同时退款并发问题

Services/Hncore.Pass.Vpn/Service/ProductOrderService.cs

@@ -859,6 +859,8 @@ FROM product_order where {where}  GROUP BY Channel,ProductName order by Channel,
 
 
         public async Task<ApiResult> Refund(int userId, string account)
+        {
+            using (await _mutex1.LockAsync())
             {
                 var reason = "";
                 if(account.Contains("-")){
@@ -989,6 +991,7 @@ FROM product_order where {where}  GROUP BY Channel,ProductName order by Channel,
 
                 return new ApiResult(1);
             }
+        }
 
         public async Task<ApiResult> CaclRefund(int userId, string account)
         {