I'd like some more around the "Interrupting system calls" section. This is a real can of worms. By default, signal() defaults to BSD semantics , which auto restarts syscalls, as do the SA_RESTART flag when the handler is established with sigaction(). Except not all calls are auto restarted, e.g. select/poll/sleep,

I'd really like to see a list of syscalls that are not restarted no matter the flags. And the macros that (implicitly) turn on SysV behavior of signal() ...