UDP Receive performance difference

[arparker]

I am currently running the same UDP receiver code on two devices; Samsung Galaxy S WiFi 5.0 and ASUS Transformer Prime. I have an XP box unicasting 8k UDP packet at 20 packets/sec. Both devices are connected to my wireless network at 54Mb but ASUS is not able to keep up with the transmission rate. The following code is what's being executed with a packet is received:

Sub UDP_PacketArrived (Packet As UDPPacket)
   Dim moddatasize As Int
   
   UDPcounter = UDPcounter + 1
   SendingHostIP = Packet.Host
'   Log(SendingHostIP)
   datasize = ((Packet.Length/4)-3)
   moddatasize = datasize/10
   If (UDPcounter Mod 20)==0 Then
      Log(UDPcounter&"  "&Packet.Length)
   End If
End Sub

No other code is running other than this interrupt. Once I stop the transmitting the ASUS continues to process packets as if I'm still transmitting to drain the internal receive buffer. Any thoughts as to why the lowly Samsung can handle this transmission but the ASUS cannot?

 

[arparker]

I was able to comment out the following line and the ASUS was able to sustain the transmission rate.

   SendingHostIP = Packet.Host

Don't know why handling strings within the PacketArrived interrupt caused poor performance on the ASUS and not the Samsung.

 

[Erel]

When you call Packet.Host the IP address needs to be resolved. This can be a heavy operation.

If you need, it is possible to add a method that will get the IP address instead of the host.

 

[electro179]

heavy operation

do you have a solution to get the Ip of Host because if I do packet.host the time operation = 3 sec .
I'd like to get directly the ip

 

[Erel]

You can use this code (requires Reflection library):

Sub GetHostAddress(packet As UDPPacket) As String
   Dim r As Reflector
   r.Target = packet
   r.Target = r.GetField("packet")
   r.Target = r.RunMethod("getAddress")
   Return r.RunMethod("getHostAddress")
End Sub

 

[electro179]

thank you but I have an error :
LastException java.lang.NoSuchFieldException: packet at line r.Target = r.GetField("packet")

I use the reflection version 2.10

 

[Erel]

Which version of Network library are you using? It should be 1.21.

 

[agraham]

Assuming 1.21 isn't there a getObject() missing to unwrap the wrapped MyDatagramPacket in order to get at its packet field?

 

[Erel]

It will be unwrapped automatically on this line:

r.Target = packet

Because r.Target expects an Object and not UDPPacketWrapper.

 

[agraham]

Ah! I forgot that - I've been back doing Basic4ppc and C# for too long

 

[electro179]

thank you
with 1.21 it s ok