rust/tests/run-pass/time.rs
2020-09-07 10:54:39 -05:00

52 lines
1.6 KiB
Rust

// compile-flags: -Zmiri-disable-isolation
use std::time::{SystemTime, Instant, Duration};
fn duration_sanity(diff: Duration) {
// On my laptop, I observed times around 15-40ms. Add 10x lee-way both ways.
assert!(diff.as_millis() > 1);
assert!(diff.as_millis() < 500);
}
// Thus far, only `libc::nanosleep`, is implemented, not `c::Sleep`.
#[cfg(unix)]
fn test_sleep() {
let before = Instant::now();
std::thread::sleep(Duration::from_millis(100));
let after = Instant::now();
assert!((after - before).as_millis() >= 100);
}
fn main() {
// Check `SystemTime`.
let now1 = SystemTime::now();
let seconds_since_epoch = now1.duration_since(SystemTime::UNIX_EPOCH).unwrap().as_secs();
let years_since_epoch = seconds_since_epoch / 3600 / 24 / 365;
let year = 1970 + years_since_epoch;
assert!(2020 <= year && year < 2100);
// Do some work to make time pass.
for _ in 0..10 { drop(vec![42]); }
let now2 = SystemTime::now();
assert!(now2 > now1);
// Sanity-check the difference we got.
let diff = now2.duration_since(now1).unwrap();
assert_eq!(now1 + diff, now2);
assert_eq!(now2 - diff, now1);
duration_sanity(diff);
// Check `Instant`.
let now1 = Instant::now();
// Do some work to make time pass.
for _ in 0..10 { drop(vec![42]); }
let now2 = Instant::now();
assert!(now2 > now1);
// Sanity-check the difference we got.
let diff = now2.duration_since(now1);
assert_eq!(now1 + diff, now2);
assert_eq!(now2 - diff, now1);
duration_sanity(diff);
#[cfg(unix)]
test_sleep();
}