85 lines
2.2 KiB
Java
85 lines
2.2 KiB
Java
// threads/InterruptingIdiom.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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// General idiom for interrupting a task
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// {Args: 1100}
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import java.util.concurrent.*;
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class NeedsCleanup {
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private final int id;
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public NeedsCleanup(int ident) {
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id = ident;
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System.out.println("NeedsCleanup " + id);
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}
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public void cleanup() {
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System.out.println("Cleaning up " + id);
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}
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}
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class Blocked3 implements Runnable {
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private volatile double d = 0.0;
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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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// point1
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NeedsCleanup n1 = new NeedsCleanup(1);
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// Start try-finally immediately after definition
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// of n1, to guarantee proper cleanup of n1:
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try {
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System.out.println("Sleeping");
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TimeUnit.SECONDS.sleep(1);
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// point2
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NeedsCleanup n2 = new NeedsCleanup(2);
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// Guarantee proper cleanup of n2:
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try {
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System.out.println("Calculating");
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// A time-consuming, non-blocking operation:
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for(int i = 1; i < 2500000; i++)
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d += (Math.PI + Math.E) / d;
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System.out.println(
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"Finished time-consuming operation");
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} finally {
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n2.cleanup();
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}
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} finally {
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n1.cleanup();
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}
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}
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System.out.println("Exiting via while() test");
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} catch(InterruptedException e) {
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System.out.println(
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"Exiting via InterruptedException");
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}
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}
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}
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public class InterruptingIdiom {
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public static void
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main(String[] args) throws Exception {
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if(args.length != 1) {
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System.out.println(
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"usage: java InterruptingIdiom delay-in-mS");
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System.exit(1);
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}
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Thread t = new Thread(new Blocked3());
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t.start();
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TimeUnit.MILLISECONDS.sleep(new Integer(args[0]));
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t.interrupt();
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}
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}
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/* Output:
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NeedsCleanup 1
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Sleeping
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NeedsCleanup 2
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Calculating
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Finished time-consuming operation
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Cleaning up 2
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Cleaning up 1
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NeedsCleanup 1
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Sleeping
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Cleaning up 1
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Exiting via InterruptedException
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*/
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