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| author | Sebastien Bacher <seb128@ubuntu.com> | 2019-01-25 11:26:25 +0100 |
|---|---|---|
| committer | Sebastien Bacher <seb128@ubuntu.com> | 2019-01-25 11:26:25 +0100 |
| commit | f54a568880bf47c2ea54c9b30d291156b34d6539 (patch) | |
| tree | aab9bb44b306da7651e8caf38bbab5cfeeb81b7d /shared/systemd/src/basic/refcnt.h | |
| parent | e8ac7dacdcf4b38addef4f8ac6ab038f9d29582c (diff) | |
| parent | bbae86d3d2997a853ca0365e8eb7a3ca7489ee09 (diff) | |
Update upstream source from tag 'upstream/1.15.2'
Update to upstream version '1.15.2' with Debian dir b4be4b7cfce96679a31cb9d423107789761e3b49
Diffstat (limited to 'shared/systemd/src/basic/refcnt.h')
| -rw-r--r-- | shared/systemd/src/basic/refcnt.h | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/shared/systemd/src/basic/refcnt.h b/shared/systemd/src/basic/refcnt.h new file mode 100644 index 00000000..40f9a84a --- /dev/null +++ b/shared/systemd/src/basic/refcnt.h @@ -0,0 +1,54 @@ +/* SPDX-License-Identifier: LGPL-2.1+ */ +#pragma once + +/* A type-safe atomic refcounter. + * + * DO NOT USE THIS UNLESS YOU ACTUALLY CARE ABOUT THREAD SAFETY! */ + +typedef struct { + volatile unsigned _value; +} RefCount; + +#define REFCNT_GET(r) ((r)._value) +#define REFCNT_INC(r) (__sync_add_and_fetch(&(r)._value, 1)) +#define REFCNT_DEC(r) (__sync_sub_and_fetch(&(r)._value, 1)) + +#define REFCNT_INIT ((RefCount) { ._value = 1 }) + +#define _DEFINE_ATOMIC_REF_FUNC(type, name, scope) \ + scope type *name##_ref(type *p) { \ + if (!p) \ + return NULL; \ + \ + assert_se(REFCNT_INC(p->n_ref) >= 2); \ + return p; \ + } + +#define _DEFINE_ATOMIC_UNREF_FUNC(type, name, free_func, scope) \ + scope type *name##_unref(type *p) { \ + if (!p) \ + return NULL; \ + \ + if (REFCNT_DEC(p->n_ref) > 0) \ + return NULL; \ + \ + return free_func(p); \ + } + +#define DEFINE_ATOMIC_REF_FUNC(type, name) \ + _DEFINE_ATOMIC_REF_FUNC(type, name,) +#define DEFINE_PUBLIC_ATOMIC_REF_FUNC(type, name) \ + _DEFINE_ATOMIC_REF_FUNC(type, name, _public_) + +#define DEFINE_ATOMIC_UNREF_FUNC(type, name, free_func) \ + _DEFINE_ATOMIC_UNREF_FUNC(type, name, free_func,) +#define DEFINE_PUBLIC_ATOMIC_UNREF_FUNC(type, name, free_func) \ + _DEFINE_ATOMIC_UNREF_FUNC(type, name, free_func, _public_) + +#define DEFINE_ATOMIC_REF_UNREF_FUNC(type, name, free_func) \ + DEFINE_ATOMIC_REF_FUNC(type, name); \ + DEFINE_ATOMIC_UNREF_FUNC(type, name, free_func); + +#define DEFINE_PUBLIC_ATOMIC_REF_UNREF_FUNC(type, name, free_func) \ + DEFINE_PUBLIC_ATOMIC_REF_FUNC(type, name); \ + DEFINE_PUBLIC_ATOMIC_UNREF_FUNC(type, name, free_func); |