From 03ca08d9bfab9d707c9eef86652690a4534f6e3d Mon Sep 17 00:00:00 2001
From: wanghui <wholery@163.com>
Date: Wed, 30 Oct 2019 18:23:13 +0800
Subject: [PATCH] fix panic when close miner

---
 lib/jsonrpc/client.go | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/lib/jsonrpc/client.go b/lib/jsonrpc/client.go
index 360e36aef..cb144de77 100644
--- a/lib/jsonrpc/client.go
+++ b/lib/jsonrpc/client.go
@@ -137,6 +137,7 @@ func (c *client) makeOutChan(ctx context.Context, ftyp reflect.Type, valOut int)
 		// unpack chan type to make sure it's reflect.BothDir
 		ctyp := reflect.ChanOf(reflect.BothDir, ftyp.Out(valOut).Elem())
 		ch := reflect.MakeChan(ctyp, 0) // todo: buffer?
+		chCtx, chCancel := context.WithCancel(ctx)
 		retVal = ch.Convert(ftyp.Out(valOut))
 
 		buf := (&list.List{}).Init()
@@ -144,6 +145,7 @@ func (c *client) makeOutChan(ctx context.Context, ftyp reflect.Type, valOut int)
 
 		return ctx, func(result []byte, ok bool) {
 			if !ok {
+				chCancel()
 				// remote channel closed, close ours too
 				ch.Close()
 				return
@@ -172,14 +174,18 @@ func (c *client) makeOutChan(ctx context.Context, ftyp reflect.Type, valOut int)
 
 			go func() {
 				for buf.Len() > 0 {
-					front := buf.Front()
+					select {
+					case <- chCtx.Done():
+						buf.Init()
+					default:
+						front := buf.Front()
+						bufLk.Unlock()
 
-					bufLk.Unlock()
+						ch.Send(front.Value.(reflect.Value).Elem())
 
-					ch.Send(front.Value.(reflect.Value).Elem()) // todo: select on ctx is probably a good idea
-
-					bufLk.Lock()
-					buf.Remove(front)
+						bufLk.Lock()
+						buf.Remove(front)
+					}
 				}
 
 				bufLk.Unlock()