Start an RMA exposure epoch
int MPI_Win_post(MPI_Group group, int assert, MPI_Win win)
- group of origin processes (handle)
- Used to optimize this call; zero may be used as a default.
See notes. (integer)
- window object (handle)
The assert argument is used to indicate special conditions for the
fence that an implementation may use to optimize the MPI_Win_post
operation. The value zero is always correct. Other assertion values
may be or'ed together. Assertions that are valid for MPI_Win_post are:
- the matching calls to MPI_WIN_START have not yet
occurred on any origin processes when the call to MPI_WIN_POST is made.
The nocheck option can be specified by a post call if and only if it is
specified by each matching start call.
- the local window was not updated by local stores (or
local get or receive calls) since last synchronization. This may avoid
the need for cache synchronization at the post call.
- the local window will not be updated by put or accumulate
calls after the post call, until the ensuing (wait) synchronization. This
may avoid the need for cache synchronization at the wait call.
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
All MPI objects (e.g., MPI_Datatype, MPI_Comm) are of type INTEGER
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
- No error; MPI routine completed successfully.