Midterm Study Guide Fall 2014

PwnHero coe518 Midterm Study Guide (2014) Page 1 of 6 COE518 Midterm Study Guide (2014) About this study guide The study guide covers many of the topics you should understand in preparation for the midterm. However, it is not comprehesive and should be viewed as minimal preparation. In particular, the midterm will not contain any of these questions and could contain questions covering topics not included in the study guide. How to use the guide The guide consists of questions and answers. Each question also indicates the estimated maximum time it should take you to answer the question. It is recommended that you try to answer the question before looking at the answer. The Questions and Answers 1. (10 minutes) Compare threads with processes indicating the commonality, the differences and the advantages/disadvantages of each. Answer: Both threads and processes run concurrently (conceptually only on a single core but literally on a multi-core architecture). They have states such as “Running”, “Ready”, “Blocked”, etc. indicating their eligibility to run or why they are inelegible. They also have priorities that are used by the scheduler to determine which to run next. Threads share global variables (the data segment), memory space and code. Threads collaborate in a single application. Threads exist within a process. (All processes consist of one or more cooperating threads.) The threads in a multi-threaded process communicate with each other. Processes are usually independent programs. Sometimes, such as piping the output of one process to the input of another, there is some interprocess communication but this does not require that the processes were developed together. DRAFT (October 20, 2014) PwnHero.com