1 /*
2 * Copyright (c) 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 package gc.g1.humongousObjects;
25
26 import jdk.test.lib.Utils;
27 import sun.hotspot.WhiteBox;
28
29 import java.util.LinkedList;
30 import java.util.List;
31 import java.util.Random;
32 import java.util.stream.Collectors;
33
34 /**
35 * @test TestNoAllocationsInHRegions
36 * @summary Checks that no additional allocations are made in humongous regions
37 * @requires vm.gc.G1
38 * @library /test/lib /
39 * @modules java.management java.base/jdk.internal.misc
40 * @build sun.hotspot.WhiteBox
41 * @run driver ClassFileInstaller sun.hotspot.WhiteBox
42 * sun.hotspot.WhiteBox$WhiteBoxPermission
43 *
44 * @run main/othervm -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:.
45 * -XX:G1HeapRegionSize=1M -Xms200m -Xmx200m -XX:MaxTenuringThreshold=0
46 * -Xlog:gc=trace:file=TestNoAllocationsInHRegions10.log
47 * gc.g1.humongousObjects.TestNoAllocationsInHRegions 30 10
48 *
49 * @run main/othervm -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:.
50 * -XX:G1HeapRegionSize=1M -Xms200m -Xmx200m -XX:MaxTenuringThreshold=0
51 * -Xlog:gc=trace:file=TestNoAllocationsInHRegions50.log
52 * gc.g1.humongousObjects.TestNoAllocationsInHRegions 30 50
53 *
54 * @run main/othervm -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:.
55 * -XX:G1HeapRegionSize=1M -Xms200m -Xmx200m -XX:MaxTenuringThreshold=0
56 * -Xlog:gc=trace:file=TestNoAllocationsInHRegions70.log
57 * gc.g1.humongousObjects.TestNoAllocationsInHRegions 30 70
58 */
59 public class TestNoAllocationsInHRegions {
60 private static final WhiteBox WB = WhiteBox.getWhiteBox();
61 private static final Random RND = Utils.getRandomInstance();
62 private static final int G1_REGION_SIZE = WB.g1RegionSize();
63 private static final int[] HUMONGOUS_SIZES = {G1_REGION_SIZE / 2, G1_REGION_SIZE + 1, G1_REGION_SIZE * 2 + 1};
64 private static final int ALLOC_THREAD_COUNT = 5;
65
66 // We fill specified part of heap with humongous objects - we need public static to prevent escape analysis to
67 // collect this field
68 public static LinkedList<byte[]> humongousAllocations = new LinkedList<>();
69
70 private static volatile boolean shouldStop = false;
71 private static volatile Error error = null;
72
73 static class Allocator implements Runnable {
74
75 private final List<byte[]> liveObjects = new LinkedList<>();
76 private int usedMemory = 0;
77 public final Runnable[] actions;
78
79 /**
80 * Maximum size of simple allocation
81 */
82 private static final int MAX_ALLOCATION_SIZE = (int) (G1_REGION_SIZE / 2 * 0.9);
83
84 /**
85 * Maximum size of dead (i.e. one which is made unreachable right after allocation) object
86 */
87 private static final int DEAD_OBJECT_MAX_SIZE = G1_REGION_SIZE / 10;
88
89 public Allocator(int maxAllocationMemory) {
90
91 actions = new Runnable[]{
92 // Allocation
93 () -> {
94 if (maxAllocationMemory - usedMemory != 0) {
95 int arraySize = RND.nextInt(Math.min(maxAllocationMemory - usedMemory,
96 MAX_ALLOCATION_SIZE));
97
98 if (arraySize != 0) {
99 byte[] allocation = new byte[arraySize];
100 liveObjects.add(allocation);
101 usedMemory += arraySize;
102
103 // Sanity check
104 if (WB.g1IsHumongous(allocation)) {
105 String errorMessage = String.format("Test Bug: Byte array of size"
106 + " %d is expected to be non-humongous but it is humongous",
107 allocation.length);
108
109 System.out.println(errorMessage);
110 error = new Error(errorMessage);
111 shouldStop = true;
112 }
113
114 // Test check
115 if (WB.g1BelongsToHumongousRegion(WB.getObjectAddress(allocation))) {
116 String errorMessage = String.format("Non-humongous allocation of byte array of "
117 + "length %d and size %d with address %d was made in Humongous Region",
118 allocation.length, WB.getObjectSize(allocation),
119 WB.getObjectAddress(allocation));
120
121 System.out.println(errorMessage);
122 error = new Error(errorMessage);
123 shouldStop = true;
124 }
125 }
126 }
127 },
128
129 // Deallocation
130 () -> {
131 if (liveObjects.size() != 0) {
132 int elementNum = RND.nextInt(liveObjects.size());
133 int shouldFree = liveObjects.get(elementNum).length;
134 liveObjects.remove(elementNum);
135 usedMemory -= shouldFree;
136 }
137 },
138
139 // Dead object allocation
140 () -> {
141 int size = RND.nextInt(DEAD_OBJECT_MAX_SIZE);
142 byte[] deadObject = new byte[size];
143 },
144
145 // Check
146 () -> {
147 List<byte[]> wrongHumongousAllocations = liveObjects.stream()
148 .filter(WB::g1IsHumongous)
149 .collect(Collectors.toList());
150
151 if (wrongHumongousAllocations.size() > 0) {
152 wrongHumongousAllocations.stream().forEach(a ->
153 System.out.format("Non-humongous allocation of byte array of length %d and"
154 + " size %d with address %d was made in Humongous Region",
155 a.length, WB.getObjectSize(a), WB.getObjectAddress(a)));
156 error = new Error("Some non-humongous allocations were made to humongous region");
157 shouldStop = true;
158 }
159 }
160 };
161 }
162
163 @Override
164 public void run() {
165 while (!shouldStop) {
166 actions[RND.nextInt(actions.length)].run();
167 Thread.yield();
168 }
169 }
170 }
171
172 public static void main(String[] args) {
173 if (args.length != 2) {
174 throw new Error("Test Bug: Expected duration (in seconds) and percent of allocated regions were not "
175 + "provided as command line argument");
176 }
177
178 // test duration
179 long duration = Integer.parseInt(args[0]) * 1000L;
180 // part of heap preallocated with humongous objects (in percents)
181 int percentOfAllocatedHeap = Integer.parseInt(args[1]);
182
183 long startTime = System.currentTimeMillis();
184
185 long initialFreeRegionsCount = WB.g1NumFreeRegions();
186 int regionsToAllocate = (int) ((double) initialFreeRegionsCount / 100.0 * percentOfAllocatedHeap);
187 long freeRegionLeft = initialFreeRegionsCount - regionsToAllocate;
188
189 System.out.println("Regions to allocate: " + regionsToAllocate + "; regions to left free: " + freeRegionLeft);
190
191 int maxMemoryPerAllocThread = (int) ((Runtime.getRuntime().freeMemory() / 100.0
192 * (100 - percentOfAllocatedHeap)) / ALLOC_THREAD_COUNT * 0.5);
193
194 System.out.println("Using " + maxMemoryPerAllocThread / 1024 + "KB for each of " + ALLOC_THREAD_COUNT
195 + " allocation threads");
196
197 while (WB.g1NumFreeRegions() > freeRegionLeft) {
198 try {
199 humongousAllocations.add(new byte[HUMONGOUS_SIZES[RND.nextInt(HUMONGOUS_SIZES.length)]]);
200 } catch (OutOfMemoryError oom) {
201 //We got OOM trying to fill heap with humongous objects
202 //It probably means that heap is fragmented which is strange since the test logic should avoid it
203 System.out.println("Warning: OOM while allocating humongous objects - it likely means "
204 + "that heap is fragmented");
205 break;
206 }
207 }
208
209 System.out.println("Initial free regions " + initialFreeRegionsCount + "; Free regions left "
210 + WB.g1NumFreeRegions());
211
212 LinkedList<Thread> threads = new LinkedList<>();
213
214 for (int i = 0; i < ALLOC_THREAD_COUNT; i++) {
215 threads.add(new Thread(new Allocator(maxMemoryPerAllocThread)));
216 }
217
218 threads.stream().forEach(Thread::start);
219
220 while ((System.currentTimeMillis() - startTime < duration) && error == null) {
221 Thread.yield();
222 }
223
224 shouldStop = true;
225 System.out.println("Finished test");
226 if (error != null) {
227 throw error;
228 }
229 }
230 }