refcnt.h revision e4ee6e5cc3e8e23e1ecc0d9fa756d9cc2534d218
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
#pragma once
/***
This file is part of systemd.
Copyright 2013 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
/* A type-safe atomic refcounter */
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 })