1 /*
2 * Copyright (c) 2011, 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.util.Map;
29
30 /**
31 * Platform-specific management interface for the thread system
32 * of the Java virtual machine.
33 * <p>
34 * This platform extension is only available to a thread
35 * implementation that supports this extension.
36 *
37 * @author Paul Hohensee
38 * @since 6u25
39 */
40
41 @jdk.Supported
42 public interface ThreadMXBean extends java.lang.management.ThreadMXBean {
43 /**
44 * Returns the total CPU time for each thread whose ID is
45 * in the input array {@code ids} in nanoseconds.
46 * The returned values are of nanoseconds precision but
47 * not necessarily nanoseconds accuracy.
48 * <p>
49 * This method is equivalent to calling the
50 * {@link ThreadMXBean#getThreadCpuTime(long)}
51 * method for each thread ID in the input array {@code ids} and setting the
52 * returned value in the corresponding element of the returned array.
53 *
54 * @param ids an array of thread IDs.
55 * @return an array of long values, each of which is the amount of CPU
56 * time the thread whose ID is in the corresponding element of the input
57 * array of IDs has used,
58 * if the thread of a specified ID exists, the thread is alive,
59 * and CPU time measurement is enabled;
60 * {@code -1} otherwise.
61 *
62 * @throws NullPointerException if {@code ids} is {@code null}
63 * @throws IllegalArgumentException if any element in the input array
64 * {@code ids} is {@code <=} {@code 0}.
65 * @throws java.lang.UnsupportedOperationException if the Java
66 * virtual machine implementation does not support CPU time
67 * measurement.
68 *
69 * @see ThreadMXBean#getThreadCpuTime(long)
70 * @see #getThreadUserTime
71 * @see ThreadMXBean#isThreadCpuTimeSupported
72 * @see ThreadMXBean#isThreadCpuTimeEnabled
73 * @see ThreadMXBean#setThreadCpuTimeEnabled
74 */
75 public long[] getThreadCpuTime(long[] ids);
76
77 /**
78 * Returns the CPU time that each thread whose ID is in the input array
79 * {@code ids} has executed in user mode in nanoseconds.
80 * The returned values are of nanoseconds precision but
81 * not necessarily nanoseconds accuracy.
82 * <p>
83 * This method is equivalent to calling the
84 * {@link ThreadMXBean#getThreadUserTime(long)}
85 * method for each thread ID in the input array {@code ids} and setting the
86 * returned value in the corresponding element of the returned array.
87 *
88 * @param ids an array of thread IDs.
89 * @return an array of long values, each of which is the amount of user
90 * mode CPU time the thread whose ID is in the corresponding element of
91 * the input array of IDs has used,
92 * if the thread of a specified ID exists, the thread is alive,
93 * and CPU time measurement is enabled;
94 * {@code -1} otherwise.
95 *
96 * @throws NullPointerException if {@code ids} is {@code null}
97 * @throws IllegalArgumentException if any element in the input array
98 * {@code ids} is {@code <=} {@code 0}.
99 * @throws java.lang.UnsupportedOperationException if the Java
100 * virtual machine implementation does not support CPU time
101 * measurement.
102 *
103 * @see ThreadMXBean#getThreadUserTime(long)
104 * @see #getThreadCpuTime
105 * @see ThreadMXBean#isThreadCpuTimeSupported
106 * @see ThreadMXBean#isThreadCpuTimeEnabled
107 * @see ThreadMXBean#setThreadCpuTimeEnabled
108 */
109 public long[] getThreadUserTime(long[] ids);
110
111 /**
112 * Returns an approximation of the total amount of memory, in bytes,
113 * allocated in heap memory for the thread of the specified ID.
114 * The returned value is an approximation because some Java virtual machine
115 * implementations may use object allocation mechanisms that result in a
116 * delay between the time an object is allocated and the time its size is
117 * recorded.
118 * <p>
119 * If the thread of the specified ID is not alive or does not exist,
120 * this method returns {@code -1}. If thread memory allocation measurement
121 * is disabled, this method returns {@code -1}.
122 * A thread is alive if it has been started and has not yet died.
123 * <p>
124 * If thread memory allocation measurement is enabled after the thread has
125 * started, the Java virtual machine implementation may choose any time up
126 * to and including the time that the capability is enabled as the point
127 * where thread memory allocation measurement starts.
128 *
129 * @param id the thread ID of a thread
130 * @return an approximation of the total memory allocated, in bytes, in
131 * heap memory for a thread of the specified ID
132 * if the thread of the specified ID exists, the thread is alive,
133 * and thread memory allocation measurement is enabled;
134 * {@code -1} otherwise.
135 *
136 * @throws IllegalArgumentException if {@code id} {@code <=} {@code 0}.
137 * @throws java.lang.UnsupportedOperationException if the Java virtual
138 * machine implementation does not support thread memory allocation
139 * measurement.
140 *
141 * @see #isThreadAllocatedMemorySupported
142 * @see #isThreadAllocatedMemoryEnabled
143 * @see #setThreadAllocatedMemoryEnabled
144 */
145 public long getThreadAllocatedBytes(long id);
146
147 /**
148 * Returns an approximation of the total amount of memory, in bytes,
149 * allocated in heap memory for each thread whose ID is in the input
150 * array {@code ids}.
151 * The returned values are approximations because some Java virtual machine
152 * implementations may use object allocation mechanisms that result in a
153 * delay between the time an object is allocated and the time its size is
154 * recorded.
155 * <p>
156 * This method is equivalent to calling the
157 * {@link #getThreadAllocatedBytes(long)}
158 * method for each thread ID in the input array {@code ids} and setting the
159 * returned value in the corresponding element of the returned array.
160 *
161 * @param ids an array of thread IDs.
162 * @return an array of long values, each of which is an approximation of
163 * the total memory allocated, in bytes, in heap memory for the thread
164 * whose ID is in the corresponding element of the input array of IDs.
165 *
166 * @throws NullPointerException if {@code ids} is {@code null}
167 * @throws IllegalArgumentException if any element in the input array
168 * {@code ids} is {@code <=} {@code 0}.
169 * @throws java.lang.UnsupportedOperationException if the Java virtual
170 * machine implementation does not support thread memory allocation
171 * measurement.
172 *
173 * @see #getThreadAllocatedBytes(long)
174 * @see #isThreadAllocatedMemorySupported
175 * @see #isThreadAllocatedMemoryEnabled
176 * @see #setThreadAllocatedMemoryEnabled
177 */
178 public long[] getThreadAllocatedBytes(long[] ids);
179
180 /**
181 * Tests if the Java virtual machine implementation supports thread memory
182 * allocation measurement.
183 *
184 * @return
185 * {@code true}
186 * if the Java virtual machine implementation supports thread memory
187 * allocation measurement;
188 * {@code false} otherwise.
189 */
190 public boolean isThreadAllocatedMemorySupported();
191
192 /**
193 * Tests if thread memory allocation measurement is enabled.
194 *
195 * @return {@code true} if thread memory allocation measurement is enabled;
196 * {@code false} otherwise.
197 *
198 * @throws java.lang.UnsupportedOperationException if the Java virtual
199 * machine does not support thread memory allocation measurement.
200 *
201 * @see #isThreadAllocatedMemorySupported
202 */
203 public boolean isThreadAllocatedMemoryEnabled();
204
205 /**
206 * Enables or disables thread memory allocation measurement. The default
207 * is platform dependent.
208 *
209 * @param enable {@code true} to enable;
210 * {@code false} to disable.
211 *
212 * @throws java.lang.UnsupportedOperationException if the Java virtual
213 * machine does not support thread memory allocation measurement.
214 *
215 * @throws java.lang.SecurityException if a security manager
216 * exists and the caller does not have
217 * ManagementPermission("control").
218 *
219 * @see #isThreadAllocatedMemorySupported
220 */
221 public void setThreadAllocatedMemoryEnabled(boolean enable);
222 }