content: /*
   * Copyright (C) 2010-2101 Alibaba Group Holding Limited.
   *
   * 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.otter.common.push.supplier;
  
  /**
   * @author zebin.xuzb 2013-1-23 下午5:08:51
   * @since 4.1.3
   */
  public abstract class AbstractDatasourceSupplier implements DatasourceSupplier {
  
      private Object             lock    = new Object();
      protected volatile boolean running = false;
  
      @Override
      public void start() {
          synchronized (lock) {
              if (isStart()) {
                  return;
              }
              doStart();
              running = true;
          }
      }
  
      @Override
      public void stop() {
          synchronized (lock) {
              if (!isStart()) {
                  return;
              }
              doStop();
              running = false;
          }
      }
  
      @Override
      public boolean isStart() {
          return running;
      }
  
      protected abstract void doStart();
  
      protected abstract void doStop();
  }
  