Question

我使用此server从C++ UDP Client接收多个数据包。当我需要一个包时，我使用Request发送Client UDP以让C++客户端发送包。当我多次执行此过程时，我会错过一些软件包并收到此错误：

GNAT.SOCKETS.SOCKET_ERROR: [11] Resource temporarily unavailable

我认为可能会导致因为客户端在服务器监听之前发送了包，但我不确定。有什么方法可以解决吗？如果这是问题，有没有办法确保在客户端发送UDP消息之前准备好我的服务器？

procedure RECEIVE_DATA (
                            DEST_UDP_PORT        : In  Integer;
                            SRC_UDP_PORT         : In  Integer;
                            WAIT_TIME            : In  DURATION;
                            MESSAGE_ADDRESS      : Out System.Address;
                            WAIT_RESULT          : Out Integer;
                            MESSAGE_SIZE         : Out Integer
                           ) is


   Address  : Sock_Addr_Type;
   Socket   : Socket_Type;
   Channel  : Stream_Access;
   Receive_Timeout : constant Duration := WAIT_TIME;
   Offset : Ada.Streams.Stream_Element_Count;
   Data   : Ada.Streams.Stream_Element_Array (1 .. 10000);

begin
   Initialize (Process_Blocking_IO => False);
   WAIT_RESULT := 0;
   MESSAGE_SIZE := 0;
   -- Create Socket
   Create_Socket (Socket, Family_Inet, Socket_Datagram);
   Set_Socket_Option (Socket => Socket,
                      Option => (Gnat.Sockets.Receive_Timeout, Timeout => Receive_Timeout));

   --Bind Address
   Address.Addr := Inet_Addr(DEFINE_IP_ADDR.IP_BOARD_ADDRESS);
   Address.Port := Port_Type(DEST_UDP_PORT);
   Bind_Socket (Socket, Address);

   Channel := Stream (Socket, Address);
   -- Receive Socket
   Ada.Streams.Read (Channel.All, Data, Offset);  

   -- Close socket
   Free (Channel);
   Close_Socket (Socket);
   WAIT_RESULT := 1;
   MESSAGE_SIZE := Integer(Offset);
   MESSAGE_ADDRESS := Data'Address;
   Finalize;
exception when E : others =>
      Ada.Text_IO.Put_Line
        (Exception_Name (E) & ": " & Exception_Message (E));
      WAIT_RESULT := 0;
      Free (Channel);
      Close_Socket (Socket);
      Finalize;      
end RECEIVE_DATA ;

Answer 1

进行以下更改

Address.Addr := Inaddr_Any;

这是您收到的地址：不是您的地址。发送时设置地址，接收时设置地址

`GNAT.SOCKETS.SOCKET_ERROR：[11]`资源暂时不可用

1 个答案: