1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
|
/*
* Copyright (C) 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");
}
errcode = MPI_File_set_view(fh, 0, MPI_INT, MPI_INT, "native", MPI_INFO_NULL);
if (errcode != MPI_SUCCESS) {
handle_error(errcode, "MPI_File_set_view");
}
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");
}
errcode = MPI_File_set_view(fh, 0, MPI_INT, MPI_INT, "native", MPI_INFO_NULL);
if (errcode != MPI_SUCCESS) {
handle_error(errcode, "MPI_File_set_view");
}
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;
}
|
