geode-core/src/main/java/org/apache/geode/cache/client/internal/PdxRegistryRecoveryListener.java

/*
 * 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 org.apache.geode.cache.client.internal;

import java.util.concurrent.atomic.AtomicInteger;

import org.apache.logging.log4j.Logger;

import org.apache.geode.internal.cache.GemFireCacheImpl;
import org.apache.geode.internal.cache.InternalCache;
import org.apache.geode.internal.logging.LogService;
import org.apache.geode.pdx.internal.TypeRegistry;

/**
 * A listener which will wipe out the PDX registry on the client side if the entire server
 * distributed system was lost and came back on line. <br>
 * <br>
 * TODO - There is a window in which all of the servers could crash and come back up and we would
 * connect to a new server before realizing that all the servers crashed. To fix this, we would need
 * to get some kind of birthdate of the server ds we connect and use that to decide if we need to
 * recover the PDX registry.
 *
 * We can also lose connectivity with the servers, even if the servers are still running. Maybe for
 * the PDX registry we need some way of telling if the PDX registry was lost at the server side in
 * the interval.
 *
 *
 *
 */
public class PdxRegistryRecoveryListener extends EndpointManager.EndpointListenerAdapter {
  private static final Logger logger = LogService.getLogger();

  private final AtomicInteger endpointCount = new AtomicInteger();
  private final InternalPool pool;

  public PdxRegistryRecoveryListener(InternalPool pool) {
    this.pool = pool;
  }

  @Override
  public void endpointCrashed(Endpoint endpoint) {
    int count = endpointCount.decrementAndGet();
    if (logger.isDebugEnabled()) {
      logger.debug("PdxRegistryRecoveryListener - EndpointCrashed. Now have {} endpoints", count);
    }
  }

  @Override
  public void endpointNoLongerInUse(Endpoint endpoint) {
    int count = endpointCount.decrementAndGet();
    if (logger.isDebugEnabled()) {
      logger.debug("PdxRegistryRecoveryListener - EndpointNoLongerInUse. Now have {} endpoints",
          count);
    }
  }

  @Override
  public void endpointNowInUse(Endpoint endpoint) {
    int count = endpointCount.incrementAndGet();
    if (logger.isDebugEnabled()) {
      logger.debug("PdxRegistryRecoveryListener - EndpointNowInUse. Now have {} endpoints", count);
    }
    if (count == 1) {
      InternalCache cache = GemFireCacheImpl.getInstance();
      if (cache == null) {
        return;
      }
      TypeRegistry registry = cache.getPdxRegistry();

      if (registry == null) {
        return;
      }
      registry.clear();
    }
  }
}