/*
 * 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.internal.offheap;

import org.apache.geode.OutOfOffHeapMemoryException;
import org.apache.geode.distributed.internal.InternalDistributedSystem;
import org.apache.geode.internal.logging.LoggingThread;

/**
 * Used to asynchronously disconnect an InternalDistributedSystem when we run out of off-heap
 * memory. If the STAY_CONNECTED_ON_OUTOFOFFHEAPMEMORY_PROPERTY sys prop is set to true then this
 * listener will not disconnect.
 */
class DisconnectingOutOfOffHeapMemoryListener implements OutOfOffHeapMemoryListener {
  private final Object lock = new Object();
  private InternalDistributedSystem ids;

  DisconnectingOutOfOffHeapMemoryListener(InternalDistributedSystem ids) {
    this.ids = ids;
  }

  @Override
  public void close() {
    synchronized (lock) {
      ids = null; // set null to prevent memory leak after closure!
    }
  }

  @Override
  public void outOfOffHeapMemory(final OutOfOffHeapMemoryException cause) {
    synchronized (lock) {
      if (ids == null) {
        return;
      }
      if (Boolean.getBoolean(OffHeapStorage.STAY_CONNECTED_ON_OUTOFOFFHEAPMEMORY_PROPERTY)) {
        return;
      }

      final InternalDistributedSystem dsToDisconnect = ids;
      ids = null; // set null to prevent memory leak after closure!

      if (dsToDisconnect.getDistributionManager().getRootCause() == null) {
        dsToDisconnect.getDistributionManager().setRootCause(cause);
      }

      Runnable runnable = () -> {
        dsToDisconnect.getLogWriter()
            .info("OffHeapStorage about to invoke disconnect on " + dsToDisconnect);
        dsToDisconnect.disconnect(cause.getMessage(), false);
      };

      // invoking disconnect is async because caller may be a DM pool thread which will block until
      // DM shutdown times out

      String name = getClass().getSimpleName() + "@" + hashCode()
          + " Handle OutOfOffHeapMemoryException Thread";
      Thread thread = new LoggingThread(name, runnable);
      thread.start();
    }
  }
}