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=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 import java.lang.ref.PhantomReference;
52 import java.lang.ref.Reference;
53 import java.lang.ref.ReferenceQueue;
54 import java.lang.ref.WeakReference;
55 import jdk.test.whitebox.WhiteBox;
56
57 public class TestReferenceRefersToShenandoah {
58 private static final WhiteBox WB = WhiteBox.getWhiteBox();
59
60 private static final class TestObject {
61 public final int value;
62
63 public TestObject(int value) {
64 this.value = value;
65 }
66 }
67
68 private static volatile TestObject testObjectNone = null;
69 private static volatile TestObject testObject1 = null;
70 private static volatile TestObject testObject2 = null;
71 private static volatile TestObject testObject3 = null;
72 private static volatile TestObject testObject4 = null;
73
74 private static ReferenceQueue<TestObject> queue = null;
75
76 private static PhantomReference<TestObject> testPhantom1 = null;
77
78 private static WeakReference<TestObject> testWeak2 = null;
79 private static WeakReference<TestObject> testWeak3 = null;
80 private static WeakReference<TestObject> testWeak4 = null;
81
82 private static void setup() {
83 testObjectNone = new TestObject(0);
84 testObject1 = new TestObject(1);
85 testObject2 = new TestObject(2);
86 testObject3 = new TestObject(3);
87 testObject4 = new TestObject(4);
88
89 queue = new ReferenceQueue<TestObject>();
90
91 testPhantom1 = new PhantomReference<TestObject>(testObject1, queue);
92
93 testWeak2 = new WeakReference<TestObject>(testObject2, queue);
94 testWeak3 = new WeakReference<TestObject>(testObject3, queue);
95 testWeak4 = new WeakReference<TestObject>(testObject4, queue);
96 }
97
98 private static void gcUntilOld(Object o) throws Exception {
99 if (!WB.isObjectInOldGen(o)) {
100 WB.fullGC();
101 if (!WB.isObjectInOldGen(o)) {
102 fail("object not promoted by full gc");
103 }
104 }
105 }
106
107 private static void gcUntilOld() throws Exception {
108 gcUntilOld(testObjectNone);
109 gcUntilOld(testObject1);
110 gcUntilOld(testObject2);
111 gcUntilOld(testObject3);
112 gcUntilOld(testObject4);
113
114 gcUntilOld(testPhantom1);
115
116 gcUntilOld(testWeak2);
117 gcUntilOld(testWeak3);
118 gcUntilOld(testWeak4);
119 }
120
121 private static void progress(String msg) {
122 System.out.println(msg);
123 }
124
125 private static void fail(String msg) throws Exception {
126 throw new RuntimeException(msg);
127 }
128
129 private static void expectCleared(Reference<TestObject> ref,
130 String which) throws Exception {
131 expectNotValue(ref, testObjectNone, which);
132 if (!ref.refersTo(null)) {
133 fail("expected " + which + " to be cleared");
134 }
135 }
136
137 private static void expectNotCleared(Reference<TestObject> ref,
138 String which) throws Exception {
139 expectNotValue(ref, testObjectNone, which);
140 if (ref.refersTo(null)) {
141 fail("expected " + which + " to not be cleared");
142 }
143 }
144
145 private static void expectValue(Reference<TestObject> ref,
146 TestObject value,
147 String which) throws Exception {
148 expectNotValue(ref, testObjectNone, which);
149 expectNotCleared(ref, which);
150 if (!ref.refersTo(value)) {
151 fail(which + " doesn't refer to expected value");
152 }
153 }
154
155 private static void expectNotValue(Reference<TestObject> ref,
156 TestObject value,
157 String which) throws Exception {
158 if (ref.refersTo(value)) {
159 fail(which + " refers to unexpected value");
160 }
161 }
162
163 private static void checkInitialStates() throws Exception {
164 expectValue(testPhantom1, testObject1, "testPhantom1");
165 expectValue(testWeak2, testObject2, "testWeak2");
166 expectValue(testWeak3, testObject3, "testWeak3");
167 expectValue(testWeak4, testObject4, "testWeak4");
168 }
169
170 private static void discardStrongReferences() {
171 // testObjectNone not dropped
172 testObject1 = null;
173 testObject2 = null;
174 // testObject3 not dropped
175 testObject4 = null;
176 }
177
178 private static void testConcurrentCollection() throws Exception {
179 progress("setup concurrent collection test");
180 setup();
181 progress("gcUntilOld");
182 gcUntilOld();
183
184 progress("acquire control of concurrent cycles");
185 WB.concurrentGCAcquireControl();
186 try {
187 progress("check initial states");
188 checkInitialStates();
189
190 progress("discard strong references");
191 discardStrongReferences();
192
193 progress("run GC to before marking completed");
194 WB.concurrentGCRunTo(WB.BEFORE_MARKING_COMPLETED);
195
196 progress("fetch test objects, possibly keeping some alive");
197 expectNotCleared(testPhantom1, "testPhantom1");
198 expectNotCleared(testWeak2, "testWeak2");
199 expectValue(testWeak3, testObject3, "testWeak3");
200
201 // For some collectors, calling get() will keep testObject4 alive.
202 if (testWeak4.get() == null) {
203 fail("testWeak4 unexpectedly == null");
204 }
205
206 progress("finish collection");
207 WB.concurrentGCRunToIdle();
208
209 progress("verify expected clears");
210 expectCleared(testPhantom1, "testPhantom1");
211 expectCleared(testWeak2, "testWeak2");
212 expectValue(testWeak3, testObject3, "testWeak3");
213 expectNotCleared(testWeak4, "testWeak4");
214
215 progress("verify get returns expected values");
216 if (testWeak2.get() != null) {
217 fail("testWeak2.get() != null");
218 }
219
220 TestObject obj3 = testWeak3.get();
221 if (obj3 == null) {
222 fail("testWeak3.get() returned null");
223 } else if (obj3.value != 3) {
224 fail("testWeak3.get().value is " + obj3.value);
225 }
226
227 TestObject obj4 = testWeak4.get();
228 if (obj4 == null) {
229 fail("testWeak4.get() returned null");
230 } else if (obj4.value != 4) {
231 fail("testWeak4.get().value is " + obj4.value);
232 }
233
234 progress("verify queue entries");
235 long timeout = 60000; // 1 minute of milliseconds.
236 while (true) {
237 Reference<? extends TestObject> ref = queue.remove(timeout);
238 if (ref == null) {
239 break;
240 } else if (ref == testPhantom1) {
241 testPhantom1 = null;
242 } else if (ref == testWeak2) {
243 testWeak2 = null;
244 } else if (ref == testWeak3) {
245 testWeak3 = null;
246 } else if (ref == testWeak4) {
247 testWeak4 = null;
248 } else {
249 fail("unexpected reference in queue");
250 }
251 }
252 if (testPhantom1 != null) {
253 fail("testPhantom1 not notified");
254 } else if (testWeak2 != null) {
255 fail("testWeak2 not notified");
256 } else if (testWeak3 == null) {
257 fail("testWeak3 notified");
258 } else if (testWeak4 == null) {
259 if (obj4 != null) {
260 fail("testWeak4 notified");
261 }
262 }
263
264 } finally {
265 progress("release control of concurrent cycles");
266 WB.concurrentGCReleaseControl();
267 }
268 progress("finished concurrent collection test");
269 }
270
271 private static void testSimpleCollection() throws Exception {
272 progress("setup simple collection test");
273 setup();
274 progress("gcUntilOld");
275 gcUntilOld();
276
277 progress("check initial states");
278 checkInitialStates();
279
280 progress("discard strong references");
281 TestObject tw4 = testWeak4.get(); // Keep testObject4 alive.
282 discardStrongReferences();
283
284 progress("collect garbage");
285 WB.fullGC();
286
287 progress("verify expected clears");
288 expectCleared(testPhantom1, "testPhantom1");
289 expectCleared(testWeak2, "testWeak2");
290 expectValue(testWeak3, testObject3, "testWeak3");
291 expectNotCleared(testWeak4, "testWeak4");
292
293 progress("verify get returns expected values");
294 if (testWeak2.get() != null) {
295 fail("testWeak2.get() != null");
296 } else if (testWeak3.get() != testObject3) {
297 fail("testWeak3.get() is not expected value");
298 } else if (testWeak4.get() != tw4) {
299 fail("testWeak4.get() is not expected value");
300 }
301
302 progress("finished simple collection test");
303 }
304
305 public static void main(String[] args) throws Exception {
306 if (WB.supportsConcurrentGCBreakpoints()) {
307 testConcurrentCollection();
308 }
309 testSimpleCollection();
310 }
311 }