!747

!721 // thread {

!include #1000774 // CircularFifoBuffer

!include #1000782 // Flag

m {

  static int port = 1234;

  static new Flag killFlag;

  p {

    installKillSwitch();

    print("Hello world. Sleeping. Port=" + port);

    killFlag.waitUntilUp();

  }

  static void installKillSwitch() ctex {

    final ServerSocket serverSocket = new ServerSocket(1234);

    //serverSocket.setSoTimeout(1000);

    daemon { // todo: higher priority

      while (true) {

        try {

          final Socket s = serverSocket.accept();

          print("connect");

          thread {

            InputStream in = s.getInputStream();

            CircularFifoBuffer<Character> b = new CircularFifoBuffer<Character>(4);

            while (true) {

              int i = in.read();

              if (i < 0) break;

              print(i);

              b.add((char) i);

              S s = getLast(b, 4);

              //print("> " + s);

              if (s == "kill")

                killMe();

            }

            print("disconnect");

          }

        } catch (SocketTimeoutException e) {

        }

      }

    }

  }

  static void killMe() {

    print("killing");

    // keepWakingUp(); // see sleep() above. Does this make sense?

    System.exit(0); // This works.

    // killFlag.raise(); // And this is a very safe way to do it too.

  }

  static S getLast(CircularFifoBuffer<Character> b, int n) {

    n = Math.min(n, b.size());

    new StringBuilder buf;

    Iterator<Character> it = b.getBackingStore().descendingIterator();

    for (int i = 0; i < n; i++)

      buf.append(it.next());

    return buf.reverse().toString();

  }

}