1*b1cdbd2cSJim Jagielski /************************************************************** 2*b1cdbd2cSJim Jagielski * 3*b1cdbd2cSJim Jagielski * Licensed to the Apache Software Foundation (ASF) under one 4*b1cdbd2cSJim Jagielski * or more contributor license agreements. See the NOTICE file 5*b1cdbd2cSJim Jagielski * distributed with this work for additional information 6*b1cdbd2cSJim Jagielski * regarding copyright ownership. The ASF licenses this file 7*b1cdbd2cSJim Jagielski * to you under the Apache License, Version 2.0 (the 8*b1cdbd2cSJim Jagielski * "License"); you may not use this file except in compliance 9*b1cdbd2cSJim Jagielski * with the License. You may obtain a copy of the License at 10*b1cdbd2cSJim Jagielski * 11*b1cdbd2cSJim Jagielski * http://www.apache.org/licenses/LICENSE-2.0 12*b1cdbd2cSJim Jagielski * 13*b1cdbd2cSJim Jagielski * Unless required by applicable law or agreed to in writing, 14*b1cdbd2cSJim Jagielski * software distributed under the License is distributed on an 15*b1cdbd2cSJim Jagielski * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 16*b1cdbd2cSJim Jagielski * KIND, either express or implied. See the License for the 17*b1cdbd2cSJim Jagielski * specific language governing permissions and limitations 18*b1cdbd2cSJim Jagielski * under the License. 19*b1cdbd2cSJim Jagielski * 20*b1cdbd2cSJim Jagielski *************************************************************/ 21*b1cdbd2cSJim Jagielski 22*b1cdbd2cSJim Jagielski 23*b1cdbd2cSJim Jagielski 24*b1cdbd2cSJim Jagielski package com.sun.star.lib.util; 25*b1cdbd2cSJim Jagielski 26*b1cdbd2cSJim Jagielski import java.util.LinkedList; 27*b1cdbd2cSJim Jagielski 28*b1cdbd2cSJim Jagielski /** 29*b1cdbd2cSJim Jagielski Helper class to asynchronously execute finalize methods. 30*b1cdbd2cSJim Jagielski 31*b1cdbd2cSJim Jagielski Current JVMs seem not to be robust against long-running finalize methods, in 32*b1cdbd2cSJim Jagielski that such long-running finalize methods may lead to OutOfMemoryErrors. This 33*b1cdbd2cSJim Jagielski class mitigates the problem by asynchronously shifting the bodies of 34*b1cdbd2cSJim Jagielski potentially long-running finalize methods into an extra thread. Classes that 35*b1cdbd2cSJim Jagielski make use of this in their finalize methods are the proxies used in the 36*b1cdbd2cSJim Jagielski intra-process JNI UNO bridge and the inter-process Java URP UNO bridge (where 37*b1cdbd2cSJim Jagielski in both cases finalizers lead to synchronous UNO release calls). 38*b1cdbd2cSJim Jagielski 39*b1cdbd2cSJim Jagielski If JVMs are getting more mature and should no longer have problems with 40*b1cdbd2cSJim Jagielski long-running finalize mehtods, this class could be removed again. 41*b1cdbd2cSJim Jagielski */ 42*b1cdbd2cSJim Jagielski public final class AsynchronousFinalizer { 43*b1cdbd2cSJim Jagielski /** 44*b1cdbd2cSJim Jagielski Add a job to be executed asynchronously. 45*b1cdbd2cSJim Jagielski 46*b1cdbd2cSJim Jagielski The run method of the given job is called exactly once. If it terminates 47*b1cdbd2cSJim Jagielski abnormally by throwing any Throwable, that is ignored. 48*b1cdbd2cSJim Jagielski 49*b1cdbd2cSJim Jagielski @param job represents the body of some finalize method; must not be null. 50*b1cdbd2cSJim Jagielski */ add(Job job)51*b1cdbd2cSJim Jagielski public static void add(Job job) { 52*b1cdbd2cSJim Jagielski synchronized (queue) { 53*b1cdbd2cSJim Jagielski boolean first = queue.isEmpty(); 54*b1cdbd2cSJim Jagielski queue.add(job); 55*b1cdbd2cSJim Jagielski if (first) { 56*b1cdbd2cSJim Jagielski queue.notify(); 57*b1cdbd2cSJim Jagielski } 58*b1cdbd2cSJim Jagielski } 59*b1cdbd2cSJim Jagielski } 60*b1cdbd2cSJim Jagielski 61*b1cdbd2cSJim Jagielski /** 62*b1cdbd2cSJim Jagielski An interface to represent bodies of finalize methods. 63*b1cdbd2cSJim Jagielski 64*b1cdbd2cSJim Jagielski Similar to Runnable, except that the run method may throw any Throwable 65*b1cdbd2cSJim Jagielski (which is effectively ignored by AsynchronousFinalizer.add, similar to 66*b1cdbd2cSJim Jagielski any Throwables raised by finalize being ignored). 67*b1cdbd2cSJim Jagielski */ 68*b1cdbd2cSJim Jagielski public interface Job { run()69*b1cdbd2cSJim Jagielski void run() throws Throwable; 70*b1cdbd2cSJim Jagielski } 71*b1cdbd2cSJim Jagielski 72*b1cdbd2cSJim Jagielski private static final LinkedList queue = new LinkedList(); 73*b1cdbd2cSJim Jagielski 74*b1cdbd2cSJim Jagielski static { 75*b1cdbd2cSJim Jagielski Thread t = new Thread() { 76*b1cdbd2cSJim Jagielski public void run() { 77*b1cdbd2cSJim Jagielski for (;;) { 78*b1cdbd2cSJim Jagielski Job j; 79*b1cdbd2cSJim Jagielski synchronized (queue) { 80*b1cdbd2cSJim Jagielski while (queue.isEmpty()) { 81*b1cdbd2cSJim Jagielski try { 82*b1cdbd2cSJim Jagielski queue.wait(); 83*b1cdbd2cSJim Jagielski } catch (InterruptedException e) {} 84*b1cdbd2cSJim Jagielski } 85*b1cdbd2cSJim Jagielski j = (Job) queue.remove(0); 86*b1cdbd2cSJim Jagielski } 87*b1cdbd2cSJim Jagielski try { 88*b1cdbd2cSJim Jagielski j.run(); 89*b1cdbd2cSJim Jagielski } catch (Throwable e) {} 90*b1cdbd2cSJim Jagielski } 91*b1cdbd2cSJim Jagielski } 92*b1cdbd2cSJim Jagielski }; 93*b1cdbd2cSJim Jagielski t.setDaemon(true); t.start()94*b1cdbd2cSJim Jagielski t.start(); 95*b1cdbd2cSJim Jagielski } 96*b1cdbd2cSJim Jagielski AsynchronousFinalizer()97*b1cdbd2cSJim Jagielski private AsynchronousFinalizer() {} 98*b1cdbd2cSJim Jagielski } 99