1 /*
2 * Copyright (c) 2014, 2019, 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;
25
26 /**
27 * @test TestSoftReferencesBehaviorOnOOME
28 * @key gc
29 * @summary Tests that all SoftReferences has been cleared at time of OOM.
30 * @requires vm.gc != "Z"
31 * @library /test/lib
32 * @modules java.base/jdk.internal.misc
33 * @run main/othervm -Xmx128m gc.TestSoftReferencesBehaviorOnOOME 512 2k
34 * @run main/othervm -Xmx128m gc.TestSoftReferencesBehaviorOnOOME 128k 256k
35 * @run main/othervm -Xmx128m gc.TestSoftReferencesBehaviorOnOOME 2k 32k
36 */
37 import jdk.test.lib.Utils;
38 import jdk.test.lib.Asserts;
39 import java.lang.ref.SoftReference;
40 import java.util.LinkedList;
41 import java.util.Random;
42
43 public class TestSoftReferencesBehaviorOnOOME {
44
45 /**
46 * Test generates a lot of soft references to objects with random payloads.
47 * Then it provokes OOME and checks that all SoftReferences has been gone
48 * @param args - [minSize] [maxSize] [freq]
49 * where
50 * - minSize - min size of random objects
51 * - maxSize - max size of random objects
52 */
53 public static void main(String[] args) {
54 long minSize = DEFAULT_MIN_SIZE;
55 long maxSize = DEFAULT_MAX_SIZE;
56
57 if ( args.length >= 2) {
58 maxSize = getBytesCount(args[1]);
59 }
60
61 if ( args.length >= 1) {
62 minSize = getBytesCount(args[0]);
63 }
64
65 new TestSoftReferencesBehaviorOnOOME().softReferencesOom(minSize, maxSize);
66 }
67
68 /**
69 * Test that all SoftReferences has been cleared at time of OOM.
70 */
71 void softReferencesOom(long minSize, long maxSize) {
72 System.out.format( "minSize = %d, maxSize = %d%n", minSize, maxSize );
73
74 LinkedList<SoftReference<byte[]>> arrSoftRefs = new LinkedList<>();
75 staticRef = arrSoftRefs;
76 LinkedList<byte[]> arrObjects = new LinkedList<>();
77 staticRef = arrObjects;
78
79 long multiplier = maxSize - minSize;
80 long numberOfNotNulledObjects = 0;
81
82 try {
83
84 // Lets allocate as many as we can - taking size of all SoftRerefences
85 // by minimum. So it can provoke some GC but we surely will allocate enough.
86 long numSofts = (long) ((0.95 * Runtime.getRuntime().totalMemory()) / minSize);
87 System.out.println("num Soft: " + numSofts);
88
89 while (numSofts-- > 0) {
90 int allocationSize = ((int) (RND_GENERATOR.nextDouble() * multiplier))
91 + (int)minSize;
92 arrSoftRefs.add(new SoftReference<byte[]>(new byte[allocationSize]));
93 }
94
95 System.out.println("free: " + Runtime.getRuntime().freeMemory());
96
97 // provoke OOME.
98 while (true) {
99 arrObjects.add(new byte[(int) Runtime.getRuntime().totalMemory()]);
100 }
101
102 } catch (OutOfMemoryError oome) {
103
104 // Clear allocated ballast, so we don't get another OOM.
105 staticRef = null;
106 arrObjects = null;
107 long oomSoftArraySize = arrSoftRefs.size();
108
109 for (SoftReference<byte[]> sr : arrSoftRefs) {
110 Object o = sr.get();
111
112 if (o != null) {
113 numberOfNotNulledObjects++;
114 }
115 }
116
117 // Make sure we clear all refs before we return failure
118 arrSoftRefs = null;
119 Asserts.assertFalse(numberOfNotNulledObjects > 0,
120 "" + numberOfNotNulledObjects + " out of "
121 + oomSoftArraySize + " SoftReferences was not "
122 + "null at time of OutOfMemoryError"
123 );
124 } finally {
125 Asserts.assertTrue(arrObjects == null, "OOME hasn't been provoked");
126 Asserts.assertTrue(arrSoftRefs == null, "OOME hasn't been provoked");
127 }
128 }
129
130 private static final long getBytesCount(String arg) {
131 String postfixes = "kMGT";
132 long mod = 1;
133
134 if (arg.trim().length() >= 2) {
135 mod = postfixes.indexOf(arg.trim().charAt(arg.length() - 1));
136
137 if (mod != -1) {
138 mod = (long) Math.pow(1024, mod+1);
139 arg = arg.substring(0, arg.length() - 1);
140 } else {
141 mod = 1; // 10^0
142 }
143 }
144
145 return Long.parseLong(arg) * mod;
146 }
147
148 private static final Random RND_GENERATOR = Utils.getRandomInstance();
149 private static final long DEFAULT_MIN_SIZE = 512;
150 private static final long DEFAULT_MAX_SIZE = 1024;
151 private static Object staticRef; // to prevent compile optimisations
152 }