This post talks about MPI_Finalize function in MPI. MPI_Finalize is the function used in the Message Passing Interface (MPI) to terminate the MPI environment. It must be called at the end of an MPI program once all communication and computation tasks are complete. It cleans up resources allocated by MPI, ensuring proper shutdown.

Syntax for MPI_Finalize

int MPI_Finalize()

Example code –

#include"stdio.h"
#include"mpi.h"

int main(int argc, char **argv)
{
	int myid, size;
	
	//Initialize MPI environment 
	MPI_Init(&argc,&argv);
	
	//Get total number of processes
	MPI_Comm_size(MPI_COMM_WORLD, &size);
	
	//Get my unique ID among all processes
	MPI_Comm_rank(MPI_COMM_WORLD, &myid);
	
	printf("Hello World from %d out of %d.\n",myid, size);
	
	//End MPI environment        
	MPI_Finalize();
}

To compile this code, use following command –

mpicc hello_world.c

To execute this code, run following command –

mpiexec -n 4 ./a.out

Output of this code will be something similar to the following –

Hello World from 0 out of 4.
Hello World from 1 out of 4.
Hello World from 2 out of 4.
Hello World from 3 out of 4.

To know more about MPI, visit our dedicated page for MPI here.

If you are new to Parallel Programming / HPC, visit our dedicated page for beginners.

References :

• MPI Standard Website
• MPI_Finalize and other information