--- /dev/null 2019-01-22 19:51:49.883716317 +0000 +++ new/test/gc/g1/mixedgc/TestOldGenCollectionUsage.java 2019-01-23 23:14:34.768283507 +0000 @@ -0,0 +1,232 @@ +/* + * Copyright (c) 2018, 2019, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * 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 TestOldGenCollectionUsage.java + * @bug 8195115 + * @summary G1 Old Gen's CollectionUsage.used is zero after mixed GC which is incorrect + * @key gc + * @requires vm.gc=="G1" | vm.gc=="null" + * @requires vm.opt.MaxGCPauseMillis == "null" + * @library /testlibrary /testlibrary/whitebox + * @build ClassFileInstaller com.oracle.java.testlibrary.* sun.hotspot.WhiteBox TestOldGenCollectionUsage + * @run main ClassFileInstaller sun.hotspot.WhiteBox + * sun.hotspot.WhiteBox$WhiteBoxPermission + * @run main/othervm -Xbootclasspath/a:. -XX:+UseG1GC -XX:+UnlockExperimentalVMOptions -XX:+UnlockDiagnosticVMOptions + * -XX:+WhiteBoxAPI -verbose:gc -XX:SurvivorRatio=1 -Xmx14m -Xms14m -XX:MaxTenuringThreshold=1 + * -XX:InitiatingHeapOccupancyPercent=100 -XX:G1MixedGCCountTarget=4 -XX:MaxGCPauseMillis=30000 + * -XX:G1HeapRegionSize=1m -XX:G1HeapWastePercent=0 -XX:G1MixedGCLiveThresholdPercent=100 + * TestOldGenCollectionUsage + */ + +import com.oracle.java.testlibrary.Asserts; +import sun.hotspot.WhiteBox; + +import java.util.ArrayList; +import java.util.List; +import java.util.Collections; + +import java.lang.management.*; + +// 8195115 says that for the "G1 Old Gen" MemoryPool, CollectionUsage.used +// is zero for G1 after a mixed collection, which is incorrect. + +public class TestOldGenCollectionUsage { + + private String poolName = "G1 Old Gen"; + private String collectorName = "G1 Young Generation"; + + public static void main(String [] args) throws Exception { + TestOldGenCollectionUsage t = new TestOldGenCollectionUsage(); + t.run(); + } + + public TestOldGenCollectionUsage() { + System.out.println("Monitor G1 Old Gen pool with G1 Young Generation collector."); + } + + public void run() { + // Find memory pool and collector + List pools = ManagementFactory.getMemoryPoolMXBeans(); + MemoryPoolMXBean pool = null; + boolean foundPool = false; + for (int i = 0; i < pools.size(); i++) { + pool = pools.get(i); + String name = pool.getName(); + if (name.contains(poolName)) { + System.out.println("Found pool: " + name); + foundPool = true; + break; + } + } + if (!foundPool) { + throw new RuntimeException(poolName + " not found, test with -XX:+UseG1GC"); + } + + List collectors = ManagementFactory.getGarbageCollectorMXBeans(); + GarbageCollectorMXBean collector = null; + boolean foundCollector = false; + for (int i = 0; i < collectors.size(); i++) { + collector = collectors.get(i); + String name = collector.getName(); + if (name.contains(collectorName)) { + System.out.println("Found collector: " + name); + foundCollector = true; + break; + } + } + if (!foundCollector) { + throw new RuntimeException(collectorName + " not found, test with -XX:+UseG1GC"); + } + + MixedGCProvoker gcProvoker = new MixedGCProvoker(); + gcProvoker.allocateOldObjects(); + + // Verify no non-zero result was stored + long usage = pool.getCollectionUsage().getUsed(); + System.out.println(poolName + ": usage after GC = " + usage); + if (usage > 0) { + throw new RuntimeException("Premature mixed collections(s)"); + } + + // Verify that collections were done + long collectionCount = collector.getCollectionCount(); + System.out.println(collectorName + ": collection count = " + + collectionCount); + long collectionTime = collector.getCollectionTime(); + System.out.println(collectorName + ": collection time = " + + collectionTime); + if (collectionCount <= 0) { + throw new RuntimeException("Collection count <= 0"); + } + if (collectionTime <= 0) { + throw new RuntimeException("Collector has not run"); + } + + gcProvoker.provokeMixedGC(); + + usage = pool.getCollectionUsage().getUsed(); + System.out.println(poolName + ": usage after GC = " + usage); + if (usage <= 0) { + throw new RuntimeException(poolName + " found with zero usage"); + } + + long newCollectionCount = collector.getCollectionCount(); + System.out.println(collectorName + ": collection count = " + + newCollectionCount); + long newCollectionTime = collector.getCollectionTime(); + System.out.println(collectorName + ": collection time = " + + newCollectionTime); + if (newCollectionCount <= collectionCount) { + throw new RuntimeException("No new collection"); + } + if (newCollectionTime <= collectionTime) { + throw new RuntimeException("Collector has not run some more"); + } + + System.out.println("Test passed."); + } + + /** + * Utility class to guarantee a mixed GC. The class allocates several arrays and + * promotes them to the oldgen. After that it tries to provoke mixed GC by + * allocating new objects. + * + * The necessary condition for guaranteed mixed GC is running MixedGCProvoker is + * running in VM with the following flags: -XX:MaxTenuringThreshold=1 -Xms12M + * -Xmx12M -XX:G1MixedGCLiveThresholdPercent=100 -XX:G1HeapWastePercent=0 + * -XX:G1HeapRegionSize=1m + */ + public class MixedGCProvoker { + private final WhiteBox WB = WhiteBox.getWhiteBox(); + private final List liveOldObjects = new ArrayList<>(); + private final List newObjects = new ArrayList<>(); + + public static final int ALLOCATION_SIZE = 20000; + public static final int ALLOCATION_COUNT = 15; + + public void allocateOldObjects() { + List deadOldObjects = new ArrayList<>(); + // Allocates buffer and promotes it to the old gen. Mix live and dead old + // objects + for (int i = 0; i < ALLOCATION_COUNT; ++i) { + liveOldObjects.add(new byte[ALLOCATION_SIZE * 5]); + deadOldObjects.add(new byte[ALLOCATION_SIZE * 5]); + } + + // Do two young collections, MaxTenuringThreshold=1 will force promotion. + // G1HeapRegionSize=1m guarantees that old gen regions will be filled. + WB.youngGC(); + WB.youngGC(); + // Check it is promoted & keep alive + Asserts.assertTrue(WB.isObjectInOldGen(liveOldObjects), + "List of the objects is suppose to be in OldGen"); + Asserts.assertTrue(WB.isObjectInOldGen(deadOldObjects), + "List of the objects is suppose to be in OldGen"); + } + + /** + * Waits until Concurent Mark Cycle finishes + * @param wb Whitebox instance + * @param sleepTime sleep time + */ + private void waitTillCMCFinished(int sleepTime) { + while (WB.g1InConcurrentMark()) { + if (sleepTime > -1) { + try { + Thread.sleep(sleepTime); + } catch (InterruptedException e) { + System.out.println("Got InterruptedException while waiting for ConcMarkCycle to finish"); + } + } + } + } + + public void provokeMixedGC() { + waitTillCMCFinished(0); + WB.g1StartConcMarkCycle(); + waitTillCMCFinished(0); + WB.youngGC(); + + System.out.println("Allocating new objects to provoke mixed GC"); + // Provoke a mixed collection. G1MixedGCLiveThresholdPercent=100 + // guarantees that full old gen regions will be included. + for (int i = 0; i < (ALLOCATION_COUNT * 20); i++) { + try { + newObjects.add(new byte[ALLOCATION_SIZE]); + } catch (OutOfMemoryError e) { + newObjects.clear(); + WB.youngGC(); + WB.youngGC(); + System.out.println("OutOfMemoryError is reported, stop allocating new objects"); + break; + } + } + // check that liveOldObjects still alive + Asserts.assertTrue(WB.isObjectInOldGen(liveOldObjects), + "List of the objects is suppose to be in OldGen"); + } + + } + +}