Real-time embedded systems

Real-time embedded systems are integral to the global technological and social space, but references still rarely offer professionals the sufficient mix of theory and practical examples required to meet intensive economic, safety, and other demands on system development. Similarly, instructors have lacked a resource to help students fully understand the field. The information was out there, though often at the abstract level, fragmented and scattered throughout literature from different engineering disciplines and computing sciences. Accounting for readers' varying practical needs and experience levels, Real Time Embedded Systems: Open-Source Operating Systems Perspective offers a holistic overview from the operating-systems perspective. It provides a long-awaited reference on real-time operating systems and their almost boundless application potential in the embedded system domain. Balancing the already abundant coverage of operating systems with the largely ignored real-time aspects, or "physicality," the authors analyze several realistic case studies to introduce vital theoretical material. They also discuss popular open-source operating systems—Linux and FreRTOS, in particular—to help embedded-system designers identify the benefits and weaknesses in deciding whether or not to adopt more traditional, less powerful, techniques for a project.

Introduction

I: Concurrent Programming Concepts

A Case Study: Vision Control

Input Output on Computers

Input/Output Operations and the Operating System

Acquiring Images froma Camera Device

Edge Detection

Finding the Center Coordinates of a Circular Shape

Real-Time Concurrent Programming Principles

The Role of Parallelism

Definition of Process

Process State

Process Life Cycle and Process State Diagram

Multithreading

Deadlock

A Simple Example

Formal Definition of Deadlock

Reasoning about Deadlock: The Resource Allocation Graph

Living with Deadlock

Deadlock Prevention

Deadlock Avoidance

Deadlock Detection and Recovery

Interprocess Communication Based on Shared Variables

Race Conditions and Critical Regions

Hardware-Assisted Lock Variables

Software-Based Mutual Exclusion

From Active to Passive Wait

Semaphores

Monitors

Interprocess Communication Based on Message Passing

Basics ofMessage Passing

Naming Scheme

Synchronization Model

Message Buffers

Message Structure and Contents

Producer---Consumer Problem with Message Passing

Interprocess Communication Primitives in POSIX/Linux

Threads and Processes

Interprocess Communication among Threads

Interprocess Communication among Processes

Clocks and Timers

Threads or Processes?

Interprocess Communication Primitives in FreeRTOS

FreeRTOS Threads and Processes

Message Queues

Counting, Binary, and Mutual Exclusion Semaphores

Clocks and Timers

Network Communication

The Ethernet Protocol

TCP/IP and UDP

Sockets

UDP Sockets

Lock and Wait-Free Communication

Basic Principles and Definitions

Multidigit Registers

Application to the Readers/Writer Problem

Universal Constructions

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II: Real-Time Scheduling Analysis

Real-Time Scheduling Based on the Cyclic Executive

Scheduling and Process Models

The Cyclic Executive

Choice of Major and Minor Cycle Length

Tasks with Large Period or Execution Time

Real-Time, Task-Based Scheduling

Fixed and Variable Task Priority

Rate Monotonic

The EarliestDeadline First Scheduler

Schedulability Analysis Based on Utilization

Processor Utilization

Sufficient Schedulability Test for Rate Monotonic

Schedulability Test for EDF

Schedulability Analysis Based on Response Time Analysis

Response Time Analysis

Computing the Worst-Case Execution Time

Aperiodic and Sporadic Tasks

Task Interactions and Blocking

The Priority Inversion Probl...