UNIVERSITY OF HOUSTON Department of Computer Science COSC 6360: Operating Systems MIDTERM March 21, 1991 CLOSED BOOK. You may have with you two sheets of notes. 1. What were the major limitations of the Version 7 implementation of the UNIX file system? (10 points) What were the major improvements brought by Berkeley 4.2? (10 points) 2. Contrast the ways MULTICS and UNIX implement directories. (6 points) Which implementation is better? Why? (4 points) THIS QUESTION WAS RELATED TO A PAPER THAT IS NOT ANYMORE IN THE READING LIST. IT WILL BE NOT BE ASKED AGAIN. 3. What are the differences between a STREAM socket and a DATAGRAM socket? (10 points) BSD IPC WAS TREATED IN MUCH GREATER DETAIL THAT SEMESTER 4. In the Berkeley IPC model, what is happening when a server process executes an accept? (10 points) BSD IPC WAS TREATED IN MUCH GREATER DETAIL THAT SEMESTER 5. Explain how file descriptor passing can simplify the establishment of a network connection in the Ninth Edition Unix System. (20 points) THIS QUESTION WAS RELATED TO A PAPER THAT IS NOT ANYMORE IN THE READING LIST. IT WILL BE NOT BE ASKED AGAIN. 6. Which of the following features of the Mach OS were already present (even under another name) in the MULTICS virtual memory system? (15 points) Copy-on Write: External Pagers: Memory Objects: Read-Write Shared Memory: Shared Libraries: THIS QUESTION WAS RELATED TO A PAPER THAT IS NOT ANYMORE IN THE READING LIST. IT WILL BE NOT BE ASKED AGAIN. 7. Describe the steps taken by MULTICS to resolve a segment fault for an ACTIVE segment that is already KNOWN to the process attempting to access it and explain at every step where the required information is to be found. (15 points) THIS QUESTION WAS RELATED TO A PAPER THAT IS NOT ANYMORE IN THE READING LIST. IT WILL BE NOT BE ASKED AGAIN.