82 lines
2.1 KiB
C
82 lines
2.1 KiB
C
/*
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* Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of the
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* License, or any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <assert.h>
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#include <gpxe/interface.h>
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/** @file
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*
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* Object communication interfaces
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*
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*/
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/**
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* Obtain reference to interface
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*
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* @v intf Interface
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* @ret intf Interface
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*
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* Increases the reference count on the interface.
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*/
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static struct interface * intf_get ( struct interface *intf ) {
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intf->refcnt ( intf, +1 );
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return intf;
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}
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/**
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* Drop reference to interface
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*
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* @v intf Interface
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*
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* Decreases the reference count on the interface.
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*/
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static void intf_put ( struct interface *intf ) {
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intf->refcnt ( intf, -1 );
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}
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/**
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* Plug an interface into a new destination interface
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*
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* @v intf Interface
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* @v dest New destination interface
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*
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* The reference to the existing destination interface is dropped, a
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* reference to the new destination interface is obtained, and the
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* interface is updated to point to the new destination interface.
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*
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* Note that there is no "unplug" call; instead you must plug the
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* interface into a null interface.
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*/
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void plug ( struct interface *intf, struct interface *dest ) {
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intf_put ( intf->dest );
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intf->dest = intf_get ( dest );
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}
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/**
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* Null update reference count
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*
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* @v intf Interface
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* @v delta Change to apply to reference count
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*
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* Use this as the refcnt() method for an interface that does not need
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* to support reference counting.
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*/
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void null_refcnt ( struct interface *intf __unused, int delta __unused ) {
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/* Do nothing */
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}
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