MPI_Win_start(3)                   Open MPI                   MPI_Win_start(3)



NAME
       MPI_Win_start - Starts an RMA access epoch for win


SYNTAX
C Syntax
       #include <mpi.h>
       int MPI_Win_start(MPI_Group group, int assert, MPI_Win win)


Fortran Syntax
       INCLUDE 'mpif.h'
       MPI_WIN_START(GROUP, ASSERT, WIN, IERROR)
            INTEGER GROUP, ASSERT, WIN, IERROR


C++ Syntax
       #include <mpi.h>
       void MPI::Win::Start(const MPI::Group& group, int assert) const


INPUT PARAMETERS
       group     The group of target processes (handle).

       assert    Program assertion (integer).

       win       Window object (handle).


OUTPUT PARAMETERS
       IERROR    Fortran only: Error status (integer).


DESCRIPTION
       MPI_Win_start is a one-sided MPI communication synchronization call
       that starts an RMA access epoch for win. RMA calls issued on win during
       this epoch must access only windows at processes in group. Each process
       in group must issue a matching call to MPI_Win_post. MPI_Win_start is
       allowed to block until the corresponding MPI_Win_post calls have been
       executed, but is not required to.

       The assert argument is used to provide assertions on the context of the
       call that may be used for various optimizations. (See Section 6.4.4 of
       the MPI-2 Standard.) A value of assert = 0 is always valid. The
       following assertion value is supported:


       MPI_MODE_NOCHECK
                 When this value is passed in to this call, the library
                 assumes that the post call on the target has been called and
                 it is not necessary for the library to check to see if such a
                 call has been made.


ERRORS
       Almost all MPI routines return an error value; C routines as the value
       of the function and Fortran routines in the last argument. C++
       functions do not return errors. If the default error handler is set to
       MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception mechanism
       will be used to throw an MPI:Exception object.

       Before the error value is returned, the current MPI error handler is
       called. By default, this error handler aborts the MPI job, except for
       I/O function errors. The error handler may be changed with
       MPI_Win_set_errhandler; 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.


SEE ALSO
       MPI_Win_post MPI_Win_complete




1.4.1                            Jan 14, 2010                 MPI_Win_start(3)
