MPI_Win_detach(3) man page (version 4.1.8)

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Table of Contents

Name

MPI_Win_attach, MPI_Win_detach - One-sided MPI call that attaches / detaches a memory region to / from a window object for RMA operations.

Syntax

C Syntax

#include <mpi.h>
MPI_Win_attach(MPI_Win win, void *base, MPI_Aint size)
MPI_Win_detach(MPI_Win win, void *base)

Fortran Syntax

USE MPI
! or the older form: INCLUDE ’mpif.h’
MPI_WIN_ATTACH(WIN, BASE, SIZE, IERROR)
 <type> BASE(*)
 INTEGER(KIND=MPI_ADDRESS_KIND) SIZE
 INTEGER WIN, IERROR

Fortran 2008 Syntax

USE mpi_f08
MPI_Win_attach(win, base, size, ierror)
 TYPE(MPI_Win), INTENT(IN) :: win
 TYPE(*), DIMENSION(..), INTENT(IN) :: base
 INTEGER(KIND=MPI_ADDRESS_KIND), INTENT(IN) :: size
 INTEGER, OPTIONAL, INTENT(OUT) :: ierror

Input Parameters

win

A window that was created with MPI_Win_create_dynamic

base

Initial address of window (choice).

size

Size of window in bytes (nonnegative integer).

Output Parameters

win

Window object returned by the call (handle).

IERROR

Fortran only: Error status (integer).

Description

MPI_Win_attach is a one-sided MPI communication call used to attach a memory region of size bytes starting at address base to a window for RMA access. The window win must have been created using MPI_Win_create_dynamic . Multiple non-overlapping memory regions may be attached to the same dynamic window. Attaching overlapping memory regions to the same dynamic window is erroneous.

If the base value used by MPI_Win_attach was allocated by MPI_Alloc_mem, the size of the window can be no larger than the value set by the MPI_ALLOC_MEM function.

MPI_Win_detach can be used to detach a previously attached memory region from win. The memory address base and win must match arguments passed to a previous call to MPI_Win_attach.

Notes

Use memory allocated by MPI_Alloc_mem to guarantee properly aligned window boundaries (such as word, double-word, cache line, page frame, and so on).

Errors

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

Before the error value is returned, the current MPI error handler is called. By default, this error handler aborts the MPI job, except for I/O function errors. The error handler may be changed with MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned. Note that MPI does not guarantee that an MPI program can continue past an error.

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Table of Contents

• Name
• Syntax
• C Syntax
• Fortran Syntax
• Fortran 2008 Syntax
• Input Parameters
• Output Parameters
• Description
• Notes
• Errors

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Page last modified: 5-Feb-2025
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