QSocketNotifier: socket notifiers cannot be disabled from another thread

[danadam]

Why do I need an evet loop. tcpSocket can signal events such as "connected","disconnected" ,"errors". I do not need to call exec. I will try it.

My mistake here, event loop isn't required. But I'm not sure if you are aware that in such case your sendMessage slot isn't executed in client thread. There are three threads here: main thread, client thread and sender thread. Socket reading is done in client thread, that's obvious. But sendMessage slot is executed either in main thread (if you make queued connection between Sender and Client) or in sender thread (if you make direct connection between Sender and Client).

Problem occurs when Client receives "sendMessage" signal of the sender, and tries to write socket.

I wrote a program like yours (two threads, Client and Sender) and I don't have that problem. Of course "QObject: Cannot create children for a parent that is in a different thread." is still there, but I wasn't able to reproduce "QSocketNotifier: socket notifiers cannot be disabled from another thread"