write异步与流量控制 4.0.29.Final （二）addMessage与ChannelOutboundBuffer（yet）

cas

    private void incrementPendingOutboundBytes(long size, boolean invokeLater) {
        if (size != 0L) {
            long newWriteBufferSize = TOTAL_PENDING_SIZE_UPDATER.addAndGet(this, size);
            if (newWriteBufferSize >= (long)this.channel.config().getWriteBufferHighWaterMark()) {
                this.setUnwritable(invokeLater);
            }

        }
    }