MPI_Win_allocate - Create and allocate an MPI Window object for one-sided
int MPI_Win_allocate(MPI_Aint size, int disp_unit, MPI_Info info,
MPI_Comm comm, void *baseptr, MPI_Win *win)
This is a collective call executed by all processes in the group of comm. On
each process, it allocates memory of at least size bytes, returns a pointer to
it, and returns a window object that can be used by all processes in comm to
perform RMA operations. The returned memory consists of size bytes local to
each process, starting at address baseptr and is associated with the window as
if the user called MPI_Win_create
on existing memory. The size argument
may be different at each process and size = 0 is valid; however, a library
might allocate and expose more memory in order to create a fast, globally
- - size of window in bytes (nonnegative integer)
- - local unit size for displacements, in bytes (positive integer)
- - info argument (handle)
- - communicator (handle)
- - base address of the window in local memory
- - window object returned by the call (handle)
This routine is thread-safe. This means that this routine may be safely used by
multiple threads without the need for any user-provided thread locks. However,
the routine is not interrupt safe. Typically, this is due to the use of memory
allocation routines such as malloc
or other non-MPICH runtime routines
that are themselves not interrupt-safe.
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
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.
- - Invalid argument. Some argument is invalid and is not identified by a
specific error class (e.g., MPI_ERR_RANK ).
- - Invalid communicator. A common error is to use a null communicator in a
call (not even allowed in MPI_Comm_rank ).
- - Invalid Info
- - Other error; use MPI_Error_string to get more information about
this error code.
MPI_Win_allocate_shared MPI_Win_create MPI_Win_create_dynamic MPI_Win_free