1. Cpr E 308 Spring 2004 Recap for Midterm Introductory Material What belongs in the OS, what doesn’t? Basic Understanding of Hardware, Memory Hierarchy

2. Cpr E 308 Spring 2004 Process What’s a process? –Unix Process Creation –Shell Assignment (fork and exec) Address Space –Stack, heap, data and text regions What data items go where? –What do fork() and exec() do to the address space

3. Cpr E 308 Spring 2004 System Calls How are they handled? –How are they different from regular function calls? –Changing from user to supervisor mode and back Some important system calls (including wait())

4. Cpr E 308 Spring 2004 Multiprogramming What is it? Process Context Switch How are interrupts involved?

5. Cpr E 308 Spring 2004 Threads When are they useful? Difference from processes Basic thread operations – creation, joining, exiting, etc Thread Implementations – User and Kernel Threads

6. Cpr E 308 Spring 2004 Mutual Exclusion and Synchronization What’s the problem with writing to shared variables simultaneously? What are critical sections, atomicity? Mutual Exclusion Problem – Clear definition

7. Cpr E 308 Spring 2004 Mutex Solutions Software Solutions –Peterson’s solution Hardware Support –TSL instruction Disabling Interrupts –Advantages and disadvantages –Doesn’t work for multiprocessors – why?

8. Cpr E 308 Spring 2004 Beyond Mutexes Condition Variables and Mutexes –Example programs using condition variables Semaphores (not in detail) Example Problems: –Producer and Consumer –Readers and Writers –Dining Philosophers – Deadlocks

9. Cpr E 308 Spring 2004 Deadlocks Conditions for a deadlock Detection Algorithm Deadlock Prevention