code: /*
   * Copyright (c) 2016-present, RxJava Contributors.
   *
   * 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 io.reactivex.rxjava3.internal.schedulers;
  
  import static org.junit.Assert.*;
  import java.util.concurrent.ConcurrentLinkedQueue;
  
  import org.junit.Test;
  
  import io.reactivex.rxjava3.core.RxJavaTest;
  import io.reactivex.rxjava3.disposables.CompositeDisposable;
  import io.reactivex.rxjava3.internal.schedulers.IoScheduler.*;
  import io.reactivex.rxjava3.testsupport.TestHelper;
  
  public class IoSchedulerInternalTest extends RxJavaTest {
  
      @Test
      public void expiredQueueEmpty() {
          ConcurrentLinkedQueue<ThreadWorker> expire = new ConcurrentLinkedQueue<>();
          CompositeDisposable cd = new CompositeDisposable();
  
          CachedWorkerPool.evictExpiredWorkers(expire, cd);
      }
  
      @Test
      public void expiredWorkerRemoved() {
          ConcurrentLinkedQueue<ThreadWorker> expire = new ConcurrentLinkedQueue<>();
          CompositeDisposable cd = new CompositeDisposable();
  
          ThreadWorker tw = new ThreadWorker(new RxThreadFactory("IoExpiryTest"));
  
          try {
              expire.add(tw);
              cd.add(tw);
  
              CachedWorkerPool.evictExpiredWorkers(expire, cd);
  
              assertTrue(tw.isDisposed());
              assertTrue(expire.isEmpty());
          } finally {
              tw.dispose();
          }
      }
  
      @Test
      public void noExpiredWorker() {
          ConcurrentLinkedQueue<ThreadWorker> expire = new ConcurrentLinkedQueue<>();
          CompositeDisposable cd = new CompositeDisposable();
  
          ThreadWorker tw = new ThreadWorker(new RxThreadFactory("IoExpiryTest"));
          tw.setExpirationTime(System.nanoTime() + 10_000_000_000L);
  
          try {
              expire.add(tw);
              cd.add(tw);
  
              CachedWorkerPool.evictExpiredWorkers(expire, cd);
  
              assertFalse(tw.isDisposed());
              assertFalse(expire.isEmpty());
          } finally {
              tw.dispose();
          }
      }
  
      @Test
      public void expireReuseRace() {
          ConcurrentLinkedQueue<ThreadWorker> expire = new ConcurrentLinkedQueue<>();
          CompositeDisposable cd = new CompositeDisposable();
  
          ThreadWorker tw = new ThreadWorker(new RxThreadFactory("IoExpiryTest"));
          tw.dispose();
  
          for (int i = 0; i < TestHelper.RACE_DEFAULT_LOOPS; i++) {
              expire.add(tw);
              cd.add(tw);
  
              TestHelper.race(
                      () -> CachedWorkerPool.evictExpiredWorkers(expire, cd),
                      () -> expire.remove(tw)
              );
          }
      }
  }
  