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
25 package gc.g1.humongousObjects;
26
27 import jdk.test.lib.Utils;
28 import sun.hotspot.WhiteBox;
29
30 import java.util.LinkedList;
31 import java.util.List;
32 import java.util.Random;
33 import java.util.stream.Collectors;
34
35 /**
36 * @test TestNoAllocationsInHRegions
37 * @summary Checks that no additional allocations are made in humongous regions
38 * @requires vm.gc.G1
39 * @library /test/lib /
40 * @modules java.management java.base/jdk.internal.misc
41 * @build sun.hotspot.WhiteBox
42 * @run driver ClassFileInstaller sun.hotspot.WhiteBox
43 * sun.hotspot.WhiteBox$WhiteBoxPermission
44 *
45 * @run main/othervm -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:.
46 * -XX:G1HeapRegionSize=1M -Xms200m -Xmx200m -XX:MaxTenuringThreshold=0
47 * -Xlog:gc=trace:file=TestNoAllocationsInHRegions10.log
48 * gc.g1.humongousObjects.TestNoAllocationsInHRegions 30 10
49 *
50 * @run main/othervm -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:.
51 * -XX:G1HeapRegionSize=1M -Xms200m -Xmx200m -XX:MaxTenuringThreshold=0
52 * -Xlog:gc=trace:file=TestNoAllocationsInHRegions50.log
53 * gc.g1.humongousObjects.TestNoAllocationsInHRegions 30 50
54 *
55 * @run main/othervm -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:.
56 * -XX:G1HeapRegionSize=1M -Xms200m -Xmx200m -XX:MaxTenuringThreshold=0
57 * -Xlog:gc=trace:file=TestNoAllocationsInHRegions70.log
58 * gc.g1.humongousObjects.TestNoAllocationsInHRegions 30 70
59 */
60 public class TestNoAllocationsInHRegions {
61 private static final WhiteBox WB = WhiteBox.getWhiteBox();
62 private static final Random RND = Utils.getRandomInstance();
63 private static final int G1_REGION_SIZE = WB.g1RegionSize();
64 private static final int[] HUMONGOUS_SIZES = {G1_REGION_SIZE / 2, G1_REGION_SIZE + 1, G1_REGION_SIZE * 2 + 1};
65 private static final int ALLOC_THREAD_COUNT = 5;
66
67 // We fill specified part of heap with humongous objects - we need public static to prevent escape analysis to
68 // collect this field
69 public static LinkedList<byte[]> humongousAllocations = new LinkedList<>();
70
71 private static volatile boolean shouldStop = false;
72 private static volatile Error error = null;
73
74 static class Allocator implements Runnable {
75
76 private final List<byte[]> liveObjects = new LinkedList<>();
77 private int usedMemory = 0;
78 public final Runnable[] actions;
79
80 /**
81 * Maximum size of simple allocation
82 */
83 private static final int MAX_ALLOCATION_SIZE = (int) (G1_REGION_SIZE / 2 * 0.9);
84
85 /**
86 * Maximum size of dead (i.e. one which is made unreachable right after allocation) object
87 */
88 private static final int DEAD_OBJECT_MAX_SIZE = G1_REGION_SIZE / 10;
89
90 public Allocator(int maxAllocationMemory) {
91
92 actions = new Runnable[]{
93 // Allocation
94 () -> {
95 if (maxAllocationMemory - usedMemory != 0) {
96 int arraySize = RND.nextInt(Math.min(maxAllocationMemory - usedMemory,
97 MAX_ALLOCATION_SIZE));
98
99 if (arraySize != 0) {
100 byte[] allocation = new byte[arraySize];
101 liveObjects.add(allocation);
102 usedMemory += arraySize;
103
104 // Sanity check
105 if (WB.g1IsHumongous(allocation)) {
106 String errorMessage = String.format("Test Bug: Byte array of size"
107 + " %d is expected to be non-humongous but it is humongous",
108 allocation.length);
109
110 System.out.println(errorMessage);
111 error = new Error(errorMessage);
112 shouldStop = true;
113 }
114
115 // Test check
116 if (WB.g1BelongsToHumongousRegion(WB.getObjectAddress(allocation))) {
117 String errorMessage = String.format("Non-humongous allocation of byte array of "
118 + "length %d and size %d with address %d was made in Humongous Region",
119 allocation.length, WB.getObjectSize(allocation),
120 WB.getObjectAddress(allocation));
121
122 System.out.println(errorMessage);
123 error = new Error(errorMessage);
124 shouldStop = true;
125 }
126 }
127 }
128 },
129
130 // Deallocation
131 () -> {
132 if (liveObjects.size() != 0) {
133 int elementNum = RND.nextInt(liveObjects.size());
134 int shouldFree = liveObjects.get(elementNum).length;
135 liveObjects.remove(elementNum);
136 usedMemory -= shouldFree;
137 }
138 },
139
140 // Dead object allocation
141 () -> {
142 int size = RND.nextInt(DEAD_OBJECT_MAX_SIZE);
143 byte[] deadObject = new byte[size];
144 },
145
146 // Check
147 () -> {
148 List<byte[]> wrongHumongousAllocations = liveObjects.stream()
149 .filter(WB::g1IsHumongous)
150 .collect(Collectors.toList());
151
152 if (wrongHumongousAllocations.size() > 0) {
153 wrongHumongousAllocations.stream().forEach(a ->
154 System.out.format("Non-humongous allocation of byte array of length %d and"
155 + " size %d with address %d was made in Humongous Region",
156 a.length, WB.getObjectSize(a), WB.getObjectAddress(a)));
157 error = new Error("Some non-humongous allocations were made to humongous region");
158 shouldStop = true;
159 }
160 }
161 };
162 }
163
164 @Override
165 public void run() {
166 while (!shouldStop) {
167 actions[RND.nextInt(actions.length)].run();
168 Thread.yield();
169 }
170 }
171 }
172
173 public static void main(String[] args) {
174 if (args.length != 2) {
175 throw new Error("Test Bug: Expected duration (in seconds) and percent of allocated regions were not "
176 + "provided as command line argument");
177 }
178
179 // test duration
180 long duration = Integer.parseInt(args[0]) * 1000L;
181 // part of heap preallocated with humongous objects (in percents)
182 int percentOfAllocatedHeap = Integer.parseInt(args[1]);
183
184 long startTime = System.currentTimeMillis();
185
186 long initialFreeRegionsCount = WB.g1NumFreeRegions();
187 int regionsToAllocate = (int) ((double) initialFreeRegionsCount / 100.0 * percentOfAllocatedHeap);
188 long freeRegionLeft = initialFreeRegionsCount - regionsToAllocate;
189
190 System.out.println("Regions to allocate: " + regionsToAllocate + "; regions to left free: " + freeRegionLeft);
191
192 int maxMemoryPerAllocThread = (int) ((Runtime.getRuntime().freeMemory() / 100.0
193 * (100 - percentOfAllocatedHeap)) / ALLOC_THREAD_COUNT * 0.5);
194
195 System.out.println("Using " + maxMemoryPerAllocThread / 1024 + "KB for each of " + ALLOC_THREAD_COUNT
196 + " allocation threads");
197
198 while (WB.g1NumFreeRegions() > freeRegionLeft) {
199 try {
200 humongousAllocations.add(new byte[HUMONGOUS_SIZES[RND.nextInt(HUMONGOUS_SIZES.length)]]);
201 } catch (OutOfMemoryError oom) {
202 //We got OOM trying to fill heap with humongous objects
203 //It probably means that heap is fragmented which is strange since the test logic should avoid it
204 System.out.println("Warning: OOM while allocating humongous objects - it likely means "
205 + "that heap is fragmented");
206 break;
207 }
208 }
209
210 System.out.println("Initial free regions " + initialFreeRegionsCount + "; Free regions left "
211 + WB.g1NumFreeRegions());
212
213 LinkedList<Thread> threads = new LinkedList<>();
214
215 for (int i = 0; i < ALLOC_THREAD_COUNT; i++) {
216 threads.add(new Thread(new Allocator(maxMemoryPerAllocThread)));
217 }
218
219 threads.stream().forEach(Thread::start);
220
221 while ((System.currentTimeMillis() - startTime < duration) && error == null) {
222 Thread.yield();
223 }
224
225 shouldStop = true;
226 System.out.println("Finished test");
227 if (error != null) {
228 throw error;
229 }
230 }
231 }