57de20dd8f
refcnt.h only exists for cases where objects are simultaneously handled by different threads. Otherwise it should not be used. The only case where this applies is sd_bus, really, and pretty much none of our APIs, since we do not claim thread-safety for them.
37 lines
1.1 KiB
C
37 lines
1.1 KiB
C
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
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#pragma once
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/***
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This file is part of systemd.
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Copyright 2013 Lennart Poettering
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systemd is free software; you can redistribute it and/or modify it
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under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or
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(at your option) any later version.
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systemd is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with systemd; If not, see <http://www.gnu.org/licenses/>.
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***/
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/* A type-safe atomic refcounter.
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*
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* DO NOT USE THIS UNLESS YOU ACTUALLY CARE ABOUT THREAD SAFETY! */
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typedef struct {
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volatile unsigned _value;
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} RefCount;
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#define REFCNT_GET(r) ((r)._value)
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#define REFCNT_INC(r) (__sync_add_and_fetch(&(r)._value, 1))
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#define REFCNT_DEC(r) (__sync_sub_and_fetch(&(r)._value, 1))
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#define REFCNT_INIT ((RefCount) { ._value = 1 })
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