content: /**
   * 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 com.alibaba.jstorm.daemon.nimbus.metric;
  
  import java.util.concurrent.BlockingDeque;
  import java.util.concurrent.LinkedBlockingDeque;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import com.alibaba.jstorm.callback.RunnableCallback;
  import com.alibaba.jstorm.daemon.nimbus.NimbusData;
  
  public class ClusterMetricsRunnable extends RunnableCallback {
      private static final Logger LOG = LoggerFactory.getLogger(ClusterMetricsRunnable.class);
  
      protected final BlockingDeque<MetricEvent> queue = new LinkedBlockingDeque<>();
  
      private ClusterMetricsContext context;
      private NimbusData nimbusData;
      private static ClusterMetricsRunnable instance;
  
      private ClusterMetricsRunnable(NimbusData nimbusData) {
          this.nimbusData = nimbusData;
          context = new ClusterMetricsContext(nimbusData);
      }
  
      public void init() {
          context.init();
      }
  
      public static ClusterMetricsRunnable mkInstance(NimbusData nimbusData) {
          synchronized (ClusterMetricsRunnable.class) {
              if (instance == null) {
                  instance = new ClusterMetricsRunnable(nimbusData);
              }
          }
  
          return instance;
      }
  
      public static ClusterMetricsRunnable getInstance() {
          return instance;
      }
  
      public static void pushEvent(MetricEvent event) {
          instance.queue.offer(event);
      }
  
      @Override
      public void run() {
          MetricEvent event = null;
          try {
              event = queue.take();
          } catch (InterruptedException ignored) {
          }
          if (event != null) {
              event.setClusterMetricsContext(context);
              nimbusData.getScheduExec().submit(event);
          }
      }
  
      @Override
      public void shutdown() {
          if (context != null) {
              context.shutdown();
          }
          
          instance = null;
      }
  
      public ClusterMetricsContext getContext() {
          return context;
      }
  }
  