reverseproxy: Fix round robin data race (#4038)

2 files changed, 4 insertions, 4 deletions

diff --git a/modules/caddyhttp/reverseproxy/reverseproxy.go b/modules/caddyhttp/reverseproxy/reverseproxy.go
index d2d01e6..9da509f 100644
--- a/modules/caddyhttp/reverseproxy/reverseproxy.go
+++ b/modules/caddyhttp/reverseproxy/reverseproxy.go
@@ -368,8 +368,8 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request, next caddyht
 	reqHost := r.Host
 	reqHeader := r.Header
 	defer func() {
-		r.Host = reqHost
-		r.Header = reqHeader
+		r.Host = reqHost     // TODO: data race, see #4038
+		r.Header = reqHeader // TODO: data race, see #4038
 	}()
 
 	start := time.Now()
diff --git a/modules/caddyhttp/reverseproxy/selectionpolicies.go b/modules/caddyhttp/reverseproxy/selectionpolicies.go
index e86e97e..dacfd11 100644
--- a/modules/caddyhttp/reverseproxy/selectionpolicies.go
+++ b/modules/caddyhttp/reverseproxy/selectionpolicies.go
@@ -221,8 +221,8 @@ func (r *RoundRobinSelection) Select(pool UpstreamPool, _ *http.Request, _ http.
 		return nil
 	}
 	for i := uint32(0); i < n; i++ {
-		atomic.AddUint32(&r.robin, 1)
-		host := pool[r.robin%n]
+		robin := atomic.AddUint32(&r.robin, 1)
+		host := pool[robin%n]
 		if host.Available() {
 			return host
 		}