[Ch15] Correct version of code magnets that works (using 2nd ed code) (dfc2f745) · Commits · examples / Head First Java 3rd Edition

src/main/java/ch15/TestThreads.java

+38 −25

Changes for src/main/java/ch15/TestThreads.java: 38 added lines, 25 removed lines.
Original line number	Diff line number	Diff line
		package ch15;

		import java.util.concurrent.ExecutionException;
		import java.util.concurrent.ExecutorService;
		import java.util.concurrent.Executors;
		import java.util.concurrent.Future;

		public class TestThreads {
		public static void main(String[] args) throws InterruptedException, ExecutionException {
		ExecutorService pool = Executors.newFixedThreadPool(2);
		Future<?> future1 = pool.submit(() -> {
		Accum a = Accum.getInstance();
		for (int i = 0; i < 98; i++) {
		a.updateCounter(1000);
		}
		});
		System.out.println(future1.isDone());
		Future<?> future2 = pool.submit(() -> {
		Accum a = Accum.getInstance();
		for (int i = 0; i < 99; i++) {
		a.updateCounter(1);
		}
		});
		pool.shutdown();
		System.out.println(Accum.getInstance().getCount());
		public static void main(String[] args) {
		ThreadOne t1 = new ThreadOne();
		ThreadTwo t2 = new ThreadTwo();
		Thread one = new Thread(t1);
		Thread two = new Thread(t2);
		one.start();
		two.start();
		}
		}

		@@ -33,12 +18,11 @@ class Accum {
		private Accum() {
		}

		// singleton
		public static Accum getInstance() {
		public static Accum getAccum() {
		return a;
		}

		public void updateCounter(int add) {
		public synchronized void updateCounter(int add) {
		counter += add;
		}

		@@ -46,3 +30,32 @@ class Accum {
		return counter;
		}
		}

		class ThreadOne implements Runnable {
		Accum a = Accum.getAccum();
		public void run() {
		for (int x = 0; x < 98; x++) {
		a.updateCounter(1000);
		try {
		Thread.sleep(50);
		} catch (InterruptedException ignored) {
		}
		}
		System.out.println("one " + a.getCount());
		}
		}

		class ThreadTwo implements Runnable {
		Accum a = Accum.getAccum();

		public void run() {
		for (int x = 0; x < 99; x++) {
		a.updateCounter(1);
		try {
		Thread.sleep(50);
		} catch (InterruptedException ignored) {
		}
		}
		System.out.println("two " + a.getCount());
		}
		}
		No newline at end of file