Agenda: (Linux) Systems Programming With C++

Three days of systems programming, interwoven with select C++ topics.

(Linux) Systems Programming

All slide material

• Linux Systems Programming

This is probably a bit too much for a three day course to present in detail; lets see what can be omitted.

• Basics

  • Files And File Descriptors

  • Processes. Can be reduced to a minimum. Zephyr does not have processes, at least not the Linux way.

  • Signals. Is there such a thing on Zephyr?

  • Time, Clocks, Timers And Notification. Core topic is that timers add weird notification features that add multiple dimensions of complexity. How’s that on Zephyr?

• Hardware interfaces: GPIO (libgpiod), I2C, SPI, PWM, HWMON. This has nothing to do with Zephyr.

• Event loops: select(), poll(), epoll()

  • The Problem

  • I/O Multiplexing

  • A Naive C++ Eventloop (poll())

  • Exercise: Graceful Termination Via SIGTERM/SIGINT

  • Exercise: Commit/Rollback Via SIGUSR1/SIGUSR2

  • Maybe have a short look into Python’s asyncio framework. Maybe only after we have looked into threading.

• Memory Management/mmap(). Can Zephyr use an MMU, and how?

• Scheduling and realtime, and priority inversion. Fun: Legendary: The Mars Pathfinder Incident

• IPC: message queues, POSIX shared memory, POSIX semaphores. How’s that on Zephyr? Inter Process Communication without processes

• Multithreading; cover POSIX threads and C++ threads in parallel

  • POSIX threads, vs. C++ threads

  • C++ memory model Very good a-ha

  • POSIX mutexes vs. C++ mutexes and scoped locking

  • POSIX condition variables vs. C++ condition variables and C++ promise/future

  • Scheduling And Realtime

C++

All slide material

• C++ >= 11

Don’t present explain basics like range-for, or auto, or Tuple Unpacking (Err, Structured Binding) - just use them in live-hacking sessions. Likewise, stay away from niche/advanced features like coroutines, or “deducing this”.

Proposed topics (apart from those already touched during Systems Programming) …

• Smart Pointers: std::unique_ptr, std::shared_ptr (And std::weak_ptr) (std::unique_ptr usage requires a bit of move-understanding, so this is a good intro)

• The Rule Of Three/Five/Zero, including move. There is a separate slide deck on move here.

• Lambda

• Perfect Forwarding

• Ranges And Views

• Concepts

• Show creative auto usage: Abbreviated function templates