Project 12: Cross-Platform Portability Layer

A portability abstraction layer that handles platform differences in file I/O, threading, memory mapping, and endianness.

Quick Reference

Attribute Value
Primary Language C
Alternative Languages None
Difficulty Level 4 - Expert
Time Estimate See main guide
Knowledge Area Portability, Systems Programming
Tooling GCC, Clang, MSVC, Docker
Prerequisites See main guide

What You Will Build

A portability abstraction layer that handles platform differences in file I/O, threading, memory mapping, and endianness.

Why It Matters

This project builds core skills that appear repeatedly in real-world systems and tooling.

Core Challenges

  • API abstraction → Maps to consistent interfaces across platforms
  • Conditional compilation → Maps to platform-specific implementations
  • Testing portability → Maps to multi-platform CI

Key Concepts

  • Map the project to core concepts before you code.

Real-World Outcome

# 1. Same code, different platforms
$ cat example.c
#include "platform.h"

int main(void) {
    plat_file_t* f = plat_file_open("test.txt", PLAT_READ);
    plat_thread_t thread = plat_thread_create(worker, NULL);
    plat_mutex_t mutex = plat_mutex_create();
    // Same API everywhere!
}

# 2. Build on different platforms
$ cmake -B build && cmake --build build
-- Detected platform: Linux
-- Using pthreads for threading
-- Using mmap for memory mapping
-- Build complete

$ cmake -B build && cmake --build build  # On Windows
-- Detected platform: Windows
-- Using Win32 threads for threading
-- Using MapViewOfFile for memory mapping
-- Build complete

# 3. Platform detection output
$ ./platform_info
Platform Layer Info:
  OS: Linux 5.15.0
  Arch: x86_64
  Byte order: Little-endian
  Pointer size: 8 bytes
  Page size: 4096 bytes
  Threading: pthreads
  Atomic support: lock-free

Implementation Guide

  1. Reproduce the simplest happy-path scenario.
  2. Build the smallest working version of the core feature.
  3. Add input validation and error handling.
  4. Add instrumentation/logging to confirm behavior.
  5. Refactor into clean modules with tests.

Milestones

  • Milestone 1: Minimal working program that runs end-to-end.
  • Milestone 2: Correct outputs for typical inputs.
  • Milestone 3: Robust handling of edge cases.
  • Milestone 4: Clean structure and documented usage.

Validation Checklist

  • Output matches the real-world outcome example
  • Handles invalid inputs safely
  • Provides clear errors and exit codes
  • Repeatable results across runs

References

  • Main guide: PROFESSIONAL_C_PROGRAMMING_MASTERY.md
  • Effective C, 2nd Edition by Robert C. Seacord