boost thread strange behaviour

From: Adham Sabry (adhamsabry1111_at_[hidden])
Date: 2020-02-29 10:22:21

hi ,
i am trying to learn executors and executors thread pools using with
boost::async
but i found strange behabiour
when i make thread pool adaptor ea and submit tasks to it and make ea00 and
submit tasks to it
if i started ea with async , it automatically starts ea00
the attached file has the code
i thought that async will only start the passed thread pool"adaptor"
But i think there is underlying thing which gather all threads of different
pools into single entity and starts them with any call to boost::async
is this a bug???
i run this from windows 7 64 by visual studio 2017