* Network Programming
  - client/server
  - ports
  - sockets
  - file descriptors
  - API: socket, bind, connect, listen, connect/accept, close
* Concurrent Servers
  - Process-based
  - Event-based
  - Thread-based
  - Pros and cons of each
* Threads
  - Difference between process and thread
  - Pthread interface/library
    - create, join, self, cancel, exit
* Data Sharing
  - Global vs local vs local static
  - What does it mean to have shared data
* Synchronization
  - Critical section
  - Ordering of thread execution (topo. sort of threads)
  - Unsafe regions of thread/process graphs
  - Mutual exclusion
    - Mutexes
      * lock/release
    - Semaphores
      * acquire/release
      * implementation and understanding of P() and V()
  - Producer/Consumer problem
  - Readers/Writers problem
  - Thread Safety
    * Four classes of unsafe functions
    * Races
    * Deadlock (define, as process graph, deterministic?)
    * Livelock
* Scheduling
  - Process State Diagram
  - Goals:
    * minimize response, maximize throughput, fairness
  - Metrics:
    * (avg) waiting time, (avg) completion time
  - Algorithms:
    - FCFS
    - RR -- time quantum
    - SRTF
    - HPF
      * Priority inversion (pre-emptive)
    - Multi-level feedback
    - Lottery 
* Docker / Containers
  - Motivation
  - Terminology: why is it called a container?
  - Composition of a container
    - What's included?
    - What's NOT included?
  - How are changes tracked?
* Files and Directories
  - Abstraction of hardware --> OS
  - 5 User Requirements on Data
  - Files
    - Operations: create, delete, open/close, read/write, seek
  - Access
    - Directories
    - Methods
      * Sequential vs. Direct
    - Naming strategies
      * Single-level
      * Two-level
      * Multi-level
    - Soft vs. Hard links
  - Directories
    - Operations: search, create, delete (rm), list (ls), rename (mv)
  - Protections and Permissions
    - Access Lists/Groups vs. Access Control Bits
* Physical Disks
  - Physical Block
    * Surface Tracks, Sectors (HD)
    * Flash Translation Layer -> Block, Page (SSD)
  - Logical Blocks
  - Scheduling: FCFS, SSTF, SCAN
  - RAID (define)
* File Organization
  - Mapping of files (and their blocks) to logical/physical blocks
  - File Descriptor
  - Implementations
    - Contiguous Allocation
    - Linked Files
    - Indexed Files
    - Multi-level Indexed Files
  - Free list management
    - Bitmap
    - Free list

* Skills Test (topics from first exam)
  - virtual memory and page faults