ThreadCpuTime.java revision 11884:b45c81ca8671 
1/*
2 * Copyright (c) 2003, 2015, 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/*
25 * @test
26 * @bug     4530538
27 * @summary Basic test of ThreadMXBean.getThreadCpuTime and
28 *          getCurrentThreadCpuTime.
29 * @author  Mandy Chung
30 * @modules java.management
31 */
32
33import java.lang.management.*;
34
35public class ThreadCpuTime {
36    private static ThreadMXBean mbean = ManagementFactory.getThreadMXBean();
37    private static boolean testFailed = false;
38    private static boolean done = false;
39    private static Object obj = new Object();
40    private static final int NUM_THREADS = 10;
41    private static Thread[] threads = new Thread[NUM_THREADS];
42    private static long[] times = new long[NUM_THREADS];
43
44    // careful about this value
45    private static final int DELTA = 100;
46
47    public static void main(String[] argv)
48        throws Exception {
49        if (!mbean.isCurrentThreadCpuTimeSupported()) {
50            return;
51        }
52
53       // disable CPU time
54        if (mbean.isThreadCpuTimeEnabled()) {
55            mbean.setThreadCpuTimeEnabled(false);
56        }
57
58        Thread curThread = Thread.currentThread();
59        long t = mbean.getCurrentThreadCpuTime();
60        if (t != -1) {
61            throw new RuntimeException("Invalid CurrenThreadCpuTime returned = " +
62                t + " expected = -1");
63        }
64
65        if (mbean.isThreadCpuTimeSupported()) {
66            long t1 = mbean.getThreadCpuTime(curThread.getId());
67            if (t1 != -1) {
68                throw new RuntimeException("Invalid ThreadCpuTime returned = " +
69                    t1 + " expected = -1");
70            }
71        }
72
73        // Enable CPU Time measurement
74        if (!mbean.isThreadCpuTimeEnabled()) {
75            mbean.setThreadCpuTimeEnabled(true);
76        }
77
78        if (!mbean.isThreadCpuTimeEnabled()) {
79            throw new RuntimeException("ThreadCpuTime is expected to be enabled");
80        }
81
82        long time = mbean.getCurrentThreadCpuTime();
83        if (time < 0) {
84            throw new RuntimeException("Invalid CPU time returned = " + time);
85        }
86
87        if (!mbean.isThreadCpuTimeSupported()) {
88            return;
89        }
90
91
92        // Expected to be time1 >= time
93        long time1 = mbean.getThreadCpuTime(curThread.getId());
94        if (time1 < time) {
95            throw new RuntimeException("CPU time " + time1 +
96                " expected >= " + time);
97        }
98        System.out.println(curThread.getName() +
99            " Current Thread Cpu Time = " + time +
100            " CPU time = " + time1);
101
102        for (int i = 0; i < NUM_THREADS; i++) {
103            threads[i] = new MyThread("MyThread-" + i);
104            threads[i].start();
105        }
106
107        waitUntilThreadBlocked();
108
109        for (int i = 0; i < NUM_THREADS; i++) {
110            times[i] = mbean.getThreadCpuTime(threads[i].getId());
111        }
112
113        goSleep(200);
114
115        for (int i = 0; i < NUM_THREADS; i++) {
116            long newTime = mbean.getThreadCpuTime(threads[i].getId());
117            if (times[i] > newTime) {
118                throw new RuntimeException("TEST FAILED: " +
119                    threads[i].getName() +
120                    " previous CPU time = " + times[i] +
121                    " > current CPU time = " + newTime);
122            }
123            if ((times[i] + DELTA) < newTime) {
124                throw new RuntimeException("TEST FAILED: " +
125                    threads[i].getName() +
126                    " CPU time = " + newTime +
127                    " previous CPU time " + times[i] +
128                    " out of expected range");
129            }
130
131            System.out.println(threads[i].getName() +
132                " Previous Cpu Time = " + times[i] +
133                " Current CPU time = " + newTime);
134        }
135
136        synchronized (obj) {
137            done = true;
138            obj.notifyAll();
139        }
140
141        for (int i = 0; i < NUM_THREADS; i++) {
142            try {
143                threads[i].join();
144            } catch (InterruptedException e) {
145                System.out.println("Unexpected exception is thrown.");
146                e.printStackTrace(System.out);
147                testFailed = true;
148                break;
149            }
150        }
151        if (testFailed) {
152            throw new RuntimeException("TEST FAILED");
153        }
154
155        System.out.println("Test passed");
156    }
157
158
159    private static void goSleep(long ms) throws Exception {
160        try {
161            Thread.sleep(ms);
162        } catch (InterruptedException e) {
163            System.out.println("Unexpected exception is thrown.");
164            throw e;
165        }
166    }
167
168    private static void waitUntilThreadBlocked()
169        throws Exception {
170        int count = 0;
171        while (count != NUM_THREADS) {
172            goSleep(100);
173            count = 0;
174            for (int i = 0; i < NUM_THREADS; i++) {
175                ThreadInfo info = mbean.getThreadInfo(threads[i].getId());
176                if (info.getThreadState() == Thread.State.WAITING) {
177                    count++;
178                }
179            }
180        }
181    }
182
183    static class MyThread extends Thread {
184        public MyThread(String name) {
185            super(name);
186        }
187
188        public void run() {
189            double sum = 0;
190            for (int i = 0; i < 5000; i++) {
191               double r = Math.random();
192               double x = Math.pow(3, r);
193               sum += x - r;
194            }
195            synchronized (obj) {
196                while (!done) {
197                    try {
198                        obj.wait();
199                    } catch (InterruptedException e) {
200                        System.out.println("Unexpected exception is thrown.");
201                        e.printStackTrace(System.out);
202                        testFailed = true;
203                        break;
204                    }
205                }
206            }
207
208            sum = 0;
209            for (int i = 0; i < 5000; i++) {
210               double r = Math.random();
211               double x = Math.pow(3, r);
212               sum += x - r;
213            }
214
215            long utime1 = mbean.getCurrentThreadUserTime();
216            long utime2 = mbean.getThreadUserTime(getId());
217            long time1 = mbean.getCurrentThreadCpuTime();
218            long time2 = mbean.getThreadCpuTime(getId());
219
220            System.out.println(getName() + ": " +
221                "CurrentThreadUserTime = " + utime1 +
222                " ThreadUserTime = " + utime2);
223            System.out.println(getName() + ": " +
224                "CurrentThreadCpuTime  = " + time1 +
225                " ThreadCpuTime  = " + time2);
226
227            if (time1 > time2) {
228                throw new RuntimeException("TEST FAILED: " + getName() +
229                    " CurrentThreadCpuTime = " + time1 +
230                    " > ThreadCpuTime = " + time2);
231            }
232/*************
233 * FIXME: Seems that on Solaris-sparc,
234 * It occasionally returns a different current thread user time > thread user time
235            if (utime1 > utime2) {
236                throw new RuntimeException("TEST FAILED: " + getName() +
237                    " CurrentThreadUserTime = " + utime1 +
238                    " > ThreadUserTime = " + utime2);
239            }
240*/
241        }
242    }
243
244}
245