109 lines
2.7 KiB
Java
109 lines
2.7 KiB
Java
// concurrency/waxomatic2/WaxOMatic2.java
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// (c)2016 MindView LLC: see Copyright.txt
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// We make no guarantees that this code is fit for any purpose.
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// Visit http://mindviewinc.com/Books/OnJava/ for more book information.
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// Using Lock and Condition objects.
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package concurrency.waxomatic2;
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import java.util.concurrent.*;
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import java.util.concurrent.locks.*;
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class Car {
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private Lock lock = new ReentrantLock();
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private Condition condition = lock.newCondition();
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private boolean waxOn = false;
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public void waxed() {
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lock.lock();
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try {
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waxOn = true; // Ready to buff
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condition.signalAll();
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} finally {
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lock.unlock();
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}
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}
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public void buffed() {
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lock.lock();
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try {
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waxOn = false; // Ready for another coat of wax
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condition.signalAll();
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} finally {
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lock.unlock();
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}
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}
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public void waitForWaxing() throws InterruptedException {
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lock.lock();
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try {
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while(waxOn == false)
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condition.await();
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} finally {
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lock.unlock();
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}
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}
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public void waitForBuffing() throws InterruptedException{
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lock.lock();
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try {
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while(waxOn == true)
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condition.await();
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} finally {
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lock.unlock();
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}
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}
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}
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class WaxOn implements Runnable {
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private Car car;
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public WaxOn(Car c) { car = c; }
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@Override
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public void run() {
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try {
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while(!Thread.interrupted()) {
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System.out.print("Wax On! ");
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TimeUnit.MILLISECONDS.sleep(200);
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car.waxed();
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car.waitForBuffing();
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}
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} catch(InterruptedException e) {
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System.out.println("Exiting via interrupt");
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}
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System.out.println("Ending Wax On task");
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}
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}
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class WaxOff implements Runnable {
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private Car car;
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public WaxOff(Car c) { car = c; }
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@Override
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public void run() {
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try {
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while(!Thread.interrupted()) {
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car.waitForWaxing();
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System.out.print("Wax Off! ");
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TimeUnit.MILLISECONDS.sleep(200);
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car.buffed();
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}
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} catch(InterruptedException e) {
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System.out.println("Exiting via interrupt");
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}
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System.out.println("Ending Wax Off task");
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}
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}
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public class WaxOMatic2 {
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public static void main(String[] args) throws Exception {
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Car car = new Car();
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ExecutorService exec = Executors.newCachedThreadPool();
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exec.execute(new WaxOff(car));
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exec.execute(new WaxOn(car));
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TimeUnit.SECONDS.sleep(5);
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exec.shutdownNow();
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}
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}
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/* Output:
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Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On!
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Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off!
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Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On!
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Wax Off! Wax On! Wax Off! Wax On! Exiting via interrupt
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Exiting via interrupt
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Ending Wax On task
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Ending Wax Off task
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*/
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