[TxPool] Fix duplicate transactions in account (0xPolygon#575)

* fixes gossip transaction ending up in enqueued next to the original 

* fixes "failed to apply tx: incorrect nonce" logs

txpool/lookup_map.go

@@ -12,14 +12,19 @@ type lookupMap struct {
 	all map[types.Hash]*types.Transaction
 }
 
-// add inserts the given transaction into the map. [thread-safe]
-func (m *lookupMap) add(txs ...*types.Transaction) {
+// add inserts the given transaction into the map. Returns false
+// if it already exists. [thread-safe]
+func (m *lookupMap) add(tx *types.Transaction) bool {
 	m.Lock()
 	defer m.Unlock()
 
-	for _, tx := range txs {
-		m.all[tx.Hash] = tx
+	if _, exists := m.all[tx.Hash]; exists {
+		return false
 	}
+
+	m.all[tx.Hash] = tx
+
+	return true
 }
 
 // remove removes the given transactions from the map. [thread-safe]

txpool/txpool.go

@@ -589,20 +589,9 @@ func (p *TxPool) addTx(origin txOrigin, tx *types.Transaction) error {
 
 	tx.ComputeHash()
 
-	// check if already known
-	if _, ok := p.index.get(tx.Hash); ok {
-		if origin == gossip {
-			// silently drop known tx
-			// that is gossiped back
-			p.logger.Debug(
-				"dropping known gossiped transaction",
-				"hash", tx.Hash.String(),
-			)
-
-			return nil
-		} else {
-			return ErrAlreadyKnown
-		}
+	//	add to index
+	if ok := p.index.add(tx); !ok {
+		return ErrAlreadyKnown
 	}
 
 	// initialize account for this address once
@@ -632,13 +621,13 @@ func (p *TxPool) handleEnqueueRequest(req enqueueRequest) {
 	if err := account.enqueue(tx); err != nil {
 		p.logger.Error("enqueue request", "err", err)
 
+		p.index.remove(tx)
+
 		return
 	}
 
 	p.logger.Debug("enqueue request", "hash", tx.Hash.String())
 
-	// update state
-	p.index.add(tx)
 	p.gauge.increase(slotsRequired(tx))
 
 	p.eventManager.signalEvent(proto.EventType_ENQUEUED, tx.Hash)
@@ -693,14 +682,20 @@ func (p *TxPool) addGossipTx(obj interface{}) {
 
 	// decode tx
 	if err := tx.UnmarshalRLP(raw.Raw.Value); err != nil {
-		p.logger.Error("failed to decode broadcasted tx", "err", err)
+		p.logger.Error("failed to decode broadcast tx", "err", err)
 
 		return
 	}
 
 	// add tx
 	if err := p.addTx(gossip, tx); err != nil {
-		p.logger.Error("failed to add broadcasted txn", "err", err)
+		if errors.Is(err, ErrAlreadyKnown) {
+			p.logger.Debug("rejecting known tx (gossip)", "hash", tx.Hash.String())
+
+			return
+		}
+
+		p.logger.Error("failed to add broadcast tx", "err", err, "hash", tx.Hash.String())
 	}
 }
 

txpool/txpool_test.go

@@ -389,6 +389,8 @@ func TestAddGossipTx(t *testing.T) {
 }
 
 func TestDropKnownGossipTx(t *testing.T) {
+	t.Parallel()
+
 	pool, err := newTestPool()
 	assert.NoError(t, err)
 	pool.SetSigner(&mockSigner{})
@@ -397,18 +399,18 @@ func TestDropKnownGossipTx(t *testing.T) {
 
 	// send tx as local
 	go func() {
-		err := pool.addTx(local, tx)
-		assert.NoError(t, err)
+		assert.NoError(t, pool.addTx(local, tx))
 	}()
-	pool.handleEnqueueRequest(<-pool.enqueueReqCh)
+	<-pool.enqueueReqCh
 
-	assert.Equal(t, uint64(1), pool.accounts.get(addr1).enqueued.length())
+	_, exists := pool.index.get(tx.Hash)
+	assert.True(t, exists)
 
 	// send tx as gossip (will be discarded)
-	err = pool.addTx(gossip, tx)
-	assert.Nil(t, err)
-
-	assert.Equal(t, uint64(1), pool.accounts.get(addr1).enqueued.length())
+	assert.ErrorIs(t,
+		pool.addTx(gossip, tx),
+		ErrAlreadyKnown,
+	)
 }
 
 func TestAddHandler(t *testing.T) {