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

["Alex R. Mosteo" <devnull@mailinator.com>]

Jeffrey Creem wrote:
> 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).

Ah ok, so I was totally out of the mark. :/

> 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?