Скачать или смотреть OS I (CSCI 4120)- "Atomic CAS, Spinlocks, Semaphores: Critical Section Problems in Depth!" F25-W12D2

00:00:00 recap of the last lecture
00:00:58 Compare ans Swap (CAS) Instruction
00:05:57 Solving critical section problem through CAS
00:14:07 Issues with critical section problem solved through CAS
00:19:08 Improving the CAS based solution to ensure bounded waiting
00:31:01 Mutex locks
00:36:12 Spin locks and issue of busy waiting
00:47:17 Sempahores
00:53:14 Binary and counting semaphores
00:55:32 Using binary semaphore for solving critical section problem
01:00:39 Closing

In this video, we explore how modern CPUs handle synchronization without relying on OS-level mutexes. Starting from the low-level compare-and-swap (CAS) instruction, we build up to robust solutions for the critical section problem in concurrent systems.

✅ What you'll learn:

What is compare-and-swap (CAS) and how it works atomically

How CAS can solve the critical section problem — and where it fails

Why CAS-based solutions do not satisfy bounded waiting

How to improve CAS with spinlock mechanisms

Introduction to semaphores and their role in synchronization

Example of a binary semaphore implementation and usage

Practical insights into hardware vs OS-level synchronization

🧠 Ideal for students, embedded developers, and systems programmers looking to understand concurrency from the ground up.