This contains modifictaions to harvards os161, which is an introduction to working with operating systems. In these files I implemented locks, cv's, and sempahores. I didn't include all operating system files, just because it would be VERY large lol. I added the files that I thought were the most important. Since it only includes these files, you can't run anything :(, however it provides a good template about how sempharoes would work when mutiple threads are trying to access a shared resources. Hope you all enjoy :)