From 1880cf8da239899ef27e61e46caf68eb87cfac06 Mon Sep 17 00:00:00 2001
From: Gyuho Lee <gyuhox@gmail.com>
Date: Thu, 21 Dec 2017 15:57:38 -0800
Subject: [PATCH] clientv3/leasing: fix racey waitSession

Signed-off-by: Gyuho Lee <gyuhox@gmail.com>
---
 clientv3/leasing/kv.go | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/clientv3/leasing/kv.go b/clientv3/leasing/kv.go
index d44182b10..5a5e2312b 100644
--- a/clientv3/leasing/kv.go
+++ b/clientv3/leasing/kv.go
@@ -445,8 +445,11 @@ func (lkv *leasingKV) revokeLeaseKvs(ctx context.Context, kvs []*mvccpb.KeyValue
 }
 
 func (lkv *leasingKV) waitSession(ctx context.Context) error {
+	lkv.leases.mu.RLock()
+	sessionc := lkv.sessionc
+	lkv.leases.mu.RUnlock()
 	select {
-	case <-lkv.sessionc:
+	case <-sessionc:
 		return nil
 	case <-lkv.ctx.Done():
 		return lkv.ctx.Err()