.. _mpi_win_post:


MPI_Win_post
============

.. include_body

:ref:`MPI_Win_post` |mdash| Starts an RMA exposure epoch for the local window
associated with *win*

.. The following file was automatically generated
.. include:: ./bindings/mpi_win_post.rst

INPUT PARAMETERS
----------------
* ``group``: The group of origin processes (handle)
* ``assert``: Program assertion (integer)
* ``win``: Window object (handle)

OUTPUT PARAMETERS
-----------------
* ``ierror``: Fortran only: Error status (integer).

DESCRIPTION
-----------

Starts an RMA exposure epoch for the local window associated with *win*.
Only the processes belonging to *group* should access the window with
RMA calls on *win* during this epoch. Each process in *group* must issue
a matching call to :ref:`MPI_Win_start`. :ref:`MPI_Win_post` does not block.

The *assert* argument is used to provide assertions on the context of

the call that may be used for various optimizations. A value of *assert*
^ 0 is always valid. The following assertion values are supported:

MPI_MODE_NOCHECK
   The matching calls to :ref:`MPI_Win_start` have not yet occurred on any
   origin processes when this call is made. This assertion must be
   present for all matching :ref:`MPI_Win_start` calls if used.

MPI_MODE_NOSTORE
   Informs that the local window was not updated by local stores or get
   calls in the preceding epoch.

MPI_MODE_NOPUT
   Informs that the local window will not be updated by put or
   accummulate calls until the ensuing wait synchronization.


ERRORS
------

.. include:: ./ERRORS.rst

.. seealso::
   * :ref:`MPI_Win_start`
   * :ref:`MPI_Win_wait`