oracular (3) MPI_Win_start.openmpi.3.gz

Provided by: openmpi-doc_4.1.6-13.3ubuntu2_all bug

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
       USE MPI
       ! or the older form: INCLUDE 'mpif.h'
       MPI_WIN_START(GROUP, ASSERT, WIN, IERROR)
            INTEGER GROUP, ASSERT, WIN, IERROR


Fortran 2008 Syntax
       USE mpi_f08
       MPI_Win_start(group, assert, win, ierror)
            TYPE(MPI_Group), INTENT(IN) :: group
            INTEGER, INTENT(IN) :: assert
            TYPE(MPI_Win), INTENT(IN) :: win
            INTEGER, OPTIONAL, INTENT(OUT) :: 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