/**
    *
    * 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.
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  package org.apache.hadoop.hbase.monitoring;
  
  import static org.junit.Assert.*;
  
  import java.util.concurrent.atomic.AtomicBoolean;
  
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.hbase.testclassification.SmallTests;
  import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
  import org.junit.Test;
  import org.junit.experimental.categories.Category;
  
  @Category(SmallTests.class)
  public class TestTaskMonitor {
  
    @Test
    public void testTaskMonitorBasics() {
      TaskMonitor tm = new TaskMonitor();
      assertTrue("Task monitor should start empty",
          tm.getTasks().isEmpty());
      
      // Make a task and fetch it back out
      MonitoredTask task = tm.createStatus("Test task");
      MonitoredTask taskFromTm = tm.getTasks().get(0);
      
      // Make sure the state is reasonable.
      assertEquals(task.getDescription(), taskFromTm.getDescription());
      assertEquals(-1, taskFromTm.getCompletionTimestamp());
      assertEquals(MonitoredTask.State.RUNNING, taskFromTm.getState());
      
      // Mark it as finished
      task.markComplete("Finished!");
      assertEquals(MonitoredTask.State.COMPLETE, task.getState());
      
      // It should still show up in the TaskMonitor list
      assertEquals(1, tm.getTasks().size());
      
      // If we mark its completion time back a few minutes, it should get gced
      task.expireNow();
      assertEquals(0, tm.getTasks().size());
  
      tm.shutdown();
    }
    
    @Test
    public void testTasksGetAbortedOnLeak() throws InterruptedException {
      final TaskMonitor tm = new TaskMonitor();
      assertTrue("Task monitor should start empty",
          tm.getTasks().isEmpty());
      
      final AtomicBoolean threadSuccess = new AtomicBoolean(false);
      // Make a task in some other thread and leak it
      Thread t = new Thread() {
        @Override
        public void run() {
          MonitoredTask task = tm.createStatus("Test task");    
          assertEquals(MonitoredTask.State.RUNNING, task.getState());
          threadSuccess.set(true);
        }
      };
      t.start();
      t.join();
      // Make sure the thread saw the correct state
      assertTrue(threadSuccess.get());
      
      // Make sure the leaked reference gets cleared
      System.gc();
      System.gc();
      System.gc();
      
      // Now it should be aborted 
      MonitoredTask taskFromTm = tm.getTasks().get(0);
      assertEquals(MonitoredTask.State.ABORTED, taskFromTm.getState());
  
      tm.shutdown();
    }
    
    @Test
    public void testTaskLimit() throws Exception {
      TaskMonitor tm = new TaskMonitor();
      for (int i = 0; i < TaskMonitor.DEFAULT_MAX_TASKS + 10; i++) {
       tm.createStatus("task " + i);
     }
     // Make sure it was limited correctly
     assertEquals(TaskMonitor.DEFAULT_MAX_TASKS, tm.getTasks().size());
     // Make sure we culled the earlier tasks, not later
     // (i.e. tasks 0 through 9 should have been deleted)
     assertEquals("task 10", tm.getTasks().get(0).getDescription());
 
     tm.shutdown();
   }
 
   @Test
   public void testStatusJournal() {
     TaskMonitor tm = new TaskMonitor();
     MonitoredTask task = tm.createStatus("Test task");
     assertTrue(task.getStatusJournal().isEmpty());
     task.disableStatusJournal();
     task.setStatus("status1");
     // journal should be empty since it is disabled
     assertTrue(task.getStatusJournal().isEmpty());
     task.enableStatusJournal(true);
     // check existing status entered in journal
     assertEquals("status1", task.getStatusJournal().get(0).getStatus());
     assertTrue(task.getStatusJournal().get(0).getTimeStamp() > 0);
     task.disableStatusJournal();
     task.setStatus("status2");
     // check status 2 not added since disabled
     assertEquals(1, task.getStatusJournal().size());
     task.enableStatusJournal(false);
     // size should still be 1 since we didn't include current status
     assertEquals(1, task.getStatusJournal().size());
     task.setStatus("status3");
     assertEquals("status3", task.getStatusJournal().get(1).getStatus());
 
     tm.shutdown();
   }
 
   @Test
   public void testWarnStuckTasks() throws Exception {
     final int INTERVAL = 1000;
     Configuration conf = new Configuration();
     conf.setLong(TaskMonitor.RPC_WARN_TIME_KEY, INTERVAL);
     conf.setLong(TaskMonitor.MONITOR_INTERVAL_KEY, INTERVAL);
     final TaskMonitor tm = new TaskMonitor(conf);
     MonitoredRPCHandler t = tm.createRPCStatus("test task");
     long then = EnvironmentEdgeManager.currentTime();
     t.setRPC("testMethod", new Object[0], then);
     Thread.sleep(INTERVAL * 2);
     assertTrue("We did not warn", t.getWarnTime() > then);
     tm.shutdown();
   }
 
 }