From: Willy Tarreau <w@1wt.eu>
Date: Thu, 3 Apr 2025 09:59:31 +0000 (+0200)
Subject: CLEANUP: atomics: also replace __sync_synchronize() with __atomic_thread_fence()
X-Git-Tag: v3.2-dev10~37
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f435a2e518;p=thirdparty%2Fhaproxy.git

CLEANUP: atomics: also replace __sync_synchronize() with __atomic_thread_fence()

The drop of older compilers also allows us to focus on clearer
barriers, so let's use them.
---

diff --git a/include/haproxy/atomic.h b/include/haproxy/atomic.h
index 5f5a06601..36e024603 100644
--- a/include/haproxy/atomic.h
+++ b/include/haproxy/atomic.h
@@ -685,12 +685,13 @@ static __inline int __ha_cas_dw(void *target, void *compare, void *set)
 
 #else /* unknown / unhandled architecture, fall back to generic barriers */
 
-#define __ha_barrier_atomic_load __sync_synchronize
-#define __ha_barrier_atomic_store __sync_synchronize
-#define __ha_barrier_atomic_full __sync_synchronize
-#define __ha_barrier_load __sync_synchronize
-#define __ha_barrier_store __sync_synchronize
-#define __ha_barrier_full __sync_synchronize
+#define __ha_barrier_atomic_load  __atomic_thread_fence(__ATOMIC_ACQUIRE)
+#define __ha_barrier_atomic_store __atomic_thread_fence(__ATOMIC_RELEASE)
+#define __ha_barrier_atomic_full  __atomic_thread_fence(__ATOMIC_SEQ_CST)
+#define __ha_barrier_load         __atomic_thread_fence(__ATOMIC_ACQUIRE)
+#define __ha_barrier_store        __atomic_thread_fence(__ATOMIC_RELEASE)
+#define __ha_barrier_full         __atomic_thread_fence(__ATOMIC_SEQ_CST)
+
 /* Note: there is no generic DWCAS */
 
 /* short-lived CPU relaxation */