---
name: "MPI_Win_create_dynamic"
section: "3"
platform: "linux"
package: "openmpi"
version: "5.0.11-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/MPI_Win_create_dynamic"
---

# MPI\_Win\_create\_dynamic(3)

*MPI\_Win\_create\_dynamic* — One-sided MPI call that returns a window object for RMA operations.

## SYNTAX

### C Syntax

```
#include <mpi.h>
MPI_Win_create_dynamic(MPI_Info info, MPI_Comm comm, MPI_Win *win)
```

### Fortran Syntax

```
USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_WIN_CREATE_DYNAMIC(INFO, COMM, WIN, IERROR)
     INTEGER INFO, COMM, WIN, IERROR
```

### Fortran 2008 Syntax

```
USE mpi_f08
MPI_Win_create_dynamic(info, comm, win, ierror)
     TYPE(MPI_Info), INTENT(IN) :: info
     TYPE(MPI_Comm), INTENT(IN) :: comm
     TYPE(MPI_Win), INTENT(OUT) :: win
     INTEGER, OPTIONAL, INTENT(OUT) :: ierror
```

## INPUT PARAMETERS

- •

  **info**: Info argument (handle).

- •

  **comm**: Communicator (handle).

## OUTPUT PARAMETERS

- •

  **win**: Window object returned by the call (handle).

- •

  **ierror**: Fortran only: Error status (integer).

## DESCRIPTION

*MPI\_Win\_create\_dynamic* is a one-sided MPI communication collective call executed by all processes in the group of *comm*. It returns a window object without memory attached that can be used by these processes to perform RMA operations.

A window created with *MPI\_Win\_create\_dynamic* requires the *target\_disp* argument for all RMA communication functions to be the actual address at the target.

The following info keys are supported:

- **no\_locks**

  If set to *true*, then the implementation may assume that the local window is never locked (by a call to *MPI\_Win\_lock* or MPI\_Win\_lock\_all). Setting this value if only active synchronization may allow the implementation to enable certain optimizations.

- **accumulate\_ordering**

  By default, accumulate operations from one initiator to one target on the same window memory location are strictly ordered. If the info key accumulate\_ordering is set to *none*, no ordering of accumulate operations guaranteed. They key can also be a comma-separated list of required orderings consisting of *rar*, *war*, *raw*, and *waw* for read-after-read, write-after-read, read-after-write, and write-after-write, respectively. Looser ordering constraints are likely to result in improved performance.

- **accumulate\_ops**

  If set to *same\_op*, the implementation will assume that all concurrent accumulate calls to the same target address will use the same operation. If set to *same\_op\_no\_op*, then the implementation will assume that all concurrent accumulate calls to the same target address will use the same operation or MPI\_NO\_OP. The default is *same\_op\_no\_op*.

## NOTES

Since dynamically attaching memory to a window is a local operation, one has to communicate the actual address at the target using *MPI\_Get\_address* and some communication.

Dynamic memory does not have any *disp\_unit* associated and requires correct offset calculations with proper type handling.

## ERRORS

Almost all MPI routines return an error value; C routines as the return result of the function and Fortran routines in the last argument.

Before the error value is returned, the current MPI error handler associated with the communication object (e.g., communicator, window, file) is called. If no communication object is associated with the MPI call, then the call is considered attached to MPI\_COMM\_SELF and will call the associated MPI error handler. When MPI\_COMM\_SELF is not initialized (i.e., before *MPI\_Init*/*MPI\_Init\_thread*, after *MPI\_Finalize*, or when using the Sessions Model exclusively) the error raises the initial error handler. The initial error handler can be changed by calling *MPI\_Comm\_set\_errhandler* on MPI\_COMM\_SELF when using the World model, or the mpi\_initial\_errhandler CLI argument to mpiexec or info key to *MPI\_Comm\_spawn*/*MPI\_Comm\_spawn\_multiple*. If no other appropriate error handler has been set, then the MPI\_ERRORS\_RETURN error handler is called for MPI I/O functions and the MPI\_ERRORS\_ABORT error handler is called for all other MPI functions.

Open MPI includes three predefined error handlers that can be used:

- •

  **MPI\_ERRORS\_ARE\_FATAL** Causes the program to abort all connected MPI processes.

- •

  **MPI\_ERRORS\_ABORT** An error handler that can be invoked on a communicator, window, file, or session. When called on a communicator, it acts as if *MPI\_Abort* was called on that communicator. If called on a window or file, acts as if *MPI\_Abort* was called on a communicator containing the group of processes in the corresponding window or file. If called on a session, aborts only the local process.

- •

  **MPI\_ERRORS\_RETURN** Returns an error code to the application.

MPI applications can also implement their own error handlers by calling:

- •

  *MPI\_Comm\_create\_errhandler* then *MPI\_Comm\_set\_errhandler*

- •

  *MPI\_File\_create\_errhandler* then *MPI\_File\_set\_errhandler*

- •

  *MPI\_Session\_create\_errhandler* then *MPI\_Session\_set\_errhandler* or at *MPI\_Session\_init*

- •

  *MPI\_Win\_create\_errhandler* then *MPI\_Win\_set\_errhandler*

Note that MPI does not guarantee that an MPI program can continue past an error.

See the *MPI man page* for a full list of *MPI error codes*.

See the Error Handling section of the MPI-3.1 standard for more information.

**SEE ALSO:**

- •

  *MPI\_Win\_attach*

- •

  *MPI\_Win\_detach*

- •

  *MPI\_Get\_address*

## COPYRIGHT

2003-2026, The Open MPI Community