| /************************************************************************** |
| * |
| * 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 */ |