Pipes vs. sync

Question

I am studying inter-thread communication, and all i read about are sync blocks (and volatile). But what about PipedStreams ?
Are there ever debates: "shall we use pipes, or synchronization" Or, is the choice so obvious there is never a debate? Or is it impossible to compare a Pipe with a sync block (ike "apples vs. oranges")? I can only imagine very simple test cases for pipes. Maybe, its almost similar to opening a socket with a different thread on the same host. (Except for possible firewall issues) one could maybe use circular sockets in a similar way to a standard pipes???? Anyway, thanks for reading.

Answer 1

Thank you for your insight regarding Pipes . I think I will put pipe knowledge near the bottom of my long list of "Things to Learn" in Java. Since I made the test code tonight, here it is. I am not really sure if it attests to my point:
public class Main extends Thread {
  public static void main(String[] args) {  new Main().start();  }
  public void run() {
    PipedInputStream pin = new PipedInputStream();
    PipedOutputStream pout = new PipedOutputStream(pin);
    CopyMe copyMe = new CopyMe();
    copyMe.id = -1;
    ObjectOutputStream oos = new ObjectOutputStream(pout);
    oos.writeObject(copyMe);
    ObjectInputStream ois = new ObjectInputStream(pin);
    CopyMe copyMe2 = (CopyMe) ois.readObject();
    copyMe2.id = 15;
    copyMe.start();
    copyMe2.start();
public class CopyMe extends Thread implements Serializable {
  public int id = -1;
  public void run() {
    List<Integer> list = new ArrayList<Integer>();
    for (;;) {
      if (id > 0) {  for (int i = 1; i < id; i += 2) {  list.add(i); }  }
      System.out.println("________--> " + list.size());
      Thread.sleep(1221);
}I read in the API, "twisting / serializing" two pipes in one thread is deadlock prone. But, since I started studying pipes (again) I thought about deadlock safety with pipes between 2 threads. And I just got conflicted feeling about deep-copy and serialization and cloning. I am ok, and thank you for your time.