MPI_File_read_ordered - Reads a file at a location specified by a shared file pointer (blocking, collective).

NAME  SYNTAX  C Syntax  Fortran Syntax  Fortran 2008 Syntax  INPUT PARAMETERS  OUTPUT PARAMETERS  DESCRIPTION  ERRORS 

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NAME

MPI_File_read_ordered − Reads a file at a location specified by a shared file pointer (blocking, collective).

SYNTAX

C Syntax

#include <mpi.h>
int MPI_File_read_ordered(MPI_File fh, void *buf,

		int count, MPI_Datatype datatype,
		MPI_Status *status)

Fortran Syntax

USE MPI
! or the older form: INCLUDE ’mpif.h’
MPI_FILE_READ_ORDERED(FH, BUF, COUNT, DATATYPE,

	STATUS, IERROR)
	<type>			BUF(*)
	INTEGER			FH, COUNT, DATATYPE, STATUS(MPI_STATUS_SIZE), IERROR

Fortran 2008 Syntax

USE mpi_f08
MPI_File_read_ordered(fh, buf, count, datatype, status, ierror)

	TYPE(MPI_File), INTENT(IN) :: fh
	TYPE(*), DIMENSION(..) :: buf
	INTEGER, INTENT(IN) :: count
	TYPE(MPI_Datatype), INTENT(IN) :: datatype
	TYPE(MPI_Status) :: status
	INTEGER, OPTIONAL, INTENT(OUT) :: ierror

INPUT PARAMETERS

	fh		File handle (handle).
	count		Number of elements in buffer (integer).
	datatype		Data type of each buffer element (handle).

OUTPUT PARAMETERS

	buf		Initial address of buffer (choice).
	status		Status object (Status).
	IERROR		Fortran only: Error status (integer).

DESCRIPTION

MPI_File_read_ordered is a collective routine. This routine must be called by all processes in the communicator group associated with the file handle fh. Each process may pass different argument values for the datatype and count arguments. Each process attempts to read, from the file associated with fh, a total number of count data items having datatype type into the user’s buffer buf. For each process, the location in the file at which data is read is the position at which the shared file pointer would be after all processes whose ranks within the group are less than that of this process had read their data. MPI_File_read_ordered returns the actual number of datatype elements read in status. The shared file pointer is updated by the amounts of data requested by all processes of the group.

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.

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