1, time.Millisecond)
-					if err == queue.ErrTimeout {
-						break
-					}
-					syncTask := task[0].(SyncBlockTask)
-					msg := proto_node.ConstructBlockchainSyncMessage(proto_node.GET_BLOCK, syncTask.blockHash)
-					peerConfig.w.Write(msg)
-					peerConfig.w.Flush()
-					var content []byte
-					content, peerConfig.err = p2p.ReadMessageContent(peerConfig.conn)
-					if peerConfig.err != nil {
-						peerConfig.trusted = false
-						return
-					}
-					block, err := blockchain.DeserializeBlock(content)
-					if err == nil {
-						bc.Blocks[syncTask.index] = block
-					}
-				}
-			}(&configPeer, taskSyncQueue, bc)
+	wg.Add(activePeerNumber)
+	for _, configPeer := range syncConfig.peers {
+		if configPeer.err != nil {
+			continue
 		}
-		wg.Wait()
+		go func(peerConfig *SyncPeerConfig, taskSyncQueue *queue.Queue, bc *blockchain.Blockchain) {
+			defer wg.Done()
+			for !taskSyncQueue.Empty() {
+				task, err := taskSyncQueue.Poll(1, time.Millisecond)
+				if err == queue.ErrTimeout {
+					break
+				}
+				syncTask := task[0].(SyncBlockTask)
+				msg := proto_node.ConstructBlockchainSyncMessage(proto_node.GET_BLOCK, syncTask.blockHash)
+				peerConfig.w.Write(msg)
+				peerConfig.w.Flush()
+				var content []byte
+				content, peerConfig.err = p2p.ReadMessageContent(peerConfig.conn)
+				if peerConfig.err != nil {
+					peerConfig.trusted = false
+					return
+				}
+				block, err := blockchain.DeserializeBlock(content)
+				if err == nil {
+					bc.Blocks[syncTask.index] = block
+				}
+			}
+		}(&configPeer, taskSyncQueue, bc)
 	}
+	wg.Wait()
 	return bc
 }