NAME

       MPI_Win_fence -  Synchronizes one-sided communications on a window

SYNOPSIS

       #include <mpi.h>
       int
       MPI_Win_fence(int assertion, MPI_Win win)

INPUT PARAMETERS

       assertion
              - program assertion (integer)
       win    - window object (handle)

NOTES

       The  MPI  call  MPI_WIN_FENCE(assert,  win)  synchronizes  RMA  calls  on win. The call is
       collective on the group of win. All RMA operations on win originating at a  given  process
       and  started  before  the  fence  call will complete at that process before the fence call
       returns. They will be completed at their target before  the  fence  call  returns  at  the
       target.  RMA  operations  on  win  started  by a process after the fence call returns will
       access their target window only after MPI_WIN_FENCE has been called by the target process.

       Calls to MPI_WIN_FENCE should both precede and follow calls to put, get or accumulate that
       are synchronized with fence calls.

NOTES FOR FORTRAN

       All  MPI  routines  in  Fortran  (except  for MPI_WTIME and MPI_WTICK ) have an additional
       argument ierr at the end of the argument list.  ierr  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 the call statement.

       All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in Fortran.

USAGE WITH IMPI EXTENSIONS

       The IMPI standard only supports MPI-1 functions.  Hence, this function  is  currently  not
       designed to operate within an IMPI job.

ERRORS

       If  an  error occurs in an MPI function, the current MPI error handler is called to handle
       it.  By default, this error handler aborts the MPI job.  The error handler may be  changed
       with  MPI_Errhandler_set  ;  the predefined error handler MPI_ERRORS_RETURN may be used to
       cause error values to be returned (in C and Fortran; this error handler is less useful  in
       with  the  C++  MPI  bindings.   The predefined error handler MPI::ERRORS_THROW_EXCEPTIONS
       should be used in C++ if the error value needs to be recovered).  Note that MPI  does  not
       guarantee that an MPI program can continue past an error.

       All  MPI  routines  (except MPI_Wtime and MPI_Wtick ) return an error value; C routines as
       the value of the function and Fortran routines in the last argument.  The C++ bindings for
       MPI  do  not  return  error  values;  instead,  error  values are communicated by throwing
       exceptions of type MPI::Exception (but not by default).  Exceptions are only thrown if the
       error value is not MPI::SUCCESS .

       Note that if the MPI::ERRORS_RETURN handler is set in C++, while MPI functions will return
       upon an error, there will be no way to recover what the actual error value was.
       MPI_SUCCESS
              - No error; MPI routine completed successfully.
       MPI_ERR_WIN
              - Invalid window.  A common error is to use a null window in a call.
       MPI_ERR_EPOCH
              - This error indicates than an operation has been attempted on a  "closed"  window.
              Certain  one-sided operations can only be performed on windows whose epoch has been
              started with MPI_Win_start.
       MPI_ERR_OTHER
              - Other error; use MPI_Error_string to get more information about this error code.

              seealso    MPI_Put(3),     MPI_Get(3),     MPI_Win_create(3),     MPI_Win_start(3),
              MPI_Win_complete(3),   MPI_Accumulate(3),   MPI_Win_free(3),  MPI_Win_get_group(3),
              MPI_Win_get_group(3), MPI_Win_wait(3)

MORE INFORMATION

       For more information, please see the official MPI Forum web site, which contains the  text
       of both the MPI-1 and MPI-2 standards.  These documents contain detailed information about
       each MPI function (most of which is not duplicated in these man pages).

       http://www.mpi-forum.org/

LOCATION

       wfence.c