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

LAM/MPI 7.1.4                                       6/24/2006                                   MPI_Win_fence(3)