NAME

       MPI_Win_start -  Starts an RMA access epoch

SYNOPSIS

       #include <mpi.h>
       int MPI_Win_start(MPI_Group group, int assertion, MPI_Win win)

INPUT PARAMETERS

       group  - group of origin processes (handle)
       assertion
              - program assertion (integer)
       win    - window object (handle)

NOTES

       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. RMA accesses to
       each target window will be delayed, if necessary, until the target process executed the matching call  to
       MPI_WIN_POST.  MPI_WIN_START is allowed to block until the corresponding MPI_WIN_POST calls are executed,
       but is not required to.

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_GROUP
              - Null group passed to function.
       MPI_ERR_OTHER
              - Other error; use MPI_Error_string to get more information about this error code.
       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.

SEE ALSO

       MPI_Put(3),  MPI_Get(3),  MPI_Win_create(3),  MPI_Accumulate(3),  MPI_Win_complete(3),  MPI_Win_fence(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

       wstart.c

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