sync checkTxn and insertTxn (#187)

common/yerror/basic_error.go

@@ -23,6 +23,7 @@ var (
 	PoolOverflow  error = errors.New("pool size is full")
 	TxnTimeoutErr error = errors.New("Txn time out")
 	TxnTooLarge   error = errors.New("the size of txn is too large")
+	TxnDuplicated error = errors.New("Transaction duplicated")
 )
 
 var ErrBlockNotFound error = errors.New("block not found")

core/kernel/handle_input.go

@@ -3,6 +3,7 @@ package kernel
 import (
 	"github.com/sirupsen/logrus"
 	"github.com/yu-org/yu/common"
+	"github.com/yu-org/yu/common/yerror"
 	"github.com/yu-org/yu/core"
 	"github.com/yu-org/yu/core/context"
 	. "github.com/yu-org/yu/core/types"
@@ -21,11 +22,7 @@ func (k *Kernel) HandleTxn(signedWrCall *core.SignedWrCall) error {
 		return err
 	}
 
-	if k.CheckReplayAttack(stxn.TxnHash) {
-		return nil
-	}
-
-	err = k.Pool.CheckTxn(stxn)
+	err = k.handleTxnLocally(stxn)
 	if err != nil {
 		return err
 	}
@@ -37,6 +34,19 @@ func (k *Kernel) HandleTxn(signedWrCall *core.SignedWrCall) error {
 		}
 	}()
 
+	return nil
+}
+
+func (k *Kernel) handleTxnLocally(stxn *SignedTxn) error {
+	k.mutex.Lock()
+	defer k.mutex.Unlock()
+	if k.CheckReplayAttack(stxn.TxnHash) {
+		return yerror.TxnDuplicated
+	}
+	err := k.Pool.CheckTxn(stxn)
+	if err != nil {
+		return err
+	}
 	return k.Pool.Insert(stxn)
 }
 

core/kernel/kernel.go

@@ -13,7 +13,7 @@ import (
 )
 
 type Kernel struct {
-	sync.Mutex
+	mutex sync.Mutex
 
 	cfg *KernelConf