Systems Programming Labs (TUM)

This repository contains solutions for the Systems Programming practical course at TUM.

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Repository Structure

.
├── README.md
├── task00-sort
├── task01-syscalls
├── task02-fileio
├── task03-processes
├── task04-concurrency
├── task05-memory
├── task06-sockets
└── task07-llvm

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Tasks

task00-sort

• External sort implementation under memory constraints
• Supports ascending and reverse order (-r)

➡️ See: task00-sort/

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task01-syscalls

• System call wrappers using syscall()
• Direct syscall invocation via inline assembly
• Minimal syscall tracer using ptrace()

➡️ See: task01-syscalls/

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task02-fileio

• In-memory filesystem implemented using FUSE
• Supports hierarchical files and directories
• Read / write / append operations
• Symbolic links and filesystem statistics
• Log-based crash recovery (operation replay)

➡️ See: task02-fileio/

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task03-processes

• Unix-like shell implementation
• Multi-stage pipeline execution using pipe
• Input / output redirection
• Background process execution
• Builtin process management commands:
  • wait
  • kill
  • exit
• Flex/Bison-based command parser

➡️ See: task03-processes/

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task04-concurrency

• Spinlock implementation using C11 atomics
• Lock-based hashmap with per-bucket locking
• Lock-free hashmap using compare-and-swap (CAS)
• Logical deletion and physical unlinking

➡️ See: task04-concurrency/

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task05-memory

• Custom implementations of malloc, calloc, realloc, and free
• First-fit allocation with block splitting and coalescing
• Multiple cache-line-aligned arenas with per-arena locking
• Thread-local arena assignment
• Contention-sensitive heap reservation

➡️ See: task05-memory/

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task06-sockets

• Multithreaded TCP client-server application
• Protocol Buffers message serialization
• Length-prefixed message framing over TCP
• Fixed server worker pool with round-robin connection assignment
• I/O multiplexing using poll()
• Atomic shared counter with ADD, SUB, and TERMINATION operations

➡️ See: task06-sockets/

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task07-llvm

• LLVM dead code elimination pass
• Removal of trivially dead instructions, redundant branches, and simple dead stores
• Runtime instrumentation for heap and stack memory accesses
• Detection of out-of-bounds accesses and use-after-free
• Ordered allocation tracking for efficient address lookup

➡️ See: task07-llvm/

Build

Each task is self-contained.

Example:

cd task00-sort
make

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Usage

Refer to the README inside each task directory for details.

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Notes

• Target platform: Linux x86-64
• Languages: C / C++
• Each task is independent and can be built separately