mirror of https://github.com/aya-rs/aya
aya: use montonic SinceBoot for loaded_at
This commit was written to deflake test_loaded_at. The flakiness is due to the lack of monotonicity in SystemTime clock calculations. See https://github.com/aya-rs/aya/actions/runs/6340369670/job/17221591723. This PR addresses that problem by introducing a wrapper type to encapsulate the monotonically increasing duration since boot, `SinceBoot`. This type has a method `into_system_time()` to convert it into a `SystemTime`.reviewable/pr799/r2
Andrew Werner
2 years ago
parent
373fb7bf06
commit
02272cce05
@ -0,0 +1,68 @@
|
||||
//! Utilities for working with time.
|
||||
|
||||
use std::time::{Duration, SystemTime, UNIX_EPOCH};
|
||||
|
||||
/// A timestamp relative to the system boot time.
|
||||
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
|
||||
pub struct SinceBoot(Duration);
|
||||
|
||||
impl SinceBoot {
|
||||
/// The current SinceBoot.
|
||||
///
|
||||
/// Note that these calls will be monotonic.
|
||||
pub fn now() -> Self {
|
||||
Self(get_time(libc::CLOCK_BOOTTIME))
|
||||
}
|
||||
|
||||
/// Converts the timestamp to a `SystemTime`.
|
||||
///
|
||||
/// Note that this will not be robust to changes in the system clock, and thus these
|
||||
/// times should not be used for comparisons.
|
||||
pub fn into_system(self) -> SystemTime {
|
||||
let Self(since_boot) = self;
|
||||
boot_time() + since_boot
|
||||
}
|
||||
|
||||
pub(crate) fn from_nanos(nanos: u64) -> Self {
|
||||
Self(Duration::from_nanos(nanos))
|
||||
}
|
||||
}
|
||||
|
||||
fn boot_time() -> SystemTime {
|
||||
let since_boot = get_time(libc::CLOCK_BOOTTIME);
|
||||
let since_epoch = get_time(libc::CLOCK_REALTIME);
|
||||
UNIX_EPOCH + since_epoch - since_boot
|
||||
}
|
||||
|
||||
fn get_time(clock_id: libc::clockid_t) -> Duration {
|
||||
let mut time = unsafe { std::mem::zeroed::<libc::timespec>() };
|
||||
assert_eq!(
|
||||
unsafe { libc::clock_gettime(clock_id, &mut time) },
|
||||
0,
|
||||
"clock_gettime({}, _)",
|
||||
clock_id
|
||||
);
|
||||
let libc::timespec { tv_sec, tv_nsec } = time;
|
||||
Duration::new(tv_sec as u64, tv_nsec as u32)
|
||||
}
|
||||
|
||||
#[cfg(test)]
|
||||
mod test {
|
||||
use super::*;
|
||||
|
||||
#[test]
|
||||
fn test_since_boot_now_into_system_near_system_time() {
|
||||
let since_boot = SinceBoot::now().into_system();
|
||||
let system_time = SystemTime::now();
|
||||
let delta = system_time
|
||||
.duration_since(since_boot)
|
||||
.unwrap_or_else(|err| err.duration());
|
||||
const MAX_DELTA: Duration = Duration::from_micros(10);
|
||||
assert!(
|
||||
delta <= MAX_DELTA,
|
||||
"delta {delta:?} > {MAX_DELTA:?}: since_boot: {:?}, system_time: {:?}",
|
||||
since_boot,
|
||||
system_time
|
||||
);
|
||||
}
|
||||
}
|
||||
Loading…
Reference in New Issue