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.. _mpi_win_create_dynamic:
MPI_Win_create_dynamic
======================
.. include_body
:ref:`MPI_Win_create_dynamic` |mdash| One-sided MPI call that returns a window
object for RMA operations.
SYNTAX
------
C Syntax
^^^^^^^^
.. code-block:: c
#include <mpi.h>
MPI_Win_create_dynamic(MPI_Info info, MPI_Comm comm, MPI_Win *win)
Fortran Syntax
^^^^^^^^^^^^^^
.. code-block:: fortran
USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_WIN_CREATE_DYNAMIC(INFO, COMM, WIN, IERROR)
INTEGER INFO, COMM, WIN, IERROR
Fortran 2008 Syntax
^^^^^^^^^^^^^^^^^^^
.. code-block:: fortran
USE mpi_f08
MPI_Win_create_dynamic(info, comm, win, ierror)
TYPE(MPI_Info), INTENT(IN) :: info
TYPE(MPI_Comm), INTENT(IN) :: comm
TYPE(MPI_Win), INTENT(OUT) :: win
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
INPUT PARAMETERS
----------------
* ``info``: Info argument (handle).
* ``comm``: Communicator (handle).
OUTPUT PARAMETERS
-----------------
* ``win``: Window object returned by the call (handle).
* ``ierror``: Fortran only: Error status (integer).
DESCRIPTION
-----------
:ref:`MPI_Win_create_dynamic` is a one-sided MPI communication collective call
executed by all processes in the group of *comm*. It returns a window
object without memory attached that can be used by these processes to
perform RMA operations.
A window created with :ref:`MPI_Win_create_dynamic` requires the
*target_disp* argument for all RMA communication functions to be the
actual address at the target.
The following info keys are supported:
no_locks
If set to *true*, then the implementation may assume that the local
window is never locked (by a call to :ref:`MPI_Win_lock` or
MPI_Win_lock_all). Setting this value if only active synchronization
may allow the implementation to enable certain optimizations.
accumulate_ordering
By default, accumulate operations from one initiator to one target on
the same window memory location are strictly ordered. If the info key
accumulate_ordering is set to *none*, no ordering of accumulate
operations guaranteed. They key can also be a comma-separated list of
required orderings consisting of *rar*, *war*, *raw*, and *waw* for
read-after-read, write-after-read, read-after-write, and
write-after-write, respectively. Looser ordering constraints are
likely to result in improved performance.
accumulate_ops
If set to *same_op*, the implementation will assume that all
concurrent accumulate calls to the same target address will use the
same operation. If set to *same_op_no_op*, then the implementation
will assume that all concurrent accumulate calls to the same target
address will use the same operation or MPI_NO_OP. The default is
*same_op_no_op*.
NOTES
-----
Since dynamically attaching memory to a window is a local operation, one
has to communicate the actual address at the target using
:ref:`MPI_Get_address` and some communication.
Dynamic memory does not have any *disp_unit* associated and requires
correct offset calculations with proper type handling.
ERRORS
------
.. include:: ./ERRORS.rst
.. seealso::
* :ref:`MPI_Win_attach`
* :ref:`MPI_Win_detach`
* :ref:`MPI_Get_address`
|
