mpi_file_read_ordered_begin(3openmpi) [osx man page]

MPI_File_read_ordered_begin(3OpenMPI)									     MPI_File_read_ordered_begin(3OpenMPI)

NAME

       MPI_File_read_ordered_begin  -  Reads a file at a location specified by a shared file pointer; beginning part of a split collective routine
       (nonblocking).

SYNTAX

       C Syntax
	   #include <mpi.h>
	   int MPI_File_read_ordered_begin(MPI_File fh, void *buf,
		  int count, MPI_Datatype datatype)

       Fortran Syntax
	   INCLUDE 'mpif.h'
	   MPI_FILE_READ_ORDERED_BEGIN(FH, BUF, COUNT, DATATYPE, IERROR)
		 <type> 	BUF(*)
		 INTEGER	FH, COUNT, DATATYPE, IERROR

C++ Syntax
       #include <mpi.h>
       void MPI::File::Read_ordered_begin(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).

       IERROR	 Fortran only: Error status (integer).

DESCRIPTION

       MPI_File_read_ordered_begin is the beginning part of a split collective, nonblocking routine that 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 argu-
       ments. 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.

NOTES

       All the nonblocking collective routines for data access are "split" into two routines, each with _begin or _end as a  suffix.  These  split
       collective routines are subject to the semantic rules described in Section 9.4.5 of the MPI-2 standard.

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_begin(3OpenMPI)

MPI_File_read_at_all_begin(3OpenMPI)									      MPI_File_read_at_all_begin(3OpenMPI)

NAME

       MPI_File_read_at_all_begin - Reads a file at explicitly specified offsets; beginning part of a split collective routine (nonblocking).

SYNTAX

       C Syntax
	   #include <mpi.h>
	   int MPI_File_read_at_all_begin(MPI_File fh, MPI_Offset
	    offset, void *buf, int count, MPI_Datatype
	    datatype)

       Fortran Syntax (see FORTRAN 77 NOTES)
	   INCLUDE 'mpif.h'
	   MPI_FILE_READ_AT_ALL_BEGIN(FH, OFFSET, BUF,
	    COUNT, DATATYPE, IERROR)
		 <type> BUF(*)
		 INTEGER   FH, COUNT, DATATYPE, IERROR
		 INTEGER(KIND=MPI_OFFSET_KIND) OFFSET

C++ Syntax
       #include <mpi.h>
       void MPI::File::Read_at_all_begin(MPI::Offset offset, void* buf,
	    int count, const MPI::Datatype& datatype)

INPUT PARAMETERS

       fh	 File handle (handle).

       offset	 File offset (integer).

       count	 Number of elements in buffer (integer).

       datatype  Data type of each buffer element.

OUTPUT PARAMETERS

       buf	 Initial address of buffer (choice).

       IERROR	 Fortran only: Error status (integer).

DESCRIPTION

       MPI_File_read_at_all_begin  is  the beginning part of a split collective routine that attempts to read from the file associated with fh (at
       the offset position) a total number of count data items having datatype type into the user's buffer buf.  The offset is in etype units rel-
       ative  to the current view. That is, holes are not counted when locating an offset. The data is taken out of those parts of the file speci-
       fied by the current view.

FORTRAN 77 NOTES
       The MPI standard prescribes portable Fortran syntax for the OFFSET argument only for Fortran 90. FORTRAN 77 users may use the  non-portable
       syntax

	    INTEGER*MPI_OFFSET_KIND OFFSET

       where MPI_OFFSET_KIND is a constant defined in mpif.h and gives the length of the declared integer in bytes.

NOTES

       All  the  nonblocking  collective routines for data access are "split" into two routines, each with _begin or _end as a suffix. These split
       collective routines are subject to the semantic rules described in Section 9.4.5 of the MPI-2 standard.

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_at_all_begin(3OpenMPI)