Chapter 14. Critical Sections and Semaphores

Programs that manage shared resources must execute portions of code called critical sections in a mutually exclusive manner. This chapter discusses how critical sections arise and how to protect their execution by means of semaphores. After presenting an overview of the semaphore abstraction, the chapter describes POSIX named and unnamed semaphores. The closing section outlines a license manager project based on semaphores.

Objectives

• Learn about semaphores and their properties

• Experiment with synchronization

• Explore critical section behavior

• Use POSIX named and unnamed semaphores

• Understand semaphore management