DefaultNioRegistration Class — netty Architecture

Source Code

transport/src/main/java/io/netty/channel/nio/NioIoHandler.java lines 318–390

    final class DefaultNioRegistration implements IoRegistration {
        private final AtomicBoolean canceled = new AtomicBoolean();
        private final NioIoHandle handle;
        private volatile SelectionKey key;

        DefaultNioRegistration(ThreadAwareExecutor executor, NioIoHandle handle, NioIoOps initialOps, Selector selector)
                throws IOException {
            this.handle = handle;
            key = handle.selectableChannel().register(selector, initialOps.value, this);
        }

        NioIoHandle handle() {
            return handle;
        }

        void register(Selector selector) throws IOException {
            SelectionKey newKey = handle.selectableChannel().register(selector, key.interestOps(), this);
            key.cancel();
            key = newKey;
        }

        @SuppressWarnings("unchecked")
        @Override
        public <T> T attachment() {
            return (T) key;
        }

        @Override
        public boolean isValid() {
            return !canceled.get() && key.isValid();
        }

        @Override
        public long submit(IoOps ops) {
            if (!isValid()) {
                return -1;
            }
            int v = cast(ops).value;
            key.interestOps(v);
            return v;
        }

        @Override
        public boolean cancel() {
            if (!canceled.compareAndSet(false, true)) {
                return false;
            }
            key.cancel();
            cancelledKeys++;
            if (cancelledKeys >= CLEANUP_INTERVAL) {
                cancelledKeys = 0;
                needsToSelectAgain = true;
            }
            handle.unregistered();
            return true;
        }

        void close() {
            cancel();
            try {
                handle.close();
            } catch (Exception e) {
                logger.debug("Exception during closing " + handle, e);
            }
        }

        void handle(int ready) {
            if (!isValid()) {
                return;
            }
            handle.handle(this, NioIoOps.eventOf(ready));
        }
    }