content: /*
   * Copyright 1999-2018 Alibaba Group Holding Ltd.
   *
   * 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 com.alibaba.nacos.config.server.manager;
  
  import com.alibaba.nacos.api.exception.NacosException;
  import com.alibaba.nacos.common.task.AbstractDelayTask;
  import com.alibaba.nacos.common.task.engine.NacosDelayTaskExecuteEngine;
  import com.alibaba.nacos.config.server.constant.Constants;
  import com.alibaba.nacos.config.server.monitor.MetricsMonitor;
  import com.alibaba.nacos.config.server.utils.LogUtil;
  import org.slf4j.Logger;
  
  import javax.management.ObjectName;
  import java.lang.management.ManagementFactory;
  import java.util.Date;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.locks.Condition;
  
  /**
   * TaskManager, is aim to process the task which is need to be done. And this class process the task by single thread to
   * ensure task should be process successfully.
   *
   * @author huali
   */
  public final class TaskManager extends NacosDelayTaskExecuteEngine implements TaskManagerMBean {
      
      private static final Logger LOGGER = LogUtil.DEFAULT_LOG;
      
      private String name;
      
      Condition notEmpty = this.lock.newCondition();
      
      public TaskManager(String name) {
          super(name, 32, LOGGER, 100L);
          this.name = name;
      }
      
      /**
       * Close task manager.
       */
      public void close() {
          try {
              super.shutdown();
          } catch (NacosException ignored) {
          }
      }
      
      /**
       * Await for lock.
       *
       * @throws InterruptedException InterruptedException.
       */
      public void await() throws InterruptedException {
          this.lock.lock();
          try {
              while (!this.isEmpty()) {
                  this.notEmpty.await();
              }
          } finally {
              this.lock.unlock();
          }
      }
      
      /**
       * Await for lock by timeout.
       *
       * @param timeout timeout value.
       * @param unit    time unit.
       * @return success or not.
       * @throws InterruptedException InterruptedException.
       */
      public boolean await(long timeout, TimeUnit unit) throws InterruptedException {
          this.lock.lock();
          boolean isawait = false;
          try {
              while (!this.isEmpty()) {
                  isawait = this.notEmpty.await(timeout, unit);
              }
              return isawait;
          } finally {
              this.lock.unlock();
          }
      }
      
      @Override
      public void addTask(Object key, AbstractDelayTask newTask) {
          super.addTask(key, newTask);
          MetricsMonitor.getDumpTaskMonitor().set(tasks.size());
      }
      
      @Override
      public AbstractDelayTask removeTask(Object key) {
          AbstractDelayTask result = super.removeTask(key);
          MetricsMonitor.getDumpTaskMonitor().set(tasks.size());
          return result;
      }
      
      @Override
      protected void processTasks() {
          super.processTasks();
          MetricsMonitor.getDumpTaskMonitor().set(tasks.size());
          if (tasks.isEmpty()) {
              this.lock.lock();
              try {
                  this.notEmpty.signalAll();
              } finally {
                  this.lock.unlock();
              }
          }
      }
      
      @Override
      public String getTaskInfos() {
          StringBuilder sb = new StringBuilder();
          for (Object taskType : getAllProcessorKey()) {
              sb.append(taskType).append(':');
              AbstractDelayTask task = this.tasks.get(taskType);
              if (task != null) {
                  sb.append(new Date(task.getLastProcessTime()));
              } else {
                  sb.append("finished");
              }
              sb.append(Constants.NACOS_LINE_SEPARATOR);
          }
          
          return sb.toString();
      }
      
      /**
       * Init and register the mbean object.
       */
      public void init() {
          try {
              ObjectName oName = new ObjectName(this.name + ":type=" + TaskManager.class.getSimpleName());
              ManagementFactory.getPlatformMBeanServer().registerMBean(this, oName);
          } catch (Exception e) {
              LOGGER.error("registerMBean_fail", e);
          }
      }
  }
  