Name: boT120536 Date: 02/28/2001


java version "1.2.2"
Java HotSpot(TM) Server VM (2.0fcs, mixed mode, build E)
& 1.3 (which i don't have on the box i'm writing this post on)

C:\>

In sun.rmi.transport.tcp.TCPTransport, right after the ‘accept’, the code goes
on a time consuming operation of creating and starting a new Thread.

When clients connect on a (not very big mass), they out run this code and fill
up the ServerSocket's "waiting for accept" socket queue, which causes further
connection to be refused.

relevant snip from sun.rmi.transport.tcp.TCPTransport:

while (true) {
  ServerSocket myServer = server;
  if (myServer == null)
    // the server socket will be null if another thread
    // attempted to retry creating the server socket
    // and failed.
    return;

  Throwable acceptFailure = null;
  final Socket socket;

  try {
    socket = myServer.accept();

    /*
     * Find client host name (or "0.0.0.0" if from behind firewall)
     */
    InetAddress clientAddr = socket.getInetAddress();
    String clientHost = (clientAddr != null ?clientAddr.getHostAddress(): "0.0.0.0");

    /*
     * Spawn non-system thread to handle the connection
     */
    Thread t = (Thread) java.security.AccessController.doPrivileged (
        new RMIThreadAction(new ConnectionHandler(socket, clientHost),
            "TCP Connection(" + ++ threadNum + ")-" + clientHost, true, true));
    t.start();

  } catch (IOException e) {}
...
}



IMO, this is a very naive implementation. Right after 'accept', the newly
created socket should be put on a queue, and let other thread/s take care of
it, while letting the thread that listens on the ServerSocket to immediately go
back to 'accept'.
(Review ID: 116777)
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