Re: [Boost-users] How to create a certain number of threads

From: Peter Dimov (pdimov_at_[hidden])
Date: 2006-10-02 08:51:34

Monica Gretzer wrote:
> Hi,
>
>  Thanks for your answers. Now I wonder how to a certain number of
> threads which is decided at runtime and can vary between program
> runs. I send the number of threads as an argument to CreateThreads.

[...]

>  void TestThread::CreateThreads(int nb)
>  {
>      boost::thread t1( boost::bind( &TestThread::thread, this, 1));
>      boost::thread t2( boost::bind( &TestThread::thread, this, 2));
>      boost::thread t3( boost::bind( &TestThread::threas, this, 3));
>
>      t1.join();
>      t2.join();
>      t3.join();
>  }

If you really like to wait for the threads to finish (which is what you do 
with tN.join), you need to use a thread_group:

http://www.boost.org/doc/html/thread_group.html

void TestThread::CreateThreads(int nb)
{
    boost::thread_group tg;

    for( int i = 0; i < nb; ++i )
    {
        tg.create_thread( boost::bind( &TestThread::thread, this, i ) );
    }

    tg.join_all();
}