.TH MPI_Win_create_dynamic 3 "11/12/2019" " " "MPI"
.SH 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. 
.SH SYNOPSIS
.nf
int MPI_Win_create_dynamic(MPI_Info info, MPI_Comm comm, MPI_Win * win)
.fi

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 
.I MPI_Win_create
\&.


In the case of a window created with 
.I MPI_Win_create_dynamic
, the target_disp
for all RMA functions is the address at the target; i.e., the effective
window_base is 
.I 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 
.I MPI_Get_address
at the target process to
determine the address of a target memory location and communicate this address
to the origin process.

.SH INPUT PARAMETERS
.PD 0
.TP
.B info 
- info argument (handle)
.PD 1
.PD 0
.TP
.B comm 
- communicator (handle)
.PD 1

.SH OUTPUT PARAMETERS
.PD 0
.TP
.B win 
- window object returned by the call (handle)
.PD 1

.SH NOTES

Users are cautioned that displacement arithmetic can overflow in variables of
type 
.I 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 
.I MPI_Win_attach
\&.
That is, in
addition to using 
.I MPI_Win_create_dynamic
to create an MPI window, the user must
use 
.I 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.


.SH 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 
.I malloc
or other non-MPICH runtime routines that are themselves not interrupt-safe.
.SH NOTES FOR FORTRAN
All MPI routines in Fortran (except for 
.I MPI_WTIME
and 
.I MPI_WTICK
) have
an additional argument 
.I ierr
at the end of the argument list.  
.I 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
.I call
statement.

All MPI objects (e.g., 
.I MPI_Datatype
, 
.I MPI_Comm
) are of type 
.I INTEGER
in Fortran.

.SH ERRORS

All MPI routines (except 
.I MPI_Wtime
and 
.I 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 
.I MPI_Comm_set_errhandler
(for communicators),
.I MPI_File_set_errhandler
(for files), and 
.I MPI_Win_set_errhandler
(for
RMA windows).  The MPI-1 routine 
.I MPI_Errhandler_set
may be used but
its use is deprecated.  The predefined error handler
.I MPI_ERRORS_RETURN
may be used to cause error values to be returned.
Note that MPI does 
.B not
guarentee that an MPI program can continue past
an error; however, MPI implementations will attempt to continue whenever
possible.

.PD 0
.TP
.B MPI_SUCCESS 
- No error; MPI routine completed successfully.
.PD 1
.PD 0
.TP
.B MPI_ERR_ARG 
- Invalid argument.  Some argument is invalid and is not
identified by a specific error class (e.g., 
.I MPI_ERR_RANK
).
.PD 1
.PD 0
.TP
.B MPI_ERR_COMM 
- Invalid communicator.  A common error is to use a null
communicator in a call (not even allowed in 
.I MPI_Comm_rank
).
.PD 1
.PD 0
.TP
.B MPI_ERR_INFO 
- Invalid Info 
.PD 1
.PD 0
.TP
.B MPI_ERR_OTHER 
- Other error; use 
.I MPI_Error_string
to get more information
about this error code. 
.PD 1
.PD 0
.TP
.B MPI_ERR_SIZE 
- 
.PD 1

.SH SEE ALSO
MPI_Win_attach MPI_Win_detach MPI_Win_allocate MPI_Win_allocate_shared MPI_Win_create MPI_Win_free
.br