Java example source code file (ThreadAllocatedMemory.java)

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Java - Java tags/keywords

current, failed, interruptedexception, invalid, management, mythread, num_threads, object, previous, runtimeexception, string, test, threadallocatedbytes, threadallocatedmemory, threadinfo

The ThreadAllocatedMemory.java Java example source code

/*
 * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*
 * @test
 * @bug     6173675
 * @summary Basic test of ThreadMXBean.getThreadAllocatedBytes
 * @author  Paul Hohensee
 */

import java.lang.management.*;

public class ThreadAllocatedMemory {
    private static com.sun.management.ThreadMXBean mbean =
        (com.sun.management.ThreadMXBean)ManagementFactory.getThreadMXBean();
    private static boolean testFailed = false;
    private static boolean done = false;
    private static boolean done1 = false;
    private static Object obj = new Object();
    private static final int NUM_THREADS = 10;
    private static Thread[] threads = new Thread[NUM_THREADS];
    private static long[] sizes = new long[NUM_THREADS];

    public static void main(String[] argv)
        throws Exception {

        if (!mbean.isThreadAllocatedMemorySupported()) {
            return;
        }

        // disable allocated memory measurement
        if (mbean.isThreadAllocatedMemoryEnabled()) {
            mbean.setThreadAllocatedMemoryEnabled(false);
        }

        if (mbean.isThreadAllocatedMemoryEnabled()) {
            throw new RuntimeException(
                "ThreadAllocatedMemory is expected to be disabled");
        }

        Thread curThread = Thread.currentThread();
        long id = curThread.getId();

        long s = mbean.getThreadAllocatedBytes(id);
        if (s != -1) {
            throw new RuntimeException(
                "Invalid ThreadAllocatedBytes returned = " +
                s + " expected = -1");
        }

        // enable allocated memory measurement
        if (!mbean.isThreadAllocatedMemoryEnabled()) {
            mbean.setThreadAllocatedMemoryEnabled(true);
        }

        if (!mbean.isThreadAllocatedMemoryEnabled()) {
            throw new RuntimeException(
                "ThreadAllocatedMemory is expected to be enabled");
        }

        long size = mbean.getThreadAllocatedBytes(id);
        // implementation could have started measurement when
        // measurement was enabled, in which case size can be 0
        if (size < 0) {
            throw new RuntimeException(
                "Invalid allocated bytes returned = " + size);
        }

        doit();

        // Expected to be size1 >= size
        long size1 = mbean.getThreadAllocatedBytes(id);
        if (size1 < size) {
            throw new RuntimeException("Allocated bytes " + size1 +
                " expected >= " + size);
        }
        System.out.println(curThread.getName() +
            " Current thread allocated bytes = " + size +
            " allocated bytes = " + size1);


        // start threads, wait for them to block
        for (int i = 0; i < NUM_THREADS; i++) {
            threads[i] = new MyThread("MyThread-" + i);
            threads[i].start();
        }

        // threads block after doing some allocation
        waitUntilThreadBlocked();

        for (int i = 0; i < NUM_THREADS; i++) {
            sizes[i] = mbean.getThreadAllocatedBytes(threads[i].getId());
        }

        // let threads go and do some more allocation
        synchronized (obj) {
            done = true;
            obj.notifyAll();
        }

        // wait for threads to get going again.  we don't care if we
        // catch them in mid-execution or if some of them haven't
        // restarted after we're done sleeping.
        goSleep(400);

        for (int i = 0; i < NUM_THREADS; i++) {
            long newSize = mbean.getThreadAllocatedBytes(threads[i].getId());
            if (sizes[i] > newSize) {
                throw new RuntimeException("TEST FAILED: " +
                    threads[i].getName() +
                    " previous allocated bytes = " + sizes[i] +
                    " > current allocated bytes = " + newSize);
            }
            System.out.println(threads[i].getName() +
                " Previous allocated bytes = " + sizes[i] +
                " Current allocated bytes = " + newSize);
        }

        // let threads exit
        synchronized (obj) {
            done1 = true;
            obj.notifyAll();
        }

        for (int i = 0; i < NUM_THREADS; i++) {
            try {
                threads[i].join();
            } catch (InterruptedException e) {
                System.out.println("Unexpected exception is thrown.");
                e.printStackTrace(System.out);
                testFailed = true;
                break;
            }
        }
        if (testFailed) {
            throw new RuntimeException("TEST FAILED");
        }

        System.out.println("Test passed");
    }


    private static void goSleep(long ms) throws Exception {
        try {
            Thread.sleep(ms);
        } catch (InterruptedException e) {
            System.out.println("Unexpected exception is thrown.");
            throw e;
        }
    }

    private static void waitUntilThreadBlocked()
        throws Exception {
        int count = 0;
        while (count != NUM_THREADS) {
            goSleep(100);
            count = 0;
            for (int i = 0; i < NUM_THREADS; i++) {
                ThreadInfo info = mbean.getThreadInfo(threads[i].getId());
                if (info.getThreadState() == Thread.State.WAITING) {
                    count++;
                }
            }
        }
    }

    public static void doit() {
        String tmp = "";
        long hashCode = 0;
        for (int counter = 0; counter < 1000; counter++) {
            tmp += counter;
            hashCode = tmp.hashCode();
        }
        System.out.println(Thread.currentThread().getName() +
                           " hashcode: " + hashCode);
    }

    static class MyThread extends Thread {
        public MyThread(String name) {
            super(name);
        }

        public void run() {
            ThreadAllocatedMemory.doit();

            synchronized (obj) {
                while (!done) {
                    try {
                        obj.wait();
                    } catch (InterruptedException e) {
                        System.out.println("Unexpected exception is thrown.");
                        e.printStackTrace(System.out);
                        testFailed = true;
                        break;
                    }
                }
            }

            long size1 = mbean.getThreadAllocatedBytes(getId());
            ThreadAllocatedMemory.doit();
            long size2 = mbean.getThreadAllocatedBytes(getId());

            System.out.println(getName() + ": " +
                "ThreadAllocatedBytes  = " + size1 +
                " ThreadAllocatedBytes  = " + size2);

            if (size1 > size2) {
                throw new RuntimeException("TEST FAILED: " + getName() +
                    " ThreadAllocatedBytes = " + size1 +
                    " > ThreadAllocatedBytes = " + size2);
            }

            synchronized (obj) {
                while (!done1) {
                    try {
                        obj.wait();
                    } catch (InterruptedException e) {
                        System.out.println("Unexpected exception is thrown.");
                        e.printStackTrace(System.out);
                        testFailed = true;
                        break;
                    }
                }
            }
        }
    }
}