:ref:`MPI_File_get_info` |mdash| Returns a new info object containing values for current hints associated with a file.
#include <mpi.h>
int MPI_File_get_info(MPI_File fh, MPI_Info *info_used)
USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_FILE_GET_INFO(FH, INFO_USED, IERROR)
INTEGER FH, INFO_USED, IERROR
USE mpi_f08
MPI_File_get_info(fh, info_used, ierror)
TYPE(MPI_File), INTENT(IN) :: fh
TYPE(MPI_Info), INTENT(OUT) :: info_used
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
fh
: File handle (handle).
info_used
: New info object (handle).ierror
: Fortran only: Error status (integer).
:ref:`MPI_File_get_info` returns a new info object containing all the hints that the system currently associates with the file fh. The current setting of all hints actually used by the system related to this open file is returned in info_used. The user is responsible for freeing info_used via :ref:`MPI_Info_free`.
Note that the set of hints returned in info_used may be greater or smaller than the set of hints passed in to :ref:`MPI_File_open`, :ref:`MPI_File_set_view`, and :ref:`MPI_File_set_info`, as the system may not recognize some hints set by the user, and may automatically set other hints that the user has not requested to be set. See the :ref:`HINTS section <man-openmpi-mpi-file-get-info>` for a list of hints that can be set.
The following hints can be used as values for the info_used argument.
SETTABLE HINTS
shared_file_timeout
: Amount of time (in seconds) to wait for access to the shared file pointer before exiting withMPI_ERR_TIMEDOUT
.rwlock_timeout
: Amount of time (in seconds) to wait for obtaining a read or write lock on a contiguous chunk of a UNIX file before exiting withMPI_ERR_TIMEDOUT
.noncoll_read_bufsize
: Maximum size of the buffer used by MPI I/O to satisfy read requests in the noncollective data-access routines.Note
A buffer size smaller than the distance (in bytes) in a UNIX file between the first byte and the last byte of the access request causes MPI I/O to iterate and perform multiple UNIX
read()
orwrite()
calls. If the request includes multiple noncontiguous chunks of data, and the buffer size is greater than the size of those chunks, then the UNIXread()
orwrite()
(made at the MPI I/O level) will access data not requested by this process in order to reduce the total number ofwrite()
calls made. If this is not desirable behavior, you should reduce this buffer size to equal the size of the contiguous chunks within the aggregate request.noncoll_write_bufsize
: Maximum size of the buffer used by MPI I/O to satisfy write requests in the noncollective data-access routines.See the above note in
noncoll_read_bufsize
.coll_read_bufsize
: Maximum size of the buffer used by MPI I/O to satisfy read requests in the collective data-access routines.See the above note in
noncoll_read_bufsize
.coll_write_bufsize
: Maximum size of the buffer used by MPI I/O to satisfy write requests in the collective data-access routines.See the above note in
noncoll_read_bufsize
.mpiio_concurrency
: (boolean) controls whether nonblocking I/O routines can bind an extra thread to an LWP.mpiio_coll_contiguous
: (boolean) controls whether subsequent collective data accesses will request collectively contiguous regions of the file.
NON-SETTABLE HINTS
filename
: Access this hint to get the name of the file.