From d874cc8bb9ed0f836495b5eabea44def6cffe9a8 Mon Sep 17 00:00:00 2001 From: Alex Ray Date: Wed, 9 Jan 2013 18:13:28 -0800 Subject: cutils: add simple reference counter Change-Id: Iefb34abc864cb4ca2da2f1c85c45f89af8c7fe8b --- include/cutils/aref.h | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) create mode 100644 include/cutils/aref.h (limited to 'include') diff --git a/include/cutils/aref.h b/include/cutils/aref.h new file mode 100644 index 0000000..460ac02 --- /dev/null +++ b/include/cutils/aref.h @@ -0,0 +1,62 @@ +/* + * Copyright (C) 2013 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#ifndef _CUTILS_AREF_H_ +#define _CUTILS_AREF_H_ + +#include +#include + +#ifdef ANDROID_SMP +#include +#else +#include +#endif + +__BEGIN_DECLS + +#define AREF_TO_ITEM(aref, container, member) \ + (container *) (((char*) (aref)) - offsetof(container, member)) + +struct aref +{ + volatile int32_t count; +}; + +static inline void aref_init(struct aref *r) +{ + r->count = 1; +} + +static inline int32_t aref_count(struct aref *r) +{ + return r->count; +} + +static inline void aref_get(struct aref *r) +{ + android_atomic_inc(&r->count); +} + +static inline void aref_put(struct aref *r, void (*release)(struct aref *)) +{ + if (android_atomic_dec(&r->count) == 1) + release(r); +} + +__END_DECLS + +#endif // _CUTILS_AREF_H_ -- cgit v1.1