NAME

MPI_File_iread_shared - Reads a file using the shared file pointer (nonblocking, noncollective).

SYNTAX

C Syntax

#include <mpi.h>
int MPI_File_iread_shared(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_SHARED(FH, BUF, COUNT, DATATYPE, REQUEST, IERROR)
	<type>	BUF(*)
	INTEGER	FH, COUNT, DATATYPE, REQUEST, IERROR

Fortran 2008 Syntax

USE mpi_f08
MPI_File_iread_shared(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_shared(void* buf, int count,
	const MPI::Datatype& datatype)

INPUT/OUTPUT PARAMETER

fh

File handle (handle).

INPUT PARAMETERS

count

Number of elements in 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_shared is a nonblocking version of the MPI_File_read_shared interface. It uses the shared file pointer to read files. The order of serialization among the processors is not deterministic for this noncollective routine, so you need to use other methods of synchronization to impose a particular order among processors.

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++ functions 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_ERRORS_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.