/*
* Copyright (c) 2017, 2018, Red Hat, Inc. All rights reserved.
*
* 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.
*
*/
/*
* @test TestStringDedupStress
* @summary Test Shenandoah string deduplication implementation
* @key gc
* @requires vm.gc.Shenandoah & !vm.graal.enabled
* @library /test/lib
* @modules java.base/jdk.internal.misc:open
* @modules java.base/java.lang:open
* java.management
*
* @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
* -XX:+UseShenandoahGC -XX:ShenandoahGCMode=passive
* -XX:+ShenandoahDegeneratedGC
* TestStringDedupStress
*
* @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
* -XX:+UseShenandoahGC -XX:ShenandoahGCMode=passive
* -XX:-ShenandoahDegeneratedGC
* TestStringDedupStress
*/
/*
* @test TestStringDedupStress
* @summary Test Shenandoah string deduplication implementation
* @key gc
* @requires vm.gc.Shenandoah & !vm.graal.enabled
* @library /test/lib
* @modules java.base/jdk.internal.misc:open
* @modules java.base/java.lang:open
* java.management
*
* @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
* -XX:+UseShenandoahGC
* -DtargetStrings=3000000
* TestStringDedupStress
*
* @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
* -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive
* -DtargetStrings=2000000
* TestStringDedupStress
*
* @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
* -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive
* -XX:+ShenandoahOOMDuringEvacALot
* -DtargetStrings=2000000
* TestStringDedupStress
*
* @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
* -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=compact
* TestStringDedupStress
*
* @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
* -XX:+UseShenandoahGC
* -XX:ShenandoahUpdateRefsEarly=off
* -DtargetStrings=3000000
* TestStringDedupStress
*
* @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
* -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=compact
* -XX:ShenandoahUpdateRefsEarly=off
* -DtargetStrings=2000000
* TestStringDedupStress
*
* @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
* -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive
* -XX:ShenandoahUpdateRefsEarly=off
* -DtargetStrings=2000000
* TestStringDedupStress
*
* @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
* -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive
* -XX:ShenandoahUpdateRefsEarly=off -XX:+ShenandoahOOMDuringEvacALot
* -DtargetStrings=2000000
* TestStringDedupStress
*/
/*
* @test TestStringDedupStress
* @summary Test Shenandoah string deduplication implementation
* @key gc
* @requires vm.gc.Shenandoah & !vm.graal.enabled
* @library /test/lib
* @modules java.base/jdk.internal.misc:open
* @modules java.base/java.lang:open
* java.management
*
* @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
* -XX:+UseShenandoahGC -XX:ShenandoahGCMode=traversal
* TestStringDedupStress
*
* @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
* -XX:+UseShenandoahGC -XX:ShenandoahGCMode=traversal -XX:ShenandoahGCHeuristics=aggressive
* -DtargetStrings=2000000
* TestStringDedupStress
*
* @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
* -XX:+UseShenandoahGC -XX:ShenandoahGCMode=traversal
* -XX:+ShenandoahOOMDuringEvacALot
* -DtargetStrings=2000000
* TestStringDedupStress
*
* @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
* -XX:+UseShenandoahGC -XX:ShenandoahGCMode=traversal -XX:ShenandoahGCHeuristics=aggressive
* -XX:+ShenandoahOOMDuringEvacALot
* -DtargetStrings=2000000
* TestStringDedupStress
*/
import java.lang.management.*;
import java.lang.reflect.*;
import java.util.*;
import sun.misc.*;
public class TestStringDedupStress {
private static Field valueField;
private static Unsafe unsafe;
private static final int TARGET_STRINGS = Integer.getInteger("targetStrings", 2_500_000);
private static final long MAX_REWRITE_GC_CYCLES = 6;
private static final long MAX_REWRITE_TIME = 30*1000; // ms
private static final int UNIQUE_STRINGS = 20;
static {
try {
Field field = Unsafe.class.getDeclaredField("theUnsafe");
field.setAccessible(true);
unsafe = (Unsafe) field.get(null);
valueField = String.class.getDeclaredField("value");
valueField.setAccessible(true);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
private static Object getValue(String string) {
try {
return valueField.get(string);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
static class StringAndId {
private String str;
private int id;
public StringAndId(String str, int id) {
this.str = str;
this.id = id;
}
public String str() {
return str;
}
public int id() {
return id;
}
}
// Generate uniqueStrings number of strings
private static void generateStrings(ArrayList<StringAndId> strs, int uniqueStrings) {
Random rn = new Random();
for (int u = 0; u < uniqueStrings; u++) {
int n = rn.nextInt(uniqueStrings);
strs.add(new StringAndId("Unique String " + n, n));
}
}
private static int verifyDedupString(ArrayList<StringAndId> strs) {
Map<Object, StringAndId> seen = new HashMap<>(TARGET_STRINGS*2);
int total = 0;
int dedup = 0;
for (StringAndId item : strs) {
total++;
StringAndId existingItem = seen.get(getValue(item.str()));
if (existingItem == null) {
seen.put(getValue(item.str()), item);
} else {
if (item.id() != existingItem.id() ||
!item.str().equals(existingItem.str())) {
System.out.println("StringDedup error:");
System.out.println("id: " + item.id() + " != " + existingItem.id());
System.out.println("or String: " + item.str() + " != " + existingItem.str());
throw new RuntimeException("StringDedup Test failed");
} else {
dedup++;
}
}
}
System.out.println("Dedup: " + dedup + "/" + total + " unique: " + (total - dedup));
return (total - dedup);
}
static volatile ArrayList<StringAndId> astrs = new ArrayList<>();
static GarbageCollectorMXBean gcCycleMBean;
public static void main(String[] args) {
Random rn = new Random();
for (GarbageCollectorMXBean bean : ManagementFactory.getGarbageCollectorMXBeans()) {
if ("Shenandoah Cycles".equals(bean.getName())) {
gcCycleMBean = bean;
break;
}
}
if (gcCycleMBean == null) {
throw new RuntimeException("Can not find Shenandoah GC cycle mbean");
}
// Generate roughly TARGET_STRINGS strings, only UNIQUE_STRINGS are unique
int genIters = TARGET_STRINGS / UNIQUE_STRINGS;
for (int index = 0; index < genIters; index++) {
generateStrings(astrs, UNIQUE_STRINGS);
}
long cycleBeforeRewrite = gcCycleMBean.getCollectionCount();
long timeBeforeRewrite = System.currentTimeMillis();
long loop = 1;
while (true) {
int arrSize = astrs.size();
int index = rn.nextInt(arrSize);
StringAndId item = astrs.get(index);
int n = rn.nextInt(UNIQUE_STRINGS);
item.str = "Unique String " + n;
item.id = n;
if (loop++ % 1000 == 0) {
// enough GC cycles for rewritten strings to be deduplicated
if (gcCycleMBean.getCollectionCount() - cycleBeforeRewrite >= MAX_REWRITE_GC_CYCLES) {
break;
}
// enough time is spent waiting for GC to happen
if (System.currentTimeMillis() - timeBeforeRewrite >= MAX_REWRITE_TIME) {
break;
}
}
}
verifyDedupString(astrs);
}
}