Test for Zena

openmp-test.cpp

#include <omp.h>
#include <cstdlib>
#include <iostream>
#include <list>
#include <time.h>

bool ompon = false;
std::list<int> intList;
const int N = 1000;

long fib(long n){
	if (n <= 2) 
		return 1;
	else
		return fib(n-1) + fib(n-2);
}

void work(void){

	long w;
	long sum = 0;
	time_t stopclock;
	std::list<int>::iterator it;

	stopclock = time(NULL);
	#pragma omp parallel if(ompon) private(w, it) reduction(+:sum) 
	for (it = intList.begin(); it != intList.end(); it++) {
		#pragma omp single nowait
		{
			w = fib(*it);
			sum += w;
		}
	}
	stopclock = time(NULL) - stopclock;	

	std::cout << "The sum of fibs of list size " << N << std::endl << "=> is " << sum;
	if (ompon) {
		std::cout << " (openMP)" << std::endl << "Time taken with openMP: ";
	} else {
		std::cout << " (normal)" << std::endl << "Time taken without openMP: ";
	}
	std::cout << stopclock << "seconds" << std::endl << std::endl; 
}

int main(int argc, char* argv[]) {

	// Make random list of size N
	std::cout << "Generate list....";
	srand ( (unsigned int) time(NULL) );
	do {
		intList.push_back(rand() % 36 + 1);
	} while (intList.size() < N);
	std::cout << " done" << std::endl; 

	omp_set_num_threads(20);

	ompon = true;
	work();

	ompon = false;
	work();

	exit(EXIT_SUCCESS);
}

Can't remember exactly what the issue was with this code. Its OpenMP that I was looking into for Zena, something to do with the semantics of "#pragma omp single nowait" I think.