Function ulock_wait 

pub unsafe fn ulock_wait(
    op: u32,
    addr: *mut c_void,
    val: u64,
    micros: u32,
) -> Result<c_int, ApiUnsupported>

Equivalent to __ulock_wait, but lazy-loads and returns Err(ApiUnsupported) if this machine doesn’t support the API.

It’s generally faster to call this than to call ULockApi::get()?.ulock_wait(...) unless you can cache the result of get somewhere easy.

Safety

Same as __ulock_wait.