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author | Alex Ray <aray@google.com> | 2013-01-11 13:25:33 -0800 |
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committer | Android (Google) Code Review <android-gerrit@google.com> | 2013-01-11 13:25:34 -0800 |
commit | 60efde774d96493483bd948805547680dfd7f41a (patch) | |
tree | 495599ac2b55e9f32be4325b9d369bd73b8c35c8 /include | |
parent | 2c43b55814c9038f25425dd0a9b202e4fb9b5229 (diff) | |
parent | d874cc8bb9ed0f836495b5eabea44def6cffe9a8 (diff) | |
download | system_core-60efde774d96493483bd948805547680dfd7f41a.zip system_core-60efde774d96493483bd948805547680dfd7f41a.tar.gz system_core-60efde774d96493483bd948805547680dfd7f41a.tar.bz2 |
Merge "cutils: add simple reference counter"
Diffstat (limited to 'include')
-rw-r--r-- | include/cutils/aref.h | 62 |
1 files changed, 62 insertions, 0 deletions
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 <stddef.h> +#include <sys/cdefs.h> + +#ifdef ANDROID_SMP +#include <cutils/atomic-inline.h> +#else +#include <cutils/atomic.h> +#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_ |