CS 3733 Operating Systems Final Exam Review: Fall 2006

Listed here are the major topics covered on the exam.

1. Introduction: what is an operating system?

buffering, spooling, multiprogramming, time sharing

process state, process control block, concurrent processes

storage and linkage classes, the meaning of the word static.

job queue, ready queue, device queues, schedulers, performance criteria, FCFS, SJF, SJFA, round robin, priorities, preemptive scheduling, multilevel queues, multilevel feedback queues, process scheduling simulator experiments, load average and context switch calculations (like from assignment 2). Know how to do problems like the one assigned in class.

chains, fans, and trees of processes

open, close, read, write, pipe dup2, getpid, getppid.
Understand that read and write do not always process all information requested. Exception: small write to a pipe or FIFO.

file descriptors and file pointers, file descriptor table, system file table, redirection.
Understand the difference in buffering when using file descriptors and file pointers.

directories, inodes, hard links, symbolic links

general ideas, you do not have to know the syntax for creating threads

producer-consumer problem, critical sections, critical section problem, mutual exclusion, progress, bounded waiting, busy waiting, Peterson's solution, Test-and-Set, Swap, semaphores, bounded buffer with semaphores, monitors, dining philosophers, thread synchronization with mutexes

Using the signal mask, catching and ignoring signals, waiting for signals, interrupted system calls

client-server model, connectionless and connection-oriented, UICI

FCFS, SSTF, SCAN, LOOK, C-SCAN, C-LOOK

partitions, paging, TLB, virtual memory, page replacement (FIFO, LRU, optimal, second chance), calculation of effective memory access time.

• Operating System
  • in a multitasking OS, system functions may be called concurrently
  • can keep separate data structures for each process
  • protect shared data structures
• Single Process - no threads or signals
  • shared variables - use semaphores, mutexes, monitors
  • functions with side effects:
       I/O to shared resource
       use of static storage
• Threads
  • global variables are shared and must be protected.
  • Issues in returning automatic variables
• Multiple Processes
  • shared variables must be protected (including system resources)
  • If not shared variables, must find method of communication
• Single Process with signals
  • signal handler can make modifying a global variable a critical section
  • signal handlers are restricted as to how they access library functions
  • must protect errno
  • general methods used for shared variables (semaphores, etc.) do not work for signal handlers. Why?