[Qemu-devel] [PATCH v4 05/14] atomics: add atomic_test_and_set

[Emilio G. Cota]

This new helper expands to __atomic_test_and_set where available;
otherwise it expands to atomic_xchg.

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

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
-- 
2.5.0