QtConcurrent::run - initialization time

By using QtConcurrent::run the first time in an application, it seems to take about 1 second to load up.
Once this is loaded, it does almost immediately respond, which leads me to the conclusion that you are initializing a lot on the first call.

This can cause UI applications to freeze if they use QtConcurrent::run for simple task threading in their UI. For me, it forced me to do a "fake call" for QtConcurrent::run in the constructor, so I can use it lateron in my program without freezing the UI.

If there is no better performance to get in QtConcurrent::run, at least give us a clean initialization function in the namespace for our constructor, avoiding the unclean fake calls.

A small main.cpp is attached, which should show the difference between the first and the 2nd call - at least here it does:
First run: 1092
Second run: 0