Re: (Linux) GNAT socket exception - when setting No_Delay

[Jeffrey Creem <jeff@thecreems.com>]

Alex R. Mosteo wrote:
> AAFellow@hotmail.com wrote:
> 
>> Hey everyone,
>>
>> I'm actually still getting the GNAT socket exception when setting the
>> No_Delay option when I run the code.  (Ignore my previous reply - I
>> didn't realize that I still had the No_Delay code commented out.)
>>
>> Is there a known issue with setting the No_Delay via GNAT.sockets when
>> running on Linux?
> 
> 
> I'm confused, is this No_Delay the flag used for non blocking IO?
> 
> I used to do that with this code without issues:
> 
> procedure Set_Blocking_Io (This: in Object; Enabled : Boolean := True)
>    use Gnat;
> is
>    Request : Sockets.Request_Type (Sockets.Non_Blocking_Io);
> begin
>    Request.Enabled:= not Enabled;
>    Sockets.Control_Socket(This.Socket, Request);
> end Set_Blocking_Io;
> 
> where This of type Object was my higher level socket abstraction.

No delay is not related to blocking. It disables the TCP Nagle algorithm 
(http://compnetworking.about.com/od/tcpip/l/bldef_nagle.htm).

Usually one does this when you want to send small messages via TCP with 
minimal latency.

Without it, small messages are often delayed about 200msec before being 
transmitted.


Have you tried "AdaSockets" instead of GNAT sockets?