Linux Systems Programming

The material below covers “what an old UNIX greybeard knows about his favorite OS”. It is not to be seen as classical slide material, but rather as support material for didactical live programming [2].

It is not meant to be complete, and it never will be. I leave that task to other authorities - Michael Kerrisks site is heavily cited from here; he offers courses at that level.

Note that this is not an agenda for a single course. This material is a set of building blocks, used to compose a course that is adapted to the audience.

See also

• Linux Basics

Fundamentals

This section covers the stone-old UNIX concepts [1] that Linux has expanded where necessary (embedded hardware is just a file too). It forms the absolute basis for any kind of serious system level programming.

Contents

• System Calls
• Files And File Descriptors
• Processes
• Signals
• Time, Clocks, Timers And Notification

Event Driven Programming

In this section we will develop a semi-realistic application that sits upon a “database”. The application receives input and commands from multiple data sources - and it is single threaded.

Based upon our knowledge of file descriptors (“everything is a file”), we learn how to use advanced I/O multiplexing system calls to dispatch events from multiple sources inside an application that is highly reactive.

Contents

• The Problem
• I/O Multiplexing
• A Naive C++ Eventloop (poll())
• Exercise: Graceful Termination Via SIGTERM/SIGINT
• Exercise: Commit/Rollback Via SIGUSR1/SIGUSR2

Multithreading

Outdated This is course material which has done its duty already. It is in the queue for refactoring, so it will look like the “regular” material above. It can be booked nonetheless; in this case the booked topics will receive extra priority points for refactoring 😉.

Contents

• POSIX Threads

Inter Process Communication

Outdated This is course material which has done its duty already. It is in the queue for refactoring, to make it look like the “regular” material above. It can be booked nonetheless; in this case the booked topics will receive extra priority points for refactoring 😉.

Contents

• Memory Management Basics (mmap())
• Sysprog: POSIX IPC
• POSIX Message Queues

Scheduling And Realtime

Outdated This is course material which has done its duty already. It is in the queue for refactoring, to make it look like the “regular” material above. It can be booked nonetheless; in this case the booked topics will receive extra priority points for refactoring 😉.

Contents

• Scheduling And Realtime

Graphical Overview

Ad-Hoc Live Demos

• Introductory Live Hacking, Hardware-Wise (sysfs GPIO)
• Blocking I/O: What Is That?

Building Blocks For Sketches

Footnotes

[1]

The books by W. Richard Stevens impressed me when I was young, partly because they are easily read cover-to-cover. They are not quite up-to-date anymore, but I still have to mention them. Check out Advanced Programming in the Unix Environment and UNIX Network Programming.

[2]

In a course, I use to quickly explain what the topic of the next hour (or so) is. Then I’ll start to program, and while I program I explain what I do, and discuss matters. I consider this much more satisfying than a frontal lecture.