From 3f26c207560037af6cc47964da72c53d587e2def Mon Sep 17 00:00:00 2001
From: Ruslan Ermilov <ru@nginx.com>
Date: Fri, 16 Jun 2017 18:15:53 +0300
Subject: [PATCH] Added memory barrier semantics to ngx_rwlock_unlock().

---
 src/core/ngx_rwlock.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/core/ngx_rwlock.c b/src/core/ngx_rwlock.c
index 905de780a..0aed29af5 100644
--- a/src/core/ngx_rwlock.c
+++ b/src/core/ngx_rwlock.c
@@ -94,7 +94,7 @@ ngx_rwlock_unlock(ngx_atomic_t *lock)
     readers = *lock;
 
     if (readers == NGX_RWLOCK_WLOCK) {
-        *lock = 0;
+        (void) ngx_atomic_cmp_set(lock, NGX_RWLOCK_WLOCK, 0);
         return;
     }