1 /* 2 * Copyright (c) 2003, 2016, 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 26 * @bug 4530538 6980984 27 * @summary Basic unit test of memory management testing: 28 * 1) setUsageThreshold() and getUsageThreshold() 29 * 2) test low memory detection on the old generation. 30 * @author Mandy Chung 31 * 32 * @modules jdk.management 33 * 34 * @build MemoryManagement MemoryUtil 35 * @run main/othervm/timeout=600 -Xmn8m -XX:+IgnoreUnrecognizedVMOptions -XX:G1HeapRegionSize=1 -XX:-UseLargePages MemoryManagement 36 */ 37 38 import java.lang.management.*; 39 import java.util.*; 40 import javax.management.*; 41 import javax.management.openmbean.CompositeData; 42 43 public class MemoryManagement { 44 private static final MemoryMXBean mm = ManagementFactory.getMemoryMXBean(); 45 private static final List pools = 46 Collections.synchronizedList(ManagementFactory.getMemoryPoolMXBeans()); 47 private static final List managers = 48 Collections.synchronizedList(ManagementFactory.getMemoryManagerMXBeans()); 49 private static volatile MemoryPoolMXBean mpool = null; 50 private static volatile boolean trace = false; 51 private static volatile boolean testFailed = false; 52 private static final int NUM_CHUNKS = 2; 53 // Must match -Xmn set on the @run line 54 private static final int YOUNG_GEN_SIZE = 8 * 1024 * 1024; 55 private static volatile long chunkSize; 56 private static volatile int listenerInvoked = 0; 57 58 static class SensorListener implements NotificationListener { 59 public void handleNotification(Notification notif, Object handback) { 60 String type = notif.getType(); 61 if (type.equals(MemoryNotificationInfo.MEMORY_THRESHOLD_EXCEEDED) || 62 type.equals(MemoryNotificationInfo. 63 MEMORY_COLLECTION_THRESHOLD_EXCEEDED)) { 64 65 MemoryNotificationInfo minfo = MemoryNotificationInfo. 66 from((CompositeData) notif.getUserData()); 67 68 MemoryUtil.printMemoryNotificationInfo(minfo, type); 69 listenerInvoked++; 70 } 71 } 72 } 73 74 private static long newThreshold; 75 public static void main(String args[]) throws Exception { 76 if (args.length > 0 && args[0].equals("trace")) { 77 trace = true; 78 } 79 80 if (trace) { 81 MemoryUtil.printMemoryPools(pools); 82 MemoryUtil.printMemoryManagers(managers); 83 } 84 85 // Find the Old generation which supports low memory detection 86 ListIterator iter = pools.listIterator(); 87 while (iter.hasNext()) { 88 MemoryPoolMXBean p = (MemoryPoolMXBean) iter.next(); 89 if (p.getType() == MemoryType.HEAP && 90 p.isUsageThresholdSupported()) { 91 mpool = p; 92 if (trace) { 93 System.out.println("Selected memory pool for low memory " + 94 "detection."); 95 MemoryUtil.printMemoryPool(mpool); 96 } 97 break; 98 } 99 } 100 101 SensorListener listener = new SensorListener(); 102 NotificationEmitter emitter = (NotificationEmitter) mm; 103 emitter.addNotificationListener(listener, null, null); 104 105 Thread allocator = new AllocatorThread(); 106 107 // The chunk size needs to be larger than YOUNG_GEN_SIZE, 108 // otherwise we will get intermittent failures when objects 109 // end up in the young gen instead of the old gen. 110 final long epsilon = 1024; 111 chunkSize = YOUNG_GEN_SIZE + epsilon; 112 113 // Now set threshold 114 MemoryUsage mu = mpool.getUsage(); 115 newThreshold = mu.getUsed() + (chunkSize * NUM_CHUNKS); 116 117 // Sanity check. Make sure the new threshold isn't too large. 118 // Tweak the test if this fails. 119 final long headRoom = chunkSize * 2; 120 final long max = mu.getMax(); 121 if (max != -1 && newThreshold > max - headRoom) { 122 throw new RuntimeException("TEST FAILED: newThreshold: " + newThreshold + 123 " is too near the maximum old gen size: " + max + 124 " used: " + mu.getUsed() + " headRoom: " + headRoom); 125 } 126 127 System.out.println("Setting threshold for " + mpool.getName() + 128 " from " + mpool.getUsageThreshold() + " to " + newThreshold + 129 ". Current used = " + mu.getUsed()); 130 mpool.setUsageThreshold(newThreshold); 131 132 if (mpool.getUsageThreshold() != newThreshold) { 133 throw new RuntimeException("TEST FAILED: " + 134 "Threshold for Memory pool " + mpool.getName() + 135 "is " + mpool.getUsageThreshold() + " but expected to be" + 136 newThreshold); 137 } 138 139 // Start the AllocatorThread to continously allocate memory 140 System.out.println("Starting an AllocatorThread to allocate memory."); 141 allocator.start(); 142 143 try { 144 allocator.join(); 145 } catch (InterruptedException e) { 146 e.printStackTrace(); 147 System.out.println("Unexpected exception."); 148 testFailed = true; 149 } 150 151 if (listenerInvoked == 0) { 152 throw new RuntimeException("No listener is invoked"); 153 } 154 155 if (testFailed) 156 throw new RuntimeException("TEST FAILED."); 157 158 System.out.println("Test passed."); 159 160 } 161 162 static class AllocatorThread extends Thread { 163 private List objectPool = new ArrayList(); 164 public void run() { 165 int iterations = 0; 166 int numElements = (int) (chunkSize / 4); // minimal object size 167 while (listenerInvoked == 0) { 168 iterations++; 169 if (trace) { 170 System.out.println(" Iteration " + iterations + 171 ": before allocation " + 172 mpool.getUsage().getUsed()); 173 } 174 175 Object[] o = new Object[numElements]; 176 if (iterations <= NUM_CHUNKS) { 177 // only hold a reference to the first NUM_CHUNKS 178 // allocated objects 179 objectPool.add(o); 180 } 181 182 if (trace) { 183 System.out.println(" " + 184 " after allocation " + 185 mpool.getUsage().getUsed()); 186 } 187 try { 188 Thread.sleep(100); 189 } catch (InterruptedException e) { 190 e.printStackTrace(); 191 System.out.println("Unexpected exception."); 192 testFailed = true; 193 } 194 } 195 196 System.out.println("AllocatedThread finished memory allocation " + 197 " num_iteration = " + iterations); 198 } 199 } 200 201 }