pthread_mutexattr_getprotocol
int pthread_mutexattr_getprotocol(const pthread_mutexattr_t * __restrict,
PTHREAD_REQUIRE(pthread_mutexattr_getprotocol(&mattr, &protocol));
PTHREAD_REQUIRE(pthread_mutexattr_getprotocol(&mattr, &protocol));
PTHREAD_REQUIRE(pthread_mutexattr_getprotocol(&mattr,