osx man page for mpi_file_read_ordered_begin

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)