1 /*
2 * Copyright (c) 2020, 2022, 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=iu
39 * @requires vm.gc.Shenandoah
40 * @library /test/lib
41 * @build jdk.test.whitebox.WhiteBox
42 * @run driver jdk.test.lib.helpers.ClassFileInstaller jdk.test.whitebox.WhiteBox
43 * @run main/othervm
44 * -Xbootclasspath/a:.
45 * -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI
46 * -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCMode=iu
47 * gc.shenandoah.TestReferenceRefersToShenandoah
48 */
49
50 /* @test id=satb-100
51 * @requires vm.gc.Shenandoah
52 * @library /test/lib
53 * @build jdk.test.whitebox.WhiteBox
54 * @modules java.base
55 * @run main 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=satb -XX:ShenandoahGarbageThreshold=100 -Xmx100m
60 * gc.shenandoah.TestReferenceRefersToShenandoah
61 */
62
63 /* @test id=iu-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=iu -XX:ShenandoahGarbageThreshold=100 -Xmx100m
73 * gc.shenandoah.TestReferenceRefersToShenandoah
74 */
75
76 import java.lang.ref.PhantomReference;
77 import java.lang.ref.Reference;
78 import java.lang.ref.ReferenceQueue;
79 import java.lang.ref.WeakReference;
80 import jdk.test.whitebox.WhiteBox;
81
82 public class TestReferenceRefersToShenandoah {
83 private static final WhiteBox WB = WhiteBox.getWhiteBox();
84
85 private static final class TestObject {
86 public final int value;
87
88 public TestObject(int value) {
89 this.value = value;
90 }
91 }
92
93 private static volatile TestObject testObjectNone = null;
94 private static volatile TestObject testObject1 = null;
95 private static volatile TestObject testObject2 = null;
96 private static volatile TestObject testObject3 = null;
97 private static volatile TestObject testObject4 = null;
98
99 private static ReferenceQueue<TestObject> queue = null;
100
101 private static PhantomReference<TestObject> testPhantom1 = null;
102
103 private static WeakReference<TestObject> testWeak2 = null;
104 private static WeakReference<TestObject> testWeak3 = null;
105 private static WeakReference<TestObject> testWeak4 = null;
106
107 private static void setup() {
108 testObjectNone = new TestObject(0);
109 testObject1 = new TestObject(1);
110 testObject2 = new TestObject(2);
111 testObject3 = new TestObject(3);
112 testObject4 = new TestObject(4);
113
114 queue = new ReferenceQueue<TestObject>();
115
116 testPhantom1 = new PhantomReference<TestObject>(testObject1, queue);
117
118 testWeak2 = new WeakReference<TestObject>(testObject2, queue);
119 testWeak3 = new WeakReference<TestObject>(testObject3, queue);
120 testWeak4 = new WeakReference<TestObject>(testObject4, queue);
121 }
122
123 private static void gcUntilOld(Object o) throws Exception {
124 if (!WB.isObjectInOldGen(o)) {
125 WB.fullGC();
126 if (!WB.isObjectInOldGen(o)) {
127 fail("object not promoted by full gc");
128 }
129 }
130 }
131
132 private static void gcUntilOld() throws Exception {
133 gcUntilOld(testObjectNone);
134 gcUntilOld(testObject1);
135 gcUntilOld(testObject2);
136 gcUntilOld(testObject3);
137 gcUntilOld(testObject4);
138
139 gcUntilOld(testPhantom1);
140
141 gcUntilOld(testWeak2);
142 gcUntilOld(testWeak3);
143 gcUntilOld(testWeak4);
144 }
145
146 private static void progress(String msg) {
147 System.out.println(msg);
148 }
149
150 private static void fail(String msg) throws Exception {
151 throw new RuntimeException(msg);
152 }
153
154 private static void expectCleared(Reference<TestObject> ref,
155 String which) throws Exception {
156 expectNotValue(ref, testObjectNone, which);
157 if (!ref.refersTo(null)) {
158 fail("expected " + which + " to be cleared");
159 }
160 }
161
162 private static void expectNotCleared(Reference<TestObject> ref,
163 String which) throws Exception {
164 expectNotValue(ref, testObjectNone, which);
165 if (ref.refersTo(null)) {
166 fail("expected " + which + " to not be cleared");
167 }
168 }
169
170 private static void expectValue(Reference<TestObject> ref,
171 TestObject value,
172 String which) throws Exception {
173 expectNotValue(ref, testObjectNone, which);
174 expectNotCleared(ref, which);
175 if (!ref.refersTo(value)) {
176 fail(which + " doesn't refer to expected value");
177 }
178 }
179
180 private static void expectNotValue(Reference<TestObject> ref,
181 TestObject value,
182 String which) throws Exception {
183 if (ref.refersTo(value)) {
184 fail(which + " refers to unexpected value");
185 }
186 }
187
188 private static void checkInitialStates() throws Exception {
189 expectValue(testPhantom1, testObject1, "testPhantom1");
190 expectValue(testWeak2, testObject2, "testWeak2");
191 expectValue(testWeak3, testObject3, "testWeak3");
192 expectValue(testWeak4, testObject4, "testWeak4");
193 }
194
195 private static void discardStrongReferences() {
196 // testObjectNone not dropped
197 testObject1 = null;
198 testObject2 = null;
199 // testObject3 not dropped
200 testObject4 = null;
201 }
202
203 private static boolean isShenandoahIUMode() {
204 return "iu".equals(WB.getStringVMFlag("ShenandoahGCMode"));
205 }
206
207 private static void testConcurrentCollection() throws Exception {
208 progress("setup concurrent collection test");
209 setup();
210 progress("gcUntilOld");
211 gcUntilOld();
212
213 progress("acquire control of concurrent cycles");
214 WB.concurrentGCAcquireControl();
215 try {
216 progress("check initial states");
217 checkInitialStates();
218
219 progress("discard strong references");
220 discardStrongReferences();
221
222 progress("run GC to before marking completed");
223 WB.concurrentGCRunTo(WB.BEFORE_MARKING_COMPLETED);
224
225 progress("fetch test objects, possibly keeping some alive");
226 expectNotCleared(testPhantom1, "testPhantom1");
227 expectNotCleared(testWeak2, "testWeak2");
228 expectValue(testWeak3, testObject3, "testWeak3");
229
230 // For some collectors, calling get() will keep testObject4 alive.
231 if (testWeak4.get() == null) {
232 fail("testWeak4 unexpectedly == null");
233 }
234
235 progress("finish collection");
236 WB.concurrentGCRunToIdle();
237
238 progress("verify expected clears");
239 expectCleared(testPhantom1, "testPhantom1");
240 expectCleared(testWeak2, "testWeak2");
241 expectValue(testWeak3, testObject3, "testWeak3");
242 // This is true for all currently supported concurrent collectors,
243 // except Shenandoah+IU, which allows clearing refs even when
244 // accessed during concurrent marking.
245 if (isShenandoahIUMode()) {
246 expectCleared(testWeak4, "testWeak4");
247 } else {
248 expectNotCleared(testWeak4, "testWeak4");
249 }
250
251 progress("verify get returns expected values");
252 if (testWeak2.get() != null) {
253 fail("testWeak2.get() != null");
254 }
255
256 TestObject obj3 = testWeak3.get();
257 if (obj3 == null) {
258 fail("testWeak3.get() returned null");
259 } else if (obj3.value != 3) {
260 fail("testWeak3.get().value is " + obj3.value);
261 }
262
263 TestObject obj4 = testWeak4.get();
264 if (!isShenandoahIUMode()) {
265 if (obj4 == null) {
266 fail("testWeak4.get() returned null");
267 } else if (obj4.value != 4) {
268 fail("testWeak4.get().value is " + obj4.value);
269 }
270 }
271
272 progress("verify queue entries");
273 long timeout = 60000; // 1 minute of milliseconds.
274 while (true) {
275 Reference<? extends TestObject> ref = queue.remove(timeout);
276 if (ref == null) {
277 break;
278 } else if (ref == testPhantom1) {
279 testPhantom1 = null;
280 } else if (ref == testWeak2) {
281 testWeak2 = null;
282 } else if (ref == testWeak3) {
283 testWeak3 = null;
284 } else if (ref == testWeak4) {
285 testWeak4 = null;
286 } else {
287 fail("unexpected reference in queue");
288 }
289 }
290 if (testPhantom1 != null) {
291 fail("testPhantom1 not notified");
292 } else if (testWeak2 != null) {
293 fail("testWeak2 not notified");
294 } else if (testWeak3 == null) {
295 fail("testWeak3 notified");
296 } else if (testWeak4 == null) {
297 if (obj4 != null) {
298 fail("testWeak4 notified");
299 }
300 }
301
302 } finally {
303 progress("release control of concurrent cycles");
304 WB.concurrentGCReleaseControl();
305 }
306 progress("finished concurrent collection test");
307 }
308
309 private static void testSimpleCollection() throws Exception {
310 progress("setup simple collection test");
311 setup();
312 progress("gcUntilOld");
313 gcUntilOld();
314
315 progress("check initial states");
316 checkInitialStates();
317
318 progress("discard strong references");
319 TestObject tw4 = testWeak4.get(); // Keep testObject4 alive.
320 discardStrongReferences();
321
322 progress("collect garbage");
323 WB.fullGC();
324
325 progress("verify expected clears");
326 expectCleared(testPhantom1, "testPhantom1");
327 expectCleared(testWeak2, "testWeak2");
328 expectValue(testWeak3, testObject3, "testWeak3");
329 expectNotCleared(testWeak4, "testWeak4");
330
331 progress("verify get returns expected values");
332 if (testWeak2.get() != null) {
333 fail("testWeak2.get() != null");
334 } else if (testWeak3.get() != testObject3) {
335 fail("testWeak3.get() is not expected value");
336 } else if (testWeak4.get() != tw4) {
337 fail("testWeak4.get() is not expected value");
338 }
339
340 progress("finished simple collection test");
341 }
342
343 public static void main(String[] args) throws Exception {
344 if (WB.supportsConcurrentGCBreakpoints()) {
345 testConcurrentCollection();
346 }
347 testSimpleCollection();
348 }
349 }