Homework 3 : due by 5 : 00 pm on Friday , March 13 , 2015 ( Total : 100 points ) Instructor :

All homeworks should be submitted in a directory named hw 3 using svn or turnin as before. In case of problems, you should email a zip file containing the directory to [email protected] before the deadline. See course wiki for slip day policy and late submission penalties. IMPORTANT: The programming assignment in this homework is more challenging than in past homeworks. It is critical that you start early on the programming assignment to meet the deadline. Honor Code Policy: All submitted homeworks are expected to be the result of your individual effort. You are free to discuss course material and approaches to problems with your other classmates, the teaching assistants and the professor, but you should never misrepresent someone elses work as your own. If you use any material from external sources, you must provide proper attribution. Please submit your solutions to the written assignments in either a plain text file named hw 3 written.txt or a PDF file named hw 3 written.pdf in the hw 3 directory. 1.1 Future Tasks and Data-Driven Futures 1. (10 points) Summarize the similarities and differences between futures and data-driven futures in HJ-lib. In your summary, you should state if it is possible to create a race condition or a deadlock when accessing the value in the future container when using either construct. 2. (15 points) Consider the HJ-lib code fragment below that operates on an array of DataDrivenFutures. (Note that there are no get() operations in this example, so the only purpose of the put() operation is to synchronize with await clauses. For simplicity, we just use an empty string "" as the object being put into a DataDrivenFuture.) Is it possible for any instance of the async statement in line 6 to be indefinitely blocked on its await clause? If so, explain how. If not, explain why not.