[mvapich-discuss] MPI Program using FILE I/O

[shankha]

Hi,
I have a MPI program which uses ROMIO API's. The program runs and
executes fine without any issues.
The problem is I do not see the data which I wrote to the file. I
check for all possible error conditions. I am copying the program for
your reference.

The number of processes as of now is 8.
Command Line To Build the executable:

INSTAL_DIR=mpi install location.
mpicc     -IINSTAL_DIR/include   -IINSTAL_DIR/src/mpi/romio/include -g
-Wall -Wextra \
        prog.c -o executable -LINSTAL_DIR/lib -lmpich
-Wl,-RINSTAL_DIR/lib -lpthread


Command line to execute the program :
mpiexec   -np 8  ./executable


#include <stdio.h>
#include <mpi.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <stdbool.h>

#define NUM_PROCESSES 8
#define BUF_SIZE 3

#define CHECK(a) \
{ \
		if (!(a)) { \
				fprintf(stderr, \
								"(%d)Error at node %d, line %d of test program\n", \
								myrank, myrank, __LINE__); \
		} \
}

#define CHECKINTS(a, b) \
{ \
		CHECK((int)(a) == (int)(b)); \
		if ((int)(a) != (int)(b)) { \
				fprintf(stderr, "(%d)got: %x expected: %x\n", \
								myrank, (int)(a), (int)(b)); \
		} \
}


#define CHECKERRS(a, b) \
{ \
		char got_string[MPI_MAX_ERROR_STRING]; \
		char expected_string[MPI_MAX_ERROR_STRING]; \
		int  string_len; \
		int  ca, cb; \
		CHECK((int)(a) == (int)(b)); \
		if ((int)(a) != (int)(b)) { \
				MPI_Error_class(a, &ca); \
				MPI_Error_class(b, &cb); \
				CHECKINTS(ca, cb); \
				if (ca != cb) { \
						MPI_Error_string(a, got_string, &string_len); \
						MPI_Error_string(b, expected_string, &string_len); \
						fprintf(stderr, "(%d)got %d in class %d:  %s\n", \
										myrank, (int)(a), (int)ca, got_string); \
						fprintf(stderr, "(%d)expected %d in class %d:  %s\n", \
										myrank, (int)(b), (int)cb, expected_string); \
				} \
		} \
}


int
main ( int argc, char **argv )
{
		int myrank , size , i = 0, ret, amode;
		int rank_arr [ NUM_PROCESSES / 2 ][ 2 ];
		char filename [ 20 ];
		int buf [ BUF_SIZE ];
		bool odd_rank = false, even_rank = false;

		MPI_File mpi_fp;
		MPI_Group group_world, new_group [ NUM_PROCESSES / 2 ] ;
		MPI_Comm new_comm [ NUM_PROCESSES / 2 ];

		/* printf ( " %s \n ", argv [ 0 ]  );   */
		MPI_Init(&argc, &argv);
		MPI_Comm_rank ( MPI_COMM_WORLD, &myrank );
		MPI_Comm_size ( MPI_COMM_WORLD, &size );
		assert ( size == NUM_PROCESSES );

		amode = MPI_MODE_RDWR  | MPI_MODE_CREATE;


		if ( myrank == 0 )
				printf ( "Num Procs : %d \n", size );
		MPI_Barrier ( MPI_COMM_WORLD );

		printf ( " My Rank = %d \n", myrank );

		if (  ( myrank % 2 ) == 1 )
				odd_rank = true;
		else if ( ( myrank % 2 )  == 0 )
				even_rank = true;
		else
				assert ( false );

		i = 0;
		while ( i < BUF_SIZE )
		{
				buf [i] = myrank;
    i                           i++;
		}

		i = 0;
		while ( i < NUM_PROCESSES )
		{
				rank_arr [i/2][ i % 2 ] = i;
				i++;
		}


		ret = MPI_Comm_group ( MPI_COMM_WORLD, &group_world );
		CHECKERRS ( ret , MPI_SUCCESS );

		ret = MPI_Group_incl ( group_world, 2, rank_arr [ myrank/2 ] ,
						&new_group [ myrank / 2 ] );
		CHECKERRS ( ret , MPI_SUCCESS );

		ret = MPI_Comm_create ( MPI_COMM_WORLD, new_group [ myrank / 2 ] ,
						&new_comm [ myrank / 2 ] );
		CHECKERRS ( ret , MPI_SUCCESS );

		if ( new_comm [ myrank / 2] == MPI_COMM_NULL )
		{
                                        printf ( "Can't create
communicators %d \n" ,  __LINE__  );
					exit ( EXIT_FAILURE );
		}


		memset ( filename, 0 , 20 );
		strcpy ( filename, "test" );
		sprintf ( filename + strlen ( "test" ), "%d", myrank / 2 );

		ret = MPI_File_open ( new_comm [ myrank / 2 ], filename, amode,
						MPI_INFO_NULL, &mpi_fp	);
		CHECKERRS ( ret , MPI_SUCCESS );

		if ( mpi_fp == MPI_FILE_NULL )
		{
				printf ( " File cannot be opened \n");
				exit ( EXIT_FAILURE );
		}

		MPI_Barrier ( new_comm [ myrank / 2] );

		ret = MPI_File_set_view ( mpi_fp , ( myrank  % 2 ) * sizeof ( int )
* BUF_SIZE , MPI_INT,
							MPI_INT, "native", MPI_INFO_NULL );
		CHECKERRS ( ret, MPI_SUCCESS );
		
		MPI_Barrier ( new_comm [ myrank / 2] );
		
		ret = MPI_File_write_all ( mpi_fp , buf, BUF_SIZE, MPI_INT,
MPI_STATUS_IGNORE );
		CHECKERRS ( ret, MPI_SUCCESS );

		MPI_Barrier ( new_comm [ myrank / 2] );


		MPI_File_sync ( mpi_fp );
		CHECKERRS ( ret, MPI_SUCCESS );

		ret = MPI_File_close ( &mpi_fp );
		CHECKERRS ( ret, MPI_SUCCESS );

		ret = MPI_Comm_free ( &new_comm [ myrank / 2 ] );
		CHECKERRS ( ret, MPI_SUCCESS );

		ret = MPI_Group_free ( &new_group [ myrank / 2 ] );
		CHECKERRS ( ret, MPI_SUCCESS );

		ret = MPI_Group_free ( &group_world );
		CHECKERRS ( ret, MPI_SUCCESS );

		MPI_Finalize();
		return 0;
}

Thanks for your help.
-- 
Thanks
Shankha