Use channel to propagate the stop info of sandbox

Signed-off-by: Yanqiang Miao <miao.yanqiang@zte.com.cn>

pkg/store/util.go

@@ -0,0 +1,30 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package store
+
+// StopCh is used to propagate the stop information of a container.
+type StopCh chan struct{}
+
+// Stop close stopCh of the container.
+func (ch StopCh) Stop() {
+	close(ch)
+}
+
+// Stopped return the stopCh of the container as a readonly channel.
+func (ch StopCh) Stopped() <-chan struct{} {
+	return ch
+}