vendor files

vendor/k8s.io/kubernetes/pkg/util/async/runner.go

@@ -0,0 +1,58 @@
+/*
+Copyright 2014 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 async
+
+import (
+	"sync"
+)
+
+// Runner is an abstraction to make it easy to start and stop groups of things that can be
+// described by a single function which waits on a channel close to exit.
+type Runner struct {
+	lock      sync.Mutex
+	loopFuncs []func(stop chan struct{})
+	stop      *chan struct{}
+}
+
+// NewRunner makes a runner for the given function(s). The function(s) should loop until
+// the channel is closed.
+func NewRunner(f ...func(stop chan struct{})) *Runner {
+	return &Runner{loopFuncs: f}
+}
+
+// Start begins running.
+func (r *Runner) Start() {
+	r.lock.Lock()
+	defer r.lock.Unlock()
+	if r.stop == nil {
+		c := make(chan struct{})
+		r.stop = &c
+		for i := range r.loopFuncs {
+			go r.loopFuncs[i](*r.stop)
+		}
+	}
+}
+
+// Stop stops running.
+func (r *Runner) Stop() {
+	r.lock.Lock()
+	defer r.lock.Unlock()
+	if r.stop != nil {
+		close(*r.stop)
+		r.stop = nil
+	}
+}