content: /* Copyright 2010, Object Management Group, Inc.
   * Copyright 2010, PrismTech, Inc.
   * Copyright 2010, Real-Time Innovations, Inc.
   * All rights reserved.
   *
   * 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 org.omg.dds.core.status;
  
  import org.omg.dds.core.policy.DestinationOrder;
  import org.omg.dds.core.policy.Presentation;
  import org.omg.dds.core.policy.ResourceLimits;
  
  
  
  /**
   * A sample has been lost (never received).
   * The status is independent of the differences in instances, in other words, it includes all
   * samples lost across all instances of data published under the Topic.
   *
   * The following events can lead to a sample lost status:
   * <ul>
   * <li>When the {@link Presentation} QoS is used with coherentAccess set to true and {@link ResourceLimits} Qos is active
   * a sample lost can occur when all resources are consumed by incomplete transactions. In order to prevent deadlocks the
   * the current transaction is dropped which causes a SampleLost event.</li>
   *
   * <li>When the {@link DestinationOrder} QoS is set to BY_SOURCE_TIMESTAMP
   * It can happen that older data is inserted after newer data is already taken by the DataReader.
   * In this case the older data is not inserted into the DataReader and a SampleLost is reported.</li>
   * <li>When the networking service detects a gap between sequence numbers of incoming data it will report a SampleLost event</li>
   * </ul>
   *
   * @see org.omg.dds.core.event.SampleLostEvent
   */
  public abstract class SampleLostStatus extends Status
  {
      // -----------------------------------------------------------------------
      // Constants
      // -----------------------------------------------------------------------
  
      private static final long serialVersionUID = 6522885693257415947L;
  
  
  
      // -----------------------------------------------------------------------
      // Methods
      // -----------------------------------------------------------------------
  
      /**
       * Total cumulative count of all samples lost across all instances of
       * data published under the {@link org.omg.dds.topic.Topic}.
       */
      public abstract int getTotalCount();
  
      /**
       * The incremental number of samples lost since the last time the
       * listener was called or the status was read.
       */
      public abstract int getTotalCountChange();
  
  }
  