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
149
150
151
152
153
154
155
156
157
158
|
!
! Copyright (C) 2012, Northwestern University and Argonne National Laboratory
! See COPYRIGHT notice in top-level directory.
!
! $Id$
subroutine check(err, message)
implicit none
include "mpif.h"
include "pnetcdf.inc"
integer err
character message*(*)
! It is a good idea to check returned value for possible error
if (err .NE. NF_NOERR) then
write(6,*) message//' '//nfmpi_strerror(err)
call MPI_Abort(MPI_COMM_WORLD, -1, err)
endif
end ! subroutine check
program main
implicit none
include "mpif.h"
include "pnetcdf.inc"
integer i, j, ncid, varid, cmode, err, rank, nprocs
integer ierr, dummy, get_args
integer dimid(2), req(2), status(2)
integer*8 start(2), count(2), stride(2), imap(2)
integer*8 bufsize, put_size, dim_size
real var(6,4)
character*256 filename, cmd
logical verbose
call MPI_INIT(err)
call MPI_COMM_RANK(MPI_COMM_WORLD, rank, err)
call MPI_COMM_SIZE(MPI_COMM_WORLD, nprocs, err)
! take filename from command-line argument if there is any
if (rank .EQ. 0) then
filename = "testfile.nc"
ierr = get_args(2, cmd, filename, verbose, dummy)
endif
call MPI_Bcast(ierr, 1, MPI_INTEGER, 0, MPI_COMM_WORLD, err)
if (ierr .EQ. 0) goto 999
call MPI_Bcast(filename, 256, MPI_CHARACTER, 0, MPI_COMM_WORLD,
+ err)
cmode = IOR(NF_CLOBBER, NF_64BIT_DATA)
err = nfmpi_create(MPI_COMM_WORLD, filename, cmode,
+ MPI_INFO_NULL, ncid)
call check(err, 'Error at nfmpi_create ')
! define a variable of a (4*nprocs) x 6 integer array in the nc file
dim_size = 4
err = nfmpi_def_dim(ncid, 'X', dim_size*nprocs, dimid(1))
call check(err, 'Error at nfmpi_def_dim ')
dim_size = 6
err = nfmpi_def_dim(ncid, 'Y', dim_size, dimid(2))
call check(err, 'Error at nfmpi_def_dim ')
err = nfmpi_def_var(ncid, 'var', NF_INT64, 2, dimid, varid)
call check(err, 'Error at nfmpi_def_var ')
err = nfmpi_enddef(ncid)
call check(err, 'Error at nfmpi_enddef ')
! set the contents of the local write buffer var, a 4 x 6 real array
! for example, for rank == 2, var(4,6) =
! 48, 54, 60, 65,
! 49, 55, 61, 67,
! 50, 56, 62, 68,
! 51, 57, 63, 69,
! 52, 58, 64, 70,
! 53, 59, 65, 71
do j = 1, 4
do i = 1, 6
var(i,j) = (j-1)*6+(i-1) + rank*24
enddo
enddo
! bufsize must be max of data type converted before and after
bufsize = 4*6*8
err = nfmpi_buffer_attach(ncid, bufsize)
call check(err, 'Error at nfmpi_buffer_attach ')
! write var to the NC variable in the matrix transposed way
count(1) = 2
count(2) = 6
stride(1) = 1
stride(2) = 1
imap(1) = 6
imap(2) = 1
req(1) = NF_REQ_NULL ! actually not necessary, added for testing
req(2) = NF_REQ_NULL ! actually not necessary, added for testing
! write to the 1st two columns of the variable in matrix transposed way
start(1) = 1 + rank*4
start(2) = 1
err = nfmpi_bput_varm_real(ncid, varid, start, count, stride,
+ imap, var(1,1), req(1))
call check(err, 'Error at nfmpi_bput_varm_real ')
! write to the 2nd two columns of the variable in transposed way
start(1) = 3 + rank*4
start(2) = 1
err = nfmpi_bput_varm_real(ncid, varid, start, count, stride,
+ imap, var(1,3), req(2))
call check(err, 'Error at nfmpi_bput_varm_real ')
err = nfmpi_wait_all(ncid, 2, req, status)
call check(err, 'Error at nfmpi_wait_all ')
! check each bput status
do i = 1, 2
if (status(i) .ne. NF_NOERR) then
print*,'Error at bput status ', nfmpi_strerror(status(i))
endif
enddo
err = nfmpi_buffer_detach(ncid)
call check(err, 'Error at nfmpi_buffer_detach ')
! The output from command "ncmpidump test.nc" is shown below if run
! this example on 4 processes.
!
! netcdf test {
! // file format: CDF-5 (big variables)
! dimensions:
! Y = 6 ;
! X = 16 ;
! variables:
! int64 var(Y, X) ;
!data:
!
! var =
! 0, 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72, 78, 84, 90,
! 1, 7, 13, 19, 25, 31, 37, 43, 49, 55, 61, 67, 73, 79, 85, 91,
! 2, 8, 14, 20, 26, 32, 38, 44, 50, 56, 62, 68, 74, 80, 86, 92,
! 3, 9, 15, 21, 27, 33, 39, 45, 51, 57, 63, 69, 75, 81, 87, 93,
! 4, 10, 16, 22, 28, 34, 40, 46, 52, 58, 64, 70, 76, 82, 88, 94,
! 5, 11, 17, 23, 29, 35, 41, 47, 53, 59, 65, 71, 77, 83, 89, 95 ;
!
! note that the display of ncmpidump is in C array dimensional order
err = nfmpi_inq_put_size(ncid, put_size)
call check(err, 'Error at nfmpi_inq_put_size ')
! print*,'pnetcdf reports total put size by this proc =', put_size
err = nfmpi_close(ncid)
call check(err, 'Error at nfmpi_close ')
999 CALL MPI_Finalize(err)
end ! program
|
