Using sleep instead of proper thread synchronization is unreliable. Some people have slow computers like a cheap tablet or free tier cloud VM. Other people have insufficient memory for the software they run and their OS swaps.

When I need something like that, in my destructor I usually ask worker thread to shut down voluntarily (using a special posted message, manual reset event, or an atomic flag), then wait for the worker thread to quit within a reasonable timeout. If it didn’t quit within the timeout, I log a warning message if I can.