image_parts_gather.c
No OneTemporary
Actions

Subscribers

None

File Metadata

	#include <stdio.h>
	#include <mpi.h>

	#define image_size 1024

	int main(int argc, char *argv[]) {
	int myrank, mysize;
	int * imgPart;
	int * buf;
	int i;
	int partSize;
	int count;

	MPI_Request request;
	MPI_Status status;
	MPI_Status s;

	MPI_Init(&argc, &argv);
	MPI_Comm_rank(MPI_COMM_WORLD, &myrank);
	MPI_Comm_size(MPI_COMM_WORLD, &mysize);

	imgPart = (int)malloc(image_size/mysize sizeof(int));

	/* Generate image parts */
	for (i=0; i < (image_size/mysize) ; i++){
	imgPart[i] = myrank * 1;
	}
	partSize = image_size/mysize;

	/* Process 0 is the root of the collective, i.e. the receiver of all parts */
	if (myrank == 0) /* Only the root must allocate buf */
	buf = (int)malloc(image_size sizeof(int));

	MPI_Gather(imgPart, partSize, MPI_INT, buf, partSize, MPI_INT, 0, MPI_COMM_WORLD);

	free(imgPart);
	if (myrank==0) free(buf);

	MPI_Finalize();
	}