1. Multi-Threading and Load Balancing Compiled by Paul TaylorCSE3AGR Stolen mainly from Orion Granatir http://www.gamasutra.com/php-bin/article_display.php?story=4006

2. What changed? Single Thread Computer games have been used since day 0 The person to blame is Gordon Moore* * Not really it just feels good to blame someone!

3. Moore’s Law http://en.wikipedia.org/wiki/Fil e:Transistor_Count_and_Moore %27s_Law_-_2008.svg The Complexity of IC’s will go up exponentially We mutilated this into CPU speed will increase expo. This all F*#ked up a few years ago when we started pushing the boundaries of transistor miniaturisation To keep the processing increase we went with Multi core processors

4. It all goes bad.... http://www.gamasutra.com/php-bin/article_display.php?story=4006

5. Multi-Core and Threading http://www.gamasutra.com/php-bin/article_display.php?story=4006

6. Network Assimilation http://www.gamasutra.com/php-bin/article_display.php?story=4006

7. Processes and Threads

8. The first crappy threading code you’ll see CATCTATCATTC TATCTACTATC ATCTACTATCT ACTATCTACT CTTACTCAT

9. Distributing Load (You need to manage your employees)

10. That was a better Threading Model But still not good enough for today's machines

11. Distributing Load even more!

12. Learning to Share All cats need the Shovel for their Quest

13. Learning to Share Cat has the Shovel

14. Learning to Share Cat has the Loot

15. This is what Thread Locking is for Now how do we go about locking them??

16. Critical Sections When one thread enters the critical section, the others will have to wait......

17. Critical Sections And wait....

18. And wait...

19. Critical Sections Keep them small!!! A lot of CPU time can be wasted waiting.... And waiting...

20. Mutexs and Semaphores

25. A Semaphore is like using Multiple tokens (it retains a value) Critical Sections are fastest, but limited to one process Mutexs are slower, but globally accessible Semaphores are great for things like allocating your memory buffers

26. Events

32. Atomic Operations http://www.breadonthewaters.com/add/0888_nuclear_explosion_large_clipart.jpg

33. Atomic Operations 5 + 1 + 1 + 1 = 8

34. Atomic Operations 5 + 1 + 1 + 1 = 6!!

35. Atomic Operations This is why we need atomic operations

36. Atomic Operations This is why we need atomic operations

37. Deadlocks

40. Race Conditions The ‘race’ is a term for when your code expects threads to return in order, and they don’t!!!

41. Race Conditions

44. Network Code Example

49. The Main thread would then need to wait for all Network threads to finish before it resets the NetworkUpdateEvent and continues How would you solve this?

50. References http://www.gamasutra.com/php- bin/article_display.php?story=4006