Real-Time Embedded Systems Open-Source Operating Systems Perspective

From the Foreword: "…the presentation of real-time scheduling is probably the best in terms of clarity I have ever read in the professional literature. Easy to understand, which is important for busy professionals keen to acquire (or refresh) new knowledge without being bogged down in a convoluted narrative and an excessive detail overload. The authors managed to largely avoid theoretical-only presentation of the subject, which frequently affects books on operating systems. … an indispensable [resource] to gain a thorough understanding of the real-time systems from the operating systems perspective, and to stay up to date with the recent trends and actual developments of the open-source real-time operating systems." —Richard Zurawski, ISA Group, San Francisco, California, USA 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 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 Problem The Priority Inheritance Protocol The Priority Ceiling Protocol Schedulability Analysis and Examples Self-Suspension and Schedulability Analysis Self-Suspension and the Critical Instant Theorem Self-Suspension and Task Interaction Extension of the Response Time Analysis Method III: Advanced Topics Internal Structure of FreeRTOS Task Scheduler/Context Switch Synchronization Primitives Porting FreeRTOS to a New Architecture Internal Structures and Operating Principles of Linux Real-Time Extensions The Linux Scheduler Kernel Preemption The PREEMPT RT Linux Patch The Dual-Kernel Approach OS Abstraction Layer An Object Oriented Interface to Threads and Other IPC Mechanisms A Sample Multiplatform Application Control Theory and Digital Signal Processing Primer Case Study 1: Controlling the Liquid Level in a Tank Case Study 2: Implementing a Digital Low-Pass Filter