com.brienwheeler.lib.test.stepper.SteppableThread.java Source code

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Here is the source code for com.brienwheeler.lib.test.stepper.SteppableThread.java

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/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2013 Brien L. Wheeler (brienwheeler@yahoo.com)
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package com.brienwheeler.lib.test.stepper;

import java.util.concurrent.BrokenBarrierException;
import java.util.concurrent.CyclicBarrier;
import java.util.concurrent.TimeoutException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

public abstract class SteppableThread extends Thread {
    private static final boolean verbose = true; // set to true for easier debugging

    protected final Log log = LogFactory.getLog(getClass());
    private final CyclicBarrier interruptProcessed = new CyclicBarrier(2);
    private final CyclicBarrier stepDone = new CyclicBarrier(2); // this thread and a controlling thread
    private final CyclicBarrier stepStart = new CyclicBarrier(2);
    private volatile boolean firstWait = true;
    private Throwable testThrowable = null;
    private volatile boolean wasInterrupted = false;
    private long joinDelay = 10000L;

    protected abstract void onRun();

    @Override
    public final void run() {
        log.info("starting");
        try {
            onRun();
            wasInterrupted = Thread.currentThread().isInterrupted();
        } catch (Throwable e) {
            testThrowable = e;
            if (Thread.currentThread().isInterrupted())
                wasInterrupted = true;
        } finally {
            // wait to be released for thread exit
            SteppableThread.waitForNextStep();
            log.info("exiting");
        }
    }

    public void release() {
        try {
            verbose("releasing " + getName());
            if (stepStart.await() == 0)
                stepStart.reset();
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
            throw new RuntimeException(e);
        } catch (BrokenBarrierException e) {
            throw new RuntimeException(e);
        }
    }

    public void waitDone() {
        try {
            verbose("waiting for done " + getName());
            if (stepDone.await() == 0)
                stepDone.reset();
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
            throw new RuntimeException(e);
        } catch (BrokenBarrierException e) {
            throw new RuntimeException(e);
        }
    }

    public void releaseAndWaitDone() {
        release();
        waitDone();
    }

    public void waitInterrupt() {
        try {
            verbose("waiting for interrupt processed " + getName());
            if (interruptProcessed.await() == 0)
                interruptProcessed.reset();
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
            throw new RuntimeException(e);
        } catch (BrokenBarrierException e) {
            throw new RuntimeException(e);
        }
    }

    public void interruptAndWait() {
        verbose("interrupting " + getName());
        interrupt();
        waitInterrupt();
    }

    public Throwable getTestThrowable() {
        return testThrowable;
    }

    public boolean getWasInterrupted() {
        return wasInterrupted;
    }

    public void releaseAndJoin() {
        try {
            release();
            verbose("joining " + getName());
            join(joinDelay);
            if (isAlive())
                throw new RuntimeException(new TimeoutException());
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
            throw new RuntimeException(e);
        }
    }

    private void signalInterruptProcessed() {
        try {
            verbose("signalling interrupt processed " + getName());
            if (interruptProcessed.await() == 0)
                interruptProcessed.reset();
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        } catch (BrokenBarrierException e) {
            throw new RuntimeException(e);
        }
    }

    private void waitForNextStepInternal() {
        boolean interrupted = Thread.interrupted(); // test and clear

        try {
            boolean done = false;
            while (!done) {
                try {
                    if (firstWait) {
                        firstWait = false;
                    } else {
                        verbose("signalling done");
                        if (stepDone.await() == 0)
                            stepDone.reset();
                    }
                    done = true;
                } catch (InterruptedException e) {
                    verbose("interrupted");
                    interrupted = true;
                    stepDone.reset();
                    signalInterruptProcessed();
                } catch (BrokenBarrierException e) {
                    throw new RuntimeException(e);
                }
            }

            done = false;
            while (!done) {
                try {
                    verbose("waiting for release");
                    if (stepStart.await() == 0)
                        stepStart.reset();
                    done = true;
                } catch (InterruptedException e) {
                    verbose("interrupted");
                    interrupted = true;
                    stepStart.reset();
                    signalInterruptProcessed();
                } catch (BrokenBarrierException e) {
                    throw new RuntimeException(e);
                }
            }
        } finally {
            if (interrupted)
                interrupt();
        }
    }

    public static void waitForNextStep() {
        if (!(Thread.currentThread() instanceof SteppableThread))
            throw new RuntimeException("can only call waitForNextStep() from inside SteppableThread");
        ((SteppableThread) Thread.currentThread()).waitForNextStepInternal();

    }

    protected void verbose(String message) {
        if (verbose)
            log.info(message);
        else
            log.debug(message);
    }
}