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use crate::sys::time;
#[inline]
pub(super) fn monotonize(raw: time::Instant) -> time::Instant {
inner::monotonize(raw)
}
#[cfg(any(all(target_has_atomic = "64", not(target_has_atomic = "128")), target_arch = "aarch64"))]
pub mod inner {
use crate::sync::atomic::AtomicU64;
use crate::sync::atomic::Ordering::*;
use crate::sys::time;
use crate::time::Duration;
pub(in crate::time) const ZERO: time::Instant = time::Instant::zero();
const UNINITIALIZED: u64 = 0b11 << 30;
static MONO: AtomicU64 = AtomicU64::new(UNINITIALIZED);
#[inline]
pub(super) fn monotonize(raw: time::Instant) -> time::Instant {
monotonize_impl(&MONO, raw)
}
#[inline]
pub(in crate::time) fn monotonize_impl(mono: &AtomicU64, raw: time::Instant) -> time::Instant {
let delta = raw.checked_sub_instant(&ZERO).unwrap();
let secs = delta.as_secs();
let nanos = delta.subsec_nanos() as u64;
let packed = (secs << 32) | nanos;
let updated = mono.fetch_update(Relaxed, Relaxed, |old| {
(old == UNINITIALIZED || packed.wrapping_sub(old) < u64::MAX / 2).then_some(packed)
});
match updated {
Ok(_) => raw,
Err(newer) => {
let seconds_lower = newer >> 32;
let mut seconds_upper = secs & 0xffff_ffff_0000_0000;
if secs & 0xffff_ffff > seconds_lower {
seconds_upper = seconds_upper.wrapping_add(0x1_0000_0000);
}
let secs = seconds_upper | seconds_lower;
let nanos = newer as u32;
ZERO.checked_add_duration(&Duration::new(secs, nanos)).unwrap()
}
}
}
}
#[cfg(all(target_has_atomic = "128", not(target_arch = "aarch64")))]
pub mod inner {
use crate::sync::atomic::AtomicU128;
use crate::sync::atomic::Ordering::*;
use crate::sys::time;
use crate::time::Duration;
const ZERO: time::Instant = time::Instant::zero();
static MONO: AtomicU128 = AtomicU128::new(0);
#[inline]
pub(super) fn monotonize(raw: time::Instant) -> time::Instant {
let delta = raw.checked_sub_instant(&ZERO).unwrap();
let secs = delta.as_secs() as u128;
let nanos = delta.subsec_nanos() as u128;
let timestamp: u128 = secs << 64 | nanos;
let timestamp = MONO.fetch_max(timestamp, Relaxed).max(timestamp);
let secs = (timestamp >> 64) as u64;
let nanos = timestamp as u32;
ZERO.checked_add_duration(&Duration::new(secs, nanos)).unwrap()
}
}
#[cfg(not(any(target_has_atomic = "64", target_has_atomic = "128")))]
pub mod inner {
use crate::cmp;
use crate::sys::time;
use crate::sys_common::mutex::StaticMutex;
#[inline]
pub(super) fn monotonize(os_now: time::Instant) -> time::Instant {
static LOCK: StaticMutex = StaticMutex::new();
static mut LAST_NOW: time::Instant = time::Instant::zero();
unsafe {
let _lock = LOCK.lock();
let now = cmp::max(LAST_NOW, os_now);
LAST_NOW = now;
now
}
}
}