Mercurial > hg > truffle
view agent/src/share/classes/sun/jvm/hotspot/utilities/MessageQueueBackend.java @ 3945:8ed53447f690
Merge
author | iveresov |
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date | Thu, 15 Sep 2011 12:44:09 -0700 |
parents | c18cbe5936b8 |
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/* * Copyright (c) 2000, 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. * * 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 sun.jvm.hotspot.utilities; /** The backend for the message queue abstraction. This class is instantiated first and queried to provide the two "sides" of the message queue. */ import java.util.LinkedList; public class MessageQueueBackend { // The two queues private MessageQueueImpl leftRightQueue; private MessageQueueImpl rightLeftQueue; public MessageQueueBackend() { LinkedList leftRightPipe = new LinkedList(); LinkedList rightLeftPipe = new LinkedList(); leftRightQueue = new MessageQueueImpl(rightLeftPipe, leftRightPipe); rightLeftQueue = new MessageQueueImpl(leftRightPipe, rightLeftPipe); } /** Get one of the two symmetric sides of this message queue. */ public MessageQueue getFirstQueue() { return leftRightQueue; } /** Get second of the two symmetric sides of this message queue. */ public MessageQueue getSecondQueue() { return rightLeftQueue; } private class MessageQueueImpl implements MessageQueue { private LinkedList readList; private LinkedList writeList; public MessageQueueImpl(LinkedList listToReadFrom, LinkedList listToWriteTo) { readList = listToReadFrom; writeList = listToWriteTo; } public Object readMessage() { synchronized(readList) { while (readList.isEmpty()) { try { readList.wait(); } catch (InterruptedException e) { } } return readList.removeFirst(); } } public Object readMessageWithTimeout(long millis) { synchronized(readList) { if (readList.isEmpty()) { if (millis == 0) { return null; } try { readList.wait(millis); } catch (InterruptedException e) { } } // If list is still empty after wait, return null if (readList.isEmpty()) { return null; } return readList.removeFirst(); } } public void writeMessage(Object obj) { synchronized(writeList) { writeList.addLast(obj); writeList.notify(); } } } }