OnJava8-Examples/tasks/Interrupting2.java

// tasks/Interrupting2.java
// (c)2016 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://mindviewinc.com/Books/OnJava/ for more book information.
// Interrupting a task blocked with a ReentrantLock
import java.util.concurrent.*;
import java.util.concurrent.locks.*;

class BlockedMutex {
  private Lock lock = new ReentrantLock();
  public BlockedMutex() {
    // Acquire it right away, to demonstrate interruption
    // of a task blocked on a ReentrantLock:
    lock.lock();
  }
  public void f() {
    try {
      // This will never be available to a second task
      lock.lockInterruptibly(); // Special call
      System.out.println("lock acquired in f()");
    } catch(InterruptedException e) {
      System.out.println(
        "Interrupted from lock acquisition in f()");
    }
  }
}

class Blocked2 implements Runnable {
  BlockedMutex blocked = new BlockedMutex();
  @Override
  public void run() {
    System.out.println("Waiting for f() in BlockedMutex");
    blocked.f();
    System.out.println("Broken out of blocked call");
  }
}

public class Interrupting2 {
  public static void
  main(String[] args) throws Exception {
    Thread t = new Thread(new Blocked2());
    t.start();
    TimeUnit.SECONDS.sleep(1);
    System.out.println("Issuing t.interrupt()");
    t.interrupt();
  }
}
/* Output:
Waiting for f() in BlockedMutex
Issuing t.interrupt()
Interrupted from lock acquisition in f()
Broken out of blocked call
*/