[Ch15] Examples to show what's happening with executor shutdowns (7ac550fc) · Commits · examples / Head First Java 3rd Edition

src/main/java/ch15/ClosingTime.java

+42 −8

Changes for src/main/java/ch15/ClosingTime.java: 42 added lines, 8 removed lines.
Original line number	Diff line number	Diff line
		@@ -3,25 +3,37 @@ package ch15;
		import java.util.List;
		import java.util.concurrent.ExecutorService;
		import java.util.concurrent.Executors;
		import java.util.concurrent.RejectedExecutionException;
		import java.util.concurrent.TimeUnit;

		public class ClosingTime {
		public static void main(String[] args) {
		forceShutdown();
		shutdownGracefully();
		}

		static void shutdownGracefully() {
		ExecutorService threadPool = Executors.newFixedThreadPool(2);
		threadPool.execute(new LongJob("Long Job 1"));
		threadPool.execute(new ShortJob("Short Job"));
		threadPool.execute(new ShortJob("Long Job 2"));
		threadPool.execute(new ShortJob("Shouldn't start job"));
		threadPool.execute(new LongJob("Long Job 2"));
		threadPool.execute(new ShortJob("Queued job"));
		threadPool.shutdown();
		ShortJob tooLateJob = new ShortJob("Too late job");
		try {
		System.out.println("Finished? " + threadPool.awaitTermination(1, TimeUnit.SECONDS));
		threadPool.execute(tooLateJob);
		} catch (RejectedExecutionException e) {
		System.out.println("Too late to start another job!! " + tooLateJob);
		}
		System.out.println("threadPool.isShutdown() = " + threadPool.isShutdown());
		System.out.println("threadPool.isTerminated() = " + threadPool.isTerminated());

		try {
		System.out.println("Finished? " + threadPool.awaitTermination(4, TimeUnit.SECONDS));
		} catch (InterruptedException e) {
		e.printStackTrace();
		}
		System.out.println("threadPool.isShutdown() = " + threadPool.isShutdown());
		System.out.println("threadPool.isTerminated() = " + threadPool.isTerminated());
		}

		static void forceShutdown() {
		@@ -31,9 +43,29 @@ public class ClosingTime {
		threadPool.execute(new LongJob("Long Job 2"));
		threadPool.execute(new ShortJob("Shouldn't start job"));
		List<Runnable> unfinished = threadPool.shutdownNow();

		System.out.println("unfinished.size() = " + unfinished.size());
		for (Runnable runnable : unfinished) {
		System.out.println(runnable);
		}
		}

		static void forceShutdownWorkStealing() {
		ExecutorService threadPool = Executors.newWorkStealingPool(2);
		threadPool.execute(new LongJob("Long Job 1"));
		threadPool.execute(new ShortJob("Short Job"));
		threadPool.execute(new LongJob("Long Job 2"));
		threadPool.execute(new ShortJob("Shouldn't start job"));
		List<Runnable> unfinished = threadPool.shutdownNow();
		try {
		System.out.println("Finished? " + threadPool.awaitTermination(1, TimeUnit.SECONDS));
		} catch (InterruptedException e) {
		e.printStackTrace();
		}

		System.out.println("unfinished.size() = " + unfinished.size());
		for (Runnable runnable : unfinished) {
		System.out.println(((NamedJob) runnable).getJobName());
		System.out.println(runnable);
		}
		}

		@@ -46,12 +78,14 @@ abstract class NamedJob implements Runnable {
		this.jobName = jobName;
		}

		public String getJobName() {
		return jobName;
		@Override
		public String toString() {
		return "NamedJob{" +
		"jobName='" + jobName + '\'' +
		'}';
		}
		}


		class ShortJob extends NamedJob {
		ShortJob(String jobName) {
		super(jobName);