IN2140 — OS & Networking

IN2140 – Introduction to Operating Systems and Data Communication at UiO. The first encounter with systems programming in C — understanding what the OS does on behalf of user programs and how data moves between machines.

Course topics

C programming at the systems level

• Pointer arithmetic, memory layout, stack vs heap allocation
• malloc/free and manual memory management — preventing leaks and dangling pointers
• Structs, unions, bitfields for low-level data representation
• Undefined behaviour: alignment, overflow, strict aliasing

Processes and the kernel interface

• fork() / exec() / wait() — process creation and management
• fork() semantics: copy-on-write, file descriptor inheritance
• Signals: SIGINT, SIGCHLD, kill(), sigaction() handlers
• Process groups and sessions

I/O

• File descriptors as an abstraction over files, sockets, and pipes
• Blocking vs non-blocking I/O
• select() and poll() for multiplexing multiple I/O sources
• epoll (Linux) for scalable I/O event notification

Concurrency with threads

• POSIX threads (pthreads): creating threads, joining, detaching
• Mutex locks — pthread_mutex_lock/unlock, protecting shared state
• Condition variables — pthread_cond_wait/signal, producer-consumer pattern
• Race conditions, deadlock, livelock — recognising and preventing them

Networking

• Socket API — socket(), bind(), listen(), accept(), connect(), send(), recv()
• TCP vs UDP: reliability, ordering, flow control vs best-effort delivery
• Full-duplex communication — using select() or separate threads for simultaneous send/receive
• HTTP at the protocol level: request/response format, headers, status codes

CMake build system

• CMakeLists.txt structure, targets, include directories
• Out-of-source builds, debug vs release configurations
• Linking libraries (-lpthread, -lm)

Home exam

The home exam was a substantial solo programming project requiring integration of multiple course topics: process management, IPC, socket communication, and concurrent data structures — all in C with a CMake build.