Problem with UDPClient

[limelect 48]

I have a software solution but I want to understand and have

a nicer fix.

I have UDPClient and UDPServer

I receive a text from the server with a press of a button on the client.

If I press once I get the text OK Second time I get Zero in the buffer.

I made sure that the server sends the text every time.

So I made a stupid fix that works perfectly.

 

   UDPClient.ReceiveBuffer(Buf);
   if buf[0]=0 then
    UDPClient.ReceiveBuffer(Buf);

 

Any idea why it happens
I read a question about resetting the client buffer.

Further, if I delete the connection and reconnect it works.

But I am not allowed to do so as the connection has to stay with

the right peer number.

 

[Remy Lebeau 1421]

5 hours ago, limelect said:

I have UDPClient and UDPServer

Which UDP components, exactly? Indy's?  Someone else's?  Please be more specific.

5 hours ago, limelect said:

If I press once I get the text OK Second time I get Zero in the buffer.

I made sure that the server sends the text every time.

Please show your actual code on both sides.

5 hours ago, limelect said:

So I made a stupid fix that works perfectly.

The only way that makes sense is if the server is actually sending a $00 byte, OR, if you have pre-sized your Buf beforehand and ReceiveBuffer() is not filling it in (ie, is ReceiveBuffer() returning 0 bytes read as its return value?).

5 hours ago, limelect said:

Any idea why it happens

Not without seeing your actual code.

5 hours ago, limelect said:

Further, if I delete the connection and reconnect it works.

UDP is connection-less.  There is no connection to reset.

Edited August 16, 2023 by Remy Lebeau

[limelect 48]

@Remy Lebeau First thanks.

2 hours ago, Remy Lebeau said:

Which UDP components, exactly? Indy's?  Someone else's?  Please be more specific.

Indy's.

 

2 hours ago, Remy Lebeau said:

Please show your actual code on both sides.

It is so simple

UDPClient.Send('#2');

server response

         mytext := StringToBytes(s);
          UDPServer.SendBuffer(ABinding.PeerIP, ABinding.PeerPort, mytext);

2 hours ago, Remy Lebeau said:

The only way that makes sense is if the server is actually sending a $00 byte,

I am profesional to exclude that. checking with a brp on the server 

and seeing the problem in the client

 

Most of the time strings are very short.

But in that case, the string is a bit longer like maybe 100 characters.

And I expect to receive even longer strings.

 

It seems something within the receiver (client) as 

The server works perfectly.

 

 

[limelect 48]

@Remy Lebeau First thanks.

3 hours ago, Remy Lebeau said:

Which UDP components, exactly? Indy's?  Someone else's?  Please be more specific.

Indy's.

 

3 hours ago, Remy Lebeau said:

Please show your actual code on both sides.

It is so simple

UDPClient.Send('#2');

server response

         mytext := StringToBytes(s);
          UDPServer.SendBuffer(ABinding.PeerIP, ABinding.PeerPort, mytext);

3 hours ago, Remy Lebeau said:

The only way that makes sense is if the server is actually sending a $00 byte,

I am profesional to exclude that. checking with a brp on the server 

and seeing the problem in the client

 

Most of the time strings are very short.

But in that case, the string is a bit longer like maybe 100 characters.

And I expect to receive even longer strings.

 

It seems something within the receiver (client) as 

The server works perfectly.

 

If things are not  stable I will move to a different communication

 

 

[limelect 48]

OK thanks

I have written a client-server for testing and it works perfectly

So it might be that something in my huge software does the problem.

So back to the drawing board

[limelect 48]

I do not understand why I ever got into this business.?

 

Thanks my bug.