From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49377) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ar4f7-0000OI-El for qemu-devel@nongnu.org; Fri, 15 Apr 2016 10:23:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ar4f6-0007e2-Is for qemu-devel@nongnu.org; Fri, 15 Apr 2016 10:23:57 -0400 Received: from mail-wm0-x22d.google.com ([2a00:1450:400c:c09::22d]:38341) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ar4f6-0007di-Bj for qemu-devel@nongnu.org; Fri, 15 Apr 2016 10:23:56 -0400 Received: by mail-wm0-x22d.google.com with SMTP id u206so34789799wme.1 for ; Fri, 15 Apr 2016 07:23:56 -0700 (PDT) From: =?UTF-8?q?Alex=20Benn=C3=A9e?= Date: Fri, 15 Apr 2016 15:23:44 +0100 Message-Id: <1460730231-1184-7-git-send-email-alex.bennee@linaro.org> In-Reply-To: <1460730231-1184-1-git-send-email-alex.bennee@linaro.org> References: <1460730231-1184-1-git-send-email-alex.bennee@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Qemu-devel] [RFC v1 05/12] atomic: introduce cmpxchg_bool List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: mttcg@listserver.greensocs.com, fred.konrad@greensocs.com, a.rigo@virtualopensystems.com, serge.fdrv@gmail.com, cota@braap.org Cc: qemu-devel@nongnu.org, mark.burton@greensocs.com, pbonzini@redhat.com, jan.kiszka@siemens.com, rth@twiddle.net, peter.maydell@linaro.org, claudio.fontana@huawei.com, =?UTF-8?q?Alex=20Benn=C3=A9e?= This allows for slightly neater code when checking for success of a cmpxchg operation. Signed-off-by: Alex Bennée --- include/qemu/atomic.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/include/qemu/atomic.h b/include/qemu/atomic.h index 5dba7db..94e7110 100644 --- a/include/qemu/atomic.h +++ b/include/qemu/atomic.h @@ -123,6 +123,16 @@ _old; \ }) +#define atomic_bool_cmpxchg(ptr, old, new) \ + ({ \ + typeof(*ptr) _old = (old), _new = (new); \ + bool r; \ + r = __atomic_compare_exchange(ptr, &_old, &_new, false, \ + __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST); \ + r; \ + }) + + /* Provide shorter names for GCC atomic builtins, return old value */ #define atomic_fetch_inc(ptr) __atomic_fetch_add(ptr, 1, __ATOMIC_SEQ_CST) #define atomic_fetch_dec(ptr) __atomic_fetch_sub(ptr, 1, __ATOMIC_SEQ_CST) @@ -327,6 +337,7 @@ #define atomic_fetch_and __sync_fetch_and_and #define atomic_fetch_or __sync_fetch_and_or #define atomic_cmpxchg __sync_val_compare_and_swap +#define atomic_bool_cmpxchg __sync_bool_compare_and_swap #define atomic_dec_fetch(ptr) __sync_sub_and_fetch(ptr, 1) -- 2.7.4