From f3f6427586e24a827140fb8e079d553f085b0af3 Mon Sep 17 00:00:00 2001
From: nolouch <nolouch@gmail.com>
Date: Fri, 14 Sep 2018 16:07:12 +0800
Subject: [PATCH] server: prevent blocking

---
 clientv3/integration/leasing_test.go | 1 +
 etcdserver/server.go                 | 5 ++++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/clientv3/integration/leasing_test.go b/clientv3/integration/leasing_test.go
index 78826b189..a824726f0 100644
--- a/clientv3/integration/leasing_test.go
+++ b/clientv3/integration/leasing_test.go
@@ -1790,6 +1790,7 @@ func TestLeasingTxnOwnerPutBranch(t *testing.T) {
 	defer testutil.AfterTest(t)
 	clus := integration.NewClusterV3(t, &integration.ClusterConfig{Size: 3})
 	defer clus.Terminate(t)
+
 	lkv, closeLKV, err := leasing.NewKV(clus.Client(0), "foo/")
 	testutil.AssertNil(t, err)
 	defer closeLKV()
diff --git a/etcdserver/server.go b/etcdserver/server.go
index 178861745..fc070ce51 100644
--- a/etcdserver/server.go
+++ b/etcdserver/server.go
@@ -942,7 +942,10 @@ func (s *EtcdServer) run() {
 				}
 			}
 			if newLeader {
-				s.leaderChanged <- struct{}{}
+				select {
+				case s.leaderChanged <- struct{}{}:
+				default:
+				}
 			}
 			// TODO: remove the nil checking
 			// current test utility does not provide the stats