Prevent from completing tx multiple times (#330)

This commit prevents from completing (i.e. sending) the same transaction multiple times.

geth/common/types.go

@@ -150,13 +150,14 @@ type QueuedTxID string
 
 // QueuedTx holds enough information to complete the queued transaction.
 type QueuedTx struct {
-	ID      QueuedTxID
-	Hash    common.Hash
-	Context context.Context
-	Args    SendTxArgs
-	Done    chan struct{}
-	Discard chan struct{}
-	Err     error
+	ID         QueuedTxID
+	Hash       common.Hash
+	Context    context.Context
+	Args       SendTxArgs
+	InProgress bool // true if transaction is being sent
+	Done       chan struct{}
+	Discard    chan struct{}
+	Err        error
 }
 
 // SendTxArgs represents the arguments to submit a new transaction into the transaction pool.

geth/node/txqueue.go

@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/accounts/keystore"
+	gethcommon "github.com/ethereum/go-ethereum/common"
 	"github.com/status-im/status-go/geth/common"
 	"github.com/status-im/status-go/geth/log"
 )
@@ -21,10 +22,12 @@ const (
 )
 
 var (
-	ErrQueuedTxIDNotFound      = errors.New("transaction hash not found")
-	ErrQueuedTxTimedOut        = errors.New("transaction sending timed out")
-	ErrQueuedTxDiscarded       = errors.New("transaction has been discarded")
-	ErrInvalidCompleteTxSender = errors.New("transaction can only be completed by the same account which created it")
+	ErrQueuedTxIDNotFound       = errors.New("transaction hash not found")
+	ErrQueuedTxTimedOut         = errors.New("transaction sending timed out")
+	ErrQueuedTxDiscarded        = errors.New("transaction has been discarded")
+	ErrQueuedTxInProgress       = errors.New("transaction is in progress")
+	ErrQueuedTxAlreadyProcessed = errors.New("transaction has been already processed")
+	ErrInvalidCompleteTxSender  = errors.New("transaction can only be completed by the same account which created it")
 )
 
 // TxQueue is capped container that holds pending transactions
@@ -191,6 +194,33 @@ func (q *TxQueue) Remove(id common.QueuedTxID) {
 	delete(q.transactions, id)
 }
 
+// StartProcessing marks a transaction as in progress. It's thread-safe and
+// prevents from processing the same transaction multiple times.
+func (q *TxQueue) StartProcessing(tx *common.QueuedTx) error {
+	q.mu.Lock()
+	defer q.mu.Unlock()
+
+	if tx.Hash != (gethcommon.Hash{}) || tx.Err != nil {
+		return ErrQueuedTxAlreadyProcessed
+	}
+
+	if tx.InProgress {
+		return ErrQueuedTxInProgress
+	}
+
+	tx.InProgress = true
+
+	return nil
+}
+
+// StopProcessing removes the "InProgress" flag from the transaction.
+func (q *TxQueue) StopProcessing(tx *common.QueuedTx) {
+	q.mu.Lock()
+	defer q.mu.Unlock()
+
+	tx.InProgress = false
+}
+
 // Count returns number of currently queued transactions
 func (q *TxQueue) Count() int {
 	q.mu.RLock()

geth/node/txqueue_manager.go

@@ -138,6 +138,11 @@ func (m *TxQueueManager) CompleteTransaction(id common.QueuedTxID, password stri
 		return gethcommon.Hash{}, err
 	}
 
+	if err := m.txQueue.StartProcessing(queuedTx); err != nil {
+		return gethcommon.Hash{}, err
+	}
+	defer m.txQueue.StopProcessing(queuedTx)
+
 	selectedAccount, err := m.accountManager.SelectedAccount()
 	if err != nil {
 		log.Warn("failed to get a selected account", "err", err)
@@ -179,7 +184,7 @@ func (m *TxQueueManager) CompleteTransaction(id common.QueuedTxID, password stri
 
 	queuedTx.Hash = hash
 	queuedTx.Err = txErr
-	queuedTx.Done <- struct{}{} // sendTransaction() waits on this, notify so that it can return
+	queuedTx.Done <- struct{}{}
 
 	return hash, txErr
 }

geth/node/txqueue_manager_test.go

@@ -3,6 +3,7 @@ package node
 import (
 	"context"
 	"errors"
+	"sync"
 	"testing"
 
 	"github.com/ethereum/go-ethereum/accounts/keystore"
@@ -92,6 +93,69 @@ func (s *TxQueueTestSuite) TestCompleteTransaction() {
 	s.False(txQueueManager.TransactionQueue().Has(tx.ID))
 }
 
+func (s *TxQueueTestSuite) TestCompleteTransactionMultipleTimes() {
+	s.accountManagerMock.EXPECT().SelectedAccount().Return(&common.SelectedExtKey{
+		Address: common.FromAddress(TestConfig.Account1.Address),
+	}, nil)
+
+	s.nodeManagerMock.EXPECT().NodeConfig().Return(
+		params.NewNodeConfig("/tmp", params.RopstenNetworkID, true),
+	)
+
+	// TODO(adam): StatusBackend as an interface would allow a better solution.
+	// As we want to avoid network connection, we mock LES with a known error
+	// and treat as success.
+	s.nodeManagerMock.EXPECT().LightEthereumService().Return(nil, errTxAssumedSent)
+
+	txQueueManager := NewTxQueueManager(s.nodeManagerMock, s.accountManagerMock)
+
+	txQueueManager.Start()
+	defer txQueueManager.Stop()
+
+	tx := txQueueManager.CreateTransaction(context.Background(), common.SendTxArgs{
+		From: common.FromAddress(TestConfig.Account1.Address),
+		To:   common.ToAddress(TestConfig.Account2.Address),
+	})
+
+	// TransactionQueueHandler is required to enqueue a transaction.
+	txQueueManager.SetTransactionQueueHandler(func(queuedTx *common.QueuedTx) {
+		s.Equal(tx.ID, queuedTx.ID)
+	})
+
+	txQueueManager.SetTransactionReturnHandler(func(queuedTx *common.QueuedTx, err error) {
+		s.Equal(tx.ID, queuedTx.ID)
+		s.Equal(errTxAssumedSent, err)
+	})
+
+	err := txQueueManager.QueueTransaction(tx)
+	s.NoError(err)
+
+	var wg sync.WaitGroup
+	var mu sync.Mutex
+	completeTxErrors := make(map[error]int)
+	for i := 0; i < 3; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			_, err := txQueueManager.CompleteTransaction(tx.ID, TestConfig.Account1.Password)
+			mu.Lock()
+			completeTxErrors[err]++
+			mu.Unlock()
+		}()
+	}
+
+	err = txQueueManager.WaitForTransaction(tx)
+	s.Equal(errTxAssumedSent, err)
+	// Check that error is assigned to the transaction.
+	s.Equal(errTxAssumedSent, tx.Err)
+	// Transaction should be already removed from the queue.
+	s.False(txQueueManager.TransactionQueue().Has(tx.ID))
+
+	// Wait for all CompleteTransaction calls.
+	wg.Wait()
+	s.Equal(completeTxErrors[errTxAssumedSent], 1)
+}
+
 func (s *TxQueueTestSuite) TestAccountMismatch() {
 	s.accountManagerMock.EXPECT().SelectedAccount().Return(&common.SelectedExtKey{
 		Address: common.FromAddress(TestConfig.Account2.Address),