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/**************************************************************************
*
* Copyright 2009 VMware, Inc.
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sub license, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial portions
* of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
* IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
* ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
**************************************************************************/
#ifndef P_REFCNT_H
#define P_REFCNT_H
#include "p_defines.h"
#include "p_atomic.h"
#ifdef __cplusplus
extern "C" {
#endif
struct pipe_reference
{
struct pipe_atomic count;
};
static INLINE void
pipe_reference_init(struct pipe_reference *reference, unsigned count)
{
p_atomic_set(&reference->count, count);
}
static INLINE bool
pipe_is_referenced(struct pipe_reference *reference)
{
return p_atomic_read(&reference->count) != 0;
}
/**
* Set 'ptr' to point to 'reference' and update reference counting.
* The old thing pointed to, if any, will be unreferenced first.
* 'reference' may be NULL.
*/
static INLINE bool
pipe_reference(struct pipe_reference **ptr, struct pipe_reference *reference)
{
bool destroy = FALSE;
if(*ptr != reference) {
/* bump the reference.count first */
if (reference) {
assert(pipe_is_referenced(reference));
p_atomic_inc(&reference->count);
}
if (*ptr) {
assert(pipe_is_referenced(*ptr));
if (p_atomic_dec_zero(&(*ptr)->count)) {
destroy = TRUE;
}
}
*ptr = reference;
}
return destroy;
}
#ifdef __cplusplus
}
#endif
#endif /* P_REFCNT_H */
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