Аналог глобальных переменных в MPI?

#include "mpi.h"
#include <cstdio>
#include <cstdlib>
#include <cmath>

int main(int argc, char *argv[]) {
	
	long double acc = 0.0;
	long double pi = 0.0;
	long double real_pi = 3.1415926535897932384626433832795028841971693993751058209749;
	
	MPI_Init(&argc, &argv);

	int rank, size;
	const int MASTER = 0, TAG = 0;

  MPI_Comm_rank(MPI_COMM_WORLD, &rank);
  MPI_Comm_size(MPI_COMM_WORLD, &size);
	
	__int64 nIter = 10000000000 / size;
	long double start = MPI_Wtime();
	for (__int64 k = rank * nIter; k < nIter * (1 + rank); k++) {
		acc += 4 * (k % 2 == 0 ? 1.0 : -1.0) / (2.0 * k + 1);
	}
	printf("Calculated part = %.16f in %d process\n", acc, rank);

  if (rank == 0) {
		for (int i = 1; i < size; i++) {
			MPI_Status status;
			long double tmp = 0.0;
			MPI_Recv(&tmp, 1, MPI_LONG_DOUBLE, i, TAG, MPI_COMM_WORLD, &status);
			acc += tmp;
		}
		pi = acc;
		long double end = MPI_Wtime();
		printf("Calculated pi = %0.16f with %i processes in %f\n", pi, size, end - start);
	} else {
		MPI_Send(&acc, 1, MPI_LONG_DOUBLE, MASTER, TAG, MPI_COMM_WORLD);
	}

  MPI_Finalize();
	return EXIT_SUCCESS;
}

#include <cstdio>
#include <vector>
#include <mpi.h>

#include "tools.h"

using namespace std;
unsigned long long d = 1;

unsigned long long get_new_d(int ccpu)
{
	MPI_Status status;

    //printf("%d: Start sender\n",ccpu);
    if ( MPI_SUCCESS != MPI_Sendrecv(NULL,0,MPI_UNSIGNED_LONG_LONG,0,0,&d,1,MPI_UNSIGNED_LONG_LONG,0,MPI_ANY_TAG,MPI_COMM_WORLD,&status))
    	return 0;

	return d;
}

int server()
{
	MPI_Status status;

    for(; d < 10; d++) {
    	MPI_Recv(NULL, 0, MPI_UNSIGNED_LONG_LONG, MPI_ANY_SOURCE, MPI_ANY_TAG, MPI_COMM_WORLD, &status);
        MPI_Send(&d,1,MPI_UNSIGNED_LONG_LONG,status.MPI_SOURCE,0,MPI_COMM_WORLD);
    }

	return 0;
}

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

    MPI_Init(&argc, &argv);
    MPI_Comm_size(MPI_COMM_WORLD, &nprocs);
    MPI_Comm_rank(MPI_COMM_WORLD, &ccpu);

    if(ccpu == 0)
    {
    	server();
    	printf("end server\n");
    }
    else
    {
    	for(;;)
    	{
    		d=get_new_d(ccpu);
    		if(d == 0)
    			break;
    		printf("%d: %lld\n",ccpu,d);
    	}
    }

    MPI_Finalize();
    return 0;
}

int server()
{
	unsigned long long start = , end = ; // 1..59049
	MPI_Status status;
	int i=0;
	ofstream output;
	char file_name[FILENAME_MAX] = {};

	sprintf(file_name,"./d.txt");

    for(d=start; d < end; d++) {
		init_output(file_name,&output);
		output << d << endl;
		output.flush();
		close_output(&output);
    	MPI_Recv(NULL, 0, MPI_UNSIGNED_LONG_LONG, MPI_ANY_SOURCE, MPI_ANY_TAG, MPI_COMM_WORLD, &status);
        MPI_Send(&d,1,MPI_UNSIGNED_LONG_LONG,status.MPI_SOURCE,0,MPI_COMM_WORLD);
    }

    d=0;
    for(i=0;i<4095;i++) {
    	MPI_Recv(NULL, 0, MPI_UNSIGNED_LONG_LONG, MPI_ANY_SOURCE, MPI_ANY_TAG, MPI_COMM_WORLD, &status);
        MPI_Send(&d,1,MPI_UNSIGNED_LONG_LONG,status.MPI_SOURCE,0,MPI_COMM_WORLD);
    }

	return 0;
}