Code:
#include <stdio.h>
#include <mpi.h>
#include <stdlib.h> // Codeblock v8 compatibility for time calculation
#define NRA 3 // Number of rows in matrix A
#define NCA 3 // Number of columns in matrix A
#define NCB 3 // Number of columns in matrix B
#define MASTER 0 // Master process id
#define FROM_MASTER 1 // Message tag from master
#define FROM_SLAVE 2 // Message tag from slave
int main(int argc,char* argv[])
{
int process, // Number of tasks in partition
myrank, // Process ID
slave_process, // Number of slave tasks
source, // Process id of message source
dest, // Process id of message destination
mtype, // Message tag
rows, // Rows of matrix A sent to each worker
averow, extra, offset, // Variables to set rows to be sent to slave processes
i, j, k; // Multi-purpose counter variables (for loop counters - multi-d arrays)
double starttime, // Begining of execution time variable
endtime, // Ending of execution time variable
elapsed; // Total elapsed execution time
int a[NRA][NCA], // Matrix A to be multiplied
b[NCA][NCB], // Matrix B to be multiplied
c[NRA][NCB]; // Result matrix C
// MPI environment intiation
MPI_Init(&argc,&argv);
MPI_Comm_size(MPI_COMM_WORLD,&process);
MPI_Comm_rank(MPI_COMM_WORLD,&myrank);
MPI_Status status;
printf ("Process ID = %d\n", myrank); // Display all process available at runtime
slave_process = process - 1; // Total number of slave process
/***************************** Master Process Computation *************************************/
if (myrank == MASTER)
{
starttime = MPI_Wtime(); // Begin of execution time
for (i=0; i<NRA; i++)
for (j=0; j<NCA; j++)
a[i][j]= rand() % 10; // change
{
// Display Matrix A
printf("\n Matrix A \n");
printf("--------------\n");
for(i=0; i<NRA; ++i)
{
for(j=0; j<NCA; ++j)
printf("%3d", a[i][j]);
printf("\n");
}
}
for (i=0; i<NCA; i++)
for (j=0; j<NCB; j++)
b[i][j]= rand() % 10; //change
{
// Display Matrix B
printf("\n Matrix B \n");
printf("--------------\n");
for(i=0; i<NRA; ++i)
{
for(j=0; j<NCB; ++j)
printf("%3d", b[i][j]);
printf("\n");
}
}
printf("\n\n");
printf("\n\n Number of slave process = %d\n",slave_process); // Display Total number of slave process
// Send matrix to slave process
averow = NRA/slave_process;
extra = NRA%slave_process;
offset = 0;
mtype = FROM_MASTER;
for (dest=1; dest<=slave_process; dest++)
{
if (dest <= extra) // If total rows not divisible equally by slave process
rows = averow+1; // then assign extra row to a slave process
else
rows = averow; // If number of rows match number of slave process equally
printf("\n Sending %d rows to process %d\n",rows,dest);
MPI_Send(&offset, 1, MPI_INT, dest, mtype, MPI_COMM_WORLD); // Begin sending rows to all slave process
MPI_Send(&rows, 1, MPI_INT, dest, mtype, MPI_COMM_WORLD); // Rows are being sent to all slave process
MPI_Send(&a[offset][0], rows*NCA, MPI_INT, dest, mtype,MPI_COMM_WORLD); // Total number of elements being sent
MPI_Send(&b, NCA*NCB, MPI_INT, dest, mtype, MPI_COMM_WORLD); // Send all Matrix B elements to all slave process
offset = offset + rows; // Increase offset for next slave process
}
// Wait results from slave processes
mtype = FROM_SLAVE;
for (i=1; i<=slave_process; i++) // Get result from each slave process
{
source = i;
MPI_Recv(&offset, 1, MPI_INT, source, mtype, MPI_COMM_WORLD, &status);
MPI_Recv(&rows, 1, MPI_INT, source, mtype, MPI_COMM_WORLD, &status); // Result values from slave process
MPI_Recv(&c[offset][0], rows*NCB, MPI_INT, source, mtype, MPI_COMM_WORLD, &status); // Result values from slave process
}
// Display result of computation : Matrix C
printf("\nResult : Matrix C \n");
printf("-----------------\n");
for (i=0; i<NRA; i++)
{
printf("\n");
for (j=0; j<NCB; j++)
printf("%3d ", c[i][j]);
}
printf ("\n");
}
/**************************** Slave Process Computation ************************************/
if (myrank != MASTER)
{
mtype = FROM_MASTER;
MPI_Recv(&offset, 1, MPI_INT, MASTER, mtype, MPI_COMM_WORLD, &status);
printf ("\noffset =%d\n", offset);
MPI_Recv(&rows, 1, MPI_INT, MASTER, mtype, MPI_COMM_WORLD, &status);
MPI_Recv(&a, rows*NCA, MPI_INT, MASTER, mtype, MPI_COMM_WORLD, &status);
MPI_Recv(&b, NCA*NCB, MPI_INT, MASTER, mtype, MPI_COMM_WORLD, &status);
// Matrix calculation block
for (k=0; k<NCB; k++)
for (i=0; i<rows; i++)
{
c[i][k] = 0;
for (j=0; j<NCA; j++)
c[i][k] = c[i][k] + a[i][j] * b[j][k];
}
mtype = FROM_SLAVE;
MPI_Send(&offset, 1, MPI_INT, MASTER, mtype, MPI_COMM_WORLD);
MPI_Send(&rows, 1, MPI_INT, MASTER, mtype, MPI_COMM_WORLD);
MPI_Send(&c, rows*NCB, MPI_INT, MASTER, mtype, MPI_COMM_WORLD);
}
if (myrank == MASTER)
{
endtime = MPI_Wtime();
elapsed = endtime-starttime;
printf("\n\nParellel Time %f seconds\n",elapsed);
}
MPI_Finalize(); // Termination of MPI environment
}
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