104 lines
2.5 KiB
C
104 lines
2.5 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., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301, USA.
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*
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* You can also choose to distribute this program under the terms of
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* the Unmodified Binary Distribution Licence (as given in the file
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* COPYING.UBDL), provided that you have satisfied its requirements.
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*/
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FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
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#include <stdlib.h>
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#include <ipxe/refcnt.h>
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/** @file
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*
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* Reference counting
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*
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*/
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/**
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* Increment reference count
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*
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* @v refcnt Reference counter, or NULL
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*
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* If @c refcnt is NULL, no action is taken.
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*/
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void ref_increment ( struct refcnt *refcnt ) {
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if ( refcnt ) {
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refcnt->count++;
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DBGC2 ( refcnt, "REFCNT %p incremented to %d\n",
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refcnt, refcnt->count );
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}
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}
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/**
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* Decrement reference count
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*
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* @v refcnt Reference counter, or NULL
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*
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* If the reference count decreases below zero, the object's free()
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* method will be called.
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*
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* If @c refcnt is NULL, no action is taken.
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*/
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void ref_decrement ( struct refcnt *refcnt ) {
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if ( ! refcnt )
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return;
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refcnt->count--;
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DBGC2 ( refcnt, "REFCNT %p decremented to %d\n",
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refcnt, refcnt->count );
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if ( refcnt->count >= 0 )
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return;
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if ( refcnt->count < -1 ) {
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DBGC ( refcnt, "REFCNT %p decremented too far (%d)!\n",
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refcnt, refcnt->count );
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/* Avoid multiple calls to free(), which typically
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* result in memory corruption that is very hard to
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* track down.
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*/
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return;
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}
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if ( refcnt->free ) {
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DBGC ( refcnt, "REFCNT %p being freed via method %p\n",
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refcnt, refcnt->free );
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refcnt->free ( refcnt );
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} else {
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DBGC ( refcnt, "REFCNT %p being freed\n", refcnt );
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free ( refcnt );
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}
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}
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/**
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* Do not free reference-counted object
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*
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* @v refcnt Reference counter
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*
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* This is meant for initializing a reference counter structure in a
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* statically allocated object.
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*/
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void ref_no_free ( struct refcnt *refcnt __unused ) {
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/* Do nothing */
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}
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