CS208 Introduction to Computer Systems
Wednesday, 1 March 2023

+ Buffer overflow details
- Why can you call touch2/touch3
     correctly and still get a seg fault?
- Anything else?

+ pthreads_test.c
- Get pthreads_test.c from the samples page
- Get these class notes from the home page

Questions to answer
- What does p in pthreads stand for?
- Compile the program. What is "-lpthread" for?
    How (if at all) is that related to the line
    #include <pthread.h> in the source code?
- Run it. What does the program do?
- pthread_join
    - What does pthread_join do?
    - Try commenting out both pthread_join calls.
        Recompile and run. What happens and why?
    - (You'll want to uncomment those lines when you're done.)
- pthread_mutex
    - What is this type for?
    - What does "mutex" stand for?
    - Try commenting out every line that contains the substring "lock"
        Recompile and run. What happens and why? ("Why" might
        be hard to get precise about.)
- What is the role of the should_quit variable? Why not just
    use time_to_quit directly?
- (Digression: What is "stdbool.h" for? Why would you care?)
- (Digression: What does perror do? How does it decide what to print?)
- Sum up
    - What is a thread?
    - How is a thread different from a process?
    - How can threads in the same process communicate with one another?

Resources to use
- man pthread_create, etc.
- internet search
- experimentation with the sample


+ The assignment

+ More: why threads?