content: /*
   * 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 com.datastax.oss.driver.api.core;
  
  import com.datastax.oss.driver.internal.core.util.concurrent.BlockingOperation;
  import com.datastax.oss.driver.internal.core.util.concurrent.CompletableFutures;
  import edu.umd.cs.findbugs.annotations.NonNull;
  import java.util.concurrent.CompletionStage;
  
  /**
   * An object that can be closed in an asynchronous, non-blocking manner.
   *
   * <p>For convenience, this extends the JDK's {@code AutoCloseable} in order to be usable in
   * try-with-resource blocks (in that case, the <em>blocking</em> {@link #close()} will be used).
   */
  public interface AsyncAutoCloseable extends AutoCloseable {
  
    /**
     * Returns a stage that will complete when {@link #close()} or {@link #forceCloseAsync()} is
     * called, and the shutdown sequence completes.
     */
    @NonNull
    CompletionStage<Void> closeFuture();
  
    /**
     * Whether shutdown has completed.
     *
     * <p>This is a shortcut for {@code closeFuture().toCompletableFuture().isDone()}.
     */
    default boolean isClosed() {
      return closeFuture().toCompletableFuture().isDone();
    }
  
    /**
     * Initiates an orderly shutdown: no new requests are accepted, but all pending requests are
     * allowed to complete normally.
     *
     * @return a stage that will complete when the shutdown sequence is complete. Multiple calls to
     *     this method or {@link #forceCloseAsync()} always return the same instance.
     */
    @NonNull
    CompletionStage<Void> closeAsync();
  
    /**
     * Initiates a forced shutdown of this instance: no new requests are accepted, and all pending
     * requests will complete with an exception.
     *
     * @return a stage that will complete when the shutdown sequence is complete. Multiple calls to
     *     this method or {@link #close()} always return the same instance.
     */
    @NonNull
    CompletionStage<Void> forceCloseAsync();
  
    /**
     * {@inheritDoc}
     *
     * <p>This method is implemented by calling {@link #closeAsync()} and blocking on the result. This
     * should not be called on a driver thread.
     */
    @Override
    default void close() {
      BlockingOperation.checkNotDriverThread();
      CompletableFutures.getUninterruptibly(closeAsync().toCompletableFuture());
    }
  }
  