RFR: 8287580: (se) CancelledKeyException during channel registration [v3]

[Alan Bateman]

On Thu, 2 Jun 2022 22:14:27 GMT, Brian Burkhalter <bpb at openjdk.org> wrote:

>> Ignore `CancelledKeyException` during registration.
>
> Brian Burkhalter has updated the pull request incrementally with one additional commit since the last revision:
> 
>   8287580: Revert change to AbstractSelectableChannel; reduce iterations in test

Here's a suggestion for a test that is closer to what I suggested in one of the early messages. The main difference is that there is a loop calling selectNow so that the cancelled key is flushed and subsequent calls to register work as a new registration. 


import java.nio.channels.*;

public class CancelDuringRegister {

    private static volatile boolean done;

    public static void main(String[] args) throws Exception {
        try (Selector sel = Selector.open()) {

            // create thread to cancel all keys in the selector's key set
            var thread = new Thread(() -> {
                while (!done) {
                    sel.keys().forEach(SelectionKey::cancel);
                }
            });
            thread.start();

            try (SocketChannel sc = SocketChannel.open()) {
                sc.configureBlocking(false);
                for (int i = 0; i <100_000; i++) {
                    sc.register(sel, SelectionKey.OP_READ);
                    sel.selectNow();
                }
            } finally {
                done = true;
                thread.join();
            }
        }
    }
}

-------------

PR: https://git.openjdk.java.net/jdk/pull/8978