From 04a7b50a020906e8e5cd32dfce378125606ce97d Mon Sep 17 00:00:00 2001
From: Ted Yu <yuzhihong@gmail.com>
Date: Thu, 18 Apr 2019 14:00:42 -0700
Subject: [PATCH] Use read lock in ready#check

---
 staging/src/k8s.io/apiserver/pkg/storage/cacher/cacher.go | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/staging/src/k8s.io/apiserver/pkg/storage/cacher/cacher.go b/staging/src/k8s.io/apiserver/pkg/storage/cacher/cacher.go
index cb1e11437aa..19a2841fc9f 100644
--- a/staging/src/k8s.io/apiserver/pkg/storage/cacher/cacher.go
+++ b/staging/src/k8s.io/apiserver/pkg/storage/cacher/cacher.go
@@ -1245,7 +1245,7 @@ type ready struct {
 }
 
 func newReady() *ready {
-	return &ready{c: sync.NewCond(&sync.Mutex{})}
+	return &ready{c: sync.NewCond(&sync.RWMutex{})}
 }
 
 func (r *ready) wait() {
@@ -1259,8 +1259,9 @@ func (r *ready) wait() {
 // TODO: Make check() function more sophisticated, in particular
 // allow it to behave as "waitWithTimeout".
 func (r *ready) check() bool {
-	r.c.L.Lock()
-	defer r.c.L.Unlock()
+	rwMutex := r.c.L.(*sync.RWMutex)
+	rwMutex.RLock()
+	defer rwMutex.RUnlock()
 	return r.ok
 }