#include <boost/thread.hpp>
#include <iostream>
#include <cstdlib>
#include <ctime>
using namespace std;
int rows;
int cols;
int nthreads;
double **a;
boost::mutex rand_mtx;

void worker(int tid) {
	for (int i=tid;i<rows;i+=nthreads) {
			for (int j=0;j<cols;j++) {
						double value;
									rand_mtx.lock();
												value=(double) rand()/(RAND_MAX*1.0);
															rand_mtx.unlock();
																		a[i][j]=value;	
																				}
																					}
																					}
																					int main() {
																						srand(time(0));
																							rows=1000;
																								cols=1000000;
																									nthreads=100; //1+rand()%6;
																										a=new double*[rows];
																											for (int i=0;i<rows;i++) {
																													a[i]=new double[cols];
																														}
																															boost::thread_group tg;
																																for (int t=0;t<nthreads;t++) {
																																		tg.create_thread(boost::bind(worker,t));
																																			}
																																				tg.join_all();
																																					/*for (int i=0;i<rows;i++) {
																																							for (int j=0;j<cols;j++) {
																																										cout << a[i][j] << "  ";
																																												}
																																														cout << endl;
																																															}*/
																																																return 0;
																																																}