gpxe/src/core/refcnt.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 <stdlib.h>
  20 #include <gpxe/refcnt.h>
  21
  22 /** @file
  23  *
  24  * Reference counting
  25  *
  26  */
  27
  28 /**
  29  * Increment reference count
  30  *
  31  * @v refcnt            Reference counter, or NULL
  32  * @ret refcnt          Reference counter
  33  *
  34  * If @c refcnt is NULL, no action is taken.
  35  */
  36 struct refcnt * ref_get ( struct refcnt *refcnt ) {
  37
  38         if ( refcnt ) {
  39                 refcnt->refcnt++;
  40                 DBGC2 ( refcnt, "REFCNT %p incremented to %d\n",
  41                         refcnt, refcnt->refcnt );
  42         }
  43         return refcnt;
  44 }
  45
  46 /**
  47  * Decrement reference count
  48  *
  49  * @v refcnt            Reference counter, or NULL
  50  *
  51  * If the reference count decreases below zero, the object's free()
  52  * method will be called.
  53  *
  54  * If @c refcnt is NULL, no action is taken.
  55  */
  56 void ref_put ( struct refcnt *refcnt ) {
  57
  58         if ( ! refcnt )
  59                 return;
  60
  61         refcnt->refcnt--;
  62         DBGC2 ( refcnt, "REFCNT %p decremented to %d\n",
  63                 refcnt, refcnt->refcnt );
  64
  65         if ( refcnt->refcnt >= 0 )
  66                 return;
  67
  68         if ( refcnt->free ) {
  69                 DBGC ( refcnt, "REFCNT %p being freed via method %p\n",
  70                        refcnt, refcnt->free );
  71                 refcnt->free ( refcnt );
  72         } else {
  73                 DBGC ( refcnt, "REFCNT %p being freed\n", refcnt );
  74                 free ( refcnt );
  75         }
  76 }