1 /*
2 * Copyright (c) 2005, 2024, 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. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package com.sun.management;
27
28 import java.io.IOException;
29 import java.lang.management.PlatformManagedObject;
30
31 /**
32 * Diagnostic management interface for the HotSpot Virtual Machine.
33 *
34 * <p>The diagnostic MBean is registered to the platform MBeanServer
35 * as are other platform MBeans.
36 *
37 * <p>The {@code ObjectName} for uniquely identifying the diagnostic
38 * MXBean within an MBeanServer is:
39 * <blockquote>
40 * {@code com.sun.management:type=HotSpotDiagnostic}
41 * </blockquote>
42 *
43 * It can be obtained by calling the
44 * {@link PlatformManagedObject#getObjectName} method.
45 *
46 * All methods throw a {@code NullPointerException} if any input argument is
47 * {@code null} unless it's stated otherwise.
48 *
49 * @see java.lang.management.ManagementFactory#getPlatformMXBeans(Class)
50 *
51 * @since 1.6
52 */
53 public interface HotSpotDiagnosticMXBean extends PlatformManagedObject {
54 /**
55 * Dumps the heap to the {@code outputFile} file in the same
56 * format as the hprof heap dump.
57 * <p>
58 * If this method is called remotely from another process,
59 * the heap dump output is written to a file named {@code outputFile}
60 * on the machine where the target VM is running. If outputFile is
61 * a relative path, it is relative to the working directory where
62 * the target VM was started.
63 *
64 * @param outputFile the system-dependent filename
65 * @param live if {@code true} dump only <i>live</i> objects
66 * i.e. objects that are reachable from others
67 * @throws IOException if the {@code outputFile} already exists,
68 * cannot be created, opened, or written to.
69 * @throws UnsupportedOperationException if this operation is not supported.
70 * @throws IllegalArgumentException if {@code outputFile} does not end with ".hprof" suffix.
71 * @throws NullPointerException if {@code outputFile} is {@code null}.
72 */
73 public void dumpHeap(String outputFile, boolean live) throws IOException;
74
75 /**
76 * Returns a list of {@code VMOption} objects for all diagnostic options.
77 * A diagnostic option is a {@link VMOption#isWriteable writeable}
78 * VM option that can be set dynamically mainly for troubleshooting
79 * and diagnosis.
80 *
81 * @return a list of {@code VMOption} objects for all diagnostic options.
82 */
83 public java.util.List<VMOption> getDiagnosticOptions();
84
85 /**
86 * Returns a {@code VMOption} object for a VM option of the given
87 * name.
88 *
89 * @return a {@code VMOption} object for a VM option of the given name.
90 * @throws NullPointerException if name is {@code null}.
91 * @throws IllegalArgumentException if a VM option of the given name
92 * does not exist.
93 */
94 public VMOption getVMOption(String name);
95
96 /**
97 * Sets a VM option of the given name to the specified value.
98 * The new value will be reflected in a new {@code VMOption}
99 * object returned by the {@link #getVMOption} method or
100 * the {@link #getDiagnosticOptions} method. This method does
101 * not change the value of this {@code VMOption} object.
102 *
103 * @param name Name of a VM option
104 * @param value New value of the VM option to be set
105 *
106 * @throws IllegalArgumentException if the VM option of the given name
107 * does not exist.
108 * @throws IllegalArgumentException if the new value is invalid.
109 * @throws IllegalArgumentException if the VM option is not writable.
110 * @throws NullPointerException if name or value is {@code null}.
111 */
112 public void setVMOption(String name, String value);
113
114 /**
115 * Generate a thread dump to the given file in the given format. The
116 * {@code outputFile} parameter must be an absolute path to a file that
117 * does not exist.
118 *
119 * <p> The thread dump will include output for all platform threads. It may
120 * include output for some or all virtual threads.
121 *
122 * @implSpec
123 * The default implementation throws {@code UnsupportedOperationException}.
124 *
125 * @apiNote
126 * The output file is required to be an absolute path as the MXBean may be
127 * accessed remotely from a tool or program with a different current working
128 * directory.
129 *
130 * @param outputFile the path to the file to create
131 * @param format the format to use
132 * @throws IllegalArgumentException if the file path is not absolute
133 * @throws IOException if the file already exists or an I/O exception is
134 * thrown writing to the file
135 * @throws NullPointerException if either parameter is {@code null}
136 * @throws UnsupportedOperationException if this operation is not supported
137 * @since 21
138 */
139 default void dumpThreads(String outputFile, ThreadDumpFormat format) throws IOException {
140 throw new UnsupportedOperationException();
141 }
142
143 /**
144 * Thread dump format.
145 * @since 21
146 */
147 public static enum ThreadDumpFormat {
148 /**
149 * Plain text format.
150 */
151 TEXT_PLAIN,
152 /**
153 * JSON (JavaScript Object Notation) format.
154 */
155 JSON,
156 }
157 }