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.
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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
24package gc.g1.humongousObjects;
25
26import gc.testlibrary.Helpers;
27import jdk.test.lib.Asserts;
28import sun.hotspot.WhiteBox;
29
30import java.lang.ref.Reference;
31import java.lang.ref.ReferenceQueue;
32import java.lang.ref.SoftReference;
33import java.lang.ref.WeakReference;
34
35/**
36 * @test TestObjectCollected
37 * @summary checks that after different type of GCs weak/soft references to humongous object behave correspondingly to
38 * actual object behavior
39 * @requires vm.gc.G1
40 * @library /test/lib /
41 * @modules java.base/jdk.internal.misc
42 * @modules java.management
43 * @build sun.hotspot.WhiteBox
44 * @run driver ClassFileInstaller sun.hotspot.WhiteBox
45 *             sun.hotspot.WhiteBox$WhiteBoxPermission
46 *
47 * @run main/othervm -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions
48 *                   -XX:+WhiteBoxAPI -Xbootclasspath/a:. -Xms200m -Xmx200m -Xlog:gc
49 *                   -XX:InitiatingHeapOccupancyPercent=100 -XX:G1HeapRegionSize=1M -Xlog:gc=info:file=TestObjectCollected.gc.log
50 *                    gc.g1.humongousObjects.TestObjectCollected
51 */
52
53
54/**
55 * Test checks that after different type of GCs weak/soft references to humongous object behave correspondingly to
56 * actual object behavior.
57 * So if object was collected, reference.get() should return null and vice versa
58 * Since we check humongous objects after such an object is collected the region where it was allocated becomes free
59 * or/and change type to non-humongous. Two WhiteBox method were used - first returns if a region containing certain
60 * address is free and second - if a region containing certain address is humongous
61 */
62
63public class TestObjectCollected {
64    /**
65     * Provides methods to initiate GC of requested type
66     */
67    private enum GC {
68        YOUNG_CG {
69            @Override
70            public void provoke() {
71                WHITE_BOX.youngGC();
72            }
73        },
74        FULL_GC {
75            @Override
76            public void provoke() {
77                System.gc();
78            }
79        },
80        CMC {
81            @Override
82            public void provoke() {
83                Helpers.waitTillCMCFinished(WHITE_BOX, 0);
84                WHITE_BOX.g1StartConcMarkCycle();
85                Helpers.waitTillCMCFinished(WHITE_BOX, 0);
86            }
87        },
88        FULL_GC_MEMORY_PRESSURE {
89            @Override
90            public void provoke() {
91                WHITE_BOX.fullGC();
92            }
93        };
94        private static final WhiteBox WHITE_BOX = WhiteBox.getWhiteBox();
95
96        public abstract void provoke();
97    }
98
99    /**
100     * Factory for weak and soft references.
101     * Allocates byte array of ALLOCATION_SIZE and returns weak/soft reference on it.
102     */
103    private enum REF_FACTORY {
104        WEAK {
105            @Override
106            public Reference<byte[]> create() {
107                return new WeakReference<>(new byte[ALLOCATION_SIZE], referenceQueqe);
108            }
109        },
110        SOFT {
111            @Override
112            public Reference<byte[]> create() {
113                return new SoftReference<>(new byte[ALLOCATION_SIZE], referenceQueqe);
114            }
115        };
116
117        private static final ReferenceQueue<byte[]> referenceQueqe = new ReferenceQueue<>();
118        private static final int ALLOCATION_SIZE = WhiteBox.getWhiteBox().g1RegionSize() * 2 / 3;
119
120        /**
121         * Factory method
122         *
123         * @return weak/soft reference on byte array of ALLOCATION_SIZE
124         */
125        public abstract Reference<byte[]> create();
126    }
127
128
129    private static final WhiteBox WHITE_BOX = WhiteBox.getWhiteBox();
130
131    /**
132     * Does actual testing:
133     * Gets a reference
134     * Gets address of referenced object using WB method
135     * Calls gc of provided type
136     * Checks that object was/was not deleted using WB methods.
137     */
138    public static void doTesting(GC gc, REF_FACTORY ref) {
139
140        System.out.println(String.format("Testing %s reference behavior after %s", ref.name(), gc.name()));
141
142        Reference reference = ref.create();
143        Asserts.assertNotNull(reference, "Test Bug: failed to allocate reference");
144        long adr = WHITE_BOX.getObjectAddress(reference.get());
145
146        //Sanity checks
147        boolean isRefNulled = (reference.get() == null);
148        boolean isRegionHumongous = WHITE_BOX.g1BelongsToHumongousRegion(adr);
149        boolean isRegionFree = WHITE_BOX.g1BelongsToFreeRegion(adr);
150
151
152        Asserts.assertEquals(isRefNulled, false,
153                "We just allocated an object but reference.get() already returned null");
154
155        Asserts.assertEquals(isRegionFree, false,
156                "We just allocated an object but WB returns that allocation region is still considered free");
157
158        Asserts.assertEquals(isRegionHumongous, true,
159                "We just allocated a humongous object but WB returns that allocation region is not humongous");
160
161        gc.provoke();
162
163        isRefNulled = (reference.get() == null);
164        isRegionHumongous = WHITE_BOX.g1BelongsToHumongousRegion(adr);
165        isRegionFree = WHITE_BOX.g1BelongsToFreeRegion(adr);
166
167        boolean isObjCollected = isRegionFree || !isRegionHumongous;
168
169        Asserts.assertEquals(isRefNulled, isObjCollected,
170                String.format("There is an inconsistensy between reference and white box "
171                                + "method behavior - one considers object referenced with "
172                                + "%s type collected and another doesn't!\n"
173                                + "\treference.get() returned %snull\n"
174                                + "\tWhiteBox methods returned that object was%s collected",
175                        reference.getClass().getSimpleName(),
176                        (isRefNulled ? "" : "not "),
177                        (isObjCollected ? "" : " not")));
178
179        System.out.println("Passed");
180    }
181
182    /**
183     * Entry point
184     *
185     * @param args not used
186     */
187    public static void main(String[] args) {
188        // Full gc - System.gc()
189        TestObjectCollected.doTesting(GC.FULL_GC, REF_FACTORY.WEAK);
190        TestObjectCollected.doTesting(GC.FULL_GC, REF_FACTORY.SOFT);
191
192        // Full gc with memory pressure - WB.fullGC() emulates that no memory left
193        TestObjectCollected.doTesting(GC.FULL_GC_MEMORY_PRESSURE, REF_FACTORY.WEAK);
194        TestObjectCollected.doTesting(GC.FULL_GC_MEMORY_PRESSURE, REF_FACTORY.SOFT);
195
196        // Young gc
197        TestObjectCollected.doTesting(GC.YOUNG_CG, REF_FACTORY.WEAK);
198        TestObjectCollected.doTesting(GC.YOUNG_CG, REF_FACTORY.SOFT);
199
200        // Concurrent mark cycle
201        TestObjectCollected.doTesting(GC.CMC, REF_FACTORY.WEAK);
202        TestObjectCollected.doTesting(GC.CMC, REF_FACTORY.SOFT);
203    }
204}
205