Merge pull request #10004 from ArtfulCoder/kubelet_health

Augmented kubelet healthz with syncLoop check.

pkg/util/atomic_value.go

@@ -0,0 +1,42 @@
+/*
+Copyright 2015 The Kubernetes Authors All rights reserved.
+
+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 util
+
+import (
+	"sync"
+)
+
+// TODO(ArtfulCoder)
+// sync/atomic/Value was added in golang 1.4
+// Once support is dropped for go 1.3, this type must be deprecated in favor of sync/atomic/Value.
+// The functions are named Load/Store to match sync/atomic/Value function names.
+type AtomicValue struct {
+	value      interface{}
+	valueMutex sync.RWMutex
+}
+
+func (at *AtomicValue) Store(val interface{}) {
+	at.valueMutex.Lock()
+	defer at.valueMutex.Unlock()
+	at.value = val
+}
+
+func (at *AtomicValue) Load() interface{} {
+	at.valueMutex.RLock()
+	defer at.valueMutex.RUnlock()
+	return at.value
+}

pkg/util/atomic_value_test.go

@@ -0,0 +1,50 @@
+/*
+Copyright 2014 The Kubernetes Authors All rights reserved.
+
+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 util
+
+import (
+	"testing"
+	"time"
+)
+
+func ExpectValue(t *testing.T, atomicValue *AtomicValue, expectedValue interface{}) {
+	actualValue := atomicValue.Load()
+	if actualValue != expectedValue {
+		t.Error("Expected to find %v, found %v", expectedValue, actualValue)
+	}
+	ch := make(chan interface{})
+	go func() {
+		ch <- atomicValue.Load()
+	}()
+	select {
+	case actualValue = <-ch:
+		if actualValue != expectedValue {
+			t.Error("Expected to find %v, found %v", expectedValue, actualValue)
+			return
+		}
+	case <-time.After(time.Second * 5):
+		t.Error("Value could not be read")
+		return
+	}
+}
+
+func TestAtomicValue(t *testing.T) {
+	atomicValue := &AtomicValue{}
+	ExpectValue(t, atomicValue, nil)
+	atomicValue.Store(10)
+	ExpectValue(t, atomicValue, 10)
+}