From 9a6dcbf895f9da01768e64b73cec88c16157d91e Mon Sep 17 00:00:00 2001 From: Michael Biebl Date: Tue, 26 Mar 2019 23:25:23 +0100 Subject: New upstream version 1.16.0 --- shared/systemd/src/basic/refcnt.h | 54 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 shared/systemd/src/basic/refcnt.h (limited to 'shared/systemd/src/basic/refcnt.h') 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); -- cgit 1.3.0-6-gf8a5