1 /*
2 * Copyright (c) 2015, 2016, 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 package gc.g1.humongousObjects;
26
27 import gc.testlibrary.Helpers;
28 import jdk.test.lib.Asserts;
29 import sun.hotspot.WhiteBox;
30
31 import java.lang.ref.Reference;
32 import java.lang.ref.ReferenceQueue;
33 import java.lang.ref.SoftReference;
34 import java.lang.ref.WeakReference;
35
36 /**
37 * @test TestObjectCollected
38 * @summary checks that after different type of GCs weak/soft references to humongous object behave correspondingly to
39 * actual object behavior
40 * @requires vm.gc.G1
41 * @library /testlibrary /test/lib /
42 * @modules java.base/jdk.internal.misc
43 * @modules java.management
44 * @build sun.hotspot.WhiteBox
45 * gc.testlibrary.Helpers
46 * gc.g1.humongousObjects.TestObjectCollected
47 *
48 * @run driver ClassFileInstaller sun.hotspot.WhiteBox
49 * sun.hotspot.WhiteBox$WhiteBoxPermission
50 *
51 * @run main/othervm -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions
52 * -XX:+WhiteBoxAPI -Xbootclasspath/a:. -Xms200m -Xmx200m -Xlog:gc
53 * -XX:InitiatingHeapOccupancyPercent=100 -XX:G1HeapRegionSize=1M -Xlog:gc=info:file=TestObjectCollected.gc.log
54 * gc.g1.humongousObjects.TestObjectCollected
55 */
56
57
58 /**
59 * Test checks that after different type of GCs weak/soft references to humongous object behave correspondingly to
60 * actual object behavior.
61 * So if object was collected, reference.get() should return null and vice versa
62 * Since we check humongous objects after such an object is collected the region where it was allocated becomes free
63 * or/and change type to non-humongous. Two WhiteBox method were used - first returns if a region containing certain
64 * address is free and second - if a region containing certain address is humongous
65 */
66
67 public class TestObjectCollected {
68 /**
69 * Provides methods to initiate GC of requested type
70 */
71 private enum GC {
72 YOUNG_CG {
73 @Override
74 public void provoke() {
75 WHITE_BOX.youngGC();
76 }
77 },
78 FULL_GC {
79 @Override
80 public void provoke() {
81 System.gc();
82 }
83 },
84 CMC {
85 @Override
86 public void provoke() {
87 Helpers.waitTillCMCFinished(WHITE_BOX, 0);
88 WHITE_BOX.g1StartConcMarkCycle();
89 Helpers.waitTillCMCFinished(WHITE_BOX, 0);
90 }
91 },
92 FULL_GC_MEMORY_PRESSURE {
93 @Override
94 public void provoke() {
95 WHITE_BOX.fullGC();
96 }
97 };
98 private static final WhiteBox WHITE_BOX = WhiteBox.getWhiteBox();
99
100 public abstract void provoke();
101 }
102
103 /**
104 * Factory for weak and soft references.
105 * Allocates byte array of ALLOCATION_SIZE and returns weak/soft reference on it.
106 */
107 private enum REF_FACTORY {
108 WEAK {
109 @Override
110 public Reference<byte[]> create() {
111 return new WeakReference<>(new byte[ALLOCATION_SIZE], referenceQueqe);
112 }
113 },
114 SOFT {
115 @Override
116 public Reference<byte[]> create() {
117 return new SoftReference<>(new byte[ALLOCATION_SIZE], referenceQueqe);
118 }
119 };
120
121 private static final ReferenceQueue<byte[]> referenceQueqe = new ReferenceQueue<>();
122 private static final int ALLOCATION_SIZE = WhiteBox.getWhiteBox().g1RegionSize() * 2 / 3;
123
124 /**
125 * Factory method
126 *
127 * @return weak/soft reference on byte array of ALLOCATION_SIZE
128 */
129 public abstract Reference<byte[]> create();
130 }
131
132
133 private static final WhiteBox WHITE_BOX = WhiteBox.getWhiteBox();
134
135 /**
136 * Does actual testing:
137 * Gets a reference
138 * Gets address of referenced object using WB method
139 * Calls gc of provided type
140 * Checks that object was/was not deleted using WB methods.
141 */
142 public static void doTesting(GC gc, REF_FACTORY ref) {
143
144 System.out.println(String.format("Testing %s reference behavior after %s", ref.name(), gc.name()));
145
146 Reference reference = ref.create();
147 Asserts.assertNotNull(reference, "Test Bug: failed to allocate reference");
148 long adr = WHITE_BOX.getObjectAddress(reference.get());
149
150 //Sanity checks
151 boolean isRefNulled = (reference.get() == null);
152 boolean isRegionHumongous = WHITE_BOX.g1BelongsToHumongousRegion(adr);
153 boolean isRegionFree = WHITE_BOX.g1BelongsToFreeRegion(adr);
154
155
156 Asserts.assertEquals(isRefNulled, false,
157 "We just allocated an object but reference.get() already returned null");
158
159 Asserts.assertEquals(isRegionFree, false,
160 "We just allocated an object but WB returns that allocation region is still considered free");
161
162 Asserts.assertEquals(isRegionHumongous, true,
163 "We just allocated a humongous object but WB returns that allocation region is not humongous");
164
165 gc.provoke();
166
167 isRefNulled = (reference.get() == null);
168 isRegionHumongous = WHITE_BOX.g1BelongsToHumongousRegion(adr);
169 isRegionFree = WHITE_BOX.g1BelongsToFreeRegion(adr);
170
171 boolean isObjCollected = isRegionFree || !isRegionHumongous;
172
173 Asserts.assertEquals(isRefNulled, isObjCollected,
174 String.format("There is an inconsistensy between reference and white box "
175 + "method behavior - one considers object referenced with "
176 + "%s type collected and another doesn't!\n"
177 + "\treference.get() returned %snull\n"
178 + "\tWhiteBox methods returned that object was%s collected",
179 reference.getClass().getSimpleName(),
180 (isRefNulled ? "" : "not "),
181 (isObjCollected ? "" : " not")));
182
183 System.out.println("Passed");
184 }
185
186 /**
187 * Entry point
188 *
189 * @param args not used
190 */
191 public static void main(String[] args) {
192 // Full gc - System.gc()
193 TestObjectCollected.doTesting(GC.FULL_GC, REF_FACTORY.WEAK);
194 TestObjectCollected.doTesting(GC.FULL_GC, REF_FACTORY.SOFT);
195
196 // Full gc with memory pressure - WB.fullGC() emulates that no memory left
197 TestObjectCollected.doTesting(GC.FULL_GC_MEMORY_PRESSURE, REF_FACTORY.WEAK);
198 TestObjectCollected.doTesting(GC.FULL_GC_MEMORY_PRESSURE, REF_FACTORY.SOFT);
199
200 // Young gc
201 TestObjectCollected.doTesting(GC.YOUNG_CG, REF_FACTORY.WEAK);
202 TestObjectCollected.doTesting(GC.YOUNG_CG, REF_FACTORY.SOFT);
203
204 // Concurrent mark cycle
205 TestObjectCollected.doTesting(GC.CMC, REF_FACTORY.WEAK);
206 TestObjectCollected.doTesting(GC.CMC, REF_FACTORY.SOFT);
207 }
208 }