/*D
   MPI_Win_fence - Perform an MPI fence synchronization on a MPI window

Synopsis:
.vb
int MPI_Win_fence(int assert, MPI_Win win)
.ve

Input Parameters:
+ assert - program assertion (integer)
- win - window object (handle)

Notes:
The 'assert' argument is used to indicate special conditions for the
fence that an implementation may use to optimize the 'MPI_Win_fence'
operation.  The value zero is always correct.  Other assertion values
may be or''ed together.  Assertions that are valid for 'MPI_Win_fence' are\:

+ MPI_MODE_NOSTORE - the local window was not updated by local stores
  (or local get or receive calls) since last synchronization.
. MPI_MODE_NOPUT - the local window will not be updated by put or accumulate
  calls after the fence call, until the ensuing (fence) synchronization.
. MPI_MODE_NOPRECEDE - the fence does not complete any sequence of locally
  issued RMA calls. If this assertion is given by any process in the window
  group, then it must be given by all processes in the group.
- MPI_MODE_NOSUCCEED - the fence does not start any sequence of locally
  issued RMA calls. If the assertion is given by any process in the window
  group, then it must be given by all processes in the group.

.N ThreadSafe

.N Fortran

.N Errors
.N MPI_SUCCESS
.N MPI_ERR_ARG
.N MPI_ERR_WIN
.N MPI_ERR_OTHER

D*/

