doBeginRead() — netty Function Reference

Source Code

codec-http2/src/main/java/io/netty/handler/codec/http2/AbstractHttp2StreamChannel.java lines 864–907

        void doBeginRead() {
            if (readStatus == ReadStatus.IDLE) {
                // Don't wait for the user to request a read to notify of channel closure.
                if (readEOS && (inboundBuffer == null || inboundBuffer.isEmpty())) {
                    // Double check there is nothing left to flush such as a window update frame.
                    flush();
                    unsafe.closeForcibly();
                }
            } else {
                do { // Process messages until there are none left (or the user stopped requesting) and also handle EOS.
                    Object message = pollQueuedMessage();
                    if (message == null) {
                        // Double check there is nothing left to flush such as a window update frame.
                        flush();
                        if (readEOS) {
                            unsafe.closeForcibly();
                        }
                        break;
                    }
                    final RecvByteBufAllocator.Handle allocHandle = recvBufAllocHandle();
                    allocHandle.reset(config());
                    boolean continueReading = false;
                    do {
                        doRead0((Http2Frame) message, allocHandle);
                    } while ((readEOS || (continueReading = allocHandle.continueReading()))
                            && (message = pollQueuedMessage()) != null);

                    if (continueReading && isParentReadInProgress() && !readEOS) {
                        // Currently the parent and child channel are on the same EventLoop thread. If the parent is
                        // currently reading it is possible that more frames will be delivered to this child channel. In
                        // the case that this child channel still wants to read we delay the channelReadComplete on this
                        // child channel until the parent is done reading.
                        maybeAddChannelToReadCompletePendingQueue();
                    } else {
                        notifyReadComplete(allocHandle, true, true);

                        // While in the read loop reset the readState AFTER calling readComplete (or other pipeline
                        // callbacks) to prevents re-entry into this method (if autoRead is disabled and the user calls
                        // read on each readComplete) and StackOverflowException.
                        resetReadStatus();
                    }
                } while (readStatus != ReadStatus.IDLE);
            }
        }