Multithreading Programming in C++ Training Course

Challenges and Concurrency Problems

• Hardware limitations of platforms - hardware threads, pipelines, cache coherence
• Fundamental concepts related to multithreaded programming (correctness of multithreaded programs, liveness, deadlock, livelock, race conditions, atomicity, memory models, Flynn's taxonomy)
• Available mechanisms in C++ for implementing multithreading and multiprocessing
• Standard library implementation - features from C++14 to today (C++2a)
• Implementation available in Boost - differences compared to the standard library

Processes and Threads

• Multiprocess vs multithreaded applications
• Operating system and threads (short overview of available implementations)
• Process and thread synchronization mechanisms
• Structural implementation of synchronization
• Specifics of multithreading implementation in an object-oriented approach (role of RAII pattern)

Memory Model in C++

• Objects and memory locations
• Ordering operations and enforcing them
• Relations: synchronization, precedence, ordering of operations for atomic actions, release sequences
• Memory barriers
• Atomic operations

Thread Management in C++14 and Newer

• std::thread class and running threads
• Thread identification
• Attaching and detaching threads
• Threads and standard containers
• Exception handling in C++14 threads

Mutual Exclusion and Critical Sections

• Simple mutual exclusion principles
• Concepts (types) of available blocking objects
• Quick introduction to time handling in C++14 (chrono library)
• std::mutex, std::timed_mutex, std::shared_mutex classes and derivatives
• RAII pattern in lock handling (std::lock_guard, std::unique_lock)
• Dependent and deferred locks (std::lock)
• Ownership and co-ownership of locks and threads
• Readers-writers problem
• One-time initialization
• Thread-local (private) memory (std::thread_local)

Locks and Thread Synchronization

• Semaphore operations
• Recursive locks
• Locks with defined locking levels
• Decision variables and cooperation with locks
• Implementation of active and passive barriers (Idle Waits, Busy Waits)
• Resuming thread execution
• Communication between threads (Actor model and CSP)

Asynchronous Tasks

• Asynchronous events and their handling
• Futures
• Promises
• Packaged tasks

Atomic Types

• Standard atomic types
• Universal atomic flag (std::atomic_flag)
• Template class "std::atomic[T]" and its specializations
• Helper functions (free functions) of std::atomic types

Specifics of Multithreaded API Design

• Designing structures using locks - coarse-grained and fine-grained locks
• Concurrency code efficiency - estimation and measurement techniques
• Data partitioning
• Scalability of solutions
• Error handling and exceptional situations in application architecture

Testing and Debugging Multithreaded Applications

• Code reviews for multithreaded operations
• Specifics of testing multithreaded applications
• Unit tests
• Increasing the probability of emergency situations for testing
• Formal methods for testing multithreaded applications
• Architectural patterns of multithreaded applications and testing and debugging (overview)

Advanced Thread Management

• Dependent threads (Saga pattern)
• Avoiding data access contention
• Controlled stopping and interrupting threads
• Interrupting blocking calls
• Interrupt handling
• Work stealing
• Interrupting tasks during application shutdown

Multithreading Design Patterns

• Types and purposes of multithreading patterns
• Pattern application scope
• Thread Pool
• Active Object pattern
• Thread-Safe Queue
• Producer-Consumer pattern
• Monitor pattern
• Multithreading safety of GoF patterns