NAME

       MPI_Win_allocate -  Create and allocate an MPI Window object for one-sided communication.

SYNOPSIS

       int MPI_Win_allocate(MPI_Aint size, int disp_unit, MPI_Info info,
                         MPI_Comm comm, void *baseptr, MPI_Win *win)

       This  is  a collective call executed by all processes in the group of comm. On each process, it allocates
       memory of at least size bytes, returns a pointer to it, and returns a window object that can be  used  by
       all processes in comm to perform RMA operations. The returned memory consists of size bytes local to each
       process, starting at  address  baseptr  and  is  associated  with  the  window  as  if  the  user  called
       MPI_Win_create  on  existing  memory.  The size argument may be different at each process and size = 0 is
       valid; however, a library might allocate and expose more memory in  order  to  create  a  fast,  globally
       symmetric allocation.

INPUT PARAMETERS

       size   - size of window in bytes (nonnegative integer)
       disp_unit
              - local unit size for displacements, in bytes (positive integer)
       info   - info argument (handle)
       comm   - communicator (handle)

OUTPUT PARAMETERS

       baseptr
              - base address of the window in local memory
       win    - window object returned by the call (handle)

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 guarentee 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_COMM
              - Invalid communicator.  A common error is to use a null communicator in a call (not even  allowed
              in MPI_Comm_rank ).
       MPI_ERR_INFO
              - Invalid Info
       MPI_ERR_OTHER
              - Other error; use MPI_Error_string to get more information about this error code.
       MPI_ERR_SIZE
              -

SEE ALSO

       MPI_Win_allocate_shared MPI_Win_create MPI_Win_create_dynamic MPI_Win_free

                                                   11/12/2016                                MPI_Win_allocate(3)