...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
boost::interprocess::interprocess_upgradable_mutex::control_word_t
// In header: <boost/interprocess/sync/interprocess_upgradable_mutex.hpp> struct control_word_t { unsigned exclusive_in; unsigned upgradable_in; unsigned num_upr_shar; };