| /* |
| * Copyright (c) 2013, Google, 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, sublicense, 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 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 NONINFRINGEMENT. |
| * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 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 __REFCOUNT_H |
| #define __REFCOUNT_H |
| |
| #include <arch/ops.h> |
| #include <compiler.h> |
| |
| typedef struct refcount { |
| volatile int cnt; |
| } refcount_t; |
| |
| typedef void (*refcount_destroy_func)(refcount_t* ref); |
| |
| static inline __ALWAYS_INLINE void refcount_init(refcount_t* ref) { |
| /* TODO: silly, but don't have atomic_set, or a clean |
| * write barrier */ |
| atomic_and(&ref->cnt, 0); |
| atomic_add(&ref->cnt, 1); |
| } |
| |
| static inline __ALWAYS_INLINE void refcount_inc(refcount_t* ref) { |
| atomic_add(&ref->cnt, 1); |
| } |
| |
| static inline __ALWAYS_INLINE void refcount_dec(refcount_t* ref, |
| refcount_destroy_func destroy) { |
| /* decerementing from 1? destroy */ |
| if (atomic_add(&ref->cnt, -1) == 1) |
| destroy(ref); |
| } |
| |
| #endif |