| 1 | /* |
| 2 | * $Id: NativeLeakDetectionThread.java,v 1.3 2005/06/28 06:42:53 hastings Exp $ |
| 3 | * |
| 4 | * (c) Copyright, Moebius Solutions, Inc., 2004 |
| 5 | * |
| 6 | * All Rights Reserved |
| 7 | * |
| 8 | * This material may be reproduced by or for the U. S. Government |
| 9 | * pursuant to the copyright license under the clause at |
| 10 | * DFARS 252.227-7014 (OCT 2001). |
| 11 | */ |
| 12 | |
| 13 | package com.moesol.bindings; |
| 14 | |
| 15 | import java.lang.ref.Reference; |
| 16 | import java.lang.ref.ReferenceQueue; |
| 17 | import java.util.logging.Logger; |
| 18 | |
| 19 | /** |
| 20 | * This singleton thread checks for native resource leaks. |
| 21 | * Use getQ to get a RefenceQueue suitable for |
| 22 | * the PhantomReference contructor. Derive a class |
| 23 | * from PhantomRefernce that implements the NativeResourceChecker |
| 24 | * interface. |
| 25 | * When the referent become phantomly reachable |
| 26 | * NativeResourceChecker.check is called. |
| 27 | * |
| 28 | * @author robert |
| 29 | */ |
| 30 | public class NativeLeakDetectionThread extends Thread { |
| 31 | /** @return the leak detection thread. */ |
| 32 | public static NativeLeakDetectionThread instance() { |
| 33 | return s_instance; |
| 34 | } |
| 35 | private NativeLeakDetectionThread() { |
| 36 | super("NativeLeakDetectionThread"); |
| 37 | setDaemon(true); |
| 38 | } |
| 39 | private static NativeLeakDetectionThread s_instance; |
| 40 | static { |
| 41 | s_instance = new NativeLeakDetectionThread(); |
| 42 | s_instance.start(); |
| 43 | } |
| 44 | |
| 45 | /** Thread entry point */ |
| 46 | public void run() { |
| 47 | while (true) { |
| 48 | try { |
| 49 | Reference r = getQ().remove(100); |
| 50 | if (r == null) { |
| 51 | continue; |
| 52 | } |
| 53 | r.clear(); |
| 54 | if (!isExpectedReference(r)) { |
| 55 | logger.severe("Unexpected reference"); |
| 56 | continue; |
| 57 | } |
| 58 | NativeResourceChecker c = (NativeResourceChecker)r; |
| 59 | c.check(); |
| 60 | } catch (InterruptedException e) { |
| 61 | // goodbye |
| 62 | return; |
| 63 | } |
| 64 | } |
| 65 | } |
| 66 | |
| 67 | /** Stop the leak detection thread */ |
| 68 | public void stopRunning() { |
| 69 | interrupt(); |
| 70 | } |
| 71 | private boolean isExpectedReference(Reference r) { |
| 72 | return r instanceof NativeResourceChecker; |
| 73 | } |
| 74 | |
| 75 | /** @return get the reference Q **/ |
| 76 | public ReferenceQueue getQ() { |
| 77 | return m_refq; |
| 78 | } |
| 79 | |
| 80 | private ReferenceQueue m_refq = new ReferenceQueue(); |
| 81 | private static Logger logger |
| 82 | = Logger.getLogger(NativeLeakDetectionThread.class.getName()); |
| 83 | } |