MPIFilereadallbegin(3OpenMPI) MPIFilereadallbegin(3OpenMPI)

NAME
       MMPPIIFFiilleerreeaaddaallllbbeeggiinn - Reads a file starting at the locations speci-
       fied by individual file pointers; beginning part of a split  collective
       routine (nonblocking).


SSYYNNTTAAXX
       C Syntax
           #include 
           int MPIFilereadallbegin(MPIFile fh, void *buf,
                  int count, MPIDatatype datatype)

       Fortran Syntax
           INCLUDE 'mpif.h'
           MPIFILEREADALLBEGIN(FH, BUF, COUNT, DATATYPE, IERROR)
                          BUF(*)
                 INTEGER        FH, COUNT, DATATYPE, IERROR


CC++++ SSyynnttaaxx
       #include 
       void MPI::File::Readallbegin(void* buf, int count,
            const MPI::Datatype& datatype)


IINNPPUUTT//OOUUTTPPUUTT PPAARRAAMMEETTEERR
       fh        File handle (handle).


IINNPPUUTT PPAARRAAMMEETTEERRSS
       count     Number of elements in buffer (integer).

       datatype  Data type of each buffer element (handle).


OOUUTTPPUUTT PPAARRAAMMEETTEERRSS
       buf       Initial address of buffer (choice).

       IERROR    Fortran only: Error status (integer).


DESCRIPTION
       MPIFilereadallbegin  is  the  beginning  part of a split collective
       operation that attempts to read from the file associated  with  fh  (at
       the  current individual file pointer position maintained by the system)
       a total number of count data items having datatype type into the user's
       buffer buf.  The data is taken out of those parts of the file specified
       by the current view.


NNOOTTEESS
       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 Sec-
       tion 9.4.5 of the MPI-2 standard.


EERRRROORRSS
       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::ERRORSTHROWEXCEPTIONS, 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   MPIERRORSRETURN.   The   error   handler  may  be  changed  with
       MPIFileseterrhandler;     the     predefined      error      handler
       MPIERRORSAREFATAL  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 2006MPIFilereadallbegin(3OpenMPI)