50

pthreads: the thread under std::thread, its two identities, and the six controls the standard does not give you

pthreads runs one facet per subcommand over the per-thread controls POSIX offers and the C++ standard library does not expose: gettid() versus the opaque pthread_t (and why the main thread's tid equals the pid), pthread_setname_np landing in /proc/self/task//comm with a 16-character name refused as ERANGE, pthread_attr_setstacksize giving exactly 262144 against an 8388608 default with sub-PTHREAD_STACK_MIN requests refused as EINVAL, per-thread pthread_setaffinity_np putting two workers on two CPUs while the caller's mask is untouched, SCHED_OTHER at priority 0 with an unprivileged SCHED_FIFO refused as EPERM, and pthread_cancel unwinding C++ destructors -- plus the trap where a catch (...) that does not rethrow aborts the process with FATAL: exception not rethrown. Verified on the Fedora 44 host with glibc 2.43: verify.lua PASS 45/FAIL 0, local, unprivileged, offline, with std::thread::native_handle_type static_asserted to be pthread_t.

⏱ 55 minutesChapter 50Compendium: 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.