/* * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package com.sun.xml.internal.ws.api.pipe; import java.security.AccessController; import java.security.PrivilegedAction; /** * Interception for {@link Fiber} context switch. * *
* Even though pipeline runs asynchronously, sometimes it's desirable * to bind some state to the current thread running a fiber. Such state * may include security subject (in terms of {@link AccessController#doPrivileged}), * or a transaction. * *
* This mechanism makes it possible to do such things, by allowing * some code to be executed before and after a thread executes a fiber. * *
* The design also encapsulates the entire fiber execution in a single * opaque method invocation {@link Work#execute}, allowing the use of * finally block. * * * @author Kohsuke Kawaguchi */ public interface FiberContextSwitchInterceptor { /** * Allows the interception of the fiber execution. * *
* This method needs to be implemented like this: * *
* <R,P> R execute( Fiber f, P p, Work<R,P> work ) { * // do some preparation work * ... * try { * // invoke * return work.execute(p); * } finally { * // do some clean up work * ... * } * } ** *
* While somewhat unintuitive,
* this interception mechanism enables the interceptor to wrap
* the whole fiber execution into a {@link AccessController#doPrivileged(PrivilegedAction)},
* for example.
*
* @param f
* {@link Fiber} to be executed.
* @param p
* The opaque parameter value for {@link Work}. Simply pass this value to
* {@link Work#execute(Object)}.
* @return
* The opaque return value from the the {@link Work}. Simply return
* the value from {@link Work#execute(Object)}.
*/
* The parameter and the return value is controlled by the
* JAX-WS runtime, and interceptors should simply treat
* them as opaque values.
*/
R execute(P param);
}
}