Concurrency and Multithreading with Modern C++

Objectives

• Cover C++ memory model.
• Covers multithreading features in C++17 (including C++14/11)
• Covers Multithreading and Concurrency features in C++20.
• Covers C++17 parallel standard algorithms.
• Covers best practices and common pitfalls.

Audience

Software engineers with hands-on experience using C++11/14/17. Prior multithreading experience is not required but is recommended.

Delivery

• This course will combine theory and hands-on live code demonstration.
• Attendees will practice learnt concepts and techniques by solving specially designed exercises.
• Hands-on practice is ~30% of each session time.

Schedule

• 2 days

Syllabus

1. Introduction to Multithreading and Concurrency
   1. What is parallelism?
   1. What is concurrency?
   1. Thread vs. Process
   1. Review of modern CPUs and memory architecture
   1. Amdhal Law.
2. std::thread
   1. What is a thread – OS perspective
   1. Starting new threads
   1. Passing arguments to new threads
   1. Background threads
   1. Getting results from new threads
   1. Join and dispatch
   1. Yield and sleep
3. Sharing State
   1. Problems with sharing state
   1. Threads and global variables
   1. Threads and thread_local variables

• Atomic operations.
  • Once flags
  • Race conditions.
  • Synchronization with mutex
  • Mutex types
• Mutex locks
  • Working with RAII-based locks
  • Unique locks
  • Deadlocks
  • Deadlocks avoidance
• Multiple Readers Single Writer Problem
  • Shared Locks
  • Why no upgradable locks
  • Bias and Fairness
• Condition Variables
  • Condition variables and mutex
  • Implementing waitable data structures.
  • Spurious wakeup and avoidance
• Async Processing
  • std::async and std::future
  • Packaged tasks
• C++20 Joinable Thread
  • jthread
  • Stop tokens
• Additional Synchronization Tools
  • Counting semaphores
  • Barrier
  • Latch
• Parallel standard algorithm in C++17
  • Execution policies in C++17 and C++20
  • What algorithms are available?
  • Demo with Intel Thread Building Blocks