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
|
/*
* ADIOS is freely available under the terms of the BSD license described
* in the COPYING file in the top level directory of this source distribution.
*
* Copyright (c) 2008 - 2009. UT-BATTELLE, LLC. All rights reserved.
*/
/*************************************************************/
/* Example of reading arrays in ADIOS */
/* which were written from the same number of processors */
/* */
/* Similar example is manual/2_adios_read.c */
/*************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include "mpi.h"
#include "adios.h"
#include "public/adios_read.h"
int main (int argc, char ** argv)
{
/* application data structures */
int rank;
int NX, NY;
double *t;
int *p;
/* MPI and ADIOS data structures */
MPI_Comm comm = MPI_COMM_WORLD;
/* MPI and ADIOS setup */
MPI_Init (&argc, &argv);
MPI_Comm_rank (comm, &rank);
adios_read_init_method(ADIOS_READ_METHOD_FLEXPATH, comm, "");
/* First read in the scalars to calculate the size of the arrays */
/* get everything from single process - rank 0 for now*/
ADIOS_SELECTION process_select;
process_select.type=ADIOS_SELECTION_WRITEBLOCK;
process_select.u.block.index = rank;
/* read the size of arrays using local inq_var */
/* Note: at this moment, timeout is not handled. It blocks until writer appears */
ADIOS_FILE* afile = adios_read_open("arrays", ADIOS_READ_METHOD_FLEXPATH, comm,
ADIOS_LOCKMODE_NONE, 30.0);
/* Read arrays for each time step */
while(adios_errno != err_end_of_stream){
ADIOS_VARINFO* nx_info = adios_inq_var( afile, "NX");
if(nx_info->value) {
NX = *((int *)nx_info->value);
}
ADIOS_VARINFO* ny_info = adios_inq_var( afile, "NY");
if(ny_info->value) {
NY = *((int *)ny_info->value);
}
/* Allocate space for the arrays */
t = (double *) malloc (NX*NY*sizeof(double));
p = (int *) malloc (NX*sizeof(int));
memset(t, 0, NX*NY*sizeof(double));
memset(p, 0, NX*sizeof(int));
/* schedule a read of the arrays */
adios_schedule_read (afile, &process_select, "var_double_2Darray", 0, 1, t);
adios_schedule_read (afile, &process_select, "var_int_1Darray", 0, 1, p);
/* commit request and retrieve data */
adios_perform_reads (afile, 1);
/* print result */
printf("Results Rank=%d Step=%d p[] = [%d, %d,...] t[][] = [%.2f, %.2f]\n",
rank, afile->current_step, p[0], p[1], t[0], t[1]);
/* block until next step is available (30 sec timeout unsupported) */
adios_release_step(afile);
adios_advance_step(afile, 0, 30);
MPI_Barrier (comm);
/* shutdown ADIOS and MPI */
}
adios_read_close(afile);
/* wait until all readers finish */
adios_read_finalize_method(ADIOS_READ_METHOD_FLEXPATH);
MPI_Finalize ();
return 0;
}
|
