1 /*
2 * Copyright (c) 2015, 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 TestTargetSurvivorRatioFlag
26 * @key gc
27 * @summary Verify that option TargetSurvivorRatio affects survivor space occupancy after minor GC.
28 * @library /testlibrary /test/lib
29 * @modules java.base/sun.misc
30 * java.management
31 * @build TestTargetSurvivorRatioFlag
32 * @run main ClassFileInstaller sun.hotspot.WhiteBox
33 * @run driver TestTargetSurvivorRatioFlag
34 */
35
36 import jdk.test.lib.AllocationHelper;
37 import java.lang.management.GarbageCollectorMXBean;
38 import java.util.Arrays;
39 import java.util.Collections;
40 import java.util.LinkedList;
41 import java.util.List;
42 import java.util.regex.Matcher;
43 import java.util.regex.Pattern;
44 import jdk.test.lib.HeapRegionUsageTool;
45 import sun.misc.Unsafe;
46 import jdk.test.lib.OutputAnalyzer;
47 import jdk.test.lib.ProcessTools;
48 import jdk.test.lib.Utils;
49 import sun.hotspot.WhiteBox;
50
51 /* In order to test that TargetSurvivorRatio affects survivor space occupancy
52 * we setup fixed MaxTenuringThreshold and then verifying that if size of allocated
53 * objects is lower than (survivor_size * TargetSurvivorRatio / 100) then objects
54 * will stay in survivor space until MaxTenuringThreshold minor GC cycles.
55 * If more than (survivor_size * TargetSurvivorRatio / 100) objects were allocated,
56 * then we verify that after MaxTenuringThreshold minor GC cycles survivor space
57 * is almost empty.
58 */
59 public class TestTargetSurvivorRatioFlag {
60
61 public static final long M = 1024 * 1024;
62
63 // VM option values
64 public static final long MAX_NEW_SIZE = 40 * M;
65 public static final int SURVIVOR_RATIO = 8;
66 public static final int MAX_TENURING_THRESHOLD = 15;
67
68 // Value used to estimate amount of memory that should be allocated
69 // and placed in survivor space.
70 public static final double DELTA = 0.25;
71
72 // Max variance of observed ratio
73 public static double VARIANCE = 1;
74
75 // Messages used by debuggee
76 public static final String UNSUPPORTED_GC = "Unsupported GC";
77 public static final String START_TEST = "Start test";
78 public static final String END_TEST = "End test";
79
80 // Patterns used during log parsing
81 public static final String TENURING_DISTRIBUTION = "Desired survivor size";
82 public static final String AGE_TABLE_ENTRY = ".*-[\\s]+age[\\s]+([0-9]+):[\\s]+([0-9]+)[\\s]+bytes,[\\s]+([0-9]+)[\\s]+total";
83 public static final String MAX_SURVIVOR_SIZE = "Max survivor size: ([0-9]+)";
84
85 public static void main(String args[]) throws Exception {
86
87 LinkedList<String> options = new LinkedList<>(Arrays.asList(Utils.getTestJavaOpts()));
88
89 // Need to consider the effect of TargetPLABWastePct=1 for G1 GC
90 if (options.contains("-XX:+UseG1GC")) {
91 VARIANCE = 2;
92 } else {
93 VARIANCE = 1;
94 }
95
96 negativeTest(-1, options);
97 negativeTest(101, options);
98
99 positiveTest(20, options);
100 positiveTest(30, options);
101 positiveTest(55, options);
102 positiveTest(70, options);
103 }
104
105 /**
106 * Verify that VM will fail to start with specified TargetSurvivorRatio
107 *
108 * @param ratio value of TargetSurvivorRatio
109 * @param options additional VM options
110 */
111 public static void negativeTest(int ratio, LinkedList<String> options) throws Exception {
112 LinkedList<String> vmOptions = new LinkedList<>(options);
113 vmOptions.add("-XX:TargetSurvivorRatio=" + ratio);
114 vmOptions.add("-version");
115
116 ProcessBuilder procBuilder = ProcessTools.createJavaProcessBuilder(vmOptions.toArray(new String[vmOptions.size()]));
117 OutputAnalyzer analyzer = new OutputAnalyzer(procBuilder.start());
118
119 analyzer.shouldHaveExitValue(1);
120 analyzer.shouldContain("Error: Could not create the Java Virtual Machine.");
121 }
122
123 /**
124 * Verify that actual survivor space usage ratio conforms specified TargetSurvivorRatio
125 *
126 * @param ratio value of TargetSurvivorRatio
127 * @param options additional VM options
128 */
129 public static void positiveTest(int ratio, LinkedList<String> options) throws Exception {
130 LinkedList<String> vmOptions = new LinkedList<>(options);
131 Collections.addAll(vmOptions,
132 "-Xbootclasspath/a:.",
133 "-XX:+UnlockDiagnosticVMOptions",
134 "-XX:+WhiteBoxAPI",
135 "-XX:+UseAdaptiveSizePolicy",
136 "-Xlog:gc+age=trace",
137 "-XX:MaxTenuringThreshold=" + MAX_TENURING_THRESHOLD,
138 "-XX:NewSize=" + MAX_NEW_SIZE,
139 "-XX:MaxNewSize=" + MAX_NEW_SIZE,
140 "-XX:InitialHeapSize=" + 2 * MAX_NEW_SIZE,
141 "-XX:MaxHeapSize=" + 2 * MAX_NEW_SIZE,
142 "-XX:SurvivorRatio=" + SURVIVOR_RATIO,
143 "-XX:TargetSurvivorRatio=" + ratio,
144 // For reducing variance of survivor size.
145 "-XX:TargetPLABWastePct=" + 1,
146 TargetSurvivorRatioVerifier.class.getName(),
147 Integer.toString(ratio)
148 );
149
150 ProcessBuilder procBuilder = ProcessTools.createJavaProcessBuilder(vmOptions.toArray(new String[vmOptions.size()]));
151 OutputAnalyzer analyzer = new OutputAnalyzer(procBuilder.start());
152
153 analyzer.shouldHaveExitValue(0);
154
155 String output = analyzer.getOutput();
156
157 // Test avoids verification for parallel GC
158 if (!output.contains(UNSUPPORTED_GC)) {
159 // Two tests should be done - when actual ratio is lower than TargetSurvivorRatio
160 // and when it is higher. We chech that output contains results for exactly two tests.
161 List<Double> ratios = parseTestOutput(output);
162
163 if (ratios.size() != 2) {
164 System.out.println(output);
165 throw new RuntimeException("Expected number of ratios extraced for output is 2,"
166 + " but " + ratios.size() + " ratios were extracted");
167 }
168
169 // At the end of the first test survivor space usage ratio should lies between
170 // TargetSurvivorRatio and TargetSurvivorRatio - 2*DELTA
171 if (ratio < ratios.get(0) || ratio - ratios.get(0) > VARIANCE) {
172 System.out.println(output);
173 throw new RuntimeException("Survivor space usage ratio expected to be close to "
174 + ratio + ", but observed ratio is: " + ratios.get(0));
175 }
176
177 // After second test survivor space should be almost empty.
178 if (ratios.get(1) > VARIANCE) {
179 System.out.println(output);
180 throw new RuntimeException("Survivor space expected to be empty due to "
181 + "TargetSurvivorRatio overlimit, however observed "
182 + "survivor space usage ratio is: " + ratios.get(1));
183 }
184 } else {
185 System.out.println("Selected GC does not support TargetSurvivorRatio option.");
186 }
187 }
188
189 /**
190 * Parse output produced by TargetSurvivorRatioVerifier.
191 *
192 * @param output output obtained from TargetSurvivorRatioVerifier
193 * @return list of parsed test results, where each result is an actual
194 * survivor ratio after MaxTenuringThreshold minor GC cycles.
195 */
196 public static List<Double> parseTestOutput(String output) {
197 List<Double> ratios = new LinkedList<Double>();
198 String lines[] = output.split("[\n\r]");
199 boolean testStarted = false;
200 long survivorSize = 0;
201 long survivorOccupancy = 0;
202 int gcCount = 0;
203 Pattern ageTableEntry = Pattern.compile(AGE_TABLE_ENTRY);
204 Pattern maxSurvivorSize = Pattern.compile(MAX_SURVIVOR_SIZE);
205 for (String line : lines) {
206 if (Pattern.matches(MAX_SURVIVOR_SIZE, line)) {
207 // We found estimated survivor space size
208 Matcher m = maxSurvivorSize.matcher(line);
209 m.find();
210 survivorSize = Long.valueOf(m.group(1));
211 } else if (line.contains(START_TEST) && !testStarted) {
212 // Start collecting test results
213 testStarted = true;
214 gcCount = 0;
215 } else if (testStarted) {
216 if (line.contains(TENURING_DISTRIBUTION)) {
217 // We found start of output emitted by -XX:+PrintTenuringDistribution
218 // If it is associated with "MaxTenuringThreshold" GC cycle, then it's
219 // time to report observed survivor usage ratio
220 gcCount++;
221 double survivorRatio = survivorOccupancy / (double) survivorSize;
222 if (gcCount == MAX_TENURING_THRESHOLD || gcCount == MAX_TENURING_THRESHOLD * 2) {
223 ratios.add(survivorRatio * 100.0);
224 testStarted = false;
225 }
226 survivorOccupancy = 0;
227 } else if (Pattern.matches(AGE_TABLE_ENTRY, line)) {
228 // Obtain survivor space usage from "total" age table log entry
229 Matcher m = ageTableEntry.matcher(line);
230 m.find();
231 survivorOccupancy = Long.valueOf(m.group(3));
232 } else if (line.contains(END_TEST)) {
233 // It is expected to find at least MaxTenuringThreshold GC events
234 // until test end
235 if (gcCount < MAX_TENURING_THRESHOLD) {
236 throw new RuntimeException("Observed " + gcCount + " GC events, "
237 + "while it is expected to see at least "
238 + MAX_TENURING_THRESHOLD);
239 }
240 testStarted = false;
241 }
242 }
243 }
244 return ratios;
245 }
246
247 public static class TargetSurvivorRatioVerifier {
248
249 static final WhiteBox wb = WhiteBox.getWhiteBox();
250 static final Unsafe unsafe = Utils.getUnsafe();
251
252 // Desired size of memory allocated at once
253 public static final int CHUNK_SIZE = 1024;
254 // Length of byte[] array that will have occupy CHUNK_SIZE bytes in heap
255 public static final int ARRAY_LENGTH = CHUNK_SIZE - Unsafe.ARRAY_BYTE_BASE_OFFSET;
256
257 public static void main(String args[]) throws Exception {
258 if (args.length != 1) {
259 throw new IllegalArgumentException("Expected 1 arg: <ratio>");
260 }
261 if (GCTypes.YoungGCType.getYoungGCType() == GCTypes.YoungGCType.PSNew) {
262 System.out.println(UNSUPPORTED_GC);
263 return;
264 }
265
266 int ratio = Integer.valueOf(args[0]);
267 long maxSurvivorSize = getMaxSurvivorSize();
268 System.out.println("Max survivor size: " + maxSurvivorSize);
269
270 allocateMemory(ratio - DELTA, maxSurvivorSize);
271 allocateMemory(ratio + DELTA, maxSurvivorSize);
272 }
273
274 /**
275 * Allocate (<b>ratio</b> * <b>maxSize</b> / 100) bytes of objects
276 * and force at least "MaxTenuringThreshold" minor GCs.
277 *
278 * @param ratio ratio used to calculate how many objects should be allocated
279 * @param maxSize estimated max survivor space size
280 */
281 public static void allocateMemory(double ratio, long maxSize) throws Exception {
282 GarbageCollectorMXBean youngGCBean = GCTypes.YoungGCType.getYoungGCBean();
283 long garbageSize = (long) (maxSize * (ratio / 100.0));
284 int arrayLength = (int) (garbageSize / CHUNK_SIZE);
285 AllocationHelper allocator = new AllocationHelper(1, arrayLength, ARRAY_LENGTH, null);
286
287 System.out.println(START_TEST);
288 System.gc();
289 final long initialGcId = youngGCBean.getCollectionCount();
290 // allocate memory
291 allocator.allocateMemoryAndVerify();
292
293 // force minor GC
294 while (youngGCBean.getCollectionCount() <= initialGcId + MAX_TENURING_THRESHOLD * 2) {
295 byte b[] = new byte[ARRAY_LENGTH];
296 }
297
298 allocator.release();
299 System.out.println(END_TEST);
300 }
301
302 /**
303 * Estimate max survivor space size.
304 *
305 * For non-G1 GC returns value reported by MemoryPoolMXBean
306 * associated with survivor space.
307 * For G1 GC return max number of survivor regions * region size.
308 * Number if survivor regions estimated from MaxNewSize and SurvivorRatio.
309 */
310 public static long getMaxSurvivorSize() {
311 if (GCTypes.YoungGCType.getYoungGCType() == GCTypes.YoungGCType.G1) {
312 int youngLength = (int) Math.max(MAX_NEW_SIZE / wb.g1RegionSize(), 1);
313 return (long) Math.ceil(youngLength / (double) SURVIVOR_RATIO) * wb.g1RegionSize();
314 } else {
315 return HeapRegionUsageTool.getSurvivorUsage().getMax();
316 }
317 }
318 }
319 }