#include <iostream>
#include <sys/wait.h>
#include <cmath>

#include "collectiveScheduler.hpp"

using namespace std;

CollectiveScheduler::CollectiveScheduler();
CollectiveScheduler::~CollectiveScheduler();

int CollectiveScherduler::partition(double* s, int low, int high){
	double pivot=s[high];
	int i=low-1;
	for (int j=low; j<high; j++){
		if (s[j] < pivot){
			i++;
			double temp = s[i];
			s[i]=s[j];
			s[j]=temp;
			}
		}
	double temp = s[i + 1];
	s[i+1]=s[high];
	s[high]=temp;

return i+1;
}

void CollectiveScheduler::quick_sort(double* s, int low, int high){
	if (low<high){
		int pi=partition(s, low, high);
		quick_sort(s, low, pi-1);
		quick_sort(s, pi+1, high);
		}
}

void CollectiveScheduler::execute(int levels, int rows, int n, double* data){
	pid_t root=getpid();
	for (int i=0; i<levels; i++){
		fork();
	}
	if (getpid() != root){
		int worker_id= getpid() % root;
		int worker_count = pow(2, levels) -1;

		for (int r=0; r<rows; r++){
			if (r % worker_count == worker_id % worker_count){
				quick_sort(data +(r * n), 0, n-1);
				}
			}
			_exit(0);
		}
	else {
		while (waitpid(-1, NULL, 0) >0);
		}
}