MPI_Get_address - Get the address of a location in memory
int MPI_Get_address(const void *location, MPI_Aint *address)
- - location in caller memory (choice)
- - address of location (address integer)
This routine is provided for both the Fortran and C programmers. On many
systems, the address returned by this routine will be the same as produced by
the C &
operator, but this is not required in C and may not be true
of systems with word- rather than byte-oriented instructions or systems with
segmented address spaces.
This routine should be used instead of MPI_Address
This routine is both thread- and interrupt-safe. This means that this routine
may safely be used by multiple threads and from within a signal handler.
All MPI routines in Fortran (except for MPI_WTIME
have an additional argument ierr
at the end of the argument list.
is an integer and has the same meaning as the return value of the
routine in C. In Fortran, MPI routines are subroutines, and are invoked with
All MPI objects (e.g., MPI_Datatype
) are of type
In Fortran, the integer type is always signed. This can cause problems on
systems where the address fits into a four byte unsigned integer but the value
is larger than the largest signed integer. For example, a system with more
than 2 GBytes of memory may have addresses that do not fit within a four byte
signed integer. Unfortunately, there is no easy solution to this problem, as
there is no Fortran datatype that can be used here (using a longer integer
type will cause other problems, as well as surprising users when the size of
the integer type is larger that the size of a pointer in C). In this case, it
is recommended that you use C to manipulate addresses.
All MPI routines (except MPI_Wtime
) return an error
value; C routines as the value of the function and Fortran routines in the
last argument. Before the value is returned, the current MPI error handler is
called. By default, this error handler aborts the MPI job. The error handler
may be changed with MPI_Comm_set_errhandler
(for files), and MPI_Win_set_errhandler
(for RMA windows). The MPI-1 routine MPI_Errhandler_set
may be used but
its use is deprecated. The predefined error handler MPI_ERRORS_RETURN
may be used to cause error values to be returned. Note that MPI does
guarentee that an MPI program can continue past an error; however,
MPI implementations will attempt to continue whenever possible.
- - No error; MPI routine completed successfully.
- - Other error; use MPI_Error_string to get more information about
this error code.