oracular (3) MPI_Get_address.openmpi.3.gz

NAME

       MPI_Get_address - Gets the address of a location in memory.

SYNTAX

C Syntax

       #include <mpi.h>
       int MPI_Get_address(const void *location, MPI_Aint *address)

Fortran Syntax

       USE MPI
       ! or the older form: INCLUDE 'mpif.h'
       MPI_GET_ADDRESS(LOCATION, ADDRESS, IERROR)
            <type> LOCATION(*)
            INTEGER(KIND=MPI_ADDRESS_KIND) ADDRESS
            INTEGER   IERROR

Fortran 2008 Syntax

       USE mpi_f08
       MPI_Get_address(location, address, ierror)
            TYPE(*), DIMENSION(..), ASYNCHRONOUS :: location
            INTEGER(KIND=MPI_ADDRESS_KIND), INTENT(OUT) :: address
            INTEGER, OPTIONAL, INTENT(OUT) :: ierror

C++ Syntax

       #include <mpi.h>
       MPI::Aint MPI::Get_address(void* location)

INPUT PARAMETERS

       location  Location in caller memory (choice).

OUTPUT PARAMETERS

       address   Address of location (integer).

       IERROR    Fortran only: Error status (integer).

DESCRIPTION

       MPI_Get_address returns the byte address of a location in memory.

       Example: Using MPI_Get_address for an array.

       EAL A(100,100)
          INTEGER I1, I2, DIFF
          CALL MPI_GET_ADDRESS(A(1,1), I1, IERROR)
          CALL MPI_GET_ADDRESS(A(10,10), I2, IERROR)
          DIFF = I2 - I1
       ! The value of DIFF is 909*sizeofreal; the values of I1 and I2 are
       ! implementation dependent.

NOTES

       Current  Fortran  MPI  codes  will  run unmodified and will port to any system. However, they may fail if
       addresses larger than 2^32 - 1 are used in the program. New codes should be written so that they use  the
       new functions. This provides compatibility with C/C++ and avoids errors on 64-bit architectures. However,
       such newly written codes may need to be (slightly) rewritten to port to old Fortran 77 environments  that
       do not support KIND declarations.

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.  By  default,  this  error
       handler  aborts  the  MPI  job,  except  for  I/O  function errors. The error handler may be changed with
       MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN may be used to cause error values
       to be returned. Note that MPI does not guarantee that an MPI program can continue past an error.