code: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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 org.apache.datasketches.memory.internal;
  
  import static org.apache.datasketches.memory.internal.Util.getResourceFile;
  import static org.testng.Assert.assertTrue;
  import static org.testng.Assert.fail;
  
  import java.io.File;
  
  import org.apache.datasketches.memory.Memory;
  import org.apache.datasketches.memory.WritableMemory;
  import org.testng.annotations.BeforeClass;
  import org.testng.annotations.Test;
  
  public class ThreadTest {
  
    File file;
    Memory mem;
    WritableMemory wmem;
    Thread altThread;
  
    @BeforeClass
    public void prepareFileAndMemory() {
      UtilTest.setGettysburgAddressFileToReadOnly();
      file = getResourceFile("GettysburgAddress.txt");
      assertTrue(AllocateDirectWritableMap.isFileReadOnly(file));
    }
  
    void initMap() {
      mem = Memory.map(file); assertTrue(mem.isValid());
    }
  
    void initDirectMem() {
      wmem = WritableMemory.allocateDirect(1024); assertTrue(wmem.isValid());
    }
  
    Runnable tryMapClose = () -> {
      try { mem.close(); fail(); }
      catch (IllegalStateException expected) { }
    };
  
    Runnable tryDirectClose = () -> {
      try { wmem.close(); fail(); }
      catch (IllegalStateException expected) { }
    };
  
    @Test
    public void runTests() {
      initMap();
      altThread = new Thread(tryMapClose, "altThread"); altThread.start();
      mem.close();
      initDirectMem();
      altThread = new Thread(tryDirectClose, "altThread"); altThread.start();
      wmem.close();
    }
  
  }
  
  