Function pthread_rwlock_clockrdlock 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn pthread_rwlock_clockrdlock(
    rwlock: *mut pthread_rwlock_t,
    clock_id: clockid_t,
    abstime: *const timespec,
) -> c_int

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