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MPI_Get_address(3) MPI MPI_Get_address(3)
MPI_Get_address - Get the address of a location in memory
int MPI_Get_address(MPICH2_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 .
THREAD AND INTERRUPT SAFETY
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
NOTES FOR FORTRAN
All MPI routines in Fortran (except for MPI_WTIME and MPI_WTICK ) have
an additional argument ierr at the end of the argument list. ierr 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
the call statement.
All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in
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 and MPI_Wtick ) 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
communicators), MPI_File_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 not 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.