netCDF  4.2.1.1
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dparallel.c
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1 
8 #include <config.h>
9 #include <netcdf_f.h>
10 #include "ncdispatch.h"
11 
12 /* This function creates a file for use with parallel I/O. */
13 int
14 nc_create_par(const char *path, int cmode, MPI_Comm comm,
15  MPI_Info info, int *ncidp)
16 {
17 #ifndef USE_PARALLEL
18  return NC_ENOPAR;
19 #else
20  NC_MPI_INFO data;
21  MPI_Comm comm_c = 0;
22  MPI_Info info_c = 0;
23 
24  /* One of these two parallel IO modes must be chosen by the user,
25  * or else pnetcdf must be in use. */
26  if (!(cmode & NC_MPIIO || cmode & NC_MPIPOSIX) &&
27  !(cmode & NC_PNETCDF))
28  return NC_EINVAL;
29 
30  comm_c = (MPI_Comm)comm;
31  info_c = (MPI_Info)info;
32 
33  data.comm = comm_c;
34  data.info = info_c;
35  return NC_create(path, cmode, 0, 0, NULL, 1, &data, ncidp);
36 #endif /* USE_PARALLEL */
37 }
38 
39 /* This function opens a file for parallel I/O. */
40 int
41 nc_open_par(const char *path, int mode, MPI_Comm comm,
42  MPI_Info info, int *ncidp)
43 {
44 #ifndef USE_PARALLEL
45  return NC_ENOPAR;
46 #else
47  NC_MPI_INFO mpi_data;
48 
49  /* One of these two parallel IO modes must be chosen by the user,
50  * or else pnetcdf must be in use. */
51  if (!(mode & NC_MPIIO || mode & NC_MPIPOSIX) &&
52  !(mode & NC_PNETCDF))
53  return NC_EINVAL;
54 
55  mpi_data.comm = comm;
56  mpi_data.info = info;
57 
58  return NC_open(path, mode, 0, NULL, 1, &mpi_data, ncidp);
59 #endif /* USE_PARALLEL */
60 }
61 
62 /* Fortran needs to pass MPI comm/info as integers. */
63 int
64 nc_open_par_fortran(const char *path, int mode, int comm,
65  int info, int *ncidp)
66 {
67 #ifndef USE_PARALLEL
68  return NC_ENOPAR;
69 #else
70 
71  MPI_Comm comm_c = 0;
72  MPI_Info info_c = 0;
73 
74  /* Convert fortran comm and info to C comm and info, if there is a
75  * function to do so. Otherwise just pass them. */
76 #ifdef HAVE_MPI_COMM_F2C
77  comm_c = MPI_Comm_f2c(comm);
78  info_c = MPI_Info_f2c(info);
79 #else
80  comm_c = (MPI_Comm)comm;
81  info_c = (MPI_Info)info;
82 #endif
83 
84  return nc_open_par(path, mode, comm_c, info_c, ncidp);
85 #endif
86 }
87 
88 /* This function will change the parallel access of a variable from
89  * independent to collective. */
90 int
91 nc_var_par_access(int ncid, int varid, int par_access)
92 {
93  NC* ncp;
94  int stat = NC_NOERR;
95 
96  if ((stat = NC_check_id(ncid, &ncp)))
97  return stat;
98 
99 #ifndef USE_PARALLEL
100  return NC_ENOPAR;
101 #else
102  return ncp->dispatch->var_par_access(ncid,varid,par_access);
103 #endif
104 }
105 
106 /* when calling from fortran: convert MPI_Comm and MPI_Info to C */
107 int
108 nc_create_par_fortran(const char *path, int cmode, int comm,
109  int info, int *ncidp)
110 {
111 #ifndef USE_PARALLEL
112  return NC_ENOPAR;
113 #else
114  MPI_Comm comm_c = 0;
115  MPI_Info info_c = 0;
116 #ifdef USE_PARALLEL
117 #ifdef HAVE_MPI_COMM_F2C
118  comm_c = MPI_Comm_f2c(comm);
119  info_c = MPI_Info_f2c(info);
120 #else
121  comm_c = (MPI_Comm)comm;
122  info_c = (MPI_Info)info;
123 #endif
124 #endif
125  return nc_create_par(path, cmode, comm_c, info_c, ncidp);
126 #endif
127 }
128 
129 
130 

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