jdk/test/java/lang/management/ThreadMXBean/ResetPeakThreadCount.java - platform/libcore - Git at Google

 /*
  * Copyright (c) 2003, 2015, 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     4892507 8020875 8021335
  * @summary Basic Test for the following reset methods:
  *          - ThreadMXBean.resetPeakThreadCount()
  * @author  Mandy Chung
  * @author  Jaroslav Bachorik
  *
  * @build ResetPeakThreadCount
  * @build ThreadDump
  * @run main/othervm ResetPeakThreadCount
  */

 import java.lang.management.*;

 public class ResetPeakThreadCount {
     // initial number of new threads started
     private static final int DAEMON_THREADS_1 = 8;
     private static final int EXPECTED_PEAK_DELTA_1 = 8;

     // Terminate half of the threads started
     private static final int TERMINATE_1 = 4;

     // start new threads but expected the peak unchanged
     private static final int DAEMON_THREADS_2 = 2;
     private static final int EXPECTED_PEAK_DELTA_2 = 0;

     // peak thread count reset before starting new threads
     private static final int DAEMON_THREADS_3 = 4;
     private static final int EXPECTED_PEAK_DELTA_3 = 4;

     private static final int TERMINATE_2 = 8;

     private static final int TERMINATE_3 = 2;

     private static final int ALL_THREADS = DAEMON_THREADS_1 +
         DAEMON_THREADS_2 + DAEMON_THREADS_3;
     // barrier for threads communication
     private static final Barrier barrier = new Barrier(DAEMON_THREADS_1);

     private static final Thread allThreads[] = new Thread[ALL_THREADS];
     private static final boolean live[] = new boolean[ALL_THREADS];
     private static final ThreadMXBean mbean = ManagementFactory.getThreadMXBean();
     private static volatile boolean testFailed = false;

     public static void main(String[] argv) throws Exception {
         // This test does not expect any threads to be created
         // by the test harness after main() is invoked.
         // The checkThreadCount() method is to produce more
         // diagnostic information in case any unexpected test failure occur.
         long previous = mbean.getThreadCount();
         long current = previous;

         // reset the peak to start from a scratch
         resetPeak(current);

         // start DAEMON_THREADS_1 number of threads
         current = startThreads(0, DAEMON_THREADS_1, EXPECTED_PEAK_DELTA_1);

         checkThreadCount(previous, current, DAEMON_THREADS_1);
         previous = current;

         // terminate TERMINATE_1 number of threads and reset peak
         current = terminateThreads(0, TERMINATE_1);

         checkThreadCount(previous, current, TERMINATE_1 * -1);

         previous = current;

         // start DAEMON_THREADS_2 number of threads
         // expected peak is unchanged
         current = startThreads(DAEMON_THREADS_1, DAEMON_THREADS_2,
                                EXPECTED_PEAK_DELTA_2);

         checkThreadCount(previous, current, DAEMON_THREADS_2);
         previous = current;

         // Reset the peak
         resetPeak(current);

         // start DAEMON_THREADS_3 number of threads
         current = startThreads(DAEMON_THREADS_1 + DAEMON_THREADS_2,
                                DAEMON_THREADS_3, EXPECTED_PEAK_DELTA_3);

         checkThreadCount(previous, current, DAEMON_THREADS_3);
         previous = current;

         // terminate TERMINATE_2 number of threads and reset peak
         current = terminateThreads(TERMINATE_1, TERMINATE_2);

         checkThreadCount(previous, current, TERMINATE_2 * -1);
         previous = current;

         resetPeak(current);

         // terminate TERMINATE_3 number of threads and reset peak
         current = terminateThreads(TERMINATE_1 + TERMINATE_2, TERMINATE_3);

         checkThreadCount(previous, current, TERMINATE_3 * -1);
         resetPeak(current);

         if (testFailed)
             throw new RuntimeException("TEST FAILED.");

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

     private static long startThreads(int from, int count, int delta) throws InterruptedException {
         // get current peak thread count
         long peak1 = mbean.getPeakThreadCount();
         long current = mbean.getThreadCount();

         // Start threads and wait to be sure they all are alive
         System.out.println("Starting " + count + " threads....");
         barrier.set(count);
         synchronized(live) {
             for (int i = from; i < (from + count); i++) {
                 live[i] = true;
                 allThreads[i] = new MyThread(i);
                 allThreads[i].setDaemon(true);
                 allThreads[i].start();
             }
         }
         // wait until all threads have started.
         barrier.await();

         // get peak thread count after daemon threads have started
         long peak2 = mbean.getPeakThreadCount();

         System.out.println("   Current = " + mbean.getThreadCount() +
             " Peak before = " + peak1 + " after: " + peak2);

         if (peak2 != (peak1 + delta)) {
             throw new RuntimeException("Current Peak = " + peak2 +
                 " Expected to be == previous peak = " + peak1 + " + " +
                 delta);
         }
         // wait until the current thread count gets incremented
         while (mbean.getThreadCount() < (current + count)) {
             Thread.sleep(100);
         }
         current = mbean.getThreadCount();
         System.out.println("   Live thread count before returns " + current);
         return current;
     }

     private static long terminateThreads(int from, int count) throws InterruptedException {
         // get current peak thread count
         long peak1 = mbean.getPeakThreadCount();

         // Stop daemon threads and wait to be sure they all are dead
         System.out.println("Terminating " + count + " threads....");
         barrier.set(count);
         synchronized(live) {
             for (int i = from; i < (from+count); i++) {
                 live[i] = false;
             }
             live.notifyAll();
         }
         // wait until daemon threads terminated.
         barrier.await();

         // get peak thread count after daemon threads have terminated
         long peak2 = mbean.getPeakThreadCount();
         // assuming no system thread is added
         if (peak2 != peak1) {
             throw new RuntimeException("Current Peak = " + peak2 +
                 " Expected to be = previous peak = " + peak1);
         }

         for (int i = from; i < (from+count); i++) {
             allThreads[i].join();
         }

         // there is a race in the counter update logic somewhere causing
         // the thread counters go ff
         // we need to give the terminated threads some extra time to really die
         // JDK-8021335
         Thread.sleep(500);

         long current = mbean.getThreadCount();
         System.out.println("   Live thread count before returns " + current);
         return current;
     }

     private static void resetPeak(long expectedCount) {
         long peak3 = mbean.getPeakThreadCount();
         long current = mbean.getThreadCount();

         // Nightly testing showed some intermittent failure.
         // Check here to get diagnostic information if some strange
         // behavior occurs.
         checkThreadCount(expectedCount, current, 0);

         // Reset peak thread count
         mbean.resetPeakThreadCount();

         long afterResetPeak = mbean.getPeakThreadCount();
         long afterResetCurrent = mbean.getThreadCount();
         System.out.println("Reset peak before = " + peak3 +
             " current = " + current +
             " after reset peak = " + afterResetPeak +
             " current = " + afterResetCurrent);

         if (afterResetPeak != current) {
             throw new RuntimeException("Current Peak after reset = " +
                 afterResetPeak +
                 " Expected to be = current count = " + current);
         }
     }

     private static void checkThreadCount(long previous, long current, int expectedDelta) {
         if (current != previous + expectedDelta) {
             ThreadDump.threadDump();
             throw new RuntimeException("***** Unexpected thread count:" +
                                " previous = " + previous +
                                " current = " + current +
                                " delta = " + expectedDelta + "*****");
         }
     }

     // The MyThread thread lives as long as correspondent live[i] value is true
     private static class MyThread extends Thread {
         int id;

         MyThread(int id) {
             this.id = id;
         }

         public void run() {
             // signal started
             barrier.signal();
             synchronized(live) {
                 while (live[id]) {
                     try {
                         live.wait(100);
                     } catch (InterruptedException e) {
                         System.out.println("Unexpected exception is thrown.");
                         e.printStackTrace(System.out);
                         testFailed = true;
                     }
                 }
             }
             // signal about to exit
             barrier.signal();
         }
     }

 }
	/*
	* Copyright (c) 2003, 2015, 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 4892507 8020875 8021335
	* @summary Basic Test for the following reset methods:
	* - ThreadMXBean.resetPeakThreadCount()
	* @author Mandy Chung
	* @author Jaroslav Bachorik
	*
	* @build ResetPeakThreadCount
	* @build ThreadDump
	* @run main/othervm ResetPeakThreadCount
	*/

	import java.lang.management.*;

	public class ResetPeakThreadCount {
	// initial number of new threads started
	private static final int DAEMON_THREADS_1 = 8;
	private static final int EXPECTED_PEAK_DELTA_1 = 8;

	// Terminate half of the threads started
	private static final int TERMINATE_1 = 4;

	// start new threads but expected the peak unchanged
	private static final int DAEMON_THREADS_2 = 2;
	private static final int EXPECTED_PEAK_DELTA_2 = 0;

	// peak thread count reset before starting new threads
	private static final int DAEMON_THREADS_3 = 4;
	private static final int EXPECTED_PEAK_DELTA_3 = 4;

	private static final int TERMINATE_2 = 8;

	private static final int TERMINATE_3 = 2;

	private static final int ALL_THREADS = DAEMON_THREADS_1 +
	DAEMON_THREADS_2 + DAEMON_THREADS_3;
	// barrier for threads communication
	private static final Barrier barrier = new Barrier(DAEMON_THREADS_1);

	private static final Thread allThreads[] = new Thread[ALL_THREADS];
	private static final boolean live[] = new boolean[ALL_THREADS];
	private static final ThreadMXBean mbean = ManagementFactory.getThreadMXBean();
	private static volatile boolean testFailed = false;

	public static void main(String[] argv) throws Exception {
	// This test does not expect any threads to be created
	// by the test harness after main() is invoked.
	// The checkThreadCount() method is to produce more
	// diagnostic information in case any unexpected test failure occur.
	long previous = mbean.getThreadCount();
	long current = previous;

	// reset the peak to start from a scratch
	resetPeak(current);

	// start DAEMON_THREADS_1 number of threads
	current = startThreads(0, DAEMON_THREADS_1, EXPECTED_PEAK_DELTA_1);

	checkThreadCount(previous, current, DAEMON_THREADS_1);
	previous = current;

	// terminate TERMINATE_1 number of threads and reset peak
	current = terminateThreads(0, TERMINATE_1);

	checkThreadCount(previous, current, TERMINATE_1 * -1);

	previous = current;

	// start DAEMON_THREADS_2 number of threads
	// expected peak is unchanged
	current = startThreads(DAEMON_THREADS_1, DAEMON_THREADS_2,
	EXPECTED_PEAK_DELTA_2);

	checkThreadCount(previous, current, DAEMON_THREADS_2);
	previous = current;

	// Reset the peak
	resetPeak(current);

	// start DAEMON_THREADS_3 number of threads
	current = startThreads(DAEMON_THREADS_1 + DAEMON_THREADS_2,
	DAEMON_THREADS_3, EXPECTED_PEAK_DELTA_3);

	checkThreadCount(previous, current, DAEMON_THREADS_3);
	previous = current;

	// terminate TERMINATE_2 number of threads and reset peak
	current = terminateThreads(TERMINATE_1, TERMINATE_2);

	checkThreadCount(previous, current, TERMINATE_2 * -1);
	previous = current;

	resetPeak(current);

	// terminate TERMINATE_3 number of threads and reset peak
	current = terminateThreads(TERMINATE_1 + TERMINATE_2, TERMINATE_3);

	checkThreadCount(previous, current, TERMINATE_3 * -1);
	resetPeak(current);

	if (testFailed)
	throw new RuntimeException("TEST FAILED.");

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

	private static long startThreads(int from, int count, int delta) throws InterruptedException {
	// get current peak thread count
	long peak1 = mbean.getPeakThreadCount();
	long current = mbean.getThreadCount();

	// Start threads and wait to be sure they all are alive
	System.out.println("Starting " + count + " threads....");
	barrier.set(count);
	synchronized(live) {
	for (int i = from; i < (from + count); i++) {
	live[i] = true;
	allThreads[i] = new MyThread(i);
	allThreads[i].setDaemon(true);
	allThreads[i].start();
	}
	}
	// wait until all threads have started.
	barrier.await();

	// get peak thread count after daemon threads have started
	long peak2 = mbean.getPeakThreadCount();

	System.out.println(" Current = " + mbean.getThreadCount() +
	" Peak before = " + peak1 + " after: " + peak2);

	if (peak2 != (peak1 + delta)) {
	throw new RuntimeException("Current Peak = " + peak2 +
	" Expected to be == previous peak = " + peak1 + " + " +
	delta);
	}
	// wait until the current thread count gets incremented
	while (mbean.getThreadCount() < (current + count)) {
	Thread.sleep(100);
	}
	current = mbean.getThreadCount();
	System.out.println(" Live thread count before returns " + current);
	return current;
	}

	private static long terminateThreads(int from, int count) throws InterruptedException {
	// get current peak thread count
	long peak1 = mbean.getPeakThreadCount();

	// Stop daemon threads and wait to be sure they all are dead
	System.out.println("Terminating " + count + " threads....");
	barrier.set(count);
	synchronized(live) {
	for (int i = from; i < (from+count); i++) {
	live[i] = false;
	}
	live.notifyAll();
	}
	// wait until daemon threads terminated.
	barrier.await();

	// get peak thread count after daemon threads have terminated
	long peak2 = mbean.getPeakThreadCount();
	// assuming no system thread is added
	if (peak2 != peak1) {
	throw new RuntimeException("Current Peak = " + peak2 +
	" Expected to be = previous peak = " + peak1);
	}

	for (int i = from; i < (from+count); i++) {
	allThreads[i].join();
	}

	// there is a race in the counter update logic somewhere causing
	// the thread counters go ff
	// we need to give the terminated threads some extra time to really die
	// JDK-8021335
	Thread.sleep(500);

	long current = mbean.getThreadCount();
	System.out.println(" Live thread count before returns " + current);
	return current;
	}

	private static void resetPeak(long expectedCount) {
	long peak3 = mbean.getPeakThreadCount();
	long current = mbean.getThreadCount();

	// Nightly testing showed some intermittent failure.
	// Check here to get diagnostic information if some strange
	// behavior occurs.
	checkThreadCount(expectedCount, current, 0);

	// Reset peak thread count
	mbean.resetPeakThreadCount();

	long afterResetPeak = mbean.getPeakThreadCount();
	long afterResetCurrent = mbean.getThreadCount();
	System.out.println("Reset peak before = " + peak3 +
	" current = " + current +
	" after reset peak = " + afterResetPeak +
	" current = " + afterResetCurrent);

	if (afterResetPeak != current) {
	throw new RuntimeException("Current Peak after reset = " +
	afterResetPeak +
	" Expected to be = current count = " + current);
	}
	}

	private static void checkThreadCount(long previous, long current, int expectedDelta) {
	if (current != previous + expectedDelta) {
	ThreadDump.threadDump();
	throw new RuntimeException("***** Unexpected thread count:" +
	" previous = " + previous +
	" current = " + current +
	" delta = " + expectedDelta + "*****");
	}
	}

	// The MyThread thread lives as long as correspondent live[i] value is true
	private static class MyThread extends Thread {
	int id;

	MyThread(int id) {
	this.id = id;
	}

	public void run() {
	// signal started
	barrier.signal();
	synchronized(live) {
	while (live[id]) {
	try {
	live.wait(100);
	} catch (InterruptedException e) {
	System.out.println("Unexpected exception is thrown.");
	e.printStackTrace(System.out);
	testFailed = true;
	}
	}
	}
	// signal about to exit
	barrier.signal();
	}
	}

	}