core: fixed race condition in the transaction pool

Removed `Stop/Start` mechanism from the transaction pool.

core/transaction_pool.go

@@ -50,7 +50,7 @@ type TxPool struct {
 }
 
 func NewTxPool(eventMux *event.TypeMux, currentStateFn stateFn, gasLimitFn func() *big.Int) *TxPool {
-	return &TxPool{
+	pool := &TxPool{
 		pending:      make(map[common.Hash]*types.Transaction),
 		queue:        make(map[common.Address]map[common.Hash]*types.Transaction),
 		quit:         make(chan bool),
@@ -59,9 +59,12 @@ func NewTxPool(eventMux *event.TypeMux, currentStateFn stateFn, gasLimitFn func(
 		gasLimit:     gasLimitFn,
 		pendingState: state.ManageState(currentStateFn()),
 	}
+	go pool.eventLoop()
+
+	return pool
 }
 
-func (pool *TxPool) Start() {
+func (pool *TxPool) eventLoop() {
 	// Track chain events. When a chain events occurs (new chain canon block)
 	// we need to know the new state. The new state will help us determine
 	// the nonces in the managed state
@@ -169,15 +172,10 @@ func (pool *TxPool) validateTx(tx *types.Transaction) error {
 	return nil
 }
 
+// validate and queue transactions.
 func (self *TxPool) add(tx *types.Transaction) error {
 	hash := tx.Hash()
 
-	/* XXX I'm unsure about this. This is extremely dangerous and may result
-	 in total black listing of certain transactions
-	if self.invalidHashes.Has(hash) {
-		return fmt.Errorf("Invalid transaction (%x)", hash[:4])
-	}
-	*/
 	if self.pending[hash] != nil {
 		return fmt.Errorf("Known transaction (%x)", hash[:4])
 	}
@@ -207,6 +205,30 @@ func (self *TxPool) add(tx *types.Transaction) error {
 	return nil
 }
 
+// queueTx will queue an unknown transaction
+func (self *TxPool) queueTx(hash common.Hash, tx *types.Transaction) {
+	from, _ := tx.From() // already validated
+	if self.queue[from] == nil {
+		self.queue[from] = make(map[common.Hash]*types.Transaction)
+	}
+	self.queue[from][hash] = tx
+}
+
+// addTx will add a transaction to the pending (processable queue) list of transactions
+func (pool *TxPool) addTx(hash common.Hash, addr common.Address, tx *types.Transaction) {
+	if _, ok := pool.pending[hash]; !ok {
+		pool.pending[hash] = tx
+
+		// Increment the nonce on the pending state. This can only happen if
+		// the nonce is +1 to the previous one.
+		pool.pendingState.SetNonce(addr, tx.AccountNonce+1)
+		// Notify the subscribers. This event is posted in a goroutine
+		// because it's possible that somewhere during the post "Remove transaction"
+		// gets called which will then wait for the global tx pool lock and deadlock.
+		go pool.eventMux.Post(TxPreEvent{tx})
+	}
+}
+
 // Add queues a single transaction in the pool if it is valid.
 func (self *TxPool) Add(tx *types.Transaction) error {
 	self.mu.Lock()
@@ -290,28 +312,6 @@ func (self *TxPool) RemoveTransactions(txs types.Transactions) {
 	}
 }
 
-func (self *TxPool) queueTx(hash common.Hash, tx *types.Transaction) {
-	from, _ := tx.From() // already validated
-	if self.queue[from] == nil {
-		self.queue[from] = make(map[common.Hash]*types.Transaction)
-	}
-	self.queue[from][hash] = tx
-}
-
-func (pool *TxPool) addTx(hash common.Hash, addr common.Address, tx *types.Transaction) {
-	if _, ok := pool.pending[hash]; !ok {
-		pool.pending[hash] = tx
-
-		// Increment the nonce on the pending state. This can only happen if
-		// the nonce is +1 to the previous one.
-		pool.pendingState.SetNonce(addr, tx.AccountNonce+1)
-		// Notify the subscribers. This event is posted in a goroutine
-		// because it's possible that somewhere during the post "Remove transaction"
-		// gets called which will then wait for the global tx pool lock and deadlock.
-		go pool.eventMux.Post(TxPreEvent{tx})
-	}
-}
-
 // checkQueue moves transactions that have become processable to main pool.
 func (pool *TxPool) checkQueue() {
 	state := pool.pendingState

eth/backend.go

@@ -466,8 +466,6 @@ func (s *Ethereum) Start() error {
 		s.StartAutoDAG()
 	}
 
-	// Start services
-	go s.txPool.Start()
 	s.protocolManager.Start()
 
 	if s.whisper != nil {
@@ -513,9 +511,6 @@ func (s *Ethereum) StartForTest() {
 		ClientString:    s.net.Name,
 		ProtocolVersion: ProtocolVersion,
 	})
-
-	// Start services
-	s.txPool.Start()
 }
 
 // AddPeer connects to the given node and maintains the connection until the