p2p: use safe atomic operations when changing connFlags (#17325)

p2p/server.go

@@ -258,13 +258,18 @@ func (c *conn) is(f connFlag) bool {
 }
 
 func (c *conn) set(f connFlag, val bool) {
-	flags := connFlag(atomic.LoadInt32((*int32)(&c.flags)))
+	for {
+		oldFlags := connFlag(atomic.LoadInt32((*int32)(&c.flags)))
+		flags := oldFlags
 		if val {
 			flags |= f
 		} else {
 			flags &= ^f
 		}
-	atomic.StoreInt32((*int32)(&c.flags), int32(flags))
+		if atomic.CompareAndSwapInt32((*int32)(&c.flags), int32(oldFlags), int32(flags)) {
+			return
+		}
+	}
 }
 
 // Peers returns all connected peers.