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[v4,05/14] atomics: add atomic_test_and_set

Message ID 1461987197-31264-6-git-send-email-cota@braap.org
State New
Headers show

Commit Message

Emilio Cota April 30, 2016, 3:33 a.m. UTC 
This new helper expands to __atomic_test_and_set where available;
otherwise it expands to atomic_xchg.

Signed-off-by: Emilio G. Cota <cota@braap.org>
---
 include/qemu/atomic.h | 2 ++
 1 file changed, 2 insertions(+)

Comments

Richard Henderson May 4, 2016, 5:10 a.m. UTC | #1 
On 04/29/2016 05:33 PM, Emilio G. Cota wrote:
> This new helper expands to __atomic_test_and_set where available;
> otherwise it expands to atomic_xchg.
>
> Signed-off-by: Emilio G. Cota <cota@braap.org>

Reviewed-by: Richard Henderson <rth@twiddle.net>


r~
diff mbox

Patch

diff --git a/include/qemu/atomic.h b/include/qemu/atomic.h
index 5bc4d6c..6132dad 100644
--- a/include/qemu/atomic.h
+++ b/include/qemu/atomic.h
@@ -134,6 +134,7 @@ 
     })
 
 /* Provide shorter names for GCC atomic builtins, return old value */
+#define atomic_test_and_set(ptr) __atomic_test_and_set(ptr, __ATOMIC_SEQ_CST)
 #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)
 #define atomic_fetch_add(ptr, n) __atomic_fetch_add(ptr, n, __ATOMIC_SEQ_CST)
@@ -328,6 +329,7 @@ 
 #endif
 
 /* Provide shorter names for GCC atomic builtins.  */
+#define atomic_test_and_set(ptr) atomic_xchg(ptr, true)
 #define atomic_fetch_inc(ptr)  __sync_fetch_and_add(ptr, 1)
 #define atomic_fetch_dec(ptr)  __sync_fetch_and_add(ptr, -1)
 #define atomic_fetch_add       __sync_fetch_and_add