/* 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 runtime import ( "sync" "sync/atomic" "testing" "time" ) func Test_LatchAcquireBasic(t *testing.T) { var x Latch if !x.Acquire() { t.Fatalf("expected first acquire to succeed") } if x.Acquire() { t.Fatalf("expected second acquire to fail") } if x.Acquire() { t.Fatalf("expected third acquire to fail") } } func Test_LatchAcquireConcurrent(t *testing.T) { var x Latch const NUM = 10 ch := make(chan struct{}) var success int32 var wg sync.WaitGroup wg.Add(NUM) for i := 0; i < NUM; i++ { go func() { defer wg.Done() <-ch if x.Acquire() { atomic.AddInt32(&success, 1) } }() } time.Sleep(200 * time.Millisecond) close(ch) wg.Wait() if success != 1 { t.Fatalf("expected single acquire to succeed instead of %d", success) } }