CLOCK

pub const clockid_t = enum(u32) {
    REALTIME = 0,
    MONOTONIC = 1,
    PROCESS_CPUTIME_ID = 2,
    THREAD_CPUTIME_ID = 3,
    MONOTONIC_RAW = 4,
    REALTIME_COARSE = 5,
    MONOTONIC_COARSE = 6,
    BOOTTIME = 7,
    REALTIME_ALARM = 8,
    BOOTTIME_ALARM = 9,
    // In the linux kernel header file (time.h) is the following note:
    // * The driver implementing this got removed. The clock ID is kept as a
    // * place holder. Do not reuse!
    // Therefore, calling clock_gettime() with these IDs will result in an error.
    //
    // Some backgrond:
    // - SGI_CYCLE was for Silicon Graphics (SGI) workstations,
    // which are probably no longer in use, so it makes sense to disable
    // - TAI_CLOCK was designed as CLOCK_REALTIME(UTC) + tai_offset,
    // but tai_offset was always 0 in the kernel.
    // So there is no point in using this clock.
    // SGI_CYCLE = 10,
    // TAI = 11,
    _,
}