src/core/interface.c

   1 /*
   2  * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation; either version 2 of the
   7  * License, or any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17  */
  18
  19 #include <gpxe/interface.h>
  20
  21 /** @file
  22  *
  23  * Object communication interfaces
  24  *
  25  */
  26
  27 /**
  28  * Plug an interface into a new destination interface
  29  *
  30  * @v intf              Interface
  31  * @v dest              New destination interface
  32  *
  33  * The reference to the existing destination interface is dropped, a
  34  * reference to the new destination interface is obtained, and the
  35  * interface is updated to point to the new destination interface.
  36  *
  37  * Note that there is no "unplug" call; instead you must plug the
  38  * interface into a null interface.
  39  */
  40 void plug ( struct interface *intf, struct interface *dest ) {
  41         DBGC ( intf, "INTF %p moving from INTF %p to INTF %p\n",
  42                intf, intf->dest, dest );
  43         intf_put ( intf->dest );
  44         intf->dest = intf_get ( dest );
  45 }
  46
  47 /**
  48  * Plug two interfaces together
  49  *
  50  * @v a                 Interface A
  51  * @v b                 Interface B
  52  *
  53  * Plugs interface A into interface B, and interface B into interface
  54  * A.  (The basic plug() function is unidirectional; this function is
  55  * merely a shorthand for two calls to plug(), hence the name.)
  56  */
  57 void plug_plug ( struct interface *a, struct interface *b ) {
  58         plug ( a, b );
  59         plug ( b, a );
  60 }