content: package act.sys;
  
  /*-
   * #%L
   * ACT Framework
   * %%
   * Copyright (C) 2014 - 2019 ActFramework
   * %%
   * 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.
   * #L%
   */
  
  import com.sun.management.GarbageCollectionNotificationInfo;
  import com.sun.management.GcInfo;
  import org.osgl.$;
  
  import javax.management.Notification;
  import javax.management.NotificationEmitter;
  import javax.management.NotificationListener;
  import javax.management.openmbean.CompositeData;
  import java.lang.management.ManagementFactory;
  import java.util.List;
  
  public class GcHelper {
  
      private static volatile List<java.lang.management.GarbageCollectorMXBean> gcBeans;
  
      static {
          gcBeans = ManagementFactory.getGarbageCollectorMXBeans();
      }
  
      public static void registerGcEventListener(final $.Visitor<GcInfo> listener) {
          for (java.lang.management.GarbageCollectorMXBean mxBean : gcBeans) {
              NotificationEmitter emitter = (NotificationEmitter) mxBean;
              emitter.addNotificationListener(new NotificationListener() {
                  @Override
                  public void handleNotification(Notification notification, Object handback) {
                      if (notification.getType().equals(GarbageCollectionNotificationInfo.GARBAGE_COLLECTION_NOTIFICATION)) {
                          GarbageCollectionNotificationInfo gcInfo = GarbageCollectionNotificationInfo.from((CompositeData) notification.getUserData());
                          listener.visit(gcInfo.getGcInfo());
                      }
                  }
              }, null, null);
          }
      }
  
  }
  