| /************************************************************** |
| * |
| * 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 com.sun.star.lib.util; |
| |
| import java.util.LinkedList; |
| |
| /** |
| Helper class to asynchronously execute finalize methods. |
| |
| Current JVMs seem not to be robust against long-running finalize methods, in |
| that such long-running finalize methods may lead to OutOfMemoryErrors. This |
| class mitigates the problem by asynchronously shifting the bodies of |
| potentially long-running finalize methods into an extra thread. Classes that |
| make use of this in their finalize methods are the proxies used in the |
| intra-process JNI UNO bridge and the inter-process Java URP UNO bridge (where |
| in both cases finalizers lead to synchronous UNO release calls). |
| |
| If JVMs are getting more mature and should no longer have problems with |
| long-running finalize mehtods, this class could be removed again. |
| */ |
| public final class AsynchronousFinalizer { |
| /** |
| Add a job to be executed asynchronously. |
| |
| The run method of the given job is called exactly once. If it terminates |
| abnormally by throwing any Throwable, that is ignored. |
| |
| @param job represents the body of some finalize method; must not be null. |
| */ |
| public static void add(Job job) { |
| synchronized (queue) { |
| boolean first = queue.isEmpty(); |
| queue.add(job); |
| if (first) { |
| queue.notify(); |
| } |
| } |
| } |
| |
| /** |
| An interface to represent bodies of finalize methods. |
| |
| Similar to Runnable, except that the run method may throw any Throwable |
| (which is effectively ignored by AsynchronousFinalizer.add, similar to |
| any Throwables raised by finalize being ignored). |
| */ |
| public interface Job { |
| void run() throws Throwable; |
| } |
| |
| private static final LinkedList queue = new LinkedList(); |
| |
| static { |
| Thread t = new Thread() { |
| public void run() { |
| for (;;) { |
| Job j; |
| synchronized (queue) { |
| while (queue.isEmpty()) { |
| try { |
| queue.wait(); |
| } catch (InterruptedException e) {} |
| } |
| j = (Job) queue.remove(0); |
| } |
| try { |
| j.run(); |
| } catch (Throwable e) {} |
| } |
| } |
| }; |
| t.setDaemon(true); |
| t.start(); |
| } |
| |
| private AsynchronousFinalizer() {} |
| } |