5.1 Principles of Concurrency • 5.1.0 What is concurrency • 5.1.1 A Simple Example • 5.1.2 Race Condition • 5.1.3 Operating System Concerns • 5.1.4 Process Interaction • 5.1.5 Requirements for Mutual Exclusion 5.2 Mutual Exclusion • 5.2.1 Hardware approaches • 5.2.2 Software approaches