Wed, 03 Sep 2014 09:25:44 +0200
Merge
1 /*
2 * Copyright (c) 2014, 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 */
24 /*
25 * Common code for string deduplication tests
26 */
28 import java.lang.management.*;
29 import java.lang.reflect.*;
30 import java.security.*;
31 import java.util.*;
32 import com.oracle.java.testlibrary.*;
33 import sun.misc.*;
35 class TestStringDeduplicationTools {
36 private static final String YoungGC = "YoungGC";
37 private static final String FullGC = "FullGC";
39 private static final int Xmn = 50; // MB
40 private static final int Xms = 100; // MB
41 private static final int Xmx = 100; // MB
42 private static final int MB = 1024 * 1024;
43 private static final int StringLength = 50;
45 private static Field valueField;
46 private static Unsafe unsafe;
47 private static byte[] dummy;
49 static {
50 try {
51 Field field = Unsafe.class.getDeclaredField("theUnsafe");
52 field.setAccessible(true);
53 unsafe = (Unsafe)field.get(null);
55 valueField = String.class.getDeclaredField("value");
56 valueField.setAccessible(true);
57 } catch (Exception e) {
58 throw new RuntimeException(e);
59 }
60 }
62 private static Object getValue(String string) {
63 try {
64 return valueField.get(string);
65 } catch (Exception e) {
66 throw new RuntimeException(e);
67 }
68 }
70 private static void doFullGc(int numberOfTimes) {
71 for (int i = 0; i < numberOfTimes; i++) {
72 System.out.println("Begin: Full GC " + (i + 1) + "/" + numberOfTimes);
73 System.gc();
74 System.out.println("End: Full GC " + (i + 1) + "/" + numberOfTimes);
75 }
76 }
78 private static void doYoungGc(int numberOfTimes) {
79 // Provoke at least numberOfTimes young GCs
80 final int objectSize = 128;
81 final int maxObjectInYoung = (Xmn * MB) / objectSize;
82 for (int i = 0; i < numberOfTimes; i++) {
83 System.out.println("Begin: Young GC " + (i + 1) + "/" + numberOfTimes);
84 for (int j = 0; j < maxObjectInYoung + 1; j++) {
85 dummy = new byte[objectSize];
86 }
87 System.out.println("End: Young GC " + (i + 1) + "/" + numberOfTimes);
88 }
89 }
91 private static void forceDeduplication(int ageThreshold, String gcType) {
92 // Force deduplication to happen by either causing a FullGC or a YoungGC.
93 // We do several collections to also provoke a situation where the the
94 // deduplication thread needs to yield while processing the queue. This
95 // also tests that the references in the deduplication queue are adjusted
96 // accordingly.
97 if (gcType.equals(FullGC)) {
98 doFullGc(3);
99 } else {
100 doYoungGc(ageThreshold + 3);
101 }
102 }
104 private static String generateString(int id) {
105 StringBuilder builder = new StringBuilder(StringLength);
107 builder.append("DeduplicationTestString:" + id + ":");
109 while (builder.length() < StringLength) {
110 builder.append('X');
111 }
113 return builder.toString();
114 }
116 private static ArrayList<String> createStrings(int total, int unique) {
117 System.out.println("Creating strings: total=" + total + ", unique=" + unique);
118 if (total % unique != 0) {
119 throw new RuntimeException("Total must be divisible by unique");
120 }
122 ArrayList<String> list = new ArrayList<String>(total);
123 for (int j = 0; j < total / unique; j++) {
124 for (int i = 0; i < unique; i++) {
125 list.add(generateString(i));
126 }
127 }
129 return list;
130 }
132 private static void verifyStrings(ArrayList<String> list, int uniqueExpected) {
133 for (;;) {
134 // Check number of deduplicated strings
135 ArrayList<Object> unique = new ArrayList<Object>(uniqueExpected);
136 for (String string: list) {
137 Object value = getValue(string);
138 boolean uniqueValue = true;
139 for (Object obj: unique) {
140 if (obj == value) {
141 uniqueValue = false;
142 break;
143 }
144 }
146 if (uniqueValue) {
147 unique.add(value);
148 }
149 }
151 System.out.println("Verifying strings: total=" + list.size() +
152 ", uniqueFound=" + unique.size() +
153 ", uniqueExpected=" + uniqueExpected);
155 if (unique.size() == uniqueExpected) {
156 System.out.println("Deduplication completed");
157 break;
158 } else {
159 System.out.println("Deduplication not completed, waiting...");
161 // Give the deduplication thread time to complete
162 try {
163 Thread.sleep(1000);
164 } catch (Exception e) {
165 throw new RuntimeException(e);
166 }
167 }
168 }
169 }
171 private static OutputAnalyzer runTest(String... extraArgs) throws Exception {
172 String[] defaultArgs = new String[] {
173 "-Xmn" + Xmn + "m",
174 "-Xms" + Xms + "m",
175 "-Xmx" + Xmx + "m",
176 "-XX:+UseG1GC",
177 "-XX:+UnlockDiagnosticVMOptions",
178 "-XX:+VerifyAfterGC" // Always verify after GC
179 };
181 ArrayList<String> args = new ArrayList<String>();
182 args.addAll(Arrays.asList(defaultArgs));
183 args.addAll(Arrays.asList(extraArgs));
185 ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(args.toArray(new String[args.size()]));
186 OutputAnalyzer output = new OutputAnalyzer(pb.start());
187 System.err.println(output.getStderr());
188 System.out.println(output.getStdout());
189 return output;
190 }
192 private static class DeduplicationTest {
193 public static void main(String[] args) {
194 System.out.println("Begin: DeduplicationTest");
196 final int numberOfStrings = Integer.parseUnsignedInt(args[0]);
197 final int numberOfUniqueStrings = Integer.parseUnsignedInt(args[1]);
198 final int ageThreshold = Integer.parseUnsignedInt(args[2]);
199 final String gcType = args[3];
201 ArrayList<String> list = createStrings(numberOfStrings, numberOfUniqueStrings);
202 forceDeduplication(ageThreshold, gcType);
203 verifyStrings(list, numberOfUniqueStrings);
205 System.out.println("End: DeduplicationTest");
206 }
208 public static OutputAnalyzer run(int numberOfStrings, int ageThreshold, String gcType, String... extraArgs) throws Exception {
209 String[] defaultArgs = new String[] {
210 "-XX:+UseStringDeduplication",
211 "-XX:StringDeduplicationAgeThreshold=" + ageThreshold,
212 DeduplicationTest.class.getName(),
213 "" + numberOfStrings,
214 "" + numberOfStrings / 2,
215 "" + ageThreshold,
216 gcType
217 };
219 ArrayList<String> args = new ArrayList<String>();
220 args.addAll(Arrays.asList(extraArgs));
221 args.addAll(Arrays.asList(defaultArgs));
223 return runTest(args.toArray(new String[args.size()]));
224 }
225 }
227 private static class InternedTest {
228 public static void main(String[] args) {
229 // This test verifies that interned strings are always
230 // deduplicated when being interned, and never after
231 // being interned.
233 System.out.println("Begin: InternedTest");
235 final int ageThreshold = Integer.parseUnsignedInt(args[0]);
236 final String baseString = "DeduplicationTestString:" + InternedTest.class.getName();
238 // Create duplicate of baseString
239 StringBuilder sb1 = new StringBuilder(baseString);
240 String dupString1 = sb1.toString();
241 if (getValue(dupString1) == getValue(baseString)) {
242 throw new RuntimeException("Values should not match");
243 }
245 // Force baseString to be inspected for deduplication
246 // and be inserted into the deduplication hashtable.
247 forceDeduplication(ageThreshold, FullGC);
249 // Wait for deduplication to occur
250 while (getValue(dupString1) != getValue(baseString)) {
251 System.out.println("Waiting...");
252 try {
253 Thread.sleep(100);
254 } catch (Exception e) {
255 throw new RuntimeException(e);
256 }
257 }
259 // Create a new duplicate of baseString
260 StringBuilder sb2 = new StringBuilder(baseString);
261 String dupString2 = sb2.toString();
262 if (getValue(dupString2) == getValue(baseString)) {
263 throw new RuntimeException("Values should not match");
264 }
266 // Intern the new duplicate
267 Object beforeInternedValue = getValue(dupString2);
268 String internedString = dupString2.intern();
269 if (internedString != dupString2) {
270 throw new RuntimeException("String should match");
271 }
272 if (getValue(internedString) != getValue(baseString)) {
273 throw new RuntimeException("Values should match");
274 }
276 // Check original value of interned string, to make sure
277 // deduplication happened on the interned string and not
278 // on the base string
279 if (beforeInternedValue == getValue(baseString)) {
280 throw new RuntimeException("Values should not match");
281 }
283 System.out.println("End: InternedTest");
284 }
286 public static OutputAnalyzer run() throws Exception {
287 return runTest("-XX:+PrintGC",
288 "-XX:+PrintGCDetails",
289 "-XX:+UseStringDeduplication",
290 "-XX:+PrintStringDeduplicationStatistics",
291 "-XX:StringDeduplicationAgeThreshold=" + DefaultAgeThreshold,
292 InternedTest.class.getName(),
293 "" + DefaultAgeThreshold);
294 }
295 }
297 /*
298 * Tests
299 */
301 private static final int LargeNumberOfStrings = 10000;
302 private static final int SmallNumberOfStrings = 10;
304 private static final int MaxAgeThreshold = 15;
305 private static final int DefaultAgeThreshold = 3;
306 private static final int MinAgeThreshold = 1;
308 private static final int TooLowAgeThreshold = MinAgeThreshold - 1;
309 private static final int TooHighAgeThreshold = MaxAgeThreshold + 1;
311 public static void testYoungGC() throws Exception {
312 // Do young GC to age strings to provoke deduplication
313 OutputAnalyzer output = DeduplicationTest.run(LargeNumberOfStrings,
314 DefaultAgeThreshold,
315 YoungGC,
316 "-XX:+PrintGC",
317 "-XX:+PrintStringDeduplicationStatistics");
318 output.shouldNotContain("Full GC");
319 output.shouldContain("GC pause (G1 Evacuation Pause) (young)");
320 output.shouldContain("GC concurrent-string-deduplication");
321 output.shouldContain("Deduplicated:");
322 output.shouldHaveExitValue(0);
323 }
325 public static void testFullGC() throws Exception {
326 // Do full GC to age strings to provoke deduplication
327 OutputAnalyzer output = DeduplicationTest.run(LargeNumberOfStrings,
328 DefaultAgeThreshold,
329 FullGC,
330 "-XX:+PrintGC",
331 "-XX:+PrintStringDeduplicationStatistics");
332 output.shouldNotContain("GC pause (G1 Evacuation Pause) (young)");
333 output.shouldContain("Full GC");
334 output.shouldContain("GC concurrent-string-deduplication");
335 output.shouldContain("Deduplicated:");
336 output.shouldHaveExitValue(0);
337 }
339 public static void testTableResize() throws Exception {
340 // Test with StringDeduplicationResizeALot
341 OutputAnalyzer output = DeduplicationTest.run(LargeNumberOfStrings,
342 DefaultAgeThreshold,
343 YoungGC,
344 "-XX:+PrintGC",
345 "-XX:+PrintStringDeduplicationStatistics",
346 "-XX:+StringDeduplicationResizeALot");
347 output.shouldContain("GC concurrent-string-deduplication");
348 output.shouldContain("Deduplicated:");
349 output.shouldNotContain("Resize Count: 0");
350 output.shouldHaveExitValue(0);
351 }
353 public static void testTableRehash() throws Exception {
354 // Test with StringDeduplicationRehashALot
355 OutputAnalyzer output = DeduplicationTest.run(LargeNumberOfStrings,
356 DefaultAgeThreshold,
357 YoungGC,
358 "-XX:+PrintGC",
359 "-XX:+PrintStringDeduplicationStatistics",
360 "-XX:+StringDeduplicationRehashALot");
361 output.shouldContain("GC concurrent-string-deduplication");
362 output.shouldContain("Deduplicated:");
363 output.shouldNotContain("Rehash Count: 0");
364 output.shouldNotContain("Hash Seed: 0x0");
365 output.shouldHaveExitValue(0);
366 }
368 public static void testAgeThreshold() throws Exception {
369 OutputAnalyzer output;
371 // Test with max age theshold
372 output = DeduplicationTest.run(SmallNumberOfStrings,
373 MaxAgeThreshold,
374 YoungGC,
375 "-XX:+PrintGC",
376 "-XX:+PrintStringDeduplicationStatistics");
377 output.shouldContain("GC concurrent-string-deduplication");
378 output.shouldContain("Deduplicated:");
379 output.shouldHaveExitValue(0);
381 // Test with min age theshold
382 output = DeduplicationTest.run(SmallNumberOfStrings,
383 MinAgeThreshold,
384 YoungGC,
385 "-XX:+PrintGC",
386 "-XX:+PrintStringDeduplicationStatistics");
387 output.shouldContain("GC concurrent-string-deduplication");
388 output.shouldContain("Deduplicated:");
389 output.shouldHaveExitValue(0);
391 // Test with too low age threshold
392 output = DeduplicationTest.run(SmallNumberOfStrings,
393 TooLowAgeThreshold,
394 YoungGC);
395 output.shouldContain("StringDeduplicationAgeThreshold of " + TooLowAgeThreshold +
396 " is invalid; must be between " + MinAgeThreshold + " and " + MaxAgeThreshold);
397 output.shouldHaveExitValue(1);
399 // Test with too high age threshold
400 output = DeduplicationTest.run(SmallNumberOfStrings,
401 TooHighAgeThreshold,
402 YoungGC);
403 output.shouldContain("StringDeduplicationAgeThreshold of " + TooHighAgeThreshold +
404 " is invalid; must be between " + MinAgeThreshold + " and " + MaxAgeThreshold);
405 output.shouldHaveExitValue(1);
406 }
408 public static void testPrintOptions() throws Exception {
409 OutputAnalyzer output;
411 // Test without PrintGC and without PrintStringDeduplicationStatistics
412 output = DeduplicationTest.run(SmallNumberOfStrings,
413 DefaultAgeThreshold,
414 YoungGC);
415 output.shouldNotContain("GC concurrent-string-deduplication");
416 output.shouldNotContain("Deduplicated:");
417 output.shouldHaveExitValue(0);
419 // Test with PrintGC but without PrintStringDeduplicationStatistics
420 output = DeduplicationTest.run(SmallNumberOfStrings,
421 DefaultAgeThreshold,
422 YoungGC,
423 "-XX:+PrintGC");
424 output.shouldContain("GC concurrent-string-deduplication");
425 output.shouldNotContain("Deduplicated:");
426 output.shouldHaveExitValue(0);
427 }
429 public static void testInterned() throws Exception {
430 // Test that interned strings are deduplicated before being interned
431 OutputAnalyzer output = InternedTest.run();
432 output.shouldHaveExitValue(0);
433 }
434 }