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/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*-
* vim: ts=8 sts=4 sw=4 noexpandtab
*
* (C) 2001 by Argonne National Laboratory.
* See COPYRIGHT in top-level directory.
*/
#include "mpi.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define SIZE (65536)
#define NR_NBOPS (32)
/* Uses asynchronous I/O. Each process writes to separate files and
reads them back. The file name is taken as a command-line argument,
and the process rank is appended to it.*/
void handle_error(int errcode, const char *str);
void handle_error(int errcode, const char *str)
{
char msg[MPI_MAX_ERROR_STRING];
int resultlen;
MPI_Error_string(errcode, msg, &resultlen);
fprintf(stderr, "%s: %s\n", str, msg);
MPI_Abort(MPI_COMM_WORLD, 1);
}
int main(int argc, char **argv)
{
int *buf, i, rank, nints, len;
char *filename, *tmp;
int errs=0, toterrs;
MPI_File fh;
MPI_Status status[NR_NBOPS];
MPI_Request request[NR_NBOPS];
int errcode = 0;
MPI_Init(&argc,&argv);
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
/* process 0 takes the file name as a command-line argument and
broadcasts it to other processes */
if (!rank) {
i = 1;
while ((i < argc) && strcmp("-fname", *argv)) {
i++;
argv++;
}
if (i >= argc) {
fprintf(stderr, "\n*# Usage: async -fname filename\n\n");
MPI_Abort(MPI_COMM_WORLD, 1);
}
argv++;
len = strlen(*argv);
filename = (char *) malloc(len+10);
strcpy(filename, *argv);
MPI_Bcast(&len, 1, MPI_INT, 0, MPI_COMM_WORLD);
MPI_Bcast(filename, len+10, MPI_CHAR, 0, MPI_COMM_WORLD);
}
else {
MPI_Bcast(&len, 1, MPI_INT, 0, MPI_COMM_WORLD);
filename = (char *) malloc(len+10);
MPI_Bcast(filename, len+10, MPI_CHAR, 0, MPI_COMM_WORLD);
}
buf = (int *) malloc(SIZE);
nints = SIZE/sizeof(int);
for (i=0; i<nints; i++) buf[i] = rank*100000 + i;
/* each process opens a separate file called filename.'myrank' */
tmp = (char *) malloc(len+10);
strcpy(tmp, filename);
sprintf(filename, "%s.%d", tmp, rank);
errcode = MPI_File_open(MPI_COMM_SELF, filename,
MPI_MODE_CREATE | MPI_MODE_RDWR, MPI_INFO_NULL, &fh);
if (errcode != MPI_SUCCESS) {
handle_error(errcode, "MPI_File_open");
}
MPI_File_set_view(fh, 0, MPI_INT, MPI_INT, "native", MPI_INFO_NULL);
for (i=0; i<NR_NBOPS; i++) {
errcode = MPI_File_iwrite_at(fh, nints/NR_NBOPS*i,
buf+(nints/NR_NBOPS*i), nints/NR_NBOPS, MPI_INT, &(request[i]));
if (errcode != MPI_SUCCESS) {
handle_error(errcode, "MPI_File_iwrite");
}
}
MPI_Waitall(NR_NBOPS, request, status);
MPI_File_close(&fh);
/* reopen the file and read the data back */
for (i=0; i<nints; i++) buf[i] = 0;
errcode = MPI_File_open(MPI_COMM_SELF, filename,
MPI_MODE_CREATE | MPI_MODE_RDWR, MPI_INFO_NULL, &fh);
if (errcode != MPI_SUCCESS) {
handle_error(errcode, "MPI_File_open");
}
MPI_File_set_view(fh, 0, MPI_INT, MPI_INT, "native", MPI_INFO_NULL);
for (i=0; i<NR_NBOPS; i++) {
errcode = MPI_File_iread_at(fh, nints/NR_NBOPS*i,
buf+(nints/NR_NBOPS*i), nints/NR_NBOPS, MPI_INT, &(request[i]));
if (errcode != MPI_SUCCESS) {
handle_error(errcode, "MPI_File_open");
}
}
MPI_Waitall(NR_NBOPS, request, status);
MPI_File_close(&fh);
/* check if the data read is correct */
for (i=0; i<nints; i++) {
if (buf[i] != (rank*100000 + i)) {
errs++;
fprintf(stderr, "Process %d: error, read %d, should be %d\n", rank, buf[i], rank*100000+i);
}
}
MPI_Allreduce( &errs, &toterrs, 1, MPI_INT, MPI_SUM, MPI_COMM_WORLD );
if (rank == 0) {
if( toterrs > 0) {
fprintf( stderr, "Found %d errors\n", toterrs );
}
else {
fprintf( stdout, " No Errors\n" );
}
}
free(buf);
free(filename);
free(tmp);
MPI_Finalize();
return 0;
}
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