# HG changeset patch
# User Ruslan Ermilov <ru@nginx.com>
# Date 1497626153 -10800
# Node ID 12efcdcb8a4b77a895a42e6971478e235a914df6
# Parent  8666da1ecf332831311de0b7f20080596939ba10
Added memory barrier semantics to ngx_rwlock_unlock().

diff --git a/src/core/ngx_rwlock.c b/src/core/ngx_rwlock.c
--- 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;
     }