[Qt-interest] Writing custom asynchronous QIODevice

[Tumarov Alexander]

The articles I saw speak about how to create custom synchronous QIODevice. 
I tried to find an information about how to create an asynchronous one (like
QTcpSocket for example) without going into running threads (it is possible
to run additional thread but I want to avoid using them). Is this possible?
Is there any guide or article about this? If threads are unavoidable ( :) )
is there any information which methods should be reimplemented and what
signal should be emmited?

Thank you ahead.