Concurrency Fundamentals: Fetch-and-Add and Ticket Locks

Writing safe and efficient multi-threaded programs requires a deep understanding of how threads synchronize at the hardware level. When multiple threads access shared resources, standard locking mechanisms can cause performance bottlenecks or unfair thread starvation. This text-only course guides you through the foundational concepts of concurrency control, focusing on the powerful fetch-and-add hardware instruction. You will transition from basic synchronization principles to understanding and implementing fair, scalable ticket locks that prevent thread starvation. What you'll learn: - Understand the core principles of race conditions, mutual exclusion, and thread safety - Analyze how the atomic fetch-and-add hardware instruction guarantees thread-safe state updates - Implement a fair ticket lock mechanism to ensure threads are served in the exact order they arrive - Compare ticket locks with basic spinlocks to evaluate performance and fairness trade-offs - Explore modern memory ordering concepts and atomic operations used in contemporary systems You will start by exploring fundamental concurrency definitions and the limitations of software-only synchronization. Then, you will read through step-by-step breakdowns of atomic hardware instructions, culminating in the design and analysis of efficient, starvation-free ticket locks. This course is designed for beginner software engineers, computer science students, and systems programming enthusiasts. No prior experience with low-level hardware instructions is required, though a basic understanding of programming logic is helpful. Start reading today to build a solid foundation in low-level concurrency and hardware-assisted synchronization.