Re: [Boost-users] thread running many times

Thanks, I understand, so my group is after join_all empty, so I change my code to:

for(i=0; i < iteration; ++i) {      create thread group      run thread group with join_all for parallel part      run serial part }

so on each iteration I need to create a new thread group

The group is not empty, it contains all those boost::thread objects you put there. But actual threads associated with those objects are already over at this point. So you have to create & launch another ones.