register0() — netty Function Reference

Source Code

transport/src/main/java/io/netty/channel/AbstractChannel.java lines 366–406

        private void register0(ChannelPromise promise) {
            // check if the channel is still open as it could be closed in the mean time when the register
            // call was outside of the eventLoop
            if (!promise.setUncancellable() || !ensureOpen(promise)) {
                return;
            }
            ChannelPromise registerPromise = newPromise();
            boolean firstRegistration = neverRegistered;
            registerPromise.addListener(future -> {
                if (future.isSuccess()) {
                    neverRegistered = false;
                    registered = true;

                    // Ensure we call handlerAdded(...) before we actually notify the promise. This is needed as the
                    // user may already fire events through the pipeline in the ChannelFutureListener.
                    pipeline.invokeHandlerAddedIfNeeded();

                    safeSetSuccess(promise);
                    pipeline.fireChannelRegistered();
                    // Only fire a channelActive if the channel has never been registered. This prevents firing
                    // multiple channel actives if the channel is deregistered and re-registered.
                    if (isActive()) {
                        if (firstRegistration) {
                            pipeline.fireChannelActive();
                        } else if (config().isAutoRead()) {
                            // This channel was registered before and autoRead() is set. This means we need to
                            // begin read again so that we process inbound data.
                            //
                            // See https://github.com/netty/netty/issues/4805
                            beginRead();
                        }
                    }
                } else {
                    // Close the channel directly to avoid FD leak.
                    close(newPromise());
                    closeFuture.setClosed();
                    safeSetFailure(promise, future.cause());
                }
            });
            doRegister(registerPromise);
        }