1 /*
2 * Copyright (c) 2019, 2020, 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.z;
25
26 /*
27 * @test TestUncommit
28 * @requires vm.gc.Z
29 * @summary Test ZGC uncommit unused memory
30 * @run main/othervm -XX:+UseZGC -Xlog:gc*,gc+heap=debug,gc+stats=off -Xms128M -Xmx512M -XX:ZUncommitDelay=10 gc.z.TestUncommit true 2
31 */
32
33 /*
34 * @test TestUncommit
35 * @requires vm.gc.Z
36 * @summary Test ZGC uncommit unused memory
37 * @run main/othervm -XX:+UseZGC -Xlog:gc*,gc+heap=debug,gc+stats=off -Xms512M -Xmx512M -XX:ZUncommitDelay=10 gc.z.TestUncommit false 1
38 */
39
40 /*
41 * @test TestUncommit
42 * @requires vm.gc.Z
43 * @summary Test ZGC uncommit unused memory
44 * @run main/othervm -XX:+UseZGC -Xlog:gc*,gc+heap=debug,gc+stats=off -Xms128M -Xmx512M -XX:ZUncommitDelay=10 -XX:-ZUncommit gc.z.TestUncommit false 1
45 */
46
47 import java.util.ArrayList;
48
49 public class TestUncommit {
50 private static final int delay = 10; // seconds
51 private static final int allocSize = 200 * 1024 * 1024; // 200M
52 private static final int smallObjectSize = 4 * 1024; // 4K
53 private static final int mediumObjectSize = 2 * 1024 * 1024; // 2M
54 private static final int largeObjectSize = allocSize;
55
56 private static volatile ArrayList<byte[]> keepAlive;
57
58 private static long capacity() {
59 return Runtime.getRuntime().totalMemory();
60 }
61
62 private static void allocate(int objectSize) {
63 keepAlive = new ArrayList<>();
64 for (int i = 0; i < allocSize; i+= objectSize) {
65 keepAlive.add(new byte[objectSize]);
66 }
67 }
68
69 private static void reclaim() {
70 keepAlive = null;
71 System.gc();
72 }
73
74 private static void test(boolean enabled, int objectSize) throws Exception {
75 final var beforeAlloc = capacity();
76
77 // Allocate memory
78 allocate(objectSize);
79
80 final var afterAlloc = capacity();
81
82 // Reclaim memory
83 reclaim();
84
85 // Wait shorter than the uncommit delay
86 Thread.sleep(delay * 1000 / 2);
87
88 final var beforeUncommit = capacity();
89
90 // Wait longer than the uncommit delay
91 Thread.sleep(delay * 1000);
92
93 final var afterUncommit = capacity();
94
95 System.out.println(" Uncommit Enabled: " + enabled);
96 System.out.println(" Uncommit Delay: " + delay);
97 System.out.println(" Object Size: " + objectSize);
98 System.out.println(" Alloc Size: " + allocSize);
99 System.out.println(" Before Alloc: " + beforeAlloc);
100 System.out.println(" After Alloc: " + afterAlloc);
101 System.out.println(" Before Uncommit: " + beforeUncommit);
102 System.out.println(" After Uncommit: " + afterUncommit);
103 System.out.println();
104
105 // Verify
106 if (enabled) {
107 if (beforeUncommit == beforeAlloc) {
108 throw new Exception("Uncommitted too fast");
109 }
110
111 if (afterUncommit >= afterAlloc) {
112 throw new Exception("Uncommitted too slow");
113 }
114
115 if (afterUncommit < beforeAlloc) {
116 throw new Exception("Uncommitted too much");
117 }
118
119 if (afterUncommit > beforeAlloc) {
120 throw new Exception("Uncommitted too little");
121 }
122 } else {
123 if (afterAlloc > beforeUncommit ||
124 afterAlloc > afterUncommit) {
125 throw new Exception("Should not uncommit");
126 }
127 }
128 }
129
130 public static void main(String[] args) throws Exception {
131 final boolean enabled = Boolean.parseBoolean(args[0]);
132 final int iterations = Integer.parseInt(args[1]);
133
134 for (int i = 0; i < iterations; i++) {
135 System.out.println("Iteration " + i);
136 test(enabled, smallObjectSize);
137 test(enabled, mediumObjectSize);
138 test(enabled, largeObjectSize);
139 }
140 }
141 }