From 24077fb3f6ac4e0efb467a1e010f16894c665a67 Mon Sep 17 00:00:00 2001
From: Hitoshi Mitake <mitake.hitoshi@gmail.com>
Date: Fri, 22 Apr 2016 23:39:08 +0900
Subject: [PATCH] etcdserver: remove a data race of ServerStat

It seems that ServerStats.BecomeLeader() is missing a lock.

Fix https://github.com/coreos/etcd/issues/5155
---
 etcdserver/stats/server.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/etcdserver/stats/server.go b/etcdserver/stats/server.go
index 8e2e7701d..7ef7de4e5 100644
--- a/etcdserver/stats/server.go
+++ b/etcdserver/stats/server.go
@@ -142,6 +142,9 @@ func (ss *ServerStats) SendAppendReq(reqSize int) {
 }
 
 func (ss *ServerStats) BecomeLeader() {
+	ss.Lock()
+	defer ss.Unlock()
+
 	if ss.State != raft.StateLeader {
 		ss.State = raft.StateLeader
 		ss.LeaderInfo.Name = ss.ID