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

                                            11/9/2015                         MPI_Win_allocate(3)