Some C++ Resource Management Best Practice (Linux)

This repository explores how C++ manages resources, from doing it right with RAII, to breaking things on purpose, to managing memory without malloc.

Tested on Linux with g++.

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Requirements

• Linux
• g++ (GCC 10+ recommended)
• gdb (for the debugging example)

Check:

g++ --version
gdb --version

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Build & Run

Each folder is independent.
Compile from the project root or inside each folder.

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RAII Logger (no leaks)

What it shows

• RAII for files and locks
• No raw new / delete
• Automatic cleanup even when exceptions happen

Build & run

cd raii-logger
g++ -std=c++20 -O2 -pthread main.cpp -o raii_logger
./raii_logger

What happens

• Multiple threads write to a log file
• An exception is thrown on purpose
• File and mutex are still cleaned up safely

This demonstrates why RAII prevents leaks and deadlocks.

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Use-after-free (intentional bug)

What it shows

• A classic C/C++ memory bug
• How use-after-free happens
• How to debug it with gdb

This program is intentionally broken.

Build

cd uaf-gdb
g++ -std=c++20 -g -O0 main.cpp -o uaf

Run normally

./uaf

It may crash or behave strangely that’s the point.

Debug with gdb

gdb ./uaf

Inside gdb:

run
bt

You’ll see the crash caused by writing to memory after it was freed.

This project is about learning to recognize and debug undefined behavior.

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Fixed Arena (no malloc)

What it shows

• Manual memory management without malloc
• Fixed-size memory arena
• RAII cleanup of objects

Build & run

cd fixed-arena
g++ -std=c++20 -O2 main.cpp -o fixed_arena
./fixed_arena

What happens

• Objects are constructed inside a fixed buffer
• No heap allocation
• Destructors run automatically when the arena resets or goes out of scope

This is similar to patterns used in game engines and embedded systems.

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Folder structure

cpp-resource-management/
├── raii-logger/
├── uaf-gdb/
├── fixed-arena/
└── README.md

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Why this repo exists

• Show correct C++ resource management
• Show what goes wrong when ownership is broken
• Show low-level control without dynamic allocation