MPI_Win_fence

Perform an MPI fence synchronization on a MPI window

Synopsis



int MPI_Win_fence(int assert, MPI_Win win)






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.





Thread and Interrupt Safety



This routine is thread-safe.  This means that this routine may be
safely used by multiple threads without the need for any user-provided
thread locks.  However, the routine is not interrupt safe.  Typically,
this is due to the use of memory allocation routines such as malloc
or other non-MPICH runtime routines that are themselves not interrupt-safe.



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.



Errors



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.  Before the value is returned, the current MPI error handler is
called.  By default, this error handler aborts the MPI job.  The error handler
may be changed with MPI_Comm_set_errhandler (for communicators),
MPI_File_set_errhandler (for files), and MPI_Win_set_errhandler (for
RMA windows).  The MPI-1 routine MPI_Errhandler_set may be used but
its use is deprecated.  The predefined error handler
MPI_ERRORS_RETURN may be used to cause error values to be returned.
Note that MPI does not guarantee that an MPI program can continue past
an error; however, MPI implementations will attempt to continue whenever
possible.





MPI_SUCCESS  
 No error; MPI routine completed successfully.





MPI_ERR_ARG  
 Invalid argument.  Some argument is invalid and is not
identified by a specific error class (e.g., MPI_ERR_RANK).





MPI_ERR_WIN  
 Invalid MPI window object





MPI_ERR_OTHER  
 Other error; use MPI_Error_string to get more information
about this error code.