1 /* 2 * Copyright (c) 2013, 2019, 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. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package jdk.jfr.event.runtime; 27 28 import static jdk.testlibrary.Asserts.assertGreaterThan; 29 import static jdk.testlibrary.Asserts.assertTrue; 30 31 import java.lang.management.ManagementFactory; 32 import java.time.Duration; 33 import java.util.Collections; 34 import java.util.List; 35 import java.util.Random; 36 import java.util.concurrent.CountDownLatch; 37 38 import com.sun.management.ThreadMXBean; 39 40 import jdk.jfr.Recording; 41 import jdk.jfr.consumer.RecordedEvent; 42 import jdk.jfr.consumer.RecordedThread; 43 import jdk.testlibrary.jfr.EventNames; 44 import jdk.testlibrary.jfr.Events; 45 46 /* 47 * @test 48 * @key jfr 49 * @library /lib/testlibrary 50 * @modules jdk.jfr 51 * jdk.management 52 * 53 * @run main/othervm -XX:-UseTLAB jdk.jfr.event.runtime.TestThreadAllocationEvent 54 */ 55 56 /** 57 * The test will create a few threads that will allocate memory for a short time. 58 * During this time a number of thread_allocation events will be generated. 59 * The test will verify: 60 * 1. That number of allocated bytes is not decreasing for a thread. 61 * - This assumption is only true when not using TLABs. For this reason the 62 * test is run with -XX:-UseTLAB. When using TLABs, the code calculating the 63 * allocated bytes is using the current TLAB to do as good of an approximation 64 * as possible, but this introduces a race which might double count the current 65 * TLAB when it is full and in the middle of being switched out. 66 * 2. That sum of allocated bytes approximately matches value in ThreadMXBean. 67 */ 68 public class TestThreadAllocationEvent { 69 private static final String EVENT_NAME = EventNames.ThreadAllocationStatistics; 70 private static final String testThreadName = "testThread-"; 71 private static final long eventPeriodMillis = 50; 72 73 // The value in both the JFR event and in the ThreadMXBean is documented as 74 // an "approximation" of number of bytes allocated. 75 // To not give any false errors, we allow an error margin of 5 mb. 76 // The test will typically allocate over 600 mb, so 5 mb is an error of less than 1%. 77 private static final long allowedTotalAllocatedDiff = 5000000; 78 79 public static void main(String[] args) throws Throwable { 80 Recording recording = new Recording(); 81 recording.enable(EVENT_NAME).withPeriod(Duration.ofMillis(eventPeriodMillis)); 82 recording.start(); 83 84 AllocatorThread[] threads = new AllocatorThread[4]; 85 CountDownLatch allocationsDoneLatch = new CountDownLatch(threads.length); 86 for (int i = 0; i < threads.length; i++) { 87 threads[i] = new AllocatorThread(allocationsDoneLatch, 1000 * (i + 1)); 88 threads[i].setName(testThreadName + i); 89 threads[i].setDaemon(true); 90 threads[i].start(); 91 } 92 93 // Take regular measurements while the threads are allocating memory. 94 // Stop measurement when all threads are ready. 95 try { 96 allocationsDoneLatch.await(); 97 } catch (InterruptedException e) { 98 e.printStackTrace(); 99 } 100 // Verify that number of allocated bytes is not decreasing. 101 recording.stop(); 102 verifyAllocationsNotDecreasing(Events.fromRecording(recording), threads); 103 104 // Now allocations are done and threads are waiting to die. 105 // Make a new instant recording to get total number of allocated bytes. 106 // The reason for this extra recording is to make sure we get a JFR event 107 // after all allocations are done so we can compare the JFR value with 108 // the value reported by ThreadMXBean. 109 recording = new Recording(); 110 recording.enable(EVENT_NAME); 111 recording.start(); 112 recording.stop(); 113 verifyTotalAllocated(Events.fromRecording(recording), threads); 114 } 115 116 /** 117 * Verify that the allocated value never decreases. 118 * We only compare our own allocator threads. The reason for that is that other threads 119 * may start/stop at any time, and we do not know if other thread names are unique. 120 */ 121 private static void verifyAllocationsNotDecreasing(List<RecordedEvent> events, AllocatorThread[] threads) { 122 Collections.sort(events, (u,v) -> u.getEndTime().compareTo(v.getEndTime())); 123 long[] prevAllocated = new long[threads.length]; 124 for (RecordedEvent event : events) { 125 RecordedThread rt = Events.assertField(event, "thread").notNull().getValue(); // Check that we have a thread. 126 String name = rt.getJavaName(); 127 for (int i = 0; i < threads.length; i++) { 128 if (name.equals(threads[i].getName())) { 129 long curr = Events.assertField(event, "allocated").atLeast(prevAllocated[i]).getValue(); 130 prevAllocated[i] = curr; 131 } 132 } 133 } 134 135 for (int i = 0; i < threads.length; i++) { 136 assertGreaterThan(prevAllocated[i], 0L, "No allocations for thread " + threads[i].getName()); 137 } 138 } 139 140 /** 141 * Verify that total allocated bytes in JFR event approximately matches the value in ThreadMXBean. 142 */ 143 private static void verifyTotalAllocated(List<RecordedEvent> events, AllocatorThread[] threads) { 144 boolean[] isEventFound = new boolean[threads.length]; 145 for (RecordedEvent event : events) { 146 RecordedThread rt = Events.assertField(event, "thread").notNull().getValue(); 147 String name = rt.getJavaName(); 148 for (int i = 0; i < threads.length; ++i) { 149 if (name.equals(threads[i].getName())) { 150 System.out.println("Event:" + event); 151 long maxAllowed = threads[i].totalAllocated + allowedTotalAllocatedDiff; 152 long minAllowed = Math.max(0, threads[i].totalAllocated - allowedTotalAllocatedDiff); 153 Events.assertField(event, "allocated").atLeast(minAllowed).atMost(maxAllowed); 154 isEventFound[i] = true; 155 } 156 } 157 } 158 for (int i = 0; i < threads.length; ++i) { 159 assertTrue(isEventFound[i], "No event for thread id " + i); 160 } 161 } 162 163 /** 164 * Thread that does a number of allocations and records total number of 165 * bytes allocated as reported by ThreadMXBean. 166 */ 167 public static class AllocatorThread extends Thread { 168 private volatile long totalAllocated = -1; 169 private final int averageAllocationSize; 170 public byte[] buffer; 171 private final CountDownLatch allocationsDoneLatch; 172 173 public AllocatorThread(CountDownLatch allocationsDoneLatch, int averageAllocationSize) { 174 this.allocationsDoneLatch = allocationsDoneLatch; 175 this.averageAllocationSize = averageAllocationSize; 176 } 177 178 @Override 179 public void run() { 180 Random rand = new Random(); 181 int allocationSizeBase = averageAllocationSize / 2; 182 int allocationSizeRandom = averageAllocationSize; 183 for (int batches=0; batches<100; batches++) { 184 for (int i=0; i<1500; i++) { 185 buffer = new byte[rand.nextInt(allocationSizeRandom) + allocationSizeBase]; 186 } 187 try { 188 // No need to allocate too much data between JFR events, so do a short sleep. 189 Thread.sleep(eventPeriodMillis / 5); 190 } catch (InterruptedException e) { 191 e.printStackTrace(); 192 } 193 } 194 totalAllocated = getThreadAllocatedBytes(); 195 allocationsDoneLatch.countDown(); 196 197 // Need to keep thread alive so we can get the final JFR event. 198 // This is a daemon thread, so it will finish when the main thread finishes. 199 while (true) { 200 Thread.yield(); 201 } 202 } 203 204 private long getThreadAllocatedBytes() { 205 ThreadMXBean bean = (ThreadMXBean) ManagementFactory.getThreadMXBean(); 206 return bean.getThreadAllocatedBytes(Thread.currentThread().getId()); 207 } 208 } 209 210 }