C++ For Embedded Developers (2023-04-18 - 2023-04-20)

• Start: Monday 9:00

• 3 days

• Project on Github: https://github.com/jfasch/2023-04-18

Goal

Give an idea how an experienced C programmer can benefit from the C++ toolcase. The following aspects are covered, accompanied with many exercises.

• C++ is an object oriented language. That term alone has many facets, and a solid understanding of each is given. Constructors, destructors, automatic pointer/base-class conversion, late binding (“abstract”?), and all that.

• C++ also brings a rich toolset in form of its standard library. After a short conceptual introduction, containers and algorithms are something that is immediately useful for non-OO programmers.

• C++ does not stop there; starting from its 2011 definition, the language has undergone a major revolution. An overview is given.

Work Environment

Preferred: Ubuntu under Windows (WSL)

I suggest you use the Windows Subsystem For Linux (WSL2) (Microsoft documentation here). This sets up a virtualized Ubuntu inside Windows, together with all interoperability wazoo.

When installed, open a Ubuntu terminal, and install the software that is required for this training.

$ sudo apt update
$ sudo apt install git build-essential cmake libgtest-dev libgmock-dev

Skeleton Project Setup

Follow the instructions in the course project README to setup the initial version of the course project.

Day 1

Introduction

• Introduction

  • A Live-Hacked Tour Around The New C++

  • Outcome, including a quit-flag for the threads: intro.cpp

Some Details

• A little constexpr: constexpr.cpp

• From Lambda

  • Lambda

  • Lambda: More Capturing

  • ChatGPT bashing (“How would you compute the squares of a list of numbers with a lambda, like you would in Python?”): lambda-transform.cpp

  • More about lambda: lambda.cpp

• A little threading (more: Multithreading, C++ Memory Model)

  • And Python’s asyncio? (maybe watch the video in Pointless Blinking 🤘)

Standard Template Library

From Standard Template Library

• Standard Template Library: Basics

• std::vector (And std::copy())

• Algorithms

• Sequential Containers

• Associative Containers

OO

From Data Encapsulation

• Object Oriented Programming In Good Ol’ C

• Classes and Objects

• Custom Constructor

• Default Constructor

Day 2

Warm-Up

See also

• Threads in C++

• std::mutex And Friends

• std::atomic

• std::atomic<>. Revisit Ludwig’s ChatGPT findings, and introduce a signal handler in intro.cpp.

  • Memory visibility across multiple CPUs?

  • Cache invalidation?

  • Memory model?

• A little threading (from Multithreading, C++ Memory Model)

  • Load-modify-store conflict: race-condition.cpp

  • Fixed with mutex (and a nice little class encapsulating all that): race-condition-fixed-mutex.cpp

  • Fixed with std::atomic<>: race-condition-fixed-atomic.cpp

Sensor Exercise, Resolved

• Implement (live-hacked) test-sensor.cpp

  • https://github.com/jfasch/2023-04-18/blob/main/group-joerg/lib/sensor.h

  • sensor-registry.h

  • sensor-registry.cpp

• Discussing OO issues: OO Design Principles

OO, Cont’d

From Functions and Methods

• Overloading

• Methods

• this

• References

• static Methods

• Operator Overloading

• Exercise: Fix Issues In Project

Smart Pointers

• std::shared_ptr

• With this, fix memleak

Day 3

Smart Pointers (Continued)

• std::unique_ptr

• Morphed our “registry” universe to use those …

  • sensors-main.cpp

  • sensor-registry.h

  • sensor-registry.cpp

Heavy Weight OO 💪

Complete the pointless point class, by quickly moving across the following topics from Data Encapsulation

• Copy Constructor, Assignment Operator

• More Constructors, Destructors

• Object Copy (And Resource Management): There Be Dragons

From Inheritance And Object Oriented Design

• Inheritance Basics

• Dynamic Dispatch: Virtual Methods

• Pure Virtual Methods, And Interfaces

• Destructors And Interfaces

• C++ “Interfaces”

See live-hacked code in interfaces.cpp.

Exception Handling

From Exceptions:

• try - catch

Exercises: Containers And Algorithms

From C++ Exercises: Standard Template Library:

• Exercise: std::vector<>

• Exercise: std::map<>

• Exercise: Algorithms

• Exercise: Uniquify A Sequence

• Exercise: Filter Odd Elements

• Exercise: Filter Elements Greater Than 10

• Exercise: Generic Filter

• Exercises: Sensor Repository (std::map)

Exercises: OO And Interfaces

• Exercise: Sensor Interface (polymorphic use of different sensors)

• Averaging sensor (“Composite” pattern)

• Exercise: OneWire Sensor Class (OneWire sensor - in the Linux OneWire style)

• Exercise: OneWire Sensor Factory (factory pattern - a class that creates OneWire sensors by address)