[Ch15] Solving Ryan and Monica with an AtomicInteger (3ad5d19f) · Commits · examples / Head First Java 3rd Edition

src/main/java/ch15/RyanAndMonicaAtomicTest.java

0 → 100644

+68 −0

Changes for src/main/java/ch15/RyanAndMonicaAtomicTest.java: 68 added lines, 0 removed lines.
Original line number	Diff line number	Diff line
		package ch15;

		import java.util.concurrent.ExecutorService;
		import java.util.concurrent.Executors;
		import java.util.concurrent.TimeUnit;
		import java.util.concurrent.atomic.AtomicInteger;

		public class RyanAndMonicaAtomicTest {
		public static void main(String[] args) throws InterruptedException {
		long start = System.currentTimeMillis();
		BankAccountWithAtomic account = new BankAccountWithAtomic();
		RyanAndMonicaAtomicJob ryan = new RyanAndMonicaAtomicJob("Ryan", account);
		RyanAndMonicaAtomicJob monica = new RyanAndMonicaAtomicJob("Monica", account);
		ExecutorService executor = Executors.newFixedThreadPool(2);
		executor.execute(ryan);
		executor.execute(monica);
		executor.shutdown();
		executor.awaitTermination(1, TimeUnit.MINUTES);
		long end = System.currentTimeMillis();
		System.out.println(end - start);
		}
		}

		class RyanAndMonicaAtomicJob implements Runnable {
		private final String name;
		private final BankAccountWithAtomic account;

		RyanAndMonicaAtomicJob(String name, BankAccountWithAtomic account) {
		this.name = name;
		this.account = account;
		}

		public void run() {
		for (int i = 0; i < 10; i++) {
		account.makeWithdrawal(10, name);
		if (account.getBalance() < 0) {
		System.out.println("Overdrawn!");
		}
		}
		}
		}

		class BankAccountWithAtomic {
		private final AtomicInteger balance = new AtomicInteger(100);
		public int getBalance() {
		return balance.get();
		}

		public void makeWithdrawal(int amount, String name) {
		int initialBalance = balance.get();
		if (initialBalance >= amount) {
		System.out.println(name + " is about to withdraw");
		try {
		System.out.println(name + " is going to sleep");
		Thread.sleep(500);
		} catch (InterruptedException ex) {ex.printStackTrace();}
		System.out.println(name + " woke up.");

		balance.addAndGet(-amount);

		System.out.println(name + " completes the withdrawal");
		} else {
		System.out.println("Sorry, not enough for " + name);
		}
		}
		}

src/main/java/ch15/RyanAndMonicaSynchronizedTest.java

+4 −0

Changes for src/main/java/ch15/RyanAndMonicaSynchronizedTest.java: 4 added lines, 0 removed lines.
Original line number	Diff line number	Diff line
		@@ -6,6 +6,7 @@ import java.util.concurrent.TimeUnit;

		public class RyanAndMonicaSynchronizedTest {
		public static void main(String[] args) throws InterruptedException {
		long start = System.currentTimeMillis();
		BankAccountSynchronized account = new BankAccountSynchronized();
		RyanAndMonicaSynchronizedJob ryan = new RyanAndMonicaSynchronizedJob("Ryan", account);
		RyanAndMonicaSynchronizedJob monica = new RyanAndMonicaSynchronizedJob("Monica", account);
		@@ -13,6 +14,9 @@ public class RyanAndMonicaSynchronizedTest {
		executor.execute(ryan);
		executor.execute(monica);
		executor.shutdown();
		executor.awaitTermination(1, TimeUnit.MINUTES);
		long end = System.currentTimeMillis();
		System.out.println(end - start);
		}
		}

src/main/java/ch15/RyanAndMonicaTest.java

+6 −1

Changes for src/main/java/ch15/RyanAndMonicaTest.java: 6 added lines, 1 removed line.
Original line number	Diff line number	Diff line
		@@ -2,9 +2,11 @@ package ch15;

		import java.util.concurrent.ExecutorService;
		import java.util.concurrent.Executors;
		import java.util.concurrent.TimeUnit;

		public class RyanAndMonicaTest {
		public static void main(String[] args) {
		public static void main(String[] args) throws InterruptedException {
		long start = System.currentTimeMillis();
		BankAccount account = new BankAccount();
		RyanAndMonicaJob ryan = new RyanAndMonicaJob("Ryan", account);
		RyanAndMonicaJob monica = new RyanAndMonicaJob("Monica", account);
		@@ -12,6 +14,9 @@ public class RyanAndMonicaTest {
		executor.execute(ryan);
		executor.execute(monica);
		executor.shutdown();
		executor.awaitTermination(1, TimeUnit.MINUTES);
		long end = System.currentTimeMillis();
		System.out.println(end - start);
		}
		}