OS Code

Code for my operating system lecture at University of Klagenfurt (https://itec.aau.at/)

Build

make        # build all targets
make clean  # remove build artifacts
make format # auto-format source files (requires clang-format)

Threading

File	Description
badcnt.c	Traditional race condition demo based on ostep-code
goodcnt.c	Race-free counter using named POSIX semaphores (macOS-compatible)
goodcnt_mutex.c	Race-free counter using pthread mutex
thread-shared-vars.c	Example of threads accessing another thread's stack
runner.c	Simple program summing integers using pthreads

Synchronization

File	Description
prodcons_mutex.c	Producer-consumer problem using pthread mutex and condition variables
prodcons_sem.c	Producer-consumer problem using named POSIX semaphores (macOS-compatible)

IPC

File	Description
simple_pipe.c	Half-duplex pipe: parent writes to child
pipe_duplex.c	Duplex pipe: parent sends integer, child transforms and replies
pipe_named.c	Named pipe (FIFO): same transfer as simple_pipe but via a filesystem FIFO created with mkfifo()
shm.c	Shared memory example with race condition (System V)
sysV-msg.c	System V message queue example

Processes

File	Description
ctshell.c	A stripped-down shell named 'ctsh' ;)
signals.c	Signal handling example: parent and child exchange SIGUSR1/SIGUSR2 via explicit handlers, parent terminates child with SIGTERM

File I/O

File	Description
file_copy.c	File copy using read/write syscalls
file_copy_mmap.c	File copy using mmap