Boost Asio TCP Server 处理多个客户端

Question

I am new to network programming and the usage of Boost Asio library.

I successfully implemented a task for my requirement by modifying the Boost Asio "Blocking TCP Echo Server and Client" which performs transactions of operations between my Client and Server.

Now, I have a requirement where I need to connect multiple Clients with my Server.

I found some relevant links suggesting the usage of async_accept at the Server side.

So, I tried running the Boost Asio example: "Async TCP Echo Server" with the "Blocking TCP Echo client" , where the server distinguishes the different clients and addresses them accordingly.

But, my actual requirement should be like, instead of the Server completing the entire process for one Client, it [the server] has to perform same operations for the first client then go to the second client and perform those operations and then again come back to the first client and continue in this order until all operations are complete.

Is there any way or idea which could help me perform this flow using Boost Asio? Also I'm just using the "Blocking TCP Echo Client", which just has a normal connect() and not an async_connect() , now is that a problem?

Also, is it possible to communicate between multiple clients through the server using Boost Asio?

Thanking you very much in advance!

Answer 1

There are 2 models to handling multiple client concurrently on the server.

The one is to spawn a new thread for each client and then each thread handles each client synchronously. The second model is to use asynchronous APIs on a single thread all operating on a single service. When the accept completes, you then create a new worker thread and start the worker off the send and recv required by your protocol. You main thread goes back the accepting new connections.

With async, you prime the pump with an async accept and the call io_service run. When the accept completes, your callback runs. You now prime the pump again with further accepts (for more client) start async send and recv for the newly created client. Since all sends and recvs are non-blocking, the only time your thread sleeps is when it has nothing to do. Otherwise the io_service run method takes care of everything for you.

If you are blocking on sends and recvs, through, you cannot process more than one client concurrently.