MPI_File_read_ordered(3OpenMPI) MPI_File_read_ordered(3OpenMPI)
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
INCLUDE 'mpif.h'
MPI_FILE_READ_ORDERED(FH, BUF, COUNT, DATATYPE,
STATUS, IERROR)
<type> BUF(*)
INTEGER FH, COUNT, DATATYPE, STATUS(MPI_STATUS_SIZE), IERROR
C++ Syntax
#include <mpi.h>
void MPI::File::Read_ordered(void* buf, int count,
const MPI::Datatype& datatype, MPI::Status& status)
void MPI::File::Read_ordered(void* buf, int count,
const MPI::Datatype& datatype)
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++ 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_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.
Open MPI 1.2 September 2006 MPI_File_read_ordered(3OpenMPI)