#include <cassert>
#include <boost/thread.hpp>

boost::thread_specific_ptr<int> tsp;

void thread()
{
    if (tsp.get() == 0l) tsp.reset(new int);

    for(int i = 0; i < 10000; ++i)
    {
        unsigned cnt = ++*tsp;
        boost::thread::yield();
        assert(cnt == *tsp);
    }
}

int main()
{
    boost::thread_group threads;
    for (int i = 0; i < 30; ++i)
        threads.create_thread(& thread);
    threads.join_all();

    return 0;
}