1 /*
2 * Copyright (c) 2003, 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
26 * @bug 4530538
27 * @summary Basic unit test of memory management testing:
28 * 1) setUsageThreshold() and getUsageThreshold()
29 * 2) test low memory detection on the old generation.
30 *
31 * @author Mandy Chung
32 *
33 * @library /lib/testlibrary/
34 * @modules java.management
35 * @build jdk.testlibrary.* LowMemoryTest MemoryUtil RunUtil
36 * @run main/timeout=600 LowMemoryTest
37 * @requires vm.opt.ExplicitGCInvokesConcurrent != "true"
38 * @requires vm.opt.ExplicitGCInvokesConcurrentAndUnloadsClasses != "true"
39 * @requires vm.opt.DisableExplicitGC != "true"
40 */
41
42 import java.lang.management.*;
43 import java.util.*;
44 import java.util.concurrent.Phaser;
45 import javax.management.*;
46 import javax.management.openmbean.CompositeData;
47 import jdk.testlibrary.ProcessTools;
48 import jdk.testlibrary.JDKToolFinder;
49 import jdk.testlibrary.Utils;
50
51 public class LowMemoryTest {
52 private static final MemoryMXBean mm = ManagementFactory.getMemoryMXBean();
53 private static final List<MemoryPoolMXBean> pools = ManagementFactory.getMemoryPoolMXBeans();
54 private static final Phaser phaser = new Phaser(2);
55 private static MemoryPoolMXBean mpool = null;
56 private static boolean trace = false;
57 private static boolean testFailed = false;
58 private static final int NUM_TRIGGERS = 5;
59 private static final int NUM_CHUNKS = 2;
60 private static final int YOUNG_GEN_SIZE = 8 * 1024 * 1024;
61 private static long chunkSize;
62 private static final String classMain = "LowMemoryTest$TestMain";
63
64 /**
65 * Run the test multiple times with different GC versions.
66 * First with default command line specified by the framework.
67 * Then with GC versions specified by the test.
68 */
69 public static void main(String a[]) throws Throwable {
70 // Use a low young gen size to ensure that the
71 // allocated objects are put in the old gen.
72 final String nmFlag = "-Xmn" + YOUNG_GEN_SIZE;
73 // Using large pages will change the young gen size,
74 // make sure we don't use them for this test.
75 final String lpFlag = "-XX:-UseLargePages";
76 // Prevent G1 from selecting a large heap region size,
77 // since that would change the young gen size.
78 final String g1Flag = "-XX:G1HeapRegionSize=1m";
79
80 // Runs the test collecting subprocess I/O while it's running.
81 traceTest(classMain + ", -XX:+UseSerialGC", nmFlag, lpFlag, "-XX:+UseSerialGC");
82 traceTest(classMain + ", -XX:+UseParallelGC", nmFlag, lpFlag, "-XX:+UseParallelGC");
83 traceTest(classMain + ", -XX:+UseG1GC", nmFlag, lpFlag, "-XX:+UseG1GC", g1Flag);
84 traceTest(classMain + ", -XX:+UseConcMarkSweepGC", nmFlag, lpFlag, "-XX:+UseConcMarkSweepGC");
85 }
86
87 /*
88 * Creating command-line for running subprocess JVM:
89 *
90 * JVM command line is like:
91 * {test_jdk}/bin/java {defaultopts} -cp {test.class.path} {testopts} main
92 *
93 * {defaultopts} are the default java options set by the framework.
94 *
95 * @param testOpts java options specified by the test.
96 */
97 private static List<String> buildCommandLine(String... testOpts) {
98 List<String> opts = new ArrayList<>();
99 opts.add(JDKToolFinder.getJDKTool("java"));
100 opts.addAll(Arrays.asList(Utils.getTestJavaOpts()));
101 opts.add("-cp");
102 opts.add(System.getProperty("test.class.path", "test.class.path"));
103 opts.add("-XX:+PrintGCDetails");
104 opts.addAll(Arrays.asList(testOpts));
105 opts.add(classMain);
106
107 return opts;
108 }
109
110 /**
111 * Runs LowMemoryTest$TestMain with the passed options and redirects subprocess
112 * standard I/O to the current (parent) process. This provides a trace of what
113 * happens in the subprocess while it is runnning (and before it terminates).
114 *
115 * @param prefixName the prefix string for redirected outputs
116 * @param testOpts java options specified by the test.
117 */
118 private static void traceTest(String prefixName,
119 String... testOpts)
120 throws Throwable {
121
122 // Building command-line
123 List<String> opts = buildCommandLine(testOpts);
124
125 // We activate all tracing in subprocess
126 opts.add("trace");
127
128 // Launch separate JVM subprocess
129 String[] optsArray = opts.toArray(new String[0]);
130 ProcessBuilder pb = new ProcessBuilder(optsArray);
131 System.out.println("\n========= Tracing of subprocess " + prefixName + " =========");
132 Process p = ProcessTools.startProcess(prefixName, pb);
133
134 // Handling end of subprocess
135 try {
136 int exitCode = p.waitFor();
137 if (exitCode != 0) {
138 throw new RuntimeException(
139 "Subprocess unexpected exit value of [" + exitCode + "]. Expected 0.\n");
140 }
141 } catch (InterruptedException e) {
142 throw new RuntimeException("Parent process interrupted with exception : \n " + e + " :" );
143 }
144
145
146 }
147
148 private static volatile boolean listenerInvoked = false;
149 static class SensorListener implements NotificationListener {
150 @Override
151 public void handleNotification(Notification notif, Object handback) {
152 String type = notif.getType();
153 if (type.equals(MemoryNotificationInfo.MEMORY_THRESHOLD_EXCEEDED) ||
154 type.equals(MemoryNotificationInfo.
155 MEMORY_COLLECTION_THRESHOLD_EXCEEDED)) {
156
157 MemoryNotificationInfo minfo = MemoryNotificationInfo.
158 from((CompositeData) notif.getUserData());
159
160 MemoryUtil.printMemoryNotificationInfo(minfo, type);
161 listenerInvoked = true;
162 }
163 }
164 }
165
166 static class TestListener implements NotificationListener {
167 private boolean isRelaxed = false;
168 private int triggers = 0;
169 private final long[] count = new long[NUM_TRIGGERS * 2];
170 private final long[] usedMemory = new long[NUM_TRIGGERS * 2];
171
172 public TestListener() {
173 isRelaxed = ManagementFactory.getRuntimeMXBean().getInputArguments().contains("-XX:+UseConcMarkSweepGC");
174 }
175
176 @Override
177 public void handleNotification(Notification notif, Object handback) {
178 MemoryNotificationInfo minfo = MemoryNotificationInfo.
179 from((CompositeData) notif.getUserData());
180 count[triggers] = minfo.getCount();
181 usedMemory[triggers] = minfo.getUsage().getUsed();
182 triggers++;
183 }
184 public void checkResult() throws Exception {
185 if (!checkValue(triggers, NUM_TRIGGERS)) {
186 throw new RuntimeException("Unexpected number of triggers = " +
187 triggers + " but expected to be " + NUM_TRIGGERS);
188 }
189
190 for (int i = 0; i < triggers; i++) {
191 if (!checkValue(count[i], i + 1)) {
192 throw new RuntimeException("Unexpected count of" +
193 " notification #" + i +
194 " count = " + count[i] +
195 " but expected to be " + (i+1));
196 }
197 if (usedMemory[i] < newThreshold) {
198 throw new RuntimeException("Used memory = " +
199 usedMemory[i] + " is less than the threshold = " +
200 newThreshold);
201 }
202 }
203 }
204
205 private boolean checkValue(int value, int target) {
206 return checkValue((long)value, target);
207 }
208
209 private boolean checkValue(long value, int target) {
210 if (!isRelaxed) {
211 return value == target;
212 } else {
213 return value >= target;
214 }
215 }
216 }
217
218 private static long newThreshold;
219
220 private static class TestMain {
221 public static void main(String args[]) throws Exception {
222 if (args.length > 0 && args[0].equals("trace")) {
223 trace = true;
224 }
225
226 // Find the Old generation which supports low memory detection
227 ListIterator iter = pools.listIterator();
228 while (iter.hasNext()) {
229 MemoryPoolMXBean p = (MemoryPoolMXBean) iter.next();
230 if (p.getType() == MemoryType.HEAP &&
231 p.isUsageThresholdSupported()) {
232 mpool = p;
233 if (trace) {
234 System.out.println("Selected memory pool for low memory " +
235 "detection.");
236 MemoryUtil.printMemoryPool(mpool);
237 }
238 break;
239 }
240 }
241
242 TestListener listener = new TestListener();
243 SensorListener l2 = new SensorListener();
244 NotificationEmitter emitter = (NotificationEmitter) mm;
245 emitter.addNotificationListener(listener, null, null);
246 emitter.addNotificationListener(l2, null, null);
247
248 Thread allocator = new AllocatorThread();
249 Thread sweeper = new SweeperThread();
250
251 // The chunk size needs to be larger than YOUNG_GEN_SIZE,
252 // otherwise we will get intermittent failures when objects
253 // end up in the young gen instead of the old gen.
254 final long epsilon = 1024;
255 chunkSize = YOUNG_GEN_SIZE + epsilon;
256
257 MemoryUsage mu = mpool.getUsage();
258 newThreshold = mu.getUsed() + (chunkSize * NUM_CHUNKS);
259
260 // Sanity check. Make sure the new threshold isn't too large.
261 // Tweak the test if this fails.
262 final long headRoom = chunkSize * 2;
263 final long max = mu.getMax();
264 if (max != -1 && newThreshold > max - headRoom) {
265 throw new RuntimeException("TEST FAILED: newThreshold: " + newThreshold +
266 " is too near the maximum old gen size: " + max +
267 " used: " + mu.getUsed() + " headRoom: " + headRoom);
268 }
269
270 System.out.println("Setting threshold for " + mpool.getName() +
271 " from " + mpool.getUsageThreshold() + " to " + newThreshold +
272 ". Current used = " + mu.getUsed());
273
274 mpool.setUsageThreshold(newThreshold);
275
276 if (mpool.getUsageThreshold() != newThreshold) {
277 throw new RuntimeException("TEST FAILED: " +
278 "Threshold for Memory pool " + mpool.getName() +
279 "is " + mpool.getUsageThreshold() + " but expected to be" +
280 newThreshold);
281 }
282
283
284 allocator.start();
285 // Force Allocator start first
286 phaser.arriveAndAwaitAdvance();
287 sweeper.start();
288
289
290 try {
291 allocator.join();
292 // Wait until AllocatorThread's done
293 phaser.arriveAndAwaitAdvance();
294 sweeper.join();
295 } catch (InterruptedException e) {
296 System.out.println("Unexpected exception:" + e);
297 testFailed = true;
298 }
299
300 listener.checkResult();
301
302 if (testFailed)
303 throw new RuntimeException("TEST FAILED.");
304
305 System.out.println(RunUtil.successMessage);
306 }
307 }
308
309 private static void goSleep(long ms) {
310 try {
311 Thread.sleep(ms);
312 } catch (InterruptedException e) {
313 System.out.println("Unexpected exception:" + e);
314 testFailed = true;
315 }
316 }
317
318 private static final List<Object> objectPool = new ArrayList<>();
319 static class AllocatorThread extends Thread {
320 public void doTask() {
321 int iterations = 0;
322 int numElements = (int) (chunkSize / 4); // minimal object size
323 while (!listenerInvoked || mpool.getUsage().getUsed() < mpool.getUsageThreshold()) {
324 iterations++;
325 if (trace) {
326 System.out.println(" Iteration " + iterations +
327 ": before allocation " +
328 mpool.getUsage().getUsed());
329 }
330
331 Object[] o = new Object[numElements];
332 if (iterations <= NUM_CHUNKS) {
333 // only hold a reference to the first NUM_CHUNKS
334 // allocated objects
335 objectPool.add(o);
336 }
337
338 if (trace) {
339 System.out.println(" " +
340 " after allocation " +
341 mpool.getUsage().getUsed());
342 }
343 goSleep(100);
344 }
345 }
346 @Override
347 public void run() {
348 for (int i = 1; i <= NUM_TRIGGERS; i++) {
349 // Sync with SweeperThread's second phase.
350 phaser.arriveAndAwaitAdvance();
351 System.out.println("AllocatorThread is doing task " + i +
352 " phase " + phaser.getPhase());
353 doTask();
354 // Sync with SweeperThread's first phase.
355 phaser.arriveAndAwaitAdvance();
356 System.out.println("AllocatorThread done task " + i +
357 " phase " + phaser.getPhase());
358 if (testFailed) {
359 return;
360 }
361 }
362 }
363 }
364
365 static class SweeperThread extends Thread {
366 private void doTask() {
367 int iterations = 0;
368 if (trace) {
369 System.out.println("SweeperThread clearing allocated objects.");
370 }
371
372 for (; mpool.getUsage().getUsed() >=
373 mpool.getUsageThreshold();) {
374 // clear all allocated objects and invoke GC
375 objectPool.clear();
376 mm.gc();
377
378 if (trace) {
379 iterations++;
380 System.out.println("SweeperThread called " + iterations +
381 " time(s) MemoryMXBean.gc().");
382 }
383
384 goSleep(100);
385 }
386 }
387
388 @Override
389 public void run() {
390 for (int i = 1; i <= NUM_TRIGGERS; i++) {
391 // Sync with AllocatorThread's first phase.
392 phaser.arriveAndAwaitAdvance();
393 System.out.println("SweeperThread is doing task " + i +
394 " phase " + phaser.getPhase());
395
396 doTask();
397
398 listenerInvoked = false;
399
400 // Sync with AllocatorThread's second phase.
401 phaser.arriveAndAwaitAdvance();
402 System.out.println("SweeperThread done task " + i +
403 " phase " + phaser.getPhase());
404 if (testFailed) return;
405 }
406 }
407 }
408 }