ACM 11/02/11

Transcript

1. 3 ACM
2. H4LLOW33N Rules: 1. 2+ costumes per row. 2. ~1 story per 2 rows. Go.
3. Updates Programming Project
4. Updates ICPC
5. Announcements
6. Announcements
7. S ome = new S() Protect IP Bill • Recently renamed "the Enforcing and Protecting American Rights Against Sites Intent on Theft and Exploitation Act" • Aimed to force ISPs to deny access to website that are suspected of serving illegal content. • According to sources, any foreign website that is accused of "inducing" infringement will be blocked with no adversarial hearing.
8. S omemore = new S() SB 978 ◦ New bill in Congress concerning streaming illegal content ◦ Could be used to criminalize YouTube uploads of cover songs (piano, singing, guitar, etc) ◦ Could even criminalize people linking to copyrighted data ◦ These crimes are listed as felonies and can be punished by up to 5 years in prison.
9. FLAW #3: Multithreading!! Due to heat problems (and other stuff), recently processor speeds have slowed down. But to keep increasing the computing power of processors.... we now have MANY CORES!! When talking about multithreaded computing, there are two categories 1. Distributed Systems 2. Shared-memory systems (like your computer) For this FLAW we will only be focusing on the second.
10. FLAW #3: Multithreading!! First, understand the bane of multithreading: RACE CONDITIONS • according to Wikipedia ◦ a flaw in an electronic system or process whereby the output and/or result of the process is unexpectedly and critically dependent on the sequence or timing of other events • according to Me ◦ when the outcome of a program can depend on the execution order of the threads
11. FLAW #3: Multithreading!! Let's look at a few examples! Firstly... a perfectly fine (and stupid) serial program Secondly... a nicely parallelized copy of the first program Thirdly... parallelization gone a bit wrong. Why did it slow down? Lastly... parallelization gone... what do you think?
12. FLAW #3: Multithreading!! Multithreading libraries • POSIX Threads (pthreads) • Cilk++ • Java Thread class and Runnable interface • most languages offer some form of threading And a brief shoutout to our GPU 's! • NVIDIA GeForce 590: 1024 cores • Radeon HD 6990: 3072 cores • Really hurting encryption (md5 password cracking) ◦ 30+ billion passwords per second • CUDA (NVIDIA), Stream? (AMD), OCL (Open Source)
13. FLAW #3: Multithreading!! If this sort of thing seems interesting or fun... Check out cs140!!
14. Citation stuff SB 978: http://www.alternet. org/story/152920/new_bill_in_congress_could_turn_alternative _media_ outlets_and_youtube_singers_into_felons/ IP Protect: http://www.techdirt. com/articles/20111026/12130616523/protect-ip-renamed-e- parasites-act-would-create-great-firewall-america.shtml