RFR 15 8243099: SO_INCOMING_NAPI_ID support

[Alan Bateman]

On 30/04/2020 22:20, Ivanov, Vladimir A wrote:
> One more update at http://cr.openjdk.java.net/~sviswanathan/Vladimir/8243099/webrev.05/
> The @apiNote section was updated a little bit to concentrate on SO_INCOMING_NAPI_ID.
>
I think this is getting better but it switches from "receive queue" to 
"device queue" and then mentions "busy polling" and minimizing context 
switches which might be a bit much. What would you think of this 
alternative:


     /**
      * Identifies the receive queue that the last incoming packet for 
the socket
      * was received on.
      *
      * <p> The value of this socket option is an {@code Integer} that 
identifies a
      * receive queue that the application can use to split the incoming 
flows among
      * threads based on the queue identifier.
      *
      * <p> The socket option is read-only and any attempt to set the 
socket option
      * will throw {@code UnsupportedOperationException}.
      *
      * <p> The socket option is supported by both stream and datagram 
oriented sockets.
      * The value of the socket option is {@code 0} when the socket is 
not bound or a
      * packet has not been received.
      *
      * @apiNote
      * Network devices may have multiple queues or channels to transmit 
and receive
      * network packets. The {@code SO_INCOMING_NAPI_ID} socket option 
provides a hint
      * to the application to indicate the receive queue on which an 
incoming socket
      * connection or packets for that connection are directed to. An 
application may
      * take advantage of this by handling all socket connections 
assigned to a
      * specific queue on one thread.
      *
      * @since 15
      */