Concurrency

A race condition occurs when two or more threads access shared data concurrently, and at least one of them modifies the data.

Alternatives include lock-free data structures, atomic operations, and higher-level abstractions like message passing.

Atomic operations are operations that are executed in a single, uninterruptible step.

Most instructions are not atomic. That means that context may switch during the instruction's execution.

A 'deadlock' is a scenario where all threads in the program wait for each other to release some resource (usually locks).

Concurrency: two queues and a single coffee machine.

Parallelism: two queues and two coffee machines.

• The Deadlock Empire – game that teaches locking and concurrency
• The Little Book of Semaphores by Allen B. Downey (2016)
• What every systems programmer should know about concurrency by Matt Kline (2020)
• Seven Concurrency Models in Seven Weeks: When Threads Unravel by Paul Butcher (2014)
• Learn C++ Multi Threading in 20 Minutes - YouTube
• Atomics And Concurrency | Zaid Humayun’s Blog
• Unix Threads in C - YouTube
• C++ Concurrency in Action, Second Edition