MPI_Get_address - Gets the address of a location in memory.
126.96.36.199.1. C Syntax
#include <mpi.h> int MPI_Get_address(const void *location, MPI_Aint *address)
188.8.131.52.2. 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
184.108.40.206.3. 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
220.127.116.11. INPUT PARAMETERS
location: Location in caller memory (choice).
18.104.22.168. OUTPUT PARAMETERS
address: Address of location (integer).
ierror: Fortran only: Error status (integer).
MPI_Get_address returns the byte
address of a location in
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.
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
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.
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_FATALCauses the program to abort all connected MPI processes.
MPI_ERRORS_ABORTAn 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_RETURNReturns an error code to the application.
MPI applications can also implement their own error handlers by calling:
Note that MPI does not guarantee that an MPI program can continue past an error.
See the Error Handling section of the MPI-3.1 standard for more information.