boost::asio::async_write issue over serial channel - c++

Question

I have client server application, the flow is as explained below:
client is at windows side and do not use boost
server is at linux side and uses boost
client-server communicates over serial channel RS485. and server uses boost::asio::async_write.
client --> calls command with specific command_id --> server
client <-- sends acknowledgement <-- server
{server process the command, meanwhile the client is blocked for response}
client <-- sends response <-- server
Sometimes what happens client receives the acknowledgement but do not receive the response even if the response is sent by the server.
The pending response is later received by the client when client sends another command.
If I use boost::asio::write for serial communication there is no problem at all.
below is the code snippet for async_write
boost::asio::async_write(serial_port, boost::asio::buffer(&v_chunk[0], v_chunk.size()),
boost::bind(&Serial_channel::async_write_callback, this, boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred));
io_serv->run();
io_serv->reset();

Answer 1

The way you use the io_service will not work. First of all the run function doesn't return until the service event loop is stopped. Secondly, if you just want to use it as a "poller" then you should use poll or optionally poll_one (or perhaps run_one).
But if you do it like that, it's the same as doing a non-async write call, and you loos the benefits of the async functions.

Answer 2

referencing #Joachim comment I have changed my flow like below and it worked.
boost::asio::async_write(serial_port, boost::asio::buffer(&v_chunk[0], v_chunk.size()),
boost::bind(&Serial_channel::async_write_callback, this, boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred));
io_serv->run();
usleep(1000); // 1 millisecond delay
io_serv->reset();