| /* |
| * 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 |
| */ |
| |
| /* |
| * @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=iu |
| * TestStringDedupStress |
| * |
| * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication |
| * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=iu -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=iu |
| * -XX:+ShenandoahOOMDuringEvacALot |
| * -DtargetStrings=2000000 |
| * TestStringDedupStress |
| * |
| * @run main/othervm -Xmx1g -Xlog:gc+stats -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication |
| * -XX:+UseShenandoahGC -XX:ShenandoahGCMode=iu -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); |
| } |
| } |
