/*
 * Copyright 2008-present MongoDB, Inc.
 *
 * 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.
 *
 * Original Work: MIT License, Copyright (c) [2015-2020] all contributors
 * https://github.com/marianobarrios/tls-channel
 */

package com.mongodb.internal.connection.tlschannel;

This exception signals the caller that the operation could not continue because a CPU-intensive operation (typically a TLS handshaking) needs to be executed and the TlsChannel is configured to not run tasks. This allows the application to run these tasks in some other threads, in order to not slow the selection loop. The method that threw the exception should be retried once the task supplied by getTask() is executed and finished. 
This exception is akin to the SSL_ERROR_WANT_ASYNC error code used by OpenSSL (but note that in OpenSSL, the task is executed by the library, while with the TlsChannel, the calling code is responsible for the execution). 
See Also:
OpenSSL error
 *     documentation/**
 * This exception signals the caller that the operation could not continue because a CPU-intensive
 * operation (typically a TLS handshaking) needs to be executed and the {@link TlsChannel} is
 * configured to not run tasks. This allows the application to run these tasks in some other
 * threads, in order to not slow the selection loop. The method that threw the exception should be
 * retried once the task supplied by {@link #getTask()} is executed and finished.
 *
 * <p>This exception is akin to the SSL_ERROR_WANT_ASYNC error code used by OpenSSL (but note that
 * in OpenSSL, the task is executed by the library, while with the {@link TlsChannel}, the calling
 * code is responsible for the execution).
 *
 * @see <a href="https://www.openssl.org/docs/man1.1.0/ssl/SSL_get_error.html">OpenSSL error
 *     documentation</a>
 */
public class NeedsTaskException extends TlsChannelFlowControlException {

  private static final long serialVersionUID = -936451835836926915L;
  private final Runnable task;

  public NeedsTaskException(Runnable task) {
    this.task = task;
  }

  public Runnable getTask() {
    return task;
  }
}