UDP Lock up?

Question

Hey guys i need people to guess the solution :(.

I am using UDP sockets and what i am doing is sending player input which is about 8, 4 or whatever bytes. I am using recvfrom and sendto. It works for minutes then randomly it will lock up. This could however be because of my app logic but i want to know if anyone have experience with this and it being a UDP/Networking problem. My code is here http://www.pastie.org/486583 but i mostly want to know what i can look into to correct this problem based on your experiences.

Answer 1

Use Wireshark to figure out which side is failing.

Is it the sender not sending?

Or is it the receiver not receiving?

Answer 2

Is your GetInput() function expecting sendTo and recvFrom to always complete? UDP is not guaranteed to send or receive your messages, or in what order the messages will arrive. I think your timeouts are also set to infinity, so what is happening is every once in a while, a message fails and you wait indefinitely for a message that is already lost.

Answer 3

What does "lock up" mean?

Note that the network is allowed to lose (drop) UDP packets: your protocol ought to allow some to be lost occasionally, or be willing to retransmit.

Answer 4

What does locked up mean and who is getting locked up. You have not checked the return values of "recvfrom" & "sendto" system calls. Have you tried running Wireshark to observe the behaviour.