| 1 | #ifndef _KCOMPAT_KREF_H |
| 2 | #define _KCOMPAT_KREF_H |
| 3 | |
| 4 | /* |
| 5 | * Kernel sourcecode compatible reference counting implementation |
| 6 | * |
| 7 | * Copyright (C) 2009 Novell Inc. |
| 8 | * |
| 9 | * Author: Jan Blunck <jblunck@suse.de> |
| 10 | * |
| 11 | * This program is free software; you can redistribute it and/or modify it |
| 12 | * under the terms of the GNU Lesser General Public License version 2.1 as |
| 13 | * published by the Free Software Foundation. |
| 14 | */ |
| 15 | |
| 16 | #include <assert.h> |
| 17 | #include <urcu/uatomic_arch.h> |
| 18 | |
| 19 | struct kref { |
| 20 | long refcount; /* ATOMIC */ |
| 21 | }; |
| 22 | |
| 23 | static inline void kref_set(struct kref *ref, int val) |
| 24 | { |
| 25 | uatomic_set(&ref->refcount, val); |
| 26 | } |
| 27 | |
| 28 | static inline void kref_init(struct kref *ref) |
| 29 | { |
| 30 | kref_set(ref, 1); |
| 31 | } |
| 32 | |
| 33 | static inline void kref_get(struct kref *ref) |
| 34 | { |
| 35 | long result = uatomic_add_return(&ref->refcount, 1); |
| 36 | assert(result != 0); |
| 37 | } |
| 38 | |
| 39 | static inline void kref_put(struct kref *ref, void (*release)(struct kref *)) |
| 40 | { |
| 41 | long res = uatomic_sub_return(&ref->refcount, 1); |
| 42 | if (res == 0) |
| 43 | release(ref); |
| 44 | } |
| 45 | |
| 46 | #endif /* _KCOMPAT_KREF_H */ |