1 /*
2 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24 /*
25 * @test TestOldGenCollectionUsage.java
26 * @bug 8195115
27 * @summary G1 Old Gen's CollectionUsage.used is zero after mixed GC which is incorrect
28 * @key gc
29 * @requires vm.gc.G1
30 * @requires vm.opt.MaxGCPauseMillis == "null"
31 * @library /test/lib
32 * @modules java.base/jdk.internal.misc
33 * @modules java.management
34 * @build sun.hotspot.WhiteBox
35 * @run driver ClassFileInstaller sun.hotspot.WhiteBox
36 * @run main/othervm -Xbootclasspath/a:. -XX:+UseG1GC -XX:+UnlockExperimentalVMOptions
37 * -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -verbose:gc -XX:SurvivorRatio=1 -Xmx14m -Xms14m -XX:MaxTenuringThreshold=1 -XX:InitiatingHeapOccupancyPercent=100 -XX:-G1UseAdaptiveIHOP -XX:G1MixedGCCountTarget=4 -XX:MaxGCPauseMillis=30000 -XX:G1HeapRegionSize=1m -XX:G1HeapWastePercent=0 -XX:G1MixedGCLiveThresholdPercent=100 TestOldGenCollectionUsage
38 */
39
40 import jdk.test.lib.Asserts;
41 import sun.hotspot.WhiteBox;
42
43 import java.util.ArrayList;
44 import java.util.List;
45 import java.util.Collections;
46
47 import java.lang.management.*;
48
49 // 8195115 says that for the "G1 Old Gen" MemoryPool, CollectionUsage.used
50 // is zero for G1 after a mixed collection, which is incorrect.
51
52 public class TestOldGenCollectionUsage {
53
54 private String poolName = "G1 Old Gen";
55 private String collectorName = "G1 Young Generation";
56
57 public static void main(String [] args) throws Exception {
58 TestOldGenCollectionUsage t = new TestOldGenCollectionUsage();
59 t.run();
60 }
61
62 public TestOldGenCollectionUsage() {
63 System.out.println("Monitor G1 Old Gen pool with G1 Young Generation collector.");
64 }
65
66 public void run() {
67 // Find memory pool and collector
68 List<MemoryPoolMXBean> pools = ManagementFactory.getMemoryPoolMXBeans();
69 MemoryPoolMXBean pool = null;
70 boolean foundPool = false;
71 for (int i = 0; i < pools.size(); i++) {
72 pool = pools.get(i);
73 String name = pool.getName();
74 if (name.contains(poolName)) {
75 System.out.println("Found pool: " + name);
76 foundPool = true;
77 break;
78 }
79 }
80 if (!foundPool) {
81 throw new RuntimeException(poolName + " not found, test with -XX:+UseG1GC");
82 }
83
84 List<GarbageCollectorMXBean> collectors = ManagementFactory.getGarbageCollectorMXBeans();
85 GarbageCollectorMXBean collector = null;
86 boolean foundCollector = false;
87 for (int i = 0; i < collectors.size(); i++) {
88 collector = collectors.get(i);
89 String name = collector.getName();
90 if (name.contains(collectorName)) {
91 System.out.println("Found collector: " + name);
92 foundCollector = true;
93 break;
94 }
95 }
96 if (!foundCollector) {
97 throw new RuntimeException(collectorName + " not found, test with -XX:+UseG1GC");
98 }
99
100 MixedGCProvoker gcProvoker = new MixedGCProvoker();
101 gcProvoker.allocateOldObjects();
102
103 // Verify no non-zero result was stored
104 long usage = pool.getCollectionUsage().getUsed();
105 System.out.println(poolName + ": usage after GC = " + usage);
106 if (usage > 0) {
107 throw new RuntimeException("Premature mixed collections(s)");
108 }
109
110 // Verify that collections were done
111 long collectionCount = collector.getCollectionCount();
112 System.out.println(collectorName + ": collection count = "
113 + collectionCount);
114 long collectionTime = collector.getCollectionTime();
115 System.out.println(collectorName + ": collection time = "
116 + collectionTime);
117 if (collectionCount <= 0) {
118 throw new RuntimeException("Collection count <= 0");
119 }
120 if (collectionTime <= 0) {
121 throw new RuntimeException("Collector has not run");
122 }
123
124 gcProvoker.provokeMixedGC();
125
126 usage = pool.getCollectionUsage().getUsed();
127 System.out.println(poolName + ": usage after GC = " + usage);
128 if (usage <= 0) {
129 throw new RuntimeException(poolName + " found with zero usage");
130 }
131
132 long newCollectionCount = collector.getCollectionCount();
133 System.out.println(collectorName + ": collection count = "
134 + newCollectionCount);
135 long newCollectionTime = collector.getCollectionTime();
136 System.out.println(collectorName + ": collection time = "
137 + newCollectionTime);
138 if (newCollectionCount <= collectionCount) {
139 throw new RuntimeException("No new collection");
140 }
141 if (newCollectionTime <= collectionTime) {
142 throw new RuntimeException("Collector has not run some more");
143 }
144
145 System.out.println("Test passed.");
146 }
147
148 /**
149 * Utility class to guarantee a mixed GC. The class allocates several arrays and
150 * promotes them to the oldgen. After that it tries to provoke mixed GC by
151 * allocating new objects.
152 *
153 * The necessary condition for guaranteed mixed GC is running MixedGCProvoker is
154 * running in VM with the following flags: -XX:MaxTenuringThreshold=1 -Xms12M
155 * -Xmx12M -XX:G1MixedGCLiveThresholdPercent=100 -XX:G1HeapWastePercent=0
156 * -XX:G1HeapRegionSize=1m
157 */
158 public class MixedGCProvoker {
159 private final WhiteBox WB = WhiteBox.getWhiteBox();
160 private final List<byte[]> liveOldObjects = new ArrayList<>();
161 private final List<byte[]> newObjects = new ArrayList<>();
162
163 public static final int ALLOCATION_SIZE = 20000;
164 public static final int ALLOCATION_COUNT = 15;
165
166 public void allocateOldObjects() {
167 List<byte[]> deadOldObjects = new ArrayList<>();
168 // Allocates buffer and promotes it to the old gen. Mix live and dead old
169 // objects
170 for (int i = 0; i < ALLOCATION_COUNT; ++i) {
171 liveOldObjects.add(new byte[ALLOCATION_SIZE * 5]);
172 deadOldObjects.add(new byte[ALLOCATION_SIZE * 5]);
173 }
174
175 // Do two young collections, MaxTenuringThreshold=1 will force promotion.
176 // G1HeapRegionSize=1m guarantees that old gen regions will be filled.
177 WB.youngGC();
178 WB.youngGC();
179 // Check it is promoted & keep alive
180 Asserts.assertTrue(WB.isObjectInOldGen(liveOldObjects),
181 "List of the objects is suppose to be in OldGen");
182 Asserts.assertTrue(WB.isObjectInOldGen(deadOldObjects),
183 "List of the objects is suppose to be in OldGen");
184 }
185
186 /**
187 * Waits until Concurent Mark Cycle finishes
188 * @param wb Whitebox instance
189 * @param sleepTime sleep time
190 */
191 private void waitTillCMCFinished(int sleepTime) {
192 while (WB.g1InConcurrentMark()) {
193 if (sleepTime > -1) {
194 try {
195 Thread.sleep(sleepTime);
196 } catch (InterruptedException e) {
197 System.out.println("Got InterruptedException while waiting for ConcMarkCycle to finish");
198 }
199 }
200 }
201 }
202
203 public void provokeMixedGC() {
204 waitTillCMCFinished(0);
205 WB.g1StartConcMarkCycle();
206 waitTillCMCFinished(0);
207 WB.youngGC();
208
209 System.out.println("Allocating new objects to provoke mixed GC");
210 // Provoke a mixed collection. G1MixedGCLiveThresholdPercent=100
211 // guarantees that full old gen regions will be included.
212 for (int i = 0; i < (ALLOCATION_COUNT * 20); i++) {
213 try {
214 newObjects.add(new byte[ALLOCATION_SIZE]);
215 } catch (OutOfMemoryError e) {
216 newObjects.clear();
217 WB.youngGC();
218 WB.youngGC();
219 System.out.println("OutOfMemoryError is reported, stop allocating new objects");
220 break;
221 }
222 }
223 // check that liveOldObjects still alive
224 Asserts.assertTrue(WB.isObjectInOldGen(liveOldObjects),
225 "List of the objects is suppose to be in OldGen");
226 }
227
228 }
229
230 }