tests/pass/time.rs

   1 //@compile-flags: -Zmiri-disable-isolation
   2
   3 use std::time::{Duration, Instant, SystemTime};
   4
   5 fn duration_sanity(diff: Duration) {
   6     // On my laptop, I observed times around 15-40ms. Add 10x lee-way both ways.
   7     assert!(diff.as_millis() > 1);
   8     assert!(diff.as_millis() < 500);
   9 }
  10
  11 // Sleeping on Windows is not supported yet.
  12 #[cfg(unix)]
  13 fn test_sleep() {
  14     let before = Instant::now();
  15     std::thread::sleep(Duration::from_millis(100));
  16     let after = Instant::now();
  17     assert!((after - before).as_millis() >= 100);
  18 }
  19
  20 fn main() {
  21     // Check `SystemTime`.
  22     let now1 = SystemTime::now();
  23     let seconds_since_epoch = now1.duration_since(SystemTime::UNIX_EPOCH).unwrap().as_secs();
  24     let years_since_epoch = seconds_since_epoch / 3600 / 24 / 365;
  25     let year = 1970 + years_since_epoch;
  26     assert!(2020 <= year && year < 2100);
  27     // Do some work to make time pass.
  28     for _ in 0..10 {
  29         drop(vec![42]);
  30     }
  31     let now2 = SystemTime::now();
  32     assert!(now2 > now1);
  33     // Sanity-check the difference we got.
  34     let diff = now2.duration_since(now1).unwrap();
  35     assert_eq!(now1 + diff, now2);
  36     assert_eq!(now2 - diff, now1);
  37     duration_sanity(diff);
  38
  39     // Check `Instant`.
  40     let now1 = Instant::now();
  41     // Do some work to make time pass.
  42     for _ in 0..10 {
  43         drop(vec![42]);
  44     }
  45     let now2 = Instant::now();
  46     assert!(now2 > now1);
  47     // Sanity-check the difference we got.
  48     let diff = now2.duration_since(now1);
  49     assert_eq!(now1 + diff, now2);
  50     assert_eq!(now2 - diff, now1);
  51     duration_sanity(diff);
  52
  53     #[cfg(unix)]
  54     test_sleep();
  55 }