Difficulties with parallel query processing

[iamkisly]

Hello. I use a slightly modified example of QuoteOfTheMomentServer and encountered locks. When connecting two or more clients, the server processes requests of only one client. As soon as one of the clients is disconnected, the server begins to process the requests of the next client. But no parallelism is observed. What should I do to process them in parallel? Does it have to be some kind of thread pool? It would be great to see working examples.