View source for COMP 3000 Test 2 Study Guide 2011

==Key Concepts==

For this test, you should understand the following terms and how they interrelate:

* execve semantics
* how command line variables are processed by execve
* how environment variables are processed by execve
* signal handlers
* concurrent operation with fork
* scheduler and relationship to system calls
* priority scheduling
* round-robin scheduling
* mutual exclusion
* semaphores
* basic pthreads
* System V init scripts versus launchd
* mounting filesystems
* loopback mounting
* sparse files
* basic filesystem implementation
* VFS abstraction

In addition to reading the notes, be sure to review the assigned readings!  You will also need to know the material covered in Test 1.

==Sample Questions==

Note: these questions are more open-ended than the ones that will be on the final test.  There will also be a question session just before the test - the test will only be around 30 minutes long.

# Without errors, what does the execve system call return?
# Can a process modify its argument variables?  Environment variables?
# Who calls a signal handler?
# If a parent and child process start printing  "Parent\n" and "Child\n" to standard out, what will be the order of the output?
# In race-demo, why does the consumer sometimes finish before the producer has done hardly anything?
# What does pthread_join() do?
# How is argc calculated?  Note that argc is not specified by execve!
# What parts of the kernel would you need to re-implement in userspace in order to simulate a loopback mount?
# Why are sparse files tricky to copy?
# what is the relationship between lost+found and fsck?