1 /*
2 * Copyright (c) 2003, 2018, 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 * @author Mandy Chung
31 *
32 * @requires vm.gc == "null"
33 * @requires vm.opt.ExplicitGCInvokesConcurrent != "true"
34 * @requires vm.opt.DisableExplicitGC != "true"
35 * @library /test/lib
36 *
37 * @build LowMemoryTest MemoryUtil RunUtil
38 * @build sun.hotspot.WhiteBox
39 * @run driver ClassFileInstaller sun.hotspot.WhiteBox sun.hotspot.WhiteBox$WhiteBoxPermission
40 * @run main/othervm/timeout=600 -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:. LowMemoryTest
41 */
42
43 import java.lang.management.*;
44 import java.util.*;
45 import java.util.concurrent.Phaser;
46 import javax.management.*;
47 import javax.management.openmbean.CompositeData;
48 import jdk.test.lib.JDKToolFinder;
49 import jdk.test.lib.process.ProcessTools;
50 import jdk.test.lib.Utils;
51
52 import sun.hotspot.code.Compiler;
53
54 public class LowMemoryTest {
55 private static final MemoryMXBean mm = ManagementFactory.getMemoryMXBean();
56 private static final List<MemoryPoolMXBean> pools = ManagementFactory.getMemoryPoolMXBeans();
57 private static final Phaser phaser = new Phaser(2);
58 private static MemoryPoolMXBean mpool = null;
59 private static boolean trace = false;
60 private static boolean testFailed = false;
61 private static final int NUM_TRIGGERS = 5;
62 private static final int NUM_CHUNKS = 2;
63 private static final int YOUNG_GEN_SIZE = 8 * 1024 * 1024;
64 private static long chunkSize;
65 private static final String classMain = "LowMemoryTest$TestMain";
66
67 /**
68 * Run the test multiple times with different GC versions.
69 * First with default command line specified by the framework.
70 * Then with GC versions specified by the test.
71 */
72 public static void main(String a[]) throws Throwable {
73 // Use a low young gen size to ensure that the
74 // allocated objects are put in the old gen.
75 final String nmFlag = "-Xmn" + YOUNG_GEN_SIZE;
76 // Using large pages will change the young gen size,
77 // make sure we don't use them for this test.
78 final String lpFlag = "-XX:-UseLargePages";
79 // Prevent G1 from selecting a large heap region size,
80 // since that would change the young gen size.
81 final String g1Flag = "-XX:G1HeapRegionSize=1m";
82
83 // Runs the test collecting subprocess I/O while it's running.
84 traceTest(classMain + ", -XX:+UseSerialGC", nmFlag, lpFlag, "-XX:+UseSerialGC");
85 traceTest(classMain + ", -XX:+UseParallelGC", nmFlag, lpFlag, "-XX:+UseParallelGC");
86 traceTest(classMain + ", -XX:+UseG1GC -XX:-G1UseLegacyMonitoring", nmFlag, lpFlag,
87 "-XX:+UseG1GC", "-XX:-G1UseLegacyMonitoring", g1Flag);
88 traceTest(classMain + ", -XX:+UseG1GC -XX:+G1UseLegacyMonitoring", nmFlag, lpFlag,
89 "-XX:+UseG1GC", "-XX:+G1UseLegacyMonitoring", g1Flag);
90 if (!Compiler.isGraalEnabled()) { // Graal does not support CMS
91 traceTest(classMain + ", -XX:+UseConcMarkSweepGC", nmFlag, lpFlag,
92 "-XX:+UseConcMarkSweepGC");
93 }
94 }
95
96 /*
97 * Creating command-line for running subprocess JVM:
98 *
99 * JVM command line is like:
100 * {test_jdk}/bin/java {defaultopts} -cp {test.class.path} {testopts} main
101 *
102 * {defaultopts} are the default java options set by the framework.
103 *
104 * @param testOpts java options specified by the test.
105 */
106 private static List<String> buildCommandLine(String... testOpts) {
107 List<String> opts = new ArrayList<>();
108 opts.add(JDKToolFinder.getJDKTool("java"));
109 opts.addAll(Arrays.asList(Utils.getTestJavaOpts()));
110 opts.add("-cp");
111 opts.add(System.getProperty("test.class.path", "test.class.path"));
112 opts.add("-Xlog:gc*=debug");
113 opts.addAll(Arrays.asList(testOpts));
114 opts.add(classMain);
115
116 return opts;
117 }
118
119 /**
120 * Runs LowMemoryTest$TestMain with the passed options and redirects subprocess
121 * standard I/O to the current (parent) process. This provides a trace of what
122 * happens in the subprocess while it is runnning (and before it terminates).
123 *
124 * @param prefixName the prefix string for redirected outputs
125 * @param testOpts java options specified by the test.
126 */
127 private static void traceTest(String prefixName,
128 String... testOpts)
129 throws Throwable {
130
131 // Building command-line
132 List<String> opts = buildCommandLine(testOpts);
133
134 // We activate all tracing in subprocess
135 opts.add("trace");
136
137 // Launch separate JVM subprocess
138 String[] optsArray = opts.toArray(new String[0]);
139 ProcessBuilder pb = new ProcessBuilder(optsArray);
140 System.out.println("\n========= Tracing of subprocess " + prefixName + " =========");
141 Process p = ProcessTools.startProcess(prefixName, pb);
142
143 // Handling end of subprocess
144 try {
145 int exitCode = p.waitFor();
146 if (exitCode != 0) {
147 throw new RuntimeException(
148 "Subprocess unexpected exit value of [" + exitCode + "]. Expected 0.\n");
149 }
150 } catch (InterruptedException e) {
151 throw new RuntimeException("Parent process interrupted with exception : \n " + e + " :" );
152 }
153
154
155 }
156
157 private static volatile boolean listenerInvoked = false;
158 static class SensorListener implements NotificationListener {
159 @Override
160 public void handleNotification(Notification notif, Object handback) {
161 String type = notif.getType();
162 if (type.equals(MemoryNotificationInfo.MEMORY_THRESHOLD_EXCEEDED) ||
163 type.equals(MemoryNotificationInfo.
164 MEMORY_COLLECTION_THRESHOLD_EXCEEDED)) {
165
166 MemoryNotificationInfo minfo = MemoryNotificationInfo.
167 from((CompositeData) notif.getUserData());
168
169 MemoryUtil.printMemoryNotificationInfo(minfo, type);
170 listenerInvoked = true;
171 }
172 }
173 }
174
175 static class TestListener implements NotificationListener {
176 private boolean isRelaxed = false;
177 private int triggers = 0;
178 private final long[] count = new long[NUM_TRIGGERS * 2];
179 private final long[] usedMemory = new long[NUM_TRIGGERS * 2];
180
181 public TestListener() {
182 isRelaxed = ManagementFactory.getRuntimeMXBean().getInputArguments().contains("-XX:+UseConcMarkSweepGC");
183 }
184
185 @Override
186 public void handleNotification(Notification notif, Object handback) {
187 MemoryNotificationInfo minfo = MemoryNotificationInfo.
188 from((CompositeData) notif.getUserData());
189 count[triggers] = minfo.getCount();
190 usedMemory[triggers] = minfo.getUsage().getUsed();
191 triggers++;
192 }
193 public void checkResult() throws Exception {
194 if (!checkValue(triggers, NUM_TRIGGERS)) {
195 throw new RuntimeException("Unexpected number of triggers = " +
196 triggers + " but expected to be " + NUM_TRIGGERS);
197 }
198
199 for (int i = 0; i < triggers; i++) {
200 if (!checkValue(count[i], i + 1)) {
201 throw new RuntimeException("Unexpected count of" +
202 " notification #" + i +
203 " count = " + count[i] +
204 " but expected to be " + (i+1));
205 }
206 if (usedMemory[i] < newThreshold) {
207 throw new RuntimeException("Used memory = " +
208 usedMemory[i] + " is less than the threshold = " +
209 newThreshold);
210 }
211 }
212 }
213
214 private boolean checkValue(int value, int target) {
215 return checkValue((long)value, target);
216 }
217
218 private boolean checkValue(long value, int target) {
219 if (!isRelaxed) {
220 return value == target;
221 } else {
222 return value >= target;
223 }
224 }
225 }
226
227 private static long newThreshold;
228
229 private static class TestMain {
230 public static void main(String args[]) throws Exception {
231 if (args.length > 0 && args[0].equals("trace")) {
232 trace = true;
233 }
234
235 // Find the Old generation which supports low memory detection
236 ListIterator iter = pools.listIterator();
237 while (iter.hasNext()) {
238 MemoryPoolMXBean p = (MemoryPoolMXBean) iter.next();
239 if (p.getType() == MemoryType.HEAP &&
240 p.isUsageThresholdSupported()) {
241 if (!p.getName().equals("G1 Old Space")) {
242 // In G1, humongous objects are tracked in the old space only in
243 // legacy monitoring mode. In default mode, G1 tracks humongous
244 // objects in the humongous space, which latter also supports a
245 // usage threshold. Since we're allocating humongous objects in
246 // this test, in default mode the old space doesn't change. For
247 // this test, we use the old space in legacy mode (it's called
248 // "G1 Old Gen" and the humongous space in default mode. If we
249 // used "G1 Old Space" in default mode, notification would never
250 // happen.
251 mpool = p;
252 if (trace) {
253 System.out.println("Selected memory pool for low memory " +
254 "detection.");
255 MemoryUtil.printMemoryPool(mpool);
256 }
257 break;
258 }
259 }
260 }
261 if (mpool == null) {
262 throw new RuntimeException("TEST FAILED: No heap pool found");
263 }
264
265 TestListener listener = new TestListener();
266 SensorListener l2 = new SensorListener();
267 NotificationEmitter emitter = (NotificationEmitter) mm;
268 emitter.addNotificationListener(listener, null, null);
269 emitter.addNotificationListener(l2, null, null);
270
271 Thread allocator = new AllocatorThread();
272 Thread sweeper = new SweeperThread();
273
274 // The chunk size needs to be larger than YOUNG_GEN_SIZE,
275 // otherwise we will get intermittent failures when objects
276 // end up in the young gen instead of the old gen.
277 final long epsilon = 1024;
278 chunkSize = YOUNG_GEN_SIZE + epsilon;
279
280 MemoryUsage mu = mpool.getUsage();
281 newThreshold = mu.getUsed() + (chunkSize * NUM_CHUNKS);
282
283 // Sanity check. Make sure the new threshold isn't too large.
284 // Tweak the test if this fails.
285 final long headRoom = chunkSize * 2;
286 final long max = mu.getMax();
287 if (max != -1 && newThreshold > max - headRoom) {
288 throw new RuntimeException("TEST FAILED: newThreshold: " + newThreshold +
289 " is too near the maximum old gen size: " + max +
290 " used: " + mu.getUsed() + " headRoom: " + headRoom);
291 }
292
293 System.out.println("Setting threshold for " + mpool.getName() +
294 " from " + mpool.getUsageThreshold() + " to " + newThreshold +
295 ". Current used = " + mu.getUsed());
296
297 mpool.setUsageThreshold(newThreshold);
298
299 if (mpool.getUsageThreshold() != newThreshold) {
300 throw new RuntimeException("TEST FAILED: " +
301 "Threshold for Memory pool " + mpool.getName() +
302 "is " + mpool.getUsageThreshold() + " but expected to be" +
303 newThreshold);
304 }
305
306
307 allocator.start();
308 // Force Allocator start first
309 phaser.arriveAndAwaitAdvance();
310 sweeper.start();
311
312
313 try {
314 allocator.join();
315 // Wait until AllocatorThread's done
316 phaser.arriveAndAwaitAdvance();
317 sweeper.join();
318 } catch (InterruptedException e) {
319 System.out.println("Unexpected exception:" + e);
320 testFailed = true;
321 }
322
323 listener.checkResult();
324
325 if (testFailed)
326 throw new RuntimeException("TEST FAILED.");
327
328 System.out.println(RunUtil.successMessage);
329 }
330 }
331
332 private static void goSleep(long ms) {
333 try {
334 Thread.sleep(ms);
335 } catch (InterruptedException e) {
336 System.out.println("Unexpected exception:" + e);
337 testFailed = true;
338 }
339 }
340
341 private static final List<Object> objectPool = new ArrayList<>();
342 static class AllocatorThread extends Thread {
343 public void doTask() {
344 int iterations = 0;
345 int numElements = (int) (chunkSize / 4); // minimal object size
346 while (!listenerInvoked || mpool.getUsage().getUsed() < mpool.getUsageThreshold()) {
347 iterations++;
348 if (trace) {
349 System.out.println(" Iteration " + iterations +
350 ": before allocation " +
351 mpool.getUsage().getUsed());
352 }
353
354 Object[] o = new Object[numElements];
355 if (iterations <= NUM_CHUNKS) {
356 // only hold a reference to the first NUM_CHUNKS
357 // allocated objects
358 objectPool.add(o);
359 }
360
361 if (trace) {
362 System.out.println(" " +
363 " after allocation " +
364 mpool.getUsage().getUsed());
365 }
366 goSleep(100);
367 }
368 }
369 @Override
370 public void run() {
371 for (int i = 1; i <= NUM_TRIGGERS; i++) {
372 // Sync with SweeperThread's second phase.
373 phaser.arriveAndAwaitAdvance();
374 System.out.println("AllocatorThread is doing task " + i +
375 " phase " + phaser.getPhase());
376 doTask();
377 // Sync with SweeperThread's first phase.
378 phaser.arriveAndAwaitAdvance();
379 System.out.println("AllocatorThread done task " + i +
380 " phase " + phaser.getPhase());
381 if (testFailed) {
382 return;
383 }
384 }
385 }
386 }
387
388 static class SweeperThread extends Thread {
389 private void doTask() {
390 int iterations = 0;
391 if (trace) {
392 System.out.println("SweeperThread clearing allocated objects.");
393 }
394
395 for (; mpool.getUsage().getUsed() >=
396 mpool.getUsageThreshold();) {
397 // clear all allocated objects and invoke GC
398 objectPool.clear();
399 mm.gc();
400
401 if (trace) {
402 iterations++;
403 System.out.println("SweeperThread called " + iterations +
404 " time(s) MemoryMXBean.gc().");
405 }
406
407 goSleep(100);
408 }
409 }
410
411 @Override
412 public void run() {
413 for (int i = 1; i <= NUM_TRIGGERS; i++) {
414 // Sync with AllocatorThread's first phase.
415 phaser.arriveAndAwaitAdvance();
416 System.out.println("SweeperThread is doing task " + i +
417 " phase " + phaser.getPhase());
418
419 doTask();
420
421 listenerInvoked = false;
422
423 // Sync with AllocatorThread's second phase.
424 phaser.arriveAndAwaitAdvance();
425 System.out.println("SweeperThread done task " + i +
426 " phase " + phaser.getPhase());
427 if (testFailed) return;
428 }
429 }
430 }
431 }