Function pthread_mutexattr_setprotocol 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn pthread_mutexattr_setprotocol(
    attr: *mut pthread_mutexattr_t,
    protocol: c_int,
) -> c_int

See https://pubs.opengroup.org/onlinepubs/9799919799/functions/pthread_mutexattr_setprotocol.html.