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/*
* Copyright (c) 2011, 2018, 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.
*/
package nsk.monitoring.ThreadMXBean;
import java.util.concurrent.*;
/**
* Provide synchronization between management thread and its
* managed threads.
*/
public class BarrierHandler {
/**
* CyclicBarries for internal synchronization
*/
private CyclicBarrier monitoredThreadsBarrier, startActionBarrier,
finishActionBarrier;
/**
* Creates new BarrierHandler that will match specified Threads with
* management threads
*
* @param threads managed threads that are handled by BarrierHandler
*/
public BarrierHandler(MXBeanTestThread... threads) {
startActionBarrier = new CyclicBarrier(2);
finishActionBarrier = new CyclicBarrier(2);
monitoredThreadsBarrier = new CyclicBarrier(threads.length, new ActionThread());
}
/**
* Waits when managed thread completes iteration and some action should
* be performed by management thread. Should be called within managed thread
* only.
*
*/
public void ready() {
try {
monitoredThreadsBarrier.await();
} catch (Exception ignored) {}
}
/**
* Allows managed threads to proceed to next iteration. Should be called
* within management thread only.
*/
public void proceed() {
try {
finishActionBarrier.await();
startActionBarrier.await();
} catch (Exception ignored) {}
}
/**
* Waits until all managed threads complete first iteration. Should be
* called within management thread only.
*/
public void start() {
try {
startActionBarrier.await();
} catch (Exception ignored) {}
}
/**
* Allows managed threads to finish after last iteration. Should be called
* within management thread only.
*/
public void finish() {
try {
finishActionBarrier.await();
} catch (Exception ignored) {}
}
/**
* Action performed on main barrier. Used for synchronization between
* management and managed threads
*/
private class ActionThread extends Thread {
@Override
public void run() {
try {
startActionBarrier.await();
finishActionBarrier.await();
} catch (Exception ignored) {}
}
}
}
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