1 /*
2 * Copyright (c) 2014, 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 package com.oracle.java.testlibrary;
24
25 import static com.oracle.java.testlibrary.Asserts.assertEQ;
26 import static com.oracle.java.testlibrary.Asserts.assertFalse;
27 import static com.oracle.java.testlibrary.Asserts.assertTrue;
28 import com.sun.management.HotSpotDiagnosticMXBean;
29 import com.sun.management.VMOption;
30 import java.lang.management.ManagementFactory;
31 import java.util.Arrays;
32 import java.util.Collection;
33
34 /**
35 * A utility class to verify VMOptions which could be altered during execution.
36 *
37 * Implementation is based on {@code com.sun.management.VMOption}.
38 *
39 * The class provides methods to set and values for given options.
40 * It also contains a number of assert methods to be invoked from tests to
41 * very that an option under test correctly sets valid values and rejects
42 * invalid ones.
43 *
44 */
45 public class DynamicVMOption {
46
47 /**
48 * Private factory method to hide implementation details from tests.
49 *
50 * Those who need to work with VMOption could create it directly.
51 *
52 * @param name the VM option name, like {@code MaxHeapFreeRatio}
53 * @return an instance of com.sun.management.VMOption
54 */
55 private static VMOption getVMOption(String name) {
56 return ManagementFactory.getPlatformMXBean(HotSpotDiagnosticMXBean.class).
57 getVMOption(name);
58 }
59
60 /**
61 * Returns value of the given VM option.
62 *
63 * @param name the name of VM option
64 * @return value as string
65 */
66 public static String getValue(String name) {
67 return getVMOption(name).getValue();
68 }
69
70 /**
71 * Returns value of the given option as int.
72 *
73 * @param name the name of VM option
74 * @return value parsed as integer
75 *
76 */
77 public static int getIntValue(String name) {
78 return Integer.parseInt(getValue(name));
79 }
80
81 /**
82 * Sets VM option value.
83 *
84 * @param name the name of VM option
85 * @param value the value to be set
86 */
87 public static void setValue(String name, String value) {
88 ManagementFactory.getPlatformMXBean(HotSpotDiagnosticMXBean.class)
89 .setVMOption(name, value);
90 }
91
92
93 /**
94 * Sets VM option value.
95 *
96 * @param name the name of VM option
97 * @param value the value to be set
98 */
99 public static void setIntValue(String name, int value) {
100 setValue(name, Integer.toString(value));
101 }
102
103 /**
104 * Tests VM Option for being writable.
105 *
106 * @param name the name of VM option
107 */
108 public static void assertOptionIsWritable(String name) {
109 assertTrue(getVMOption(name).isWriteable(),
110 "Option " + name + " is expected to be writable");
111 }
112
113
114 /**
115 * Tests VM Option for being immutable.
116 *
117 * @param name of option
118 */
119 public static void assertOptionIsNotWritable(String name) {
120 assertFalse(getVMOption(name).isWriteable(),
121 "Option " + name + " is expected to be immutable");
122 }
123
124 /**
125 * Tests VM Option for a valid value.
126 * The option should be successfully set to a new value.
127 *
128 * @param name the VM option name
129 * @param value the valid value
130 */
131 public static void assertValidValue(String name, String value) {
132 setValue(name, value);
133 String newValue = getValue(name);
134 assertEQ(value, newValue,
135 "set('" + name + "'," + value + "); get('" + name + "')=" + newValue);
136 }
137
138 /**
139 * Tests VM Option for valid values.
140 *
141 * @param name the VM option name
142 * @param values the collection of valid values
143 */
144 public static void assertValidValues(String name, Collection<String> values) {
145 for (String v: values) {
146 assertValidValue(name, v);
147 }
148 }
149
150 /**
151 * Tests VM Option for an valid values.
152 *
153 * @param name the VM option name
154 * @param values the collection if invalid values
155 */
156 public static void assertValidValues(String name, String[] values) {
157 assertValidValues(name, Arrays.asList(values));
158 }
159
160
161 /**
162 * Tests VM Option for an invalid value.
163 * Attempts to set option to invalid value should cause
164 * throwing IllegalArgumentExecption.
165 *
166 * @param name the VM option name
167 * @param value the invalid value
168 */
169 public static void assertInvalidValue(String name, String value) {
170 boolean passed = false;
171 try {
172 setValue(name, value);
173 } catch (NullPointerException e) {
174 if (value == null) {
175 passed = true;
176 }
177 } catch (IllegalArgumentException e) {
178 passed = true;
179 }
180 assertTrue(passed,
181 "Expected IllegalArgumentException was not thrown, " + name + "= " + value);
182
183 }
184
185 /**
186 * Tests VM Option for an invalid values.
187 *
188 * @param name the VM option name
189 * @param values the collection if invalid values
190 */
191 public static void assertInvalidValues(String name, Collection<String> values) {
192 for (String v: values) {
193 assertInvalidValue(name, v);
194 }
195 }
196
197 /**
198 * Tests VM Option for an invalid values.
199 *
200 * @param name the VM option name
201 * @param values the array if invalid values
202 */
203 public static void assertInvalidValues(String name, String[] values) {
204 assertInvalidValues(name, Arrays.asList(values));
205 }
206 }