//: concurrency/Interrupting.java // Interrupting a blocked thread. import java.util.concurrent.*; import java.io.*; import static net.mindview.util.Print.*; class SleepBlocked implements Runnable { @Override public void run() { try { TimeUnit.SECONDS.sleep(100); } catch(InterruptedException e) { print("InterruptedException"); } print("Exiting SleepBlocked.run()"); } } class IOBlocked implements Runnable { private InputStream in; public IOBlocked(InputStream is) { in = is; } @Override public void run() { try { print("Waiting for read():"); in.read(); } catch(IOException e) { if(Thread.currentThread().isInterrupted()) { print("Interrupted from blocked I/O"); } else { throw new RuntimeException(e); } } print("Exiting IOBlocked.run()"); } } class SynchronizedBlocked implements Runnable { public synchronized void f() { while(true) // Never releases lock Thread.yield(); } public SynchronizedBlocked() { new Thread() { @Override public void run() { f(); // Lock acquired by this thread } }.start(); } @Override public void run() { print("Trying to call f()"); f(); print("Exiting SynchronizedBlocked.run()"); } } public class Interrupting { private static ExecutorService exec = Executors.newCachedThreadPool(); static void test(Runnable r) throws InterruptedException{ Future f = exec.submit(r); TimeUnit.MILLISECONDS.sleep(100); print("Interrupting " + r.getClass().getName()); f.cancel(true); // Interrupts if running print("Interrupt sent to " + r.getClass().getName()); } public static void main(String[] args) throws Exception { test(new SleepBlocked()); test(new IOBlocked(System.in)); test(new SynchronizedBlocked()); TimeUnit.SECONDS.sleep(3); print("Aborting with System.exit(0)"); System.exit(0); // ... since last 2 interrupts failed } } /* Output: (95% match) Interrupting SleepBlocked InterruptedException Exiting SleepBlocked.run() Interrupt sent to SleepBlocked Waiting for read(): Interrupting IOBlocked Interrupt sent to IOBlocked Trying to call f() Interrupting SynchronizedBlocked Interrupt sent to SynchronizedBlocked Aborting with System.exit(0) *///:~