1 /*
2 * Copyright (c) 2015, 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 TestTargetSurvivorRatioFlag
26 * @key gc
27 * @summary Verify that option TargetSurvivorRatio affects survivor space occupancy after minor GC.
28 * @requires (vm.opt.ExplicitGCInvokesConcurrent == null) | (vm.opt.ExplicitGCInvokesConcurrent == false)
29 * @requires (vm.opt.UseJVMCICompiler == null) | (vm.opt.UseJVMCICompiler == false)
30 * @library /test/lib
31 * @modules java.base/jdk.internal.misc
32 * java.management
33 * @build sun.hotspot.WhiteBox
34 * @run driver ClassFileInstaller sun.hotspot.WhiteBox
35 * @run driver TestTargetSurvivorRatioFlag
36 */
37
38 import java.lang.management.GarbageCollectorMXBean;
39 import java.util.Arrays;
40 import java.util.Collections;
41 import java.util.LinkedList;
42 import java.util.List;
43 import java.util.regex.Matcher;
44 import java.util.regex.Pattern;
45 import jdk.internal.misc.Unsafe;
46 import jdk.test.lib.process.OutputAnalyzer;
47 import jdk.test.lib.process.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 "--add-exports=java.base/jdk.internal.misc=ALL-UNNAMED",
134 "-XX:+UnlockDiagnosticVMOptions",
135 "-XX:+WhiteBoxAPI",
136 "-XX:+UseAdaptiveSizePolicy",
137 "-Xlog:gc+age=trace",
138 "-XX:MaxTenuringThreshold=" + MAX_TENURING_THRESHOLD,
139 "-XX:NewSize=" + MAX_NEW_SIZE,
140 "-XX:MaxNewSize=" + MAX_NEW_SIZE,
141 "-XX:InitialHeapSize=" + 2 * MAX_NEW_SIZE,
142 "-XX:MaxHeapSize=" + 2 * MAX_NEW_SIZE,
143 "-XX:SurvivorRatio=" + SURVIVOR_RATIO,
144 "-XX:TargetSurvivorRatio=" + ratio,
145 // For reducing variance of survivor size.
146 "-XX:TargetPLABWastePct=" + 1,
147 TargetSurvivorRatioVerifier.class.getName(),
148 Integer.toString(ratio)
149 );
150
151 ProcessBuilder procBuilder = ProcessTools.createJavaProcessBuilder(vmOptions.toArray(new String[vmOptions.size()]));
152 OutputAnalyzer analyzer = new OutputAnalyzer(procBuilder.start());
153
154 analyzer.shouldHaveExitValue(0);
155
156 String output = analyzer.getOutput();
157
158 // Test avoids verification for parallel GC
159 if (!output.contains(UNSUPPORTED_GC)) {
160 // Two tests should be done - when actual ratio is lower than TargetSurvivorRatio
161 // and when it is higher. We chech that output contains results for exactly two tests.
162 List<Double> ratios = parseTestOutput(output);
163
164 if (ratios.size() != 2) {
165 System.out.println(output);
166 throw new RuntimeException("Expected number of ratios extraced for output is 2,"
167 + " but " + ratios.size() + " ratios were extracted");
168 }
169
170 // At the end of the first test survivor space usage ratio should lies between
171 // TargetSurvivorRatio and TargetSurvivorRatio - 2*DELTA
172 if (ratio < ratios.get(0) || ratio - ratios.get(0) > VARIANCE) {
173 System.out.println(output);
174 throw new RuntimeException("Survivor space usage ratio expected to be close to "
175 + ratio + ", but observed ratio is: " + ratios.get(0));
176 }
177
178 // After second test survivor space should be almost empty.
179 if (ratios.get(1) > VARIANCE) {
180 System.out.println(output);
181 throw new RuntimeException("Survivor space expected to be empty due to "
182 + "TargetSurvivorRatio overlimit, however observed "
183 + "survivor space usage ratio is: " + ratios.get(1));
184 }
185 } else {
186 System.out.println("Selected GC does not support TargetSurvivorRatio option.");
187 }
188 }
189
190 /**
191 * Parse output produced by TargetSurvivorRatioVerifier.
192 *
193 * @param output output obtained from TargetSurvivorRatioVerifier
194 * @return list of parsed test results, where each result is an actual
195 * survivor ratio after MaxTenuringThreshold minor GC cycles.
196 */
197 public static List<Double> parseTestOutput(String output) {
198 List<Double> ratios = new LinkedList<Double>();
199 String lines[] = output.split("[\n\r]");
200 boolean testStarted = false;
201 long survivorSize = 0;
202 long survivorOccupancy = 0;
203 int gcCount = 0;
204 Pattern ageTableEntry = Pattern.compile(AGE_TABLE_ENTRY);
205 Pattern maxSurvivorSize = Pattern.compile(MAX_SURVIVOR_SIZE);
206 for (String line : lines) {
207 if (Pattern.matches(MAX_SURVIVOR_SIZE, line)) {
208 // We found estimated survivor space size
209 Matcher m = maxSurvivorSize.matcher(line);
210 m.find();
211 survivorSize = Long.valueOf(m.group(1));
212 } else if (line.contains(START_TEST) && !testStarted) {
213 // Start collecting test results
214 testStarted = true;
215 gcCount = 0;
216 } else if (testStarted) {
217 if (line.contains(TENURING_DISTRIBUTION)) {
218 // We found start of output emitted by -XX:+PrintTenuringDistribution
219 // If it is associated with "MaxTenuringThreshold" GC cycle, then it's
220 // time to report observed survivor usage ratio
221 gcCount++;
222 double survivorRatio = survivorOccupancy / (double) survivorSize;
223 if (gcCount == MAX_TENURING_THRESHOLD || gcCount == MAX_TENURING_THRESHOLD * 2) {
224 ratios.add(survivorRatio * 100.0);
225 testStarted = false;
226 }
227 survivorOccupancy = 0;
228 } else if (Pattern.matches(AGE_TABLE_ENTRY, line)) {
229 // Obtain survivor space usage from "total" age table log entry
230 Matcher m = ageTableEntry.matcher(line);
231 m.find();
232 survivorOccupancy = Long.valueOf(m.group(3));
233 } else if (line.contains(END_TEST)) {
234 // It is expected to find at least MaxTenuringThreshold GC events
235 // until test end
236 if (gcCount < MAX_TENURING_THRESHOLD) {
237 throw new RuntimeException("Observed " + gcCount + " GC events, "
238 + "while it is expected to see at least "
239 + MAX_TENURING_THRESHOLD);
240 }
241 testStarted = false;
242 }
243 }
244 }
245 return ratios;
246 }
247
248 public static class TargetSurvivorRatioVerifier {
249
250 static final WhiteBox wb = WhiteBox.getWhiteBox();
251 static final Unsafe unsafe = Unsafe.getUnsafe();
252
253 // Desired size of memory allocated at once
254 public static final int CHUNK_SIZE = 1024;
255 // Length of byte[] array that will have occupy CHUNK_SIZE bytes in heap
256 public static final int ARRAY_LENGTH = CHUNK_SIZE - Unsafe.ARRAY_BYTE_BASE_OFFSET;
257
258 public static void main(String args[]) throws Exception {
259 if (args.length != 1) {
260 throw new IllegalArgumentException("Expected 1 arg: <ratio>");
261 }
262 if (GCTypes.YoungGCType.getYoungGCType() == GCTypes.YoungGCType.PSNew) {
263 System.out.println(UNSUPPORTED_GC);
264 return;
265 }
266
267 int ratio = Integer.valueOf(args[0]);
268 long maxSurvivorSize = getMaxSurvivorSize();
269 System.out.println("Max survivor size: " + maxSurvivorSize);
270
271 allocateMemory(ratio - DELTA, maxSurvivorSize);
272 allocateMemory(ratio + DELTA, maxSurvivorSize);
273 }
274
275 /**
276 * Allocate (<b>ratio</b> * <b>maxSize</b> / 100) bytes of objects
277 * and force at least "MaxTenuringThreshold" minor GCs.
278 *
279 * @param ratio ratio used to calculate how many objects should be allocated
280 * @param maxSize estimated max survivor space size
281 */
282 public static void allocateMemory(double ratio, long maxSize) throws Exception {
283 GarbageCollectorMXBean youngGCBean = GCTypes.YoungGCType.getYoungGCBean();
284 long garbageSize = (long) (maxSize * (ratio / 100.0));
285 int arrayLength = (int) (garbageSize / CHUNK_SIZE);
286 AllocationHelper allocator = new AllocationHelper(1, arrayLength, ARRAY_LENGTH, null);
287
288 System.out.println(START_TEST);
289 System.gc();
290 final long initialGcId = youngGCBean.getCollectionCount();
291 // allocate memory
292 allocator.allocateMemoryAndVerify();
293
294 // force minor GC
295 while (youngGCBean.getCollectionCount() <= initialGcId + MAX_TENURING_THRESHOLD * 2) {
296 byte b[] = new byte[ARRAY_LENGTH];
297 }
298
299 allocator.release();
300 System.out.println(END_TEST);
301 }
302
303 /**
304 * Estimate max survivor space size.
305 *
306 * For non-G1 GC returns value reported by MemoryPoolMXBean
307 * associated with survivor space.
308 * For G1 GC return max number of survivor regions * region size.
309 * Number if survivor regions estimated from MaxNewSize and SurvivorRatio.
310 */
311 public static long getMaxSurvivorSize() {
312 if (GCTypes.YoungGCType.getYoungGCType() == GCTypes.YoungGCType.G1) {
313 int youngLength = (int) Math.max(MAX_NEW_SIZE / wb.g1RegionSize(), 1);
314 return (long) Math.ceil(youngLength / (double) SURVIVOR_RATIO) * wb.g1RegionSize();
315 } else {
316 return HeapRegionUsageTool.getSurvivorUsage().getMax();
317 }
318 }
319 }
320 }