You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
195 lines
7.0 KiB
195 lines
7.0 KiB
// MemoryControl.java
|
|
// -------------------------------------------
|
|
// (C) 2011 by Sebastian Gaebel
|
|
// first published 22.08.2011 on http://yacy.net
|
|
//
|
|
// $LastChangedDate: 2011-08-18 00:24:17 +0200 (Do, 18. Aug 2011) $
|
|
// $LastChangedRevision: 7883 $
|
|
// $LastChangedBy: orbiter $
|
|
//
|
|
// LICENSE
|
|
//
|
|
// This program is free software; you can redistribute it and/or modify
|
|
// it under the terms of the GNU General Public License as published by
|
|
// the Free Software Foundation; either version 2 of the License, or
|
|
// (at your option) any later version.
|
|
//
|
|
// This program 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 for more details.
|
|
//
|
|
// You should have received a copy of the GNU General Public License
|
|
// along with this program; if not, write to the Free Software
|
|
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
|
|
package net.yacy.kelondro.util;
|
|
|
|
import java.lang.management.ManagementFactory;
|
|
import java.lang.management.MemoryMXBean;
|
|
import java.lang.management.MemoryPoolMXBean;
|
|
import java.lang.management.MemoryUsage;
|
|
|
|
public class GenerationMemoryStrategy extends MemoryStrategy {
|
|
|
|
private final static long M = 1024l*1024l;
|
|
private MemoryPoolMXBean eden, survivor, old;
|
|
private MemoryMXBean heap;
|
|
|
|
public GenerationMemoryStrategy() {
|
|
name = "Generation Memory Strategy";
|
|
error = initPoolBeans();
|
|
heap = ManagementFactory.getMemoryMXBean();
|
|
if (lastGC == 0l) gc(10000, "initial gc - to get proper results"); // this is necessary on some GCs / vm
|
|
if (error) log.logWarning(name + ": not a generational heap");
|
|
}
|
|
|
|
/**
|
|
* memory that is free without increasing of total memory taken from os
|
|
* @return bytes
|
|
*/
|
|
protected final long free() {
|
|
return getUsage(eden, false).getCommitted() - getUsage(eden, false).getUsed();
|
|
}
|
|
|
|
/**
|
|
* memory that is available including increasing total memory up to maximum
|
|
* Smallest of both old and young
|
|
* @return bytes
|
|
*/
|
|
protected final long available() {
|
|
return available(true);
|
|
}
|
|
|
|
/**
|
|
* memory that is available including increasing total memory up to maximum
|
|
* @param force specifies whether ignoring prefered size
|
|
* @return bytes
|
|
*/
|
|
private final long available(final boolean force) {
|
|
return force & properState(force) ? Math.max(youngAvailable(), oldAvailable()) : Math.min(youngAvailable(), Math.max(M, oldAvailable()));
|
|
}
|
|
|
|
/**
|
|
* memory that is currently bound in objects
|
|
* @return used bytes
|
|
*/
|
|
protected final long used() {
|
|
return heap.getHeapMemoryUsage().getUsed();
|
|
}
|
|
|
|
/**
|
|
* currently allocated memory in the Java virtual machine; may vary over time
|
|
* @return bytes
|
|
*/
|
|
protected final long total() {
|
|
return heap.getHeapMemoryUsage().getCommitted();
|
|
}
|
|
|
|
/**
|
|
* maximum memory the Java virtual will allocate machine; may vary over time in some cases
|
|
* @return bytes
|
|
*/
|
|
protected final long maxMemory() {
|
|
return heap.getHeapMemoryUsage().getMax();
|
|
}
|
|
|
|
/**
|
|
* checks if a specified amount of bytes are available
|
|
* after the jvm recycled unused objects
|
|
*
|
|
* @param size the requested amount of free memory in bytes
|
|
* @param force specifies whether ignoring preferred size
|
|
* @return whether enough memory could be freed (or is free) or not
|
|
*/
|
|
protected final boolean request(final long size, final boolean force, boolean shortStatus) {
|
|
if (size == 0l) return true; // does not make sense to check - returning true without setting shortStatus (which also doesn't make sense to me)
|
|
final boolean unknown = size < 0l; // size < 0 indicate an unknown size - maybe from gziped streams
|
|
final boolean r = unknown? properState(force) : size < available(force);
|
|
shortStatus = !r;
|
|
return r;
|
|
}
|
|
|
|
/**
|
|
* use this to check for temporary space
|
|
* @return bytes available to allocate in Eden Space (Young Generation)
|
|
*/
|
|
private final long youngAvailable() {
|
|
final MemoryUsage usage = getUsage(eden, true);
|
|
return usage.getCommitted() - usage.getUsed();
|
|
}
|
|
|
|
/**
|
|
* @return bytes available to allocate in Tenured Space (Old Generation)
|
|
*/
|
|
private final long oldAvailable() {
|
|
final MemoryUsage usage = getUsage(old, true);
|
|
return Math.max(usage.getMax(), usage.getCommitted()) - usage.getUsed();
|
|
}
|
|
|
|
/**
|
|
* alive objects get 'moved' on gc from eden space to survior and from survior to old gen
|
|
* in a worse case (all objects of survivor alive) all objects get 'moved' from suvivor to old gen
|
|
* this method checks if there is is space left in old gen for that
|
|
*
|
|
* @return Memory is in proper state
|
|
*/
|
|
protected boolean properState() {
|
|
return properState(false);
|
|
}
|
|
|
|
/**
|
|
* @param force whether using used or committed survivor usage
|
|
* @return if survivor fits into old space
|
|
*/
|
|
private boolean properState(final boolean force) {
|
|
final long surv = force? Math.max(M, getUsage(survivor, false).getUsed()) : getUsage(survivor, false).getCommitted();
|
|
return surv < oldAvailable();
|
|
}
|
|
|
|
/**
|
|
* based on my research for a proper running jvm, this gives a guidance value for the heap size
|
|
*
|
|
* @return bytes recommend for heap size
|
|
*/
|
|
protected long recommendHeapSize() {
|
|
// the heap/old-ration is jvm-specific and can be changed by parameter - using this + 20% buffer
|
|
final double factor = 1.2 * (double)heap.getHeapMemoryUsage().getMax() / (double)getUsage(old, false).getMax();
|
|
// current needed space in old gen
|
|
final long neededOld = getUsage(old, true).getUsed() + getUsage(survivor, false).getMax();
|
|
return (long) (neededOld * factor);
|
|
}
|
|
|
|
/**
|
|
* @param collected specifies whether trying to get the memory usage after the jvm recycled unused objects
|
|
* @return MemoryUsage of given MemoryPoolMXBean
|
|
*/
|
|
private MemoryUsage getUsage(final MemoryPoolMXBean bean, final boolean collected) {
|
|
if (collected) {
|
|
try {
|
|
final MemoryUsage usage = bean.getCollectionUsage();
|
|
if (usage != null) return usage;
|
|
} catch (final IllegalArgumentException e) {
|
|
log.logWarning(name + ": ", e);
|
|
}
|
|
error = true;
|
|
log.logWarning(name + ": no colletion usage available at " + bean.getName());
|
|
}
|
|
return bean.getUsage();
|
|
}
|
|
|
|
private boolean initPoolBeans() {
|
|
for (final MemoryPoolMXBean bean : ManagementFactory.getMemoryPoolMXBeans()) {
|
|
if (bean.getName().startsWith("G1")) break; //this strategy will not run on G1
|
|
if (bean.getName().contains("Eden")) {
|
|
eden = bean;
|
|
} else if (bean.getName().contains("Survivor")) {
|
|
survivor = bean;
|
|
} else if (bean.getName().contains("Old") || bean.getName().contains("Tenured")) {
|
|
old = bean;
|
|
}
|
|
}
|
|
return eden == null || survivor == null || old == null;
|
|
}
|
|
}
|