https://docs.python.org/2/library/multiprocessing.html
from multiprocessing import Pool def f(x): return x*x if __name__ == '__main__': p = Pool(5) print(p.map(f, [1, 2, 3]))
This is what I have come up with
#include "stdafx.h"
#include <iostream>
#include <vector>
#include <unordered_map>
#include <mutex>
#include <windows.h>
#include <functional>
using namespace std;
std::mutex mtx1;
std::mutex mtx2;
unordered_map<int, double> A;
unordered_map<int, double> B;
typedef std::function<double(double)> funcDoubleToDouble;
DWORD_PTR createAffinityMask(int numCPU)
{
DWORD_PTR m = 0;
for (int i = 0; i < numCPU; i++)
{
DWORD_PTR temp = 1 << i;
m = m | temp;
}
return m;
}
double Square(double x)
{
return x * x;
}
void MapFunc(unordered_map<int, double>& source, unordered_map<int, double>& dest, int i, funcDoubleToDouble f, DWORD_PTR pmask)
{
//set processor affinity
HANDLE process = GetCurrentProcess();
BOOL success = SetProcessAffinityMask(process, pmask);
//lock global variables
mtx1.lock();
dest[i] = f(source[i]);
mtx1.unlock();
//unlock
//wait a little while to simulate processing
clock_t t = clock() + 100; // consume 100ms ...
while (clock() < t) {} // of CPU time
printf("i %d:\tlogical CPU %d\tProcessId %d\n", i, GetCurrentProcessorNumber(), GetCurrentProcessId());
}
/*
map<int, double>& source - source map data
map<int, double>& dest - destination map data
funcDoubleToDouble f - mapping function
DWORD_PTR pmask - cpu processor mask (bitmapping)
*/
void PoolMap(unordered_map<int, double>& source, unordered_map<int, double>& dest, funcDoubleToDouble f, DWORD_PTR pmask)
{
std::thread H[10];
for (int i = 0; i < 10; i++)
{
int index = i;
H[i]=thread(MapFunc, std::ref(source), std::ref(dest), i, f, pmask);
}
for (int i = 0; i < 10; i++)
{
H[i].join();
}
return;
}
int main()
{
unsigned num_cpus = std::thread::hardware_concurrency(); //retrieve the number of processors
DWORD_PTR pmask = createAffinityMask(5); // only use the first 5
std::cout << "CPU has " << num_cpus << " processors\n";
//initialize sourcevalues
for (int i=0;i<10;i++)
{
A[i] = (double) i;
}
//set pointer to the function we will use for mapping
funcDoubleToDouble f = Square;
PoolMap(A, B, f, pmask);
//show output of mapping function
for (int i = 0; i < 10; i++)
{
cout << i << ": " << B[i] << endl;
}
getchar();
return 0;
}
