One time, I wrote a small network protocol stack to handle some proprietary UDP-based protocol that supported fragmentation. Since the header on each fragment

One time, I wrote a small network protocol stack to handle some proprietary UDP-based protocol that supported fragmentation. Since the header on each fragment contained the total message size, I was able to pre-allocate the full size of the message upon receipt of the first fragment. Then, as fragments arrived, I would copy their data into their respective areas of the message. Typically, everything would arrive in order, so the message would be copied from beginning to end, piece by piece. However, since this was Ethernet/UDP, it was possible for frames to arrive out of order. This would result in the message being pieced together, with each fragment filling in its hole until all fragments have been received. I guess this is a form of a data race? Or rather, a case where a data race at least wasn't detrimental.