vendor/rustix/tests/time/y2038.rs

/// Test that `Timespec` and `Secs` support a 64-bit number of seconds,
/// avoiding the y2038 bug.
///
/// The Rust Musl target and libc crate are currently using Musl 1.1. It is
/// expected to update to Musl 1.2 at some point, at which point it'll gain a
/// 64-bit `time_t`.
///
/// 32-bit Android is [not y2038 compatible]. In theory we could use
/// `libc::syscall` and call the new syscalls ourselves, however that doesn't
/// seem worth the effort on a platform that will likely never support add
/// such support itself.
///
/// [not y2038 compatible]: https://android.googlesource.com/platform/bionic/+/refs/heads/master/docs/32-bit-abi.md#is-32_bit-on-lp32-y2038
#[cfg(not(all(target_env = "musl", target_pointer_width = "32")))]
#[cfg(not(all(target_os = "android", target_pointer_width = "32")))]
#[cfg(not(all(target_os = "emscripten", target_pointer_width = "32")))]
#[test]
fn test_y2038() {
    use rustix::time::{Secs, Timespec};

    let tv_sec: i64 = 0;
    let _ = Timespec { tv_sec, tv_nsec: 0 };
    let _: Secs = tv_sec;

    #[cfg(any(target_os = "android", target_os = "fuchsia", target_os = "linux"))]
    {
        use rustix::time::Itimerspec;

        let _ = Itimerspec {
            it_interval: Timespec { tv_sec, tv_nsec: 0 },
            it_value: Timespec { tv_sec, tv_nsec: 0 },
        };
    }
}

#[cfg(any(target_os = "android", target_os = "fuchsia", target_os = "linux"))]
#[test]
fn test_y2038_with_timerfd() {
    use rustix::time::{
        timerfd_create, timerfd_gettime, timerfd_settime, Itimerspec, TimerfdClockId, TimerfdFlags,
        TimerfdTimerFlags, Timespec,
    };

    let fd = timerfd_create(TimerfdClockId::Monotonic, TimerfdFlags::CLOEXEC).unwrap();

    let set = Itimerspec {
        it_interval: Timespec {
            tv_sec: (1_u64 << 32) as _,
            tv_nsec: 20,
        },
        it_value: Timespec {
            tv_sec: (1_u64 << 32) as _,
            tv_nsec: 21,
        },
    };
    let _old: Itimerspec = match timerfd_settime(&fd, TimerfdTimerFlags::ABSTIME, &set) {
        Ok(i) => i,

        // On 32-bit and mips64 platforms, accept `EOVERFLOW`, meaning that
        // y2038 support in `timerfd` APIs is not available on this platform
        // or this version of the platform.
        #[cfg(any(target_pointer_width = "32", target_arch = "mips64"))]
        Err(rustix::io::Errno::OVERFLOW) => return,

        Err(e) => panic!("unexpected error: {:?}", e),
    };

    let new = timerfd_gettime(&fd).unwrap();

    // The timer counts down.
    assert_eq!(set.it_interval.tv_sec, new.it_interval.tv_sec);
    assert_eq!(set.it_interval.tv_nsec, new.it_interval.tv_nsec);
    assert!(new.it_value.tv_sec <= set.it_value.tv_sec);
    assert!(
        new.it_value.tv_nsec < set.it_value.tv_nsec || new.it_value.tv_sec < set.it_value.tv_sec
    );
}