package org.cache2k.benchmarks.clockProPlus;
/*
* #%L
* Benchmarks: Clock-Pro+ and other eviction policies
* %%
* Copyright (C) 2018 - 2019 Cong Li, Intel Corporation
* %%
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
* #L%
*/
import org.apache.commons.collections4.map.HashedMap;
/**
* @author Jens Wilke
*/
@SuppressWarnings({"Duplicates", "WeakerAccess", "unused"})
public class ClockProA implements ISimpleCache {
public ClockProA(int size, ClockPro.Tuning tuning) {
this.size = size;
this.clockMap = new HashedMap<>();
this.coldTarget = (int)(this.size * tuning.getColdRatio());
this.hotTarget = this.size - this.coldTarget;
this.coldSize = 0;
this.hotSize = 0;
this.testSize = 0;
this.handHot = null;
this.handCold = null;
this.handTest = null;
this.lru = null;
}
@Override
public boolean request(Integer address) {
if (this.clockMap.containsKey(address)) {
CacheMetaData data = this.clockMap.get(address);
if (data.isResident()) {
data.setReference(true);
return true;
}
}
this.advanceHandHot();
this.advanceHandCold();
if (this.clockMap.containsKey(address)) {
CacheMetaData data = this.clockMap.get(address);
this.assertStatement(data.isInStack(),
"Error: hit a non-resident cold page out of the stack!");
this.assertStatement(!data.isReferenced(),
"Error: hit a referenced non-resident cold page");
this.adjustColdTarget(1);
this.assertStatement(this.hotSize + this.coldSize == this.size, "Error: cache not full!");
this.evictColdPage();
data.setResidentState(true);
this.testSize--;
this.coldSize++;
if (data == this.handTest) {
this.advanceHandTest();
}
this.promoteColdPage(data);
this.advanceHandCold();
return false;
}
if (this.coldSize + this.hotSize == this.size) {
this.evictColdPage();
}
CacheMetaData data = new CacheMetaData();
data.setAddress(address);
data.setResidentState(true);
this.addToClock(data);
if (this.coldSize == 0 && this.hotSize < this.hotTarget) {
data.setLIRState(true);
this.hotSize++;
} else {
data.setLIRState(false);
if (this.handCold == null) {
this.handCold = data;
}
this.coldSize++;
}
this.advanceHandCold();
this.pruneTestPages();
return false;
}
@Override
public String toString() {
return String.format("ClockPro*(%d)", this.size);
}
protected void pruneTestPages() {
while (this.coldSize + this.hotSize + this.testSize > this.size * 2) {
this.assertStatement(this.handTest.isInStack() && !this.handTest.isLIR()
&& !this.handTest.isResident(),
"Error: hand_test does not stop at a test page!");
this.removeNonresidentColdPage(this.handTest);
}
}
protected void evictColdPage() {
this.assertStatement(!this.handCold.isLIR() && this.handCold.isResident() && !this.handCold.isReferenced(),
"Error: hand_cold does not stop at a non-referenced resident cold page!");
CacheMetaData data = this.handCold;
this.handCold = this.handCold.getNext();
data.setResidentState(false);
this.coldSize--;
this.testSize++;
if (this.handTest == null) {
this.handTest = data;
}
if (!data.isInStack()) {
if (data == this.lru) {
this.lru = data.getPrevious();
}
this.removeNonresidentColdPage(data);
}
}
protected void promoteColdPage(CacheMetaData data) {
data.setLIRState(true);
this.hotSize++;
this.coldSize--;
this.moveToLRU(data);
while (this.hotSize > this.hotTarget) {
this.demoteHotPage();
}
}
protected void demoteHotPage() {
this.assertStatement(!this.handHot.isReferenced(), "Error: hand_hot stops on a referenced page!");
CacheMetaData data = this.handHot;
this.handHot = this.handHot.getNext();
data.setLIRState(false);
this.hotSize--;
this.coldSize++;
data.setInStackStatus(false);
data.demote(true);
this.moveToLRU(data);
this.advanceHandHot();
}
protected void advanceHandTest() {
if (this.testSize == 0) {
this.handTest = null;
return;
}
while (this.handTest.isLIR() || this.handTest.isResident()) {
this.handTest = this.handTest.getNext();
}
}
protected void advanceHandHot() {
if (this.hotSize == 0) {
return;
}
CacheMetaData data = this.handHot;
while (!data.isLIR() || data.isReferenced()) {
CacheMetaData nextPosition = data.getNext();
if (data.isLIR()) {
data.setReference(false);
this.lru = data;
} else {
if (data.isResident()) {
if (data.isReferenced()) {
data.setReference(false);
if (data.isDemoted()) {
this.adjustColdTarget(-1);
data.demote(false);
}
this.lru = data;
if (data.equals(this.handCold)) {
this.handCold = nextPosition;
}
} else {
data.setInStackStatus(false);
}
} else {
this.removeNonresidentColdPage(data);
}
if (data.equals(this.handTest)) {
this.handTest = nextPosition;
}
}
data = nextPosition;
}
this.handHot = data;
}
protected void advanceHandCold() {
if (this.coldSize == 0) {
return;
}
while (this.handCold.isLIR() || !this.handCold.isResident() || this.handCold.isReferenced()) {
CacheMetaData data = this.handCold;
this.handCold = this.handCold.getNext();
if (!data.isLIR()) {
if (data.isReferenced()) {
data.setReference(false);
if (data.isDemoted()) {
this.adjustColdTarget(-1);
data.demote(false);
}
if (data.isInStack()) {
this.promoteColdPage(data);
} else {
data.setInStackStatus(true);
this.moveToLRU(data);
}
}
}
}
}
protected void addToClock(CacheMetaData data) {
if (this.lru == null) {
data.linkNext(data);
this.lru = data;
this.handHot = data;
} else {
data.insertAfter(this.lru);
this.lru = data;
}
data.setInStackStatus(true);
this.clockMap.put(data.getAddress(), data);
}
protected void moveToLRU(CacheMetaData data) {
if (data == this.lru) {
return;
}
data.unlink();
data.insertAfter(this.lru);
this.lru = data;
}
protected void removeNonresidentColdPage(CacheMetaData data) {
Integer address = data.getAddress();
if (data == this.handTest) {
this.handTest = this.handTest.getNext();
}
this.clockMap.remove(address);
data.unlink();
this.testSize--;
this.advanceHandTest();
}
protected void assertStatement(boolean result, String message) {
if (!result) {
System.err.println(message);
}
}
protected void adjustColdTarget(int delta) {
this.coldTarget += delta;
if (this.coldTarget < 1) {
this.coldTarget = 1;
}
if (this.coldTarget > this.size / 2) {
this.coldTarget = this.size / 2;
}
this.hotTarget = this.size - this.coldTarget;
}
public void outputStatus() {
if (this.lru != null) {
this.lru.outputLinkedList();
}
System.out.printf("Hot_pages = %d, cold_pages = %d, hot_target = %d, cold_target = %d, ",
this.hotSize, this.coldSize, this.hotTarget, this.coldTarget);
if (this.handHot != null) {
System.out.printf("Hot: %d, ", this.handHot.getAddress());
}
if (this.handCold != null) {
System.out.printf("Cold: %d, ", this.handCold.getAddress());
}
if (this.handTest != null) {
System.out.printf("Test: %d, ", this.handTest.getAddress());
}
System.out.println();
}
protected HashedMap<Integer, CacheMetaData> clockMap;
protected CacheMetaData handHot;
protected CacheMetaData handCold;
protected CacheMetaData handTest;
protected CacheMetaData lru;
protected int size;
protected int coldSize;
protected int hotSize;
protected int testSize;
protected int coldTarget;
protected int hotTarget;
}
