CPS 1 - Spring, 1997 - Ramm 4/30/97 #41

Operating Systems

• Processor Management
  Virtual Instructions for Parallel Processing
  • True Parallel Processes vs Simulated

  • Synchronization
    • Danger of shared data
      • clock process
      • race condition
    • Deadlock
      • shared resources; partial allocation
      • prevention (simple minded)
    • Semaphores
      • atomic
    • Critical Regions
    
    
    
  • Process Creation
    • To be flexible, need dynamic creation. Control
    • UNIX fork
      • duplicates
      • parent can terminate child
      • exit, kill, wait
    • UNIX exec
    • Communication
      • Pipe

• Software Environments
  • GUI
    • Look and feel....
  • Administration/Accounting
    • Security
    • Logs
  • Compilers
    • C++
    • Java
    • Basic
    • Assemblers
  • Tools
    • Linkers
    • Debuggers
    • Editors
  • Applications
    • Word processor
    • Spreadsheet
    • Database System
    • Games

• Putting it all together
  • Historical
    • One integrated (mess!)
    • 360 Job control language
  • Modular
  • Kernel
    • System Calls: request services
    • Processor States
      • privileged instructions(kernel)
      • user
  • Shell(s)
    • command processor
  • Process management from the Unix shell
    • &, kill
    • C shell Job control
      • ^Z
      • fg
      • kill %
      • history
  • Good Operating Systems vs Bad?
    • It Depends
    • User Needs
      • What are your trying to do?
      • Are your a casual user?
      • Are your a professional user?
      • What is the nature of your typical input?
        • text (Do you touch type?)
        • selection of options
        • graphical input
      • Are you in a position to change things?
    • Robustness
    • Growth Potential