001// Copyright 2006-2013 The Apache Software Foundation 002// 003// Licensed under the Apache License, Version 2.0 (the "License"); 004// you may not use this file except in compliance with the License. 005// You may obtain a copy of the License at 006// 007// http://www.apache.org/licenses/LICENSE-2.0 008// 009// Unless required by applicable law or agreed to in writing, software 010// distributed under the License is distributed on an "AS IS" BASIS, 011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 012// See the License for the specific language governing permissions and 013// limitations under the License. 014 015package org.apache.tapestry5.ioc.services; 016 017import org.apache.tapestry5.ioc.Invokable; 018 019/** 020 * Manages per-thread data, and provides a way for listeners to know when such data should be cleaned up. Typically, 021 * data is cleaned up at the end of the request (in a web application). Tapestry IoC has any number of objects that need 022 * to know when this event occurs, so that they can clean up any per-thread/per-request state. 023 * <p/> 024 * Due to <a href="https://issues.apache.org/jira/browse/TAPESTRY-2141">TAPESTRY-2141<a> (and the underlying JDK 1.5 bug 025 * <a href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=5025230">5025230</a>), this service has expanded to 026 * manage per-thread data (not just end-of-request listeners). 027 */ 028public interface PerthreadManager 029{ 030 /** 031 * Adds a listener to the hub. All listeners are discarded at the {@link #cleanup()}. 032 * 033 * @param listener 034 * to add 035 * @deprecated Deprecated in 5.4, use {@link #addThreadCleanupCallback(Runnable)} instead. 036 */ 037 void addThreadCleanupListener(ThreadCleanupListener listener); 038 039 /** 040 * Adds a callback to be invoked when {@link #cleanup()} is invoked; callbacks are then removed. 041 * 042 * @param callback 043 * @since 5.4 044 */ 045 void addThreadCleanupCallback(Runnable callback); 046 047 /** 048 * Immediately performs a cleanup of the thread, invoking all callback, then discarding all per-thread data 049 * stored by the manager (including the list of callbacks). 050 */ 051 void cleanup(); 052 053 /** 054 * Creates a value using a unique internal key. 055 * 056 * @since 5.2.0 057 */ 058 <T> PerThreadValue<T> createValue(); 059 060 /** 061 * Invokes {@link Runnable#run()}, providing a try...finally to {@linkplain #cleanup() cleanup} after. 062 * 063 * @since 5.2.0 064 */ 065 void run(Runnable runnable); 066 067 /** 068 * Returns the result from the invocation, providing a try...finally to {@linkplain #cleanup() cleanup} after. 069 */ 070 <T> T invoke(Invokable<T> invokable); 071}