1 /*
2 * Copyright (c) 2020, 2023, 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 package gc.shenandoah;
25
26 /* @test id=satb
27 * @requires vm.gc.Shenandoah
28 * @library /test/lib
29 * @build jdk.test.whitebox.WhiteBox
30 * @run driver jdk.test.lib.helpers.ClassFileInstaller jdk.test.whitebox.WhiteBox
31 * @run main/othervm
32 * -Xbootclasspath/a:.
33 * -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI
34 * -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCMode=satb
35 * gc.shenandoah.TestReferenceRefersToShenandoah
36 */
37
38 /* @test id=satb-100
39 * @requires vm.gc.Shenandoah
40 * @library /test/lib
41 * @build jdk.test.whitebox.WhiteBox
42 * @modules java.base
43 * @run main jdk.test.lib.helpers.ClassFileInstaller jdk.test.whitebox.WhiteBox
44 * @run main/othervm
45 * -Xbootclasspath/a:.
46 * -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI
47 * -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCMode=satb -XX:ShenandoahGarbageThreshold=100 -Xmx100m
48 * gc.shenandoah.TestReferenceRefersToShenandoah
49 */
50
51 /* @test id=generational
52 * @requires vm.gc.Shenandoah
53 * @library /test/lib
54 * @build jdk.test.whitebox.WhiteBox
55 * @run driver jdk.test.lib.helpers.ClassFileInstaller jdk.test.whitebox.WhiteBox
56 * @run main/othervm
57 * -Xbootclasspath/a:.
58 * -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI
59 * -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCMode=generational
60 * gc.shenandoah.TestReferenceRefersToShenandoah
61 */
62
63 /* @test id=generational-100
64 * @requires vm.gc.Shenandoah
65 * @library /test/lib
66 * @build jdk.test.whitebox.WhiteBox
67 * @modules java.base
68 * @run main jdk.test.lib.helpers.ClassFileInstaller jdk.test.whitebox.WhiteBox
69 * @run main/othervm
70 * -Xbootclasspath/a:.
71 * -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI
72 * -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCMode=generational -XX:ShenandoahGarbageThreshold=100 -Xmx100m
73 * gc.shenandoah.TestReferenceRefersToShenandoah
74 */
75
76 /* @test id=iu
77 * @requires vm.gc.Shenandoah
78 * @library /test/lib
79 * @build jdk.test.whitebox.WhiteBox
80 * @run driver jdk.test.lib.helpers.ClassFileInstaller jdk.test.whitebox.WhiteBox
81 * @run main/othervm
82 * -Xbootclasspath/a:.
83 * -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI
84 * -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCMode=iu
85 * gc.shenandoah.TestReferenceRefersToShenandoah
86 */
87
88 /* @test id=iu-100
89 * @requires vm.gc.Shenandoah
90 * @library /test/lib
91 * @build jdk.test.whitebox.WhiteBox
92 * @modules java.base
93 * @run main jdk.test.lib.helpers.ClassFileInstaller jdk.test.whitebox.WhiteBox
94 * @run main/othervm
95 * -Xbootclasspath/a:.
96 * -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI
97 * -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCMode=iu -XX:ShenandoahGarbageThreshold=100 -Xmx100m
98 * gc.shenandoah.TestReferenceRefersToShenandoah
99 */
100
101 import java.lang.ref.PhantomReference;
102 import java.lang.ref.Reference;
103 import java.lang.ref.ReferenceQueue;
104 import java.lang.ref.WeakReference;
105 import jdk.test.whitebox.WhiteBox;
106
107 public class TestReferenceRefersToShenandoah {
108 private static final WhiteBox WB = WhiteBox.getWhiteBox();
109
110 private static final class TestObject {
111 public final int value;
112
113 public TestObject(int value) {
114 this.value = value;
115 }
116 }
117
118 private static volatile TestObject testObjectNone = null;
119 private static volatile TestObject testObject1 = null;
120 private static volatile TestObject testObject2 = null;
121 private static volatile TestObject testObject3 = null;
122 private static volatile TestObject testObject4 = null;
123
124 private static ReferenceQueue<TestObject> queue = null;
125
126 private static PhantomReference<TestObject> testPhantom1 = null;
127
128 private static WeakReference<TestObject> testWeak2 = null;
129 private static WeakReference<TestObject> testWeak3 = null;
130 private static WeakReference<TestObject> testWeak4 = null;
131
132 private static void setup() {
133 testObjectNone = new TestObject(0);
134 testObject1 = new TestObject(1);
135 testObject2 = new TestObject(2);
136 testObject3 = new TestObject(3);
137 testObject4 = new TestObject(4);
138
139 queue = new ReferenceQueue<TestObject>();
140
141 testPhantom1 = new PhantomReference<TestObject>(testObject1, queue);
142
143 testWeak2 = new WeakReference<TestObject>(testObject2, queue);
144 testWeak3 = new WeakReference<TestObject>(testObject3, queue);
145 testWeak4 = new WeakReference<TestObject>(testObject4, queue);
146 }
147
148 private static void gcUntilOld(Object o) throws Exception {
149 if (!WB.isObjectInOldGen(o)) {
150 WB.fullGC();
151 if (!WB.isObjectInOldGen(o)) {
152 // This is just a warning, because failing would
153 // be overspecifying for generational shenandoah,
154 // which need not necessarily promote objects upon
155 // a full GC.
156 warn("object not promoted by full gc");
157 }
158 }
159 }
160
161 private static void gcUntilOld() throws Exception {
162 gcUntilOld(testObjectNone);
163 gcUntilOld(testObject1);
164 gcUntilOld(testObject2);
165 gcUntilOld(testObject3);
166 gcUntilOld(testObject4);
167
168 gcUntilOld(testPhantom1);
169
170 gcUntilOld(testWeak2);
171 gcUntilOld(testWeak3);
172 gcUntilOld(testWeak4);
173 }
174
175 private static void progress(String msg) {
176 System.out.println(msg);
177 }
178
179 private static void fail(String msg) throws Exception {
180 throw new RuntimeException(msg);
181 }
182
183 private static void warn(String msg) {
184 System.out.println("Warning: " + msg);
185 }
186
187 private static void expectCleared(Reference<TestObject> ref,
188 String which) throws Exception {
189 expectNotValue(ref, testObjectNone, which);
190 if (!ref.refersTo(null)) {
191 fail("expected " + which + " to be cleared");
192 }
193 }
194
195 private static void expectNotCleared(Reference<TestObject> ref,
196 String which) throws Exception {
197 expectNotValue(ref, testObjectNone, which);
198 if (ref.refersTo(null)) {
199 fail("expected " + which + " to not be cleared");
200 }
201 }
202
203 private static void expectValue(Reference<TestObject> ref,
204 TestObject value,
205 String which) throws Exception {
206 expectNotValue(ref, testObjectNone, which);
207 expectNotCleared(ref, which);
208 if (!ref.refersTo(value)) {
209 fail(which + " doesn't refer to expected value");
210 }
211 }
212
213 private static void expectNotValue(Reference<TestObject> ref,
214 TestObject value,
215 String which) throws Exception {
216 if (ref.refersTo(value)) {
217 fail(which + " refers to unexpected value");
218 }
219 }
220
221 private static void checkInitialStates() throws Exception {
222 expectValue(testPhantom1, testObject1, "testPhantom1");
223 expectValue(testWeak2, testObject2, "testWeak2");
224 expectValue(testWeak3, testObject3, "testWeak3");
225 expectValue(testWeak4, testObject4, "testWeak4");
226 }
227
228 private static void discardStrongReferences() {
229 // testObjectNone not dropped
230 testObject1 = null;
231 testObject2 = null;
232 // testObject3 not dropped
233 testObject4 = null;
234 }
235
236 private static boolean isShenandoahIUMode() {
237 return "iu".equals(WB.getStringVMFlag("ShenandoahGCMode"));
238 }
239
240 private static void testConcurrentCollection() throws Exception {
241 progress("setup concurrent collection test");
242 setup();
243 progress("gcUntilOld");
244 gcUntilOld();
245
246 progress("acquire control of concurrent cycles");
247 WB.concurrentGCAcquireControl();
248 try {
249 progress("check initial states");
250 checkInitialStates();
251
252 progress("discard strong references");
253 discardStrongReferences();
254
255 progress("run GC to before marking completed");
256 WB.concurrentGCRunTo(WB.BEFORE_MARKING_COMPLETED);
257
258 progress("fetch test objects, possibly keeping some alive");
259 expectNotCleared(testPhantom1, "testPhantom1");
260 expectNotCleared(testWeak2, "testWeak2");
261 expectValue(testWeak3, testObject3, "testWeak3");
262
263 // For some collectors, calling get() will keep testObject4 alive.
264 if (testWeak4.get() == null) {
265 fail("testWeak4 unexpectedly == null");
266 }
267
268 progress("finish collection");
269 WB.concurrentGCRunToIdle();
270
271 progress("verify expected clears");
272 expectCleared(testPhantom1, "testPhantom1");
273 expectCleared(testWeak2, "testWeak2");
274 expectValue(testWeak3, testObject3, "testWeak3");
275 // This is true for all currently supported concurrent collectors,
276 // except Shenandoah+IU, which allows clearing refs even when
277 // accessed during concurrent marking.
278 if (isShenandoahIUMode()) {
279 expectCleared(testWeak4, "testWeak4");
280 } else {
281 expectNotCleared(testWeak4, "testWeak4");
282 }
283
284 progress("verify get returns expected values");
285 if (testWeak2.get() != null) {
286 fail("testWeak2.get() != null");
287 }
288
289 TestObject obj3 = testWeak3.get();
290 if (obj3 == null) {
291 fail("testWeak3.get() returned null");
292 } else if (obj3.value != 3) {
293 fail("testWeak3.get().value is " + obj3.value);
294 }
295
296 TestObject obj4 = testWeak4.get();
297 if (!isShenandoahIUMode()) {
298 if (obj4 == null) {
299 fail("testWeak4.get() returned null");
300 } else if (obj4.value != 4) {
301 fail("testWeak4.get().value is " + obj4.value);
302 }
303 }
304
305 progress("verify queue entries");
306 long timeout = 60000; // 1 minute of milliseconds.
307 while (true) {
308 Reference<? extends TestObject> ref = queue.remove(timeout);
309 if (ref == null) {
310 break;
311 } else if (ref == testPhantom1) {
312 testPhantom1 = null;
313 } else if (ref == testWeak2) {
314 testWeak2 = null;
315 } else if (ref == testWeak3) {
316 testWeak3 = null;
317 } else if (ref == testWeak4) {
318 testWeak4 = null;
319 } else {
320 fail("unexpected reference in queue");
321 }
322 }
323 if (testPhantom1 != null) {
324 fail("testPhantom1 not notified");
325 } else if (testWeak2 != null) {
326 fail("testWeak2 not notified");
327 } else if (testWeak3 == null) {
328 fail("testWeak3 notified");
329 } else if (testWeak4 == null) {
330 if (obj4 != null) {
331 fail("testWeak4 notified");
332 }
333 }
334
335 } finally {
336 progress("release control of concurrent cycles");
337 WB.concurrentGCReleaseControl();
338 }
339 progress("finished concurrent collection test");
340 }
341
342 private static void testSimpleCollection() throws Exception {
343 progress("setup simple collection test");
344 setup();
345 progress("gcUntilOld");
346 gcUntilOld();
347
348 progress("check initial states");
349 checkInitialStates();
350
351 progress("discard strong references");
352 TestObject tw4 = testWeak4.get(); // Keep testObject4 alive.
353 discardStrongReferences();
354
355 progress("collect garbage");
356 WB.fullGC();
357
358 progress("verify expected clears");
359 expectCleared(testPhantom1, "testPhantom1");
360 expectCleared(testWeak2, "testWeak2");
361 expectValue(testWeak3, testObject3, "testWeak3");
362 expectNotCleared(testWeak4, "testWeak4");
363
364 progress("verify get returns expected values");
365 if (testWeak2.get() != null) {
366 fail("testWeak2.get() != null");
367 } else if (testWeak3.get() != testObject3) {
368 fail("testWeak3.get() is not expected value");
369 } else if (testWeak4.get() != tw4) {
370 fail("testWeak4.get() is not expected value");
371 }
372
373 progress("finished simple collection test");
374 }
375
376 public static void main(String[] args) throws Exception {
377 if (WB.supportsConcurrentGCBreakpoints()) {
378 testConcurrentCollection();
379 }
380 testSimpleCollection();
381 }
382 }