From: Paolo Bonzini <pbonzini@redhat.com>
To: Jan Kiszka <jan.kiszka@siemens.com>
Cc: "Liu Ping Fan" <pingfank@linux.vnet.ibm.com>,
"Andreas Färber" <afaerber@suse.de>,
qemu-devel <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] [PATCH] qom: Use atomics for object refcounting
Date: Tue, 02 Jul 2013 14:00:20 +0200 [thread overview]
Message-ID: <51D2C0D4.2020108@redhat.com> (raw)
In-Reply-To: <51D2BF03.1060203@siemens.com>
Il 02/07/2013 13:52, Jan Kiszka ha scritto:
>>> But then atomic_dec_and_test or so. Letting the inc/dec return some
>>> >> value leaves room for interpretations (value of before or after the
>>> >> modification?).
>> >
>> > In qemu, I made all atomic_* functions return the old value. This is
>> > consistent with atomic_cmpxchg and atomic_xchg (where returning the new
>> > value makes no sense).
> Please avoid this ambiguity by naming the functions properly. That xchg
> returns old values is known, that dec and inc do, is surely not.
IMO the ambiguity is resolved simply by looking at the docs or existing
code, but I can rename them to atomic_fetch_{add,sub,and,or,inc,dec} and
add void versions without "fetch".
Paolo
next prev parent reply other threads:[~2013-07-02 12:47 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-02 9:36 [Qemu-devel] [PATCH] qom: Use atomics for object refcounting Jan Kiszka
2013-07-02 11:15 ` Andreas Färber
2013-07-02 11:28 ` Paolo Bonzini
2013-07-02 11:44 ` Jan Kiszka
2013-07-02 11:49 ` Paolo Bonzini
2013-07-02 11:52 ` Jan Kiszka
2013-07-02 12:00 ` Paolo Bonzini [this message]
2013-07-02 14:47 ` Anthony Liguori
2013-07-02 15:33 ` Paolo Bonzini
2013-07-02 16:36 ` Anthony Liguori
2013-07-03 1:23 ` liu ping fan
2013-07-03 16:36 ` Andreas Färber
2013-07-04 4:46 ` liu ping fan
2013-07-04 5:43 ` Andreas Färber
2013-07-04 7:21 ` liu ping fan
2013-07-04 7:59 ` Paolo Bonzini
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