Merge pull request #2105 from yyforyongyu/fix-batch-mem-leak

rpcclient: make sure batch requests are GCed

rpcclient/infrastructure.go

@@ -270,14 +270,21 @@ func (c *Client) removeRequest(id uint64) *jsonRequest {
 	c.requestLock.Lock()
 	defer c.requestLock.Unlock()
 
-	element := c.requestMap[id]
-	if element != nil {
-		delete(c.requestMap, id)
-		request := c.requestList.Remove(element).(*jsonRequest)
-		return request
+	element, ok := c.requestMap[id]
+	if !ok {
+		return nil
 	}
 
-	return nil
+	delete(c.requestMap, id)
+
+	var request *jsonRequest
+	if c.batch {
+		request = c.batchList.Remove(element).(*jsonRequest)
+	} else {
+		request = c.requestList.Remove(element).(*jsonRequest)
+	}
+
+	return request
 }
 
 // removeAllRequests removes all the jsonRequests which contain the response
@@ -1733,28 +1740,38 @@ func (c *Client) Send() error {
 		return nil
 	}
 
-	// clear batchlist in case of an error
-	defer func() {
+	batchResp, err := c.sendAsync().Receive()
+	if err != nil {
+		// Clear batchlist in case of an error.
+		//
+		// TODO(yy): need to double check to make sure there's no
+		// concurrent access to this batch list, otherwise we may miss
+		// some batched requests.
 		c.batchList = list.New()
-	}()
 
-	result, err := c.sendAsync().Receive()
-
-	if err != nil {
 		return err
 	}
 
-	for iter := c.batchList.Front(); iter != nil; iter = iter.Next() {
-		var requestError error
-		request := iter.Value.(*jsonRequest)
-		individualResult := result[request.id]
-		fullResult, err := json.Marshal(individualResult.Result)
+	// Iterate each response and send it to the corresponding request.
+	for id, resp := range batchResp {
+		// Perform a GC on batchList and requestMap before moving
+		// forward.
+		request := c.removeRequest(id)
+
+		// If there's an error, we log it and continue to the next
+		// request.
+		fullResult, err := json.Marshal(resp.Result)
 		if err != nil {
-			return err
+			log.Errorf("Unable to marshal result: %v for req=%v",
+				err, request.id)
+
+			continue
 		}
 
-		if individualResult.Error != nil {
-			requestError = individualResult.Error
+		// If there's a response error, we send it back the request.
+		var requestError error
+		if resp.Error != nil {
+			requestError = resp.Error
 		}
 
 		result := Response{
@@ -1763,5 +1780,6 @@ func (c *Client) Send() error {
 		}
 		request.responseChan <- &result
 	}
+
 	return nil
 }

wire/msgblock.go

@@ -45,6 +45,20 @@ type MsgBlock struct {
 	Transactions []*MsgTx
 }
 
+// Copy creates a deep copy of MsgBlock.
+func (msg *MsgBlock) Copy() *MsgBlock {
+	block := &MsgBlock{
+		Header:       msg.Header,
+		Transactions: make([]*MsgTx, len(msg.Transactions)),
+	}
+
+	for i, tx := range msg.Transactions {
+		block.Transactions[i] = tx.Copy()
+	}
+
+	return block
+}
+
 // AddTransaction adds a transaction to the message.
 func (msg *MsgBlock) AddTransaction(tx *MsgTx) error {
 	msg.Transactions = append(msg.Transactions, tx)