Gitorious

270fa73 by Loïc Rouchon at 2010-01-17	1	/*
	2	* $Id$
	3	*
	4	* Copyright (C) 2003-2009 JNode.org
	5	*
	6	* This library is free software; you can redistribute it and/or modify it
	7	* under the terms of the GNU Lesser General Public License as published
	8	* by the Free Software Foundation; either version 2.1 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This library is distributed in the hope that it will be useful, but
	12	* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
	13	* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
	14	* License for more details.
	15	*
	16	* You should have received a copy of the GNU Lesser General Public License
	17	* along with this library; If not, write to the Free Software Foundation, Inc.,
	18	* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
	19	*/
ea37d1f by loic at 2010-01-25	20
270fa73 by Loïc Rouchon at 2010-01-17	21	package org.jnode.vm.memmgr.generational;
	22
	23	import org.jnode.vm.Unsafe;
	24	import org.jnode.vm.scheduler.Monitor;
	25
	26	/**
	27	* @author Ewout Prangsma (epr@users.sourceforge.net)
	28	*/
	29	final class GenGCThread extends Thread {
	30
	31	/**
	32	* The manager
	33	*/
ea37d1f by loic at 2010-01-25	34	private final GenGCManager manager;
270fa73 by Loïc Rouchon at 2010-01-17	35
	36	/**
	37	* Monitor for synchronizing access to my fields
	38	*/
12865b3 by Loïc Rouchon at 2010-01-28	39	private Monitor heapMonitor;
270fa73 by Loïc Rouchon at 2010-01-17	40
	41	/**
	42	* Is a GC run requested?
	43	*/
2af7864 by Loïc Rouchon at 2010-02-01	44	private boolean runMajorNeeded;
	45	private boolean runMinorNeeded;
270fa73 by Loïc Rouchon at 2010-01-17	46
	47	/**
	48	* Is the GC currently active
	49	*/
	50	private boolean gcActive;
	51
	52	/**
	53	* Initialize this instance.
ea37d1f by loic at 2010-01-25	54	*
270fa73 by Loïc Rouchon at 2010-01-17	55	* @param manager
	56	*/
ea37d1f by loic at 2010-01-25	57	public GenGCThread(GenGCManager manager, Monitor heapMonitor) {
270fa73 by Loïc Rouchon at 2010-01-17	58	super("gc-thread");
	59	this.manager = manager;
	60	this.heapMonitor = heapMonitor;
	61	}
	62
	63	/**
2af7864 by Loïc Rouchon at 2010-02-01	64	* Trigger a major GC run.
ea37d1f by loic at 2010-01-25	65	*
	66	* @param waitToFinish
	67	* If true, block until the run is ready, if false, return
	68	* immediately.
270fa73 by Loïc Rouchon at 2010-01-17	69	*/
	70	public final void trigger(boolean waitToFinish) {
2af7864 by Loïc Rouchon at 2010-02-01	71	triggerMajor(waitToFinish);
	72	}
	73
	74	/**
	75	* Trigger a major GC run.
	76	*
	77	* @param waitToFinish
	78	* If true, block until the run is ready, if false, return
	79	* immediately.
	80	*/
	81	public final void triggerMajor(boolean waitToFinish) {
	82	if (runMajorNeeded && !waitToFinish) {
270fa73 by Loïc Rouchon at 2010-01-17	83	return;
	84	}
	85	heapMonitor.enter();
	86	try {
2af7864 by Loïc Rouchon at 2010-02-01	87	runMajorNeeded = true;
270fa73 by Loïc Rouchon at 2010-01-17	88	heapMonitor.NotifyAll();
	89	if (waitToFinish) {
2af7864 by Loïc Rouchon at 2010-02-01	90	waitForMajorCollectionEnd();
	91	}
	92	} finally {
	93	heapMonitor.exit();
	94	}
	95	}
	96
	97	/**
	98	* Trigger a minor GC run.
	99	*
	100	* @param waitToFinish
	101	* If true, block until the run is ready, if false, return
	102	* immediately.
	103	*/
	104	public final void triggerMinor(boolean waitToFinish) {
	105	if (runMinorNeeded && !waitToFinish) {
	106	return;
	107	}
	108	heapMonitor.enter();
	109	try {
	110	runMinorNeeded = true;
	111	heapMonitor.NotifyAll();
	112	if (waitToFinish) {
	113	waitForMinorCollectionEnd();
270fa73 by Loïc Rouchon at 2010-01-17	114	}
	115	} finally {
	116	heapMonitor.exit();
	117	}
	118	}
	119
	120	/**
	121	* Continue to GC.
ea37d1f by loic at 2010-01-25	122	*
270fa73 by Loïc Rouchon at 2010-01-17	123	* @see java.lang.Runnable#run()
	124	*/
ef5b586 by Loïc Rouchon at 2010-01-27	125	@Override
270fa73 by Loïc Rouchon at 2010-01-17	126	public final void run() {
	127	while (true) {
	128	try {
2af7864 by Loïc Rouchon at 2010-02-01	129	waitForGcStart();
ea37d1f by loic at 2010-01-25	130	callGc();
2af7864 by Loïc Rouchon at 2010-02-01	131	notifyGcEnd();
270fa73 by Loïc Rouchon at 2010-01-17	132	} catch (Throwable ex) {
	133	try {
	134	Unsafe.debug(ex.getMessage());
	135	Unsafe.debug('\n');
	136	Unsafe.debugStackTrace(ex);
	137	Unsafe.die("GCThread failed");
	138	} catch (Throwable ex2) {
ea37d1f by loic at 2010-01-25	139	continue;
270fa73 by Loïc Rouchon at 2010-01-17	140	}
	141	}
	142	}
	143	}
ea37d1f by loic at 2010-01-25	144
2af7864 by Loïc Rouchon at 2010-02-01	145	private void waitForMajorCollectionEnd() {
	146	while (runMajorNeeded \|\| gcActive) {
ea37d1f by loic at 2010-01-25	147	try {
	148	heapMonitor.Wait(0L);
	149	} catch (InterruptedException ex) {
	150	continue;
	151	}
	152	}
	153	}
	154
2af7864 by Loïc Rouchon at 2010-02-01	155	private void waitForMinorCollectionEnd() {
	156	while (runMinorNeeded \|\| gcActive) {
	157	try {
	158	heapMonitor.Wait(0L);
	159	} catch (InterruptedException ex) {
	160	continue;
	161	}
	162	}
ea37d1f by loic at 2010-01-25	163	}
	164
	165	private final void waitForGcStart() throws InterruptedException {
	166	heapMonitor.enter();
	167	try {
2af7864 by Loïc Rouchon at 2010-02-01	168	while (!runMajorNeeded) {
ea37d1f by loic at 2010-01-25	169	heapMonitor.Wait(0L);
	170	}
	171	gcActive = true;
	172	} finally {
	173	heapMonitor.exit();
	174	}
	175	}
	176
2af7864 by Loïc Rouchon at 2010-02-01	177	private final void callGc() throws InterruptedException {
	178	if (runMajorNeeded) {
	179	Unsafe.debug("GenGCThread.callGc(major)\n");
	180	manager.majorGC();
	181	runMinorNeeded = false;
	182	} else {
1b187f6 by Loïc Rouchon at 2010-02-03	183	Unsafe.debug("GenGCThread.callGc(minor)\n");
2af7864 by Loïc Rouchon at 2010-02-01	184	manager.minorGC();
	185	runMinorNeeded = false;
	186	}
	187	}
	188
ea37d1f by loic at 2010-01-25	189	private final void notifyGcEnd() {
	190	gcActive = false;
	191	heapMonitor.enter();
	192	try {
	193	heapMonitor.NotifyAll();
	194	} finally {
	195	heapMonitor.exit();
	196	}
	197	}
270fa73 by Loïc Rouchon at 2010-01-17	198	}