https://tomcat.apache.org/: Tomcat Connectors and HTTP parser 
/*
 *  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.coyote;


Provides a mechanism for the Coyote connectors to communicate with the AsyncContext. It is implemented in this manner so that the org.apache.coyote package does not have a dependency on the org.apache.catalina package. 
/**
 * Provides a mechanism for the Coyote connectors to communicate with the
 * {@link jakarta.servlet.AsyncContext}. It is implemented in this manner so that
 * the org.apache.coyote package does not have a dependency on the
 * org.apache.catalina package.
 */
public interface AsyncContextCallback {
    void fireOnComplete();

    
Reports if the web application associated with this async request is
available.

Returns:true if the associated web application is available, otherwise false
/**
     * Reports if the web application associated with this async request is
     * available.
     *
     * @return {@code true} if the associated web application is available,
     *         otherwise {@code false}
     */
    boolean isAvailable();

    
Used to notify the Context that async processing has started. Specifically, for the counting of in-progress async requests to work correctly, this must be called exactly once every time the AsyncStateMachine transitions from DISPATCHED to any other state. 
/**
     * Used to notify the Context that async processing has started.
     * Specifically, for the counting of in-progress async requests to work
     * correctly, this must be called exactly once every time the
     * {@link AsyncStateMachine} transitions from DISPATCHED to any other state.
     */
    void incrementInProgressAsyncCount();

    
Used to notify the Context that async processing has ended. Specifically, for the counting of in-progress async requests to work correctly, this must be called exactly once every time the AsyncStateMachine transitions to DISPATCHED from any other state. 
/**
     * Used to notify the Context that async processing has ended.
     * Specifically, for the counting of in-progress async requests to work
     * correctly, this must be called exactly once every time the
     * {@link AsyncStateMachine} transitions to DISPATCHED from any other state.
     */
    void decrementInProgressAsyncCount();
}