Posix Multithreading And Futex Programming In C From Scratch

A practical guide to POSIX multithreading and futex programming — from beginner concepts to kernel-level tuning.

What you'll learn

Understand the Fundamentals of Multithreading Programming: Grasp the core concepts of threads, processes, concurrency, and parallelism in modern computing.

Master POSIX Threads (pthreads) in C: Learn how to create, manage, and synchronize threads using POSIX API functions.

Solve Real-World Problems Using Threads: Apply multithreading techniques to solve real-world challenges such as task parallelism

Avoid Common Pitfalls in Concurrent Programming: Identify and fix issues like race conditions, deadlocks, data corruption, and thread safety.

Requirements

Basic knowledge of the C programming language: Learners should be comfortable with functions, pointers, and basic memory management in C.

Familiarity with the Linux command line: Knowing how to compile and run C programs in a Linux environment (using gcc and make) will be helpful.

A Linux-based system or a Linux virtual machine: All examples and labs are designed for Linux, so having access to a Linux terminal is essential.

Willingness to learn and explore concurrency concepts: No prior experience with multithreading is required — we’ll build from the ground up.

Description

In today’s computing world, concurrency is no longer optional — it’s essential. Modern applications must be fast, responsive, and capable of handling multiple tasks at once. This course is designed to give you a deep, practical understanding of multithreading programming in C using POSIX threads (pthreads) and futex, the powerful Linux system call for user-space synchronization.Whether you're a systems programmer, embedded developer, Linux enthusiast, or computer science student, this course will walk you through every essential concept you need — starting from the basics and building up to low-level, high-performance techniques used in real-world software.You'll begin by exploring the difference between processes and threads, understand why multithreading is more efficient, and learn how to create, manage, and terminate threads safely. From there, we’ll dive into synchronization tools like mutexes, condition variables, spinlocks, barriers, and advanced topics such as deadlocks, thread-local storage, reentrant functions, and thread safety.In the second half of the course, you’ll learn how to use futex (Fast Userspace Mutex) — a Linux kernel mechanism for fast, scalable thread synchronization. We’ll explore futex APIs, fast vs. slow paths, kernel-level optimizations, and how futex is used under the hood by libraries like glibc and pthreads.You’ll also analyze memory layout, thread stacks, how signals behave in multithreaded environments, and the difference between user and kernel space when working with threads.By the end of this course, you’ll be able to write robust, thread-safe, and high-performance multithreaded applications in C — with a deep understanding of what’s happening behind the scenes at the kernel level.

Overview

Section 1: Getting Started with Multithreading: Concepts, Benefits, and Pitfalls

Lecture 1 1.1 What is the Difference between Process & Thread

Lecture 2 1.2 Why we use Multi-Threading Programming

Lecture 3 1.3 Why Does Each Thread Have Its Own Stack

Lecture 4 1.4 What is The Race Condition

Lecture 5 1.5 Why we donot use multiple Processes instead of multithreaded

Section 2: Managing Threads API Lifecycle in POSIX Threads

Lecture 6 2.1 Thread Creation

Lecture 7 2.2 Thread Terminiation

Lecture 8 2.3 Thread Joining

Lecture 9 2.4 Thread Detaching

Lecture 10 2.5 Thread Cancellation.mp4

Section 3: Mutual Exclusion and Thread Synchronization Mechanisms in POSIX Threads

Lecture 11 3.1 What is Atomic Programming (Atomicity)

Lecture 12 3.2 Mutex - Mutual Exclusion Lock

Lecture 13 3.3 Mutex Locking and Unlocking

Lecture 14 3.4 Deadlocks Causes & Solutions

Lecture 15 3.5 Reader - Writer Locks

Lecture 16 3.6 Mutex Attributes

Section 4: Advanced Thread Synchronization and Thread-Specific Data

Lecture 17 4.1 Condition variables

Lecture 18 4.2 Producer-Consumer Example

Lecture 19 4.3 Spin Locks

Lecture 20 4.4 Barriers

Lecture 21 4.5 Thread Safety

Lecture 22 4.6 Reentrant and Non-Reentrant Functions

Lecture 23 4.7 Thread-Specific Data APIs

Lecture 24 4.8 Employing the Thread-Specific Data API

Lecture 25 4.9 Threads Local Storag & Thraead Limits

Section 5: System-Level Threading: Stack, Signals, and OS Boundaries

Lecture 26 5.1 Thread Stack in Deep

Lecture 27 5.2 Threads and Signals

Lecture 28 5.3 User VS Kernel Space

Section 6: Futexes in Depth: Advanced Synchronization and Kernel-Level Optimizations

Lecture 29 6.1 History of FUTEX

Lecture 30 6.1.1 Fast vs Slow Path

Lecture 31 6.2 Futex System Call API

Lecture 32 6.3 Implementing Mutex using Futex

Lecture 33 6.4 Implementing Condition Variables using Futex

Lecture 34 6.5 Futex Wake Optimization Strategies

Lecture 35 6.6 Kernel-Level Optimizations in Futexes

Lecture 36 6.7 Futex Hashing Efficient Thread Management in the Kernel

C programmers who want to master multithreading.,Beginner to intermediate Linux developers.,Computer science and engineering students.,Anyone preparing for systems programming, embedded systems, or software engineering interviews.