Class AsyncContextImpl

java/org/apache/catalina/core/AsyncContextImpl.java:76–716

Implementation of AsyncContext that manages the lifecycle of an asynchronous request processing operation. Each instance is associated with a single request object. If an asynchronous request starts multiple cycles of asynchronous processing, the AsyncContextImpl is re-used for all cycles. O

 * </ul>
 */
public class AsyncContextImpl implements AsyncContext, AsyncContextCallback {

    private static final Log log = LogFactory.getLog(AsyncContextImpl.class);

    /**
     * String manager for localized log messages.
     */
    protected static final StringManager sm = StringManager.getManager(AsyncContextImpl.class);

    /*
     * When a request uses a sequence of multiple start(); dispatch() with non-container threads it is possible for a
     * previous dispatch() to interfere with a following start(). This lock prevents that from happening. It is a
     * dedicated object as user code may lock on the AsyncContext so if container code also locks on that object
     * deadlocks may occur.
     */
    private final Object asyncContextLock = new Object();

    /*
     * Used to provide a thread-safe way to check the recycled status and, by implication, the validity of any local
     * copies taken before the check was made.
     */
    private final AtomicBoolean hasBeenRecycled = new AtomicBoolean(false);

    /*
     * The request object with which this instance is associated.
     */
    private volatile Request request;

    /*
     * The asynchronous request information used to start the most recent asynchronous processing.
     */
    private volatile Context context = null;
    private volatile ServletRequest servletRequest = null;
    private volatile ServletResponse servletResponse = null;

    /*
     * Per asynchronous cycle fields.
     */
    private final List<AsyncListenerWrapper> listeners = new CopyOnWriteArrayList<>();
    private volatile Runnable dispatch = null;
    // Default of 30000 (30s) is set by the connector
    private long timeout = -1;

    /*
     * Basis for async events that are passed to listeners
     */
    private volatile AsyncEvent event = null;

    /*
     * Internal flags.
     */
    private volatile boolean hasOriginalRequestAndResponse = true;
    private final AtomicBoolean hasErrorProcessingStarted = new AtomicBoolean(false);
    private final AtomicBoolean hasOnErrorReturned = new AtomicBoolean(false);


    /**
     * Constructs an AsyncContextImpl for the given request.