99 lines
2.5 KiB
Java
99 lines
2.5 KiB
Java
// threads/Interrupting.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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// Interrupting a blocked thread
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import java.util.concurrent.*;
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import java.io.*;
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class SleepBlocked implements Runnable {
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@Override
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public void run() {
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try {
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TimeUnit.SECONDS.sleep(100);
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} catch(InterruptedException e) {
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System.out.println("InterruptedException");
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}
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System.out.println("Exiting SleepBlocked.run()");
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}
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}
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class IOBlocked implements Runnable {
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private InputStream in;
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public IOBlocked(InputStream is) { in = is; }
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@Override
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public void run() {
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try {
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System.out.println("Waiting for read():");
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in.read();
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} catch(IOException e) {
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if(Thread.currentThread().isInterrupted()) {
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System.out.println(
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"Interrupted from blocked I/O");
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} else {
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throw new RuntimeException(e);
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}
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}
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System.out.println("Exiting IOBlocked.run()");
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}
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}
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class SynchronizedBlocked implements Runnable {
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public synchronized void f() {
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while(true) // Never releases lock
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Thread.yield();
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}
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public SynchronizedBlocked() {
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new Thread() {
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@Override
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public void run() {
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f(); // Lock acquired by this thread
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}
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}.start();
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}
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@Override
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public void run() {
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System.out.println("Trying to call f()");
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f();
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System.out.println(
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"Exiting SynchronizedBlocked.run()");
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}
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}
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public class Interrupting {
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private static ExecutorService exec =
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Executors.newCachedThreadPool();
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static void
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test(Runnable r) throws InterruptedException {
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Future<?> f = exec.submit(r);
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TimeUnit.MILLISECONDS.sleep(100);
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System.out.println(
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"Interrupting " + r.getClass().getName());
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f.cancel(true); // Interrupts if running
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System.out.println(
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"Interrupt sent to " + r.getClass().getName());
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}
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public static void
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main(String[] args) throws Exception {
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test(new SleepBlocked());
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test(new IOBlocked(System.in));
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test(new SynchronizedBlocked());
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TimeUnit.SECONDS.sleep(3);
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System.out.println("Aborting with System.exit(0)");
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System.exit(0); // ... since last 2 interrupts failed
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}
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}
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/* Output:
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Interrupting SleepBlocked
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InterruptedException
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Exiting SleepBlocked.run()
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Interrupt sent to SleepBlocked
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Waiting for read():
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Interrupting IOBlocked
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Interrupt sent to IOBlocked
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Trying to call f()
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Interrupting SynchronizedBlocked
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Interrupt sent to SynchronizedBlocked
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Aborting with System.exit(0)
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*/
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