MPI_File_iread(3) Open MPI MPI_File_iread(3)
NAME
MPI_File_iread - Reads a file starting at the location specified by the
individual file pointer (nonblocking, noncollective).
SYNTAX
C Syntax
#include <mpi.h>
int MPI_File_iread(MPI_File fh, void *buf, int count,
MPI_Datatype datatype, MPI_Request *request)
Fortran Syntax
USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_FILE_IREAD(FH, BUF, COUNT, DATATYPE, REQUEST, IERROR)
<type> BUF(*)
INTEGER FH, COUNT, DATATYPE, REQUEST, IERROR
Fortran 2008 Syntax
USE mpi_f08
MPI_File_iread(fh, buf, count, datatype, request, ierror)
TYPE(MPI_File), INTENT(IN) :: fh
TYPE(*), DIMENSION(..), ASYNCHRONOUS :: buf
INTEGER, INTENT(IN) :: count
TYPE(MPI_Datatype), INTENT(IN) :: datatype
TYPE(MPI_Request), INTENT(OUT) :: request
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
C++ Syntax
#include <mpi.h>
MPI::Request MPI::File::Iread(void* buf, int count,
const MPI::Datatype& datatype)
INPUT/OUTPUT PARAMETER
fh File handle (handle).
INPUT PARAMETERS
count Number of elements in the buffer (integer).
datatype Data type of each buffer element (handle).
OUTPUT PARAMETERS
buf Initial address of buffer (choice).
request Request object (handle).
IERROR Fortran only: Error status (integer).
DESCRIPTION
MPI_File_iread is a nonblocking version of MPI_File_read. It attempts
to read from the file associated with fh at the current individual file
pointer position maintained by the system in which a total number of
count data items having datatype type are read into the user's buffer
buf. The data is taken out of those parts of the file specified by the
current view. MPI_File_iread stores the number of data-type elements
actually read in status. All other fields of status are undefined. It
is erroneous to call this function if MPI_MODE_SEQUENTIAL mode was
specified when the file was opened.
ERRORS
Almost all MPI routines return an error value; C routines as the value
of the function and Fortran routines in the last argument. C++ func-
tions do not return errors. If the default error handler is set to
MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception mechanism
will be used to throw an MPI::Exception object.
Before the error value is returned, the current MPI error handler is
called. For MPI I/O function errors, the default error handler is set
to MPI_ERRORS_RETURN. The error handler may be changed with
MPI_File_set_errhandler; the predefined error handler MPI_ER-
RORS_ARE_FATAL may be used to make I/O errors fatal. Note that MPI does
not guarantee that an MPI program can continue past an error.
4.1.2 Nov 24, 2021 MPI_File_iread(3)
Generated by dwww version 1.14 on Fri Jan 24 06:00:47 CET 2025.