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?