---
name: "MPI_Get_address"
section: "3"
platform: "linux"
package: "openmpi"
version: "5.0.11-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/MPI_Get_address"
---

# MPI\_Get\_address(3)

*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
```

## 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.

```
REAL :: A(100,100)
INTEGER(MPI_ADDRESS_KIND) :: 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

This routine is provided for both Fortran and C programmers and may be useful when writing portable code. In the current release, the address returned by this routine will be the same as that produced by the C **&** operator.

C users may be tempted to avoid using *MPI\_Get\_address* and rely on the availability of the address operator **&**. Note, however, that & cast-expression is a pointer, not an address. ANSI C does not require that the value of a pointer (or the pointer cast to int) be the absolute address of the object pointed at although this is commonly the case. Furthermore, referencing may not have a unique definition on machines with a segmented address space. The use of *MPI\_Get\_address* to “reference” C variables guarantees portability to such machines as well.

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 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 return result of the function and Fortran routines in the last argument.

Before the error value is returned, the current MPI error handler associated with the communication object (e.g., communicator, window, file) is called. If no communication object is associated with the MPI call, then the call is considered attached to MPI\_COMM\_SELF and will call the associated MPI error handler. When MPI\_COMM\_SELF is not initialized (i.e., before *MPI\_Init*/*MPI\_Init\_thread*, after *MPI\_Finalize*, or when using the Sessions Model exclusively) the error raises the initial error handler. The initial error handler can be changed by calling *MPI\_Comm\_set\_errhandler* on MPI\_COMM\_SELF when using the World model, or the mpi\_initial\_errhandler CLI argument to mpiexec or info key to *MPI\_Comm\_spawn*/*MPI\_Comm\_spawn\_multiple*. If no other appropriate error handler has been set, then the MPI\_ERRORS\_RETURN error handler is called for MPI I/O functions and the MPI\_ERRORS\_ABORT error handler is called for all other MPI functions.

Open MPI includes three predefined error handlers that can be used:

- •

  **MPI\_ERRORS\_ARE\_FATAL** Causes the program to abort all connected MPI processes.

- •

  **MPI\_ERRORS\_ABORT** An error handler that can be invoked on a communicator, window, file, or session. When called on a communicator, it acts as if *MPI\_Abort* was called on that communicator. If called on a window or file, acts as if *MPI\_Abort* was called on a communicator containing the group of processes in the corresponding window or file. If called on a session, aborts only the local process.

- •

  **MPI\_ERRORS\_RETURN** Returns an error code to the application.

MPI applications can also implement their own error handlers by calling:

- •

  *MPI\_Comm\_create\_errhandler* then *MPI\_Comm\_set\_errhandler*

- •

  *MPI\_File\_create\_errhandler* then *MPI\_File\_set\_errhandler*

- •

  *MPI\_Session\_create\_errhandler* then *MPI\_Session\_set\_errhandler* or at *MPI\_Session\_init*

- •

  *MPI\_Win\_create\_errhandler* then *MPI\_Win\_set\_errhandler*

Note that MPI does not guarantee that an MPI program can continue past an error.

See the *MPI man page* for a full list of *MPI error codes*.

See the Error Handling section of the MPI-3.1 standard for more information.

## COPYRIGHT

2003-2026, The Open MPI Community