字节[256]的Boost::serial_port和asio::async_write超过200ms

我正在通过串行端口实现一些基本的通信。

根据协议，我必须在收到请求后的 225 毫秒内回复。最大封装尺寸为 256B。

因此，当我收到请求时，我创建了响应[header, lenght, payload, crc16](总共 256 B(，平均需要 30 - 40 毫秒。然后当我将该响应(字节数组(放入asio::async_write时，实际问题就会出现。该函数平均需要大约 240 毫秒来处理该字节数组。

除了我发送最大长度的包裹外，一切正常。大约需要240ms(asio::async_write(+ 40ms(封装组装(约280~300ms。

端口：9600波特，长度8，一个停止位

知道我怎样才能加快速度吗？

    void Example::do_write()
{
    if (pimpl_->WriteBuffer == nullptr)
    {
        boost::lock_guard<boost::mutex> l(pimpl_->WriteQueueMutex);
        pimpl_->WriteBufferSize = pimpl_->WriteQueue.size();
        pimpl_->WriteBuffer.reset(new byte[pimpl_->WriteQueue.size()]);
        std::move(pimpl_->WriteQueue.begin(), pimpl_->WriteQueue.end(), pimpl_->WriteBuffer.get());
        pimpl_->WriteQueue.clear();
        begin = boost::chrono::steady_clock::now();
        async_write(pimpl_->Port, asio::buffer(pimpl_->WriteBuffer.get(), pimpl_->WriteBufferSize), boost::bind(&Example::write_end, this, asio::placeholders::error));
    }
}
void Example::write_end(const system::error_code& error)
{
    if (!error)
    {
        boost::lock_guard<boost::mutex> l(pimpl_->WriteQueueMutex);
        if (pimpl_->WriteQueue.empty())
        {
            pimpl_->WriteBuffer.reset();
            pimpl_->WriteBufferSize = 0;
            end = boost::chrono::steady_clock::now();
            OutputDebugString(string("nWRITE TIME: " + to_string(boost::chrono::duration_cast<boost::chrono::milliseconds>(end - begin).count()) + "n").c_str());
            return;
        }
        pimpl_->WriteBufferSize = pimpl_->WriteQueue.size();
        pimpl_->WriteBuffer.reset(new byte[pimpl_->WriteQueue.size()]);
        std::move(pimpl_->WriteQueue.begin(), pimpl_->WriteQueue.end(), pimpl_->WriteBuffer.get());
        pimpl_->WriteQueue.clear();
        async_write(pimpl_->Port, asio::buffer(pimpl_->WriteBuffer.get(), pimpl_->WriteBufferSize), boost::bind(&Example::write_end, this, asio::placeholders::error));
    }
    else
    {
        set_error_status(true);
        do_close();
    }
}