It is all pretty good, but why there is update of "static bool" variables from signal handlers? In old-style C it must be "volatile int" (and only int), in new-

It is all pretty good, but why there is update of "static bool" variables from signal handlers? In old-style C it must be "volatile int" (and only int), in new-style moder C it must be atomic-anything (bool is ok). But access to plain "static bool" from signal handlers & main thread is race and UB.