Definition
MPI_UNSIGNED_CHAR is an MPI_Datatype that represents a unsigned character type in MPI, it corresponds to a unsigned char in C.
Datatypes
C
MPI_UNSIGNED_CHAR is an MPI_Datatype that represents a unsigned character type in MPI, it corresponds to a unsigned char in C.
#include <stdio.h>
#include <stdlib.h>
#include <mpi.h>
/**
* @brief Illustrate how to communicate a unsigned character between 2 MPI
* processes.
* @details This application is meant to be run with 2 MPI processes: 1 sender
* and 1 receiver. The former sends a unsigned character to the latter, which
* prints it.
**/
int main(int argc, char* argv[])
{
MPI_Init(&argc, &argv);
// Check that 2 MPI processes are used.
int size;
MPI_Comm_size(MPI_COMM_WORLD, &size);
if(size != 2)
{
printf("This application is meant to be run with 2 MPI processes.\n");
MPI_Abort(MPI_COMM_WORLD, EXIT_FAILURE);
}
// Get my rank and do the corresponding job.
enum role_ranks { SENDER, RECEIVER };
int my_rank;
MPI_Comm_rank(MPI_COMM_WORLD, &my_rank);
switch(my_rank)
{
case SENDER:
{
// Send the unsigned character.
unsigned char unsignedCharacterToSend = 'A';
printf("[MPI process %d] I send unsigned character: '%c'.\n", my_rank, unsignedCharacterToSend);
MPI_Ssend(&unsignedCharacterToSend, 1, MPI_UNSIGNED_CHAR, RECEIVER, 0, MPI_COMM_WORLD);
break;
}
case RECEIVER:
{
// Receive the unsigned character.
unsigned char unsignedCharacterReceived;
MPI_Recv(&unsignedCharacterReceived, 1, MPI_UNSIGNED_CHAR, SENDER, 0, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
printf("[MPI process %d] I received unsigned character: '%c'.\n", my_rank, unsignedCharacterReceived);
break;
}
}
MPI_Finalize();
return EXIT_SUCCESS;
}
#include <stdio.h>
#include <stdlib.h>
#include <mpi.h>
/**
* @brief Illustrate how to communicate an array of unsigned chars between 2 MPI
* processes.
* @details This application is meant to be run with 2 MPI processes: 1 sender
* and 1 receiver. The former sends an array of unsigned chars to the latter,
* which prints it.
**/
int main(int argc, char* argv[])
{
MPI_Init(&argc, &argv);
// Check that 2 MPI processes are used.
int size;
MPI_Comm_size(MPI_COMM_WORLD, &size);
if(size != 2)
{
printf("This application is meant to be run with 2 MPI processes.\n");
MPI_Abort(MPI_COMM_WORLD, EXIT_FAILURE);
}
// Get my rank and do the corresponding job.
enum role_ranks { SENDER, RECEIVER };
int my_rank;
MPI_Comm_rank(MPI_COMM_WORLD, &my_rank);
switch(my_rank)
{
case SENDER:
{
// Sends the array of unsigned characters
unsigned char unsignedCharsToSend[2] = { 'A', 'B' };
printf("[MPI process %d] I send unsigned chars: '%c' and '%c'.\n", my_rank, unsignedCharsToSend[0], unsignedCharsToSend[1]);
MPI_Ssend(unsignedCharsToSend, 2, MPI_UNSIGNED_CHAR, RECEIVER, 0, MPI_COMM_WORLD);
break;
}
case RECEIVER:
{
// Receives the array of unsigned characters
unsigned char unsignedCharsReceived[2];
MPI_Recv(unsignedCharsReceived, 2, MPI_UNSIGNED_CHAR, SENDER, 0, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
printf("[MPI process %d] I received unsigned chars: '%c' and '%c'.\n", my_rank, unsignedCharsReceived[0], unsignedCharsReceived[1]);
break;
}
}
MPI_Finalize();
return EXIT_SUCCESS;
}