NAME¶
MPI_Win_create_dynamic - Create an MPI Window object for one-sided
communication. This window allows memory to be dynamically exposed and
un-exposed for RMA operations.
SYNOPSIS¶
int MPI_Win_create_dynamic(MPI_Info info, MPI_Comm comm, MPI_Win *win)
This is a collective call executed by all processes in the group of comm. It
returns a window win without memory attached. Existing process memory can be
attached as described below. This routine returns a window object that can be
used by these processes to perform RMA operations on attached memory. Because
this window has special properties, it will sometimes be referred to as a
dynamic window. The info argument can be used to specify hints similar to the
info argument for
MPI_Win_create .
In the case of a window created with
MPI_Win_create_dynamic , the
target_disp for all RMA functions is the address at the target; i.e., the
effective window_base is
MPI_BOTTOM and the disp_unit is one. For
dynamic windows, the target_disp argument to RMA communication operations is
not restricted to non-negative values. Users should use
MPI_Get_address
at the target process to determine the address of a target memory location and
communicate this address to the origin process.
- info
- - info argument (handle)
- comm
- - communicator (handle)
OUTPUT PARAMETERS¶
- win
- - window object returned by the call (handle)
NOTES¶
Users are cautioned that displacement arithmetic can overflow in variables of
type
MPI_Aint and result in unexpected values on some platforms. This
issue may be addressed in a future version of MPI.
Memory in this window may not be used as the target of one-sided accesses in
this window until it is attached using the function
MPI_Win_attach .
That is, in addition to using
MPI_Win_create_dynamic to create an MPI
window, the user must use
MPI_Win_attach before any local memory may be
the target of an MPI RMA operation. Only memory that is currently accessible
may be attached.
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_attach MPI_Win_detach MPI_Win_allocate MPI_Win_allocate_shared
MPI_Win_create MPI_Win_free
LOCATION¶
/tmp/gyCYfBi4J6/mpich-3.1/src/mpi/rma/win_create_dynamic.c
