1 /*
2 * Copyright (c) 2005, 2022, 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 import jdk.internal.javac.PreviewFeature;
31
32 /**
33 * Diagnostic management interface for the HotSpot Virtual Machine.
34 *
35 * <p>The diagnostic MBean is registered to the platform MBeanServer
36 * as are other platform MBeans.
37 *
38 * <p>The {@code ObjectName} for uniquely identifying the diagnostic
39 * MXBean within an MBeanServer is:
40 * <blockquote>
41 * {@code com.sun.management:type=HotSpotDiagnostic}
42 * </blockquote>
43 *
44 * It can be obtained by calling the
45 * {@link PlatformManagedObject#getObjectName} method.
46 *
47 * All methods throw a {@code NullPointerException} if any input argument is
48 * {@code null} unless it's stated otherwise.
49 *
50 * @see java.lang.management.ManagementFactory#getPlatformMXBeans(Class)
51 */
52 public interface HotSpotDiagnosticMXBean extends PlatformManagedObject {
53 /**
54 * Dumps the heap to the {@code outputFile} file in the same
55 * format as the hprof heap dump.
56 * <p>
57 * If this method is called remotely from another process,
58 * the heap dump output is written to a file named {@code outputFile}
59 * on the machine where the target VM is running. If outputFile is
60 * a relative path, it is relative to the working directory where
61 * the target VM was started.
62 *
63 * @param outputFile the system-dependent filename
64 * @param live if {@code true} dump only <i>live</i> objects
65 * i.e. objects that are reachable from others
66 * @throws IOException if the {@code outputFile} already exists,
67 * cannot be created, opened, or written to.
68 * @throws UnsupportedOperationException if this operation is not supported.
69 * @throws IllegalArgumentException if {@code outputFile} does not end with ".hprof" suffix.
70 * @throws NullPointerException if {@code outputFile} is {@code null}.
71 * @throws SecurityException
72 * If a security manager exists and its {@link
73 * java.lang.SecurityManager#checkWrite(java.lang.String)}
74 * method denies write access to the named file
75 * or the caller does not have ManagmentPermission("control").
76 */
77 public void dumpHeap(String outputFile, boolean live) throws IOException;
78
79 /**
80 * Returns a list of {@code VMOption} objects for all diagnostic options.
81 * A diagnostic option is a {@link VMOption#isWriteable writeable}
82 * VM option that can be set dynamically mainly for troubleshooting
83 * and diagnosis.
84 *
85 * @return a list of {@code VMOption} objects for all diagnostic options.
86 */
87 public java.util.List<VMOption> getDiagnosticOptions();
88
89 /**
90 * Returns a {@code VMOption} object for a VM option of the given
91 * name.
92 *
93 * @return a {@code VMOption} object for a VM option of the given name.
94 * @throws NullPointerException if name is {@code null}.
95 * @throws IllegalArgumentException if a VM option of the given name
96 * does not exist.
97 */
98 public VMOption getVMOption(String name);
99
100 /**
101 * Sets a VM option of the given name to the specified value.
102 * The new value will be reflected in a new {@code VMOption}
103 * object returned by the {@link #getVMOption} method or
104 * the {@link #getDiagnosticOptions} method. This method does
105 * not change the value of this {@code VMOption} object.
106 *
107 * @param name Name of a VM option
108 * @param value New value of the VM option to be set
109 *
110 * @throws IllegalArgumentException if the VM option of the given name
111 * does not exist.
112 * @throws IllegalArgumentException if the new value is invalid.
113 * @throws IllegalArgumentException if the VM option is not writable.
114 * @throws NullPointerException if name or value is {@code null}.
115 *
116 * @throws java.lang.SecurityException
117 * if a security manager exists and the caller does not have
118 * ManagementPermission("control").
119 */
120 public void setVMOption(String name, String value);
121
122 /**
123 * Generate a thread dump to the given file in the given format. The
124 * {@code outputFile} parameter must be an absolute path to a file that
125 * does not exist.
126 *
127 * <p> The thread dump will include output for all platform threads. It may
128 * include output for some or all virtual threads.
129 *
130 * @implSpec
131 * The default implementation throws {@code UnsupportedOperationException}.
132 *
133 * @apiNote
134 * The output file is required to be an absolute path as the MXBean may be
135 * accessed remotely from a tool or program with a different current working
136 * directory.
137 *
138 * @param outputFile the path to the file to create
139 * @param format the format to use
140 * @throws IllegalArgumentException if the file path is not absolute
141 * @throws IOException if the file already exists or an I/O exception is
142 * thrown writing to the file
143 * @throws NullPointerException if either parameter is {@code null}
144 * @throws SecurityException
145 * if a security manager is set and its {@link
146 * SecurityManager#checkWrite(java.lang.String)} method denies write
147 * access to the file or {@link java.lang.management.ManagementPermission
148 * ManagementPermission("control")} is denied
149 * @throws UnsupportedOperationException if this operation is not supported
150 * @since 19
151 */
152 @PreviewFeature(feature = PreviewFeature.Feature.VIRTUAL_THREADS, reflective = true)
153 default void dumpThreads(String outputFile, ThreadDumpFormat format) throws IOException {
154 throw new UnsupportedOperationException();
155 }
156
157 /**
158 * Thread dump format.
159 * @since 19
160 */
161 @PreviewFeature(feature = PreviewFeature.Feature.VIRTUAL_THREADS, reflective = true)
162 public static enum ThreadDumpFormat {
163 /**
164 * Plain text format.
165 */
166 TEXT_PLAIN,
167 /**
168 * JSON (JavaScript Object Notation) format.
169 */
170 JSON,
171 }
172 }