Thanks for the feedback. I haven't gotten to that level of analysis yet, because I was more focused on a nice working solution up front, but will start digging deeper. Really however, the call to Sleep() is just an added bonus. The fix works fine without it, you just get some frame rate drop whenever the client is acting up (I have a quad core, so I don't know what the impact is for dual or single core users). I would be happy to leave it out if we could get a fix in the wine mainline for now while digging deeper into what's causing it.
The main problem is the production of thousands of small and identical udp packets essentially causing a DoS attack on their server and bogging down the upstream traffic for the user. In one test, 8500x 62 byte packets (size includes headers) were sent in 500 mS. Some users have also reported problems where their routers don't seem to handle the flood very well (crashing, etc.). It's an intermittent problem and only occurs while one's character is in specific locations in the game world. I'm also not certain that every Linux user experiences this problem and the degree will certainly vary depending upon their bandwidth.
Rob Shearman wrote:
2008/7/16 Daniel Santos daniel@bytesage.com:
- if(_lotro_hack_enabled
&& to->sa_family == AF_INET&& dwBufferCount == 1&& _lotro_hack(&get_per_thread_data()->lotro_msgs,s, lpBuffers, (struct WS_sockaddr_in*)to)) {Sleep(10);if(lpNumberOfBytesSent) {*lpNumberOfBytesSent = lpBuffers->len;}return 0;- }
Hi Daniel,
While I appreciate the effort you've gone to to fix a bug, I don't see any analysis in the bug that suggests this is the only possible solution. It seems to me as though LOTRO is calling WSASendTo in a tight loop and that it isn't such a tight loop on Windows. A +relay log will reveal which calls it is making in that thread. You can then build a similar test program and time how long each call takes on Windows and Wine and see where the difference is (although it probably won't be as simple as that as there will be other threads interacting in LOTRO). At a guess, it might simply be that Windows yields to other threads after making a call to a network function.