#include <boost/thread.hpp>
#include <boost/chrono.hpp>
#include <boost/thread/barrier.hpp>
#include <iostream>
#include <cstdlib>
#include <ctime>

using namespace std;
void worker(int id , boost::barrier &sync_point) {
	cout << "Thread: " << id << "entering work" << endl;
	boost::this_thread::sleep_for(boost::chrono::milliseconds(500));
	sync_point.wait();
	cout << "Thread: "<< id << " leaving barrier" << endl;
}

int main(){
	srand(time(0));

	int num_threads=rand()%6 +3;	
	cout <<"Creating: " << num_threads << endl;
	boost::barrier sync_point(num_threads);

	boost::thread_group tg; 
	for(int i=0; i<num_threads; i++) {
		tg.create_thread(boost::bind(worker,i,boost::ref(sync_point)));
	}
	tg.join_all();
	return 0;
}