Thread Lifecycle and RAII
In the previous chapter, we explored the underlying mechanisms of CPU caches and OS threads. Now we can finally write our first multithreaded program. But before typing std::thread, we need to consider one thing: a thread is a resource. It consumes OS kernel objects, stack space, TLS storage, and more. Just like file handles and dynamic memory, threads must be properly acquired and released—otherwise, we face undefined behavior (UB) and resource leaks.
In this chapter, we start with the basic usage of std::thread, then dive into the pitfalls of parameter passing and the semantics of ownership transfer. Finally, we use RAII to encapsulate this complexity. The goal is to make multithreaded code just as clear in ownership and deterministic in resource release as single-threaded code.