Intel TBB sort time measure

gistfile1.txt

/*
 * tbbTest.cpp
 *
 *  Created on: 2014/11/05
 *      Author: sase
 */

#include <iostream>
#include <math.h>
#include <sys/time.h>
#include <vector>
#include <algorithm>
#include <numeric>
#include "tbb/task_scheduler_init.h"
#include "tbb/parallel_sort.h"

using std::cout;
using std::endl;
using std::vector;

double gettimeofday_sec(){
	struct timeval t;
	gettimeofday(&t, NULL);
	return (double)t.tv_sec + (double)t.tv_usec * 1e-6;
}

void SortExample(const int n) {
	const int itrmax = 100;
	vector<int> a(n), b(n);
	vector<double> timeSTL, timeTBB;
	srand((unsigned) time(NULL));
	for(int itr=0; itr<itrmax; ++itr){
		// Set random array
		std::generate(a.begin(), a.end(), [](){ return rand()%100;});
		std::copy(a.begin(), a.end(), b.begin());
		double tstart = gettimeofday_sec();

		// TBB
		tbb::parallel_sort(a.data(), a.data() + n);

		double tend = gettimeofday_sec();

		// STL
		std::sort(b.begin(), b.end());

		double tendSTL = gettimeofday_sec();

		timeTBB.push_back(tend-tstart);
		timeSTL.push_back(tendSTL-tend);
	}
	cout << n << " "
			<< std::accumulate(timeTBB.begin(), timeTBB.end(), 0.0)/(double)itrmax << " "
			<< std::accumulate(timeSTL.begin(), timeSTL.end(), 0.0)/(double)itrmax << endl;
}

int main(){

	int size = 100000;
	for(int p=1; p<=6; ++p){
		tbb::task_scheduler_init init(p);
		SortExample(size);
	}

//	for(int size=10000; size<=500000; size+=10000){
//		SortExample(size);
//	}
}