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Diffstat (limited to 'src/gallium/include/pipe/p_refcnt.h')
-rw-r--r-- | src/gallium/include/pipe/p_refcnt.h | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/src/gallium/include/pipe/p_refcnt.h b/src/gallium/include/pipe/p_refcnt.h new file mode 100644 index 0000000000..1f9088b3e9 --- /dev/null +++ b/src/gallium/include/pipe/p_refcnt.h @@ -0,0 +1,96 @@ +/************************************************************************** + * + * 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 */ |