52

Boost.Thread: what the standard took, what it left, and the third way to cancel a thread

boostthread asks what survived C++11's near-wholesale standardization of Boost.Thread, and answers with four capabilities std:: still lacks in C++23 on this toolchain: future::then() and when_all composing without blocking, where a concept evaluated against std::future and boost::future on every run reports no and yes; upgrade_lock promoting a reader to a writer in place, where std::upgrade_lock is not merely absent but undeclared; thread::interrupt() throwing an ordinary boost::thread_interrupted at defined interruption points; and thread::attributes::set_stack_size yielding exactly 262144, byte-identical to ch50's pthread_attr_setstacksize. The cancellation arc closes here -- catch (...) without a rethrow aborts the process under ch50's pthread_cancel (exit 134) and leaves it alive under Boost (exit 0), while a busy loop with no interruption point ignores interrupt() entirely. Verified against system Boost 1.90.0 on the Fedora 44 host: verify.lua PASS 37/FAIL 0, no Conan, no network.

⏱ 55 minutesChapter 52Compendium: C++ Concurrency

This chapter has moved. The C++ concurrency material has its own dedicated, runnable book: C++ Concurrency and Parallelism.

It maps to Threads in Modern C++ there.

The full, runnable C++ treatment of concurrency and parallelism — threads and jthread, mutexes and the memory model, atomics and lock-free structures, futures and coroutines, fibers, Asio, NUMA and mechanical sympathy, and the low-latency patterns — now lives in that book, each chapter with a Docker or KVM-lab demo and a Lua verify.lua behind it. This book keeps its Linux systems-programming material; the C++ concurrency compendium was extracted so it could grow on its own.