// SPDX-License-Identifier: GPL-2.0 //! Time related primitives.//!//! This module contains the kernel APIs related to time and timers that//! have been ported or wrapped for usage by Rust code in the kernel.//!//! There are two types in this module://!//! - The [`Instant`] type represents a specific point in time.//! - The [`Delta`] type represents a span of time.//!//! Note that the C side uses `ktime_t` type to represent both. However, timestamp//! and timedelta are different. To avoid confusion, we use two different types.//!//! A [`Instant`] object can be created by calling the [`Instant::now()`] function.//! It represents a point in time at which the object was created.//! By calling the [`Instant::elapsed()`] method, a [`Delta`] object representing//! the elapsed time can be created. The [`Delta`] object can also be created//! by subtracting two [`Instant`] objects.//!//! A [`Delta`] type supports methods to retrieve the duration in various units.//!//! C header: [`include/linux/jiffies.h`](srctree/include/linux/jiffies.h).//! C header: [`include/linux/ktime.h`](srctree/include/linux/ktime.h). use core::marker::PhantomData;use core::ops; pub mod delay;pub mod hrtimer; /// The number of nanoseconds per microsecond.pub const NSEC_PER_USEC: i64 = bindings::NSEC_PER_USEC as i64; /// The number of nanoseconds per millisecond.pub const NSEC_PER_MSEC: i64 = bindings::NSEC_PER_MSEC as i64; /// The number of nanoseconds per second.pub const NSEC_PER_SEC: i64 = bindings::NSEC_PER_SEC as i64; /// The time unit of Linux kernel. One jiffy equals (1/HZ) second.pub type Jiffies = crate::ffi::c_ulong; /// The millisecond time unit.pub type Msecs = crate::ffi::c_uint; /// Converts milliseconds to jiffies.#[inline]pub fn msecs_to_jiffies(msecs: Msecs) -> Jiffies { // SAFETY: The `__msecs_to_jiffies` function is always safe to call no // matter what the argument is. unsafe { bindings::__msecs_to_jiffies(msecs) }} /// Trait for clock sources.////// Selection of the clock source depends on the use case. In some cases the usage of a/// particular clock is mandatory, e.g. in network protocols, filesystems. In other/// cases the user of the clock has to decide which clock is best suited for the/// purpose. In most scenarios clock [`Monotonic`] is the best choice as it/// provides a accurate monotonic notion of time (leap second smearing ignored).pub trait ClockSource { /// The kernel clock ID associated with this clock source. /// /// This constant corresponds to the C side `clockid_t` value. const ID: bindings::clockid_t; /// Get the current time from the clock source. /// /// The function must return a value in the range from 0 to `KTIME_MAX`. fn ktime_get() -> bindings::ktime_t;} /// A monotonically increasing clock.////// A nonsettable system-wide clock that represents monotonic time since as/// described by POSIX, "some unspecified point in the past". On Linux, that/// point corresponds to the number of seconds that the system has been/// running since it was booted.////// The CLOCK_MONOTONIC clock is not affected by discontinuous jumps in the/// CLOCK_REAL (e.g., if the system administrator manually changes the/// clock), but is affected by frequency adjustments. This clock does not/// count time that the system is suspended.pub struct Monotonic; impl ClockSource for Monotonic { const ID: bindings::clockid_t = bindings::CLOCK_MONOTONIC as bindings::clockid_t; fn ktime_get() -> bindings::ktime_t { // SAFETY: It is always safe to call `ktime_get()` outside of NMI context. unsafe { bindings::ktime_get() } }} /// A settable system-wide clock that measures real (i.e., wall-clock) time.////// Setting this clock requires appropriate privileges. This clock is/// affected by discontinuous jumps in the system time (e.g., if the system/// administrator manually changes the clock), and by frequency adjustments/// performed by NTP and similar applications via adjtime(3), adjtimex(2),/// clock_adjtime(2), and ntp_adjtime(3). This clock normally counts the/// number of seconds since 1970-01-01 00:00:00 Coordinated Universal Time/// (UTC) except that it ignores leap seconds; near a leap second it may be/// adjusted by leap second smearing to stay roughly in sync with UTC. Leap/// second smearing applies frequency adjustments to the clock to speed up/// or slow down the clock to account for the leap second without/// discontinuities in the clock. If leap second smearing is not applied,/// the clock will experience discontinuity around leap second adjustment.pub struct RealTime; impl ClockSource for RealTime { const ID: bindings::clockid_t = bindings::CLOCK_REALTIME as bindings::clockid_t; fn ktime_get() -> bindings::ktime_t { // SAFETY: It is always safe to call `ktime_get_real()` outside of NMI context. unsafe { bindings::ktime_get_real() } }} /// A monotonic that ticks while system is suspended.////// A nonsettable system-wide clock that is identical to CLOCK_MONOTONIC,/// except that it also includes any time that the system is suspended. This/// allows applications to get a suspend-aware monotonic clock without/// having to deal with the complications of CLOCK_REALTIME, which may have/// discontinuities if the time is changed using settimeofday(2) or similar.pub struct BootTime; impl ClockSource for BootTime { const ID: bindings::clockid_t = bindings::CLOCK_BOOTTIME as bindings::clockid_t; fn ktime_get() -> bindings::ktime_t { // SAFETY: It is always safe to call `ktime_get_boottime()` outside of NMI context. unsafe { bindings::ktime_get_boottime() } }} /// International Atomic Time.////// A system-wide clock derived from wall-clock time but counting leap seconds.////// This clock is coupled to CLOCK_REALTIME and will be set when CLOCK_REALTIME is/// set, or when the offset to CLOCK_REALTIME is changed via adjtimex(2). This/// usually happens during boot and **should** not happen during normal operations./// However, if NTP or another application adjusts CLOCK_REALTIME by leap second/// smearing, this clock will not be precise during leap second smearing.////// The acronym TAI refers to International Atomic Time.pub struct Tai; impl ClockSource for Tai { const ID: bindings::clockid_t = bindings::CLOCK_TAI as bindings::clockid_t; fn ktime_get() -> bindings::ktime_t { // SAFETY: It is always safe to call `ktime_get_tai()` outside of NMI context. unsafe { bindings::ktime_get_clocktai() } }} /// A specific point in time.////// # Invariants////// The `inner` value is in the range from 0 to `KTIME_MAX`.#[repr(transparent)]#[derive(PartialEq, PartialOrd, Eq, Ord)]pub struct Instant<C: ClockSource> { inner: bindings::ktime_t, _c: PhantomData<C>,} impl<C: ClockSource> Clone for Instant<C> { fn clone(&self) -> Self { *self }} impl<C: ClockSource> Copy for Instant<C> {} impl<C: ClockSource> Instant<C> { /// Get the current time from the clock source. #[inline] pub fn now() -> Self { // INVARIANT: The `ClockSource::ktime_get()` function returns a value in the range // from 0 to `KTIME_MAX`. Self { inner: C::ktime_get(), _c: PhantomData, } } /// Return the amount of time elapsed since the [`Instant`]. #[inline] pub fn elapsed(&self) -> Delta { Self::now() - *self } #[inline] pub(crate) fn as_nanos(&self) -> i64 { self.inner } /// Create an [`Instant`] from a `ktime_t` without checking if it is non-negative. /// /// # Panics /// /// On debug builds, this function will panic if `ktime` is not in the range from 0 to /// `KTIME_MAX`. /// /// # Safety /// /// The caller promises that `ktime` is in the range from 0 to `KTIME_MAX`. #[inline] pub(crate) unsafe fn from_ktime(ktime: bindings::ktime_t) -> Self { debug_assert!(ktime >= 0); // INVARIANT: Our safety contract ensures that `ktime` is in the range from 0 to // `KTIME_MAX`. Self { inner: ktime, _c: PhantomData, } }} impl<C: ClockSource> ops::Sub for Instant<C> { type Output = Delta; // By the type invariant, it never overflows. #[inline] fn sub(self, other: Instant<C>) -> Delta { Delta { nanos: self.inner - other.inner, } }} impl<T: ClockSource> ops::Add<Delta> for Instant<T> { type Output = Self; #[inline] fn add(self, rhs: Delta) -> Self::Output { // INVARIANT: With arithmetic over/underflow checks enabled, this will panic if we overflow // (e.g. go above `KTIME_MAX`) let res = self.inner + rhs.nanos; // INVARIANT: With overflow checks enabled, we verify here that the value is >= 0 #[cfg(CONFIG_RUST_OVERFLOW_CHECKS)] assert!(res >= 0); Self { inner: res, _c: PhantomData, } }} impl<T: ClockSource> ops::Sub<Delta> for Instant<T> { type Output = Self; #[inline] fn sub(self, rhs: Delta) -> Self::Output { // INVARIANT: With arithmetic over/underflow checks enabled, this will panic if we overflow // (e.g. go above `KTIME_MAX`) let res = self.inner - rhs.nanos; // INVARIANT: With overflow checks enabled, we verify here that the value is >= 0 #[cfg(CONFIG_RUST_OVERFLOW_CHECKS)] assert!(res >= 0); Self { inner: res, _c: PhantomData, } }} /// A span of time.////// This struct represents a span of time, with its value stored as nanoseconds./// The value can represent any valid i64 value, including negative, zero, and/// positive numbers.#[derive(Copy, Clone, PartialEq, PartialOrd, Eq, Ord, Debug)]pub struct Delta { nanos: i64,} impl ops::Add for Delta { type Output = Self; #[inline] fn add(self, rhs: Self) -> Self { Self { nanos: self.nanos + rhs.nanos, } }} impl ops::AddAssign for Delta { #[inline] fn add_assign(&mut self, rhs: Self) { self.nanos += rhs.nanos; }} impl ops::Sub for Delta { type Output = Self; #[inline] fn sub(self, rhs: Self) -> Self::Output { Self { nanos: self.nanos - rhs.nanos, } }} impl ops::SubAssign for Delta { #[inline] fn sub_assign(&mut self, rhs: Self) { self.nanos -= rhs.nanos; }} impl ops::Mul<i64> for Delta { type Output = Self; #[inline] fn mul(self, rhs: i64) -> Self::Output { Self { nanos: self.nanos * rhs, } }} impl ops::MulAssign<i64> for Delta { #[inline] fn mul_assign(&mut self, rhs: i64) { self.nanos *= rhs; }} impl ops::Div for Delta { type Output = i64; #[inline] fn div(self, rhs: Self) -> Self::Output { #[cfg(CONFIG_64BIT)] { self.nanos / rhs.nanos } #[cfg(not(CONFIG_64BIT))] { // SAFETY: This function is always safe to call regardless of the input values unsafe { bindings::div64_s64(self.nanos, rhs.nanos) } } }} impl Delta { /// A span of time equal to zero. pub const ZERO: Self = Self { nanos: 0 }; /// Create a new [`Delta`] from a number of microseconds. /// /// The `micros` can range from -9_223_372_036_854_775 to 9_223_372_036_854_775. /// If `micros` is outside this range, `i64::MIN` is used for negative values, /// and `i64::MAX` is used for positive values due to saturation. #[inline] pub const fn from_micros(micros: i64) -> Self { Self { nanos: micros.saturating_mul(NSEC_PER_USEC), } } /// Create a new [`Delta`] from a number of milliseconds. /// /// The `millis` can range from -9_223_372_036_854 to 9_223_372_036_854. /// If `millis` is outside this range, `i64::MIN` is used for negative values, /// and `i64::MAX` is used for positive values due to saturation. #[inline] pub const fn from_millis(millis: i64) -> Self { Self { nanos: millis.saturating_mul(NSEC_PER_MSEC), } } /// Create a new [`Delta`] from a number of seconds. /// /// The `secs` can range from -9_223_372_036 to 9_223_372_036. /// If `secs` is outside this range, `i64::MIN` is used for negative values, /// and `i64::MAX` is used for positive values due to saturation. #[inline] pub const fn from_secs(secs: i64) -> Self { Self { nanos: secs.saturating_mul(NSEC_PER_SEC), } } /// Return `true` if the [`Delta`] spans no time. #[inline] pub fn is_zero(self) -> bool { self.as_nanos() == 0 } /// Return `true` if the [`Delta`] spans a negative amount of time. #[inline] pub fn is_negative(self) -> bool { self.as_nanos() < 0 } /// Return the number of nanoseconds in the [`Delta`]. #[inline] pub const fn as_nanos(self) -> i64 { self.nanos } /// Return the smallest number of microseconds greater than or equal /// to the value in the [`Delta`]. #[inline] pub fn as_micros_ceil(self) -> i64 { #[cfg(CONFIG_64BIT)] { self.as_nanos().saturating_add(NSEC_PER_USEC - 1) / NSEC_PER_USEC } #[cfg(not(CONFIG_64BIT))] // SAFETY: It is always safe to call `ktime_to_us()` with any value. unsafe { bindings::ktime_to_us(self.as_nanos().saturating_add(NSEC_PER_USEC - 1)) } } /// Return the number of milliseconds in the [`Delta`]. #[inline] pub fn as_millis(self) -> i64 { #[cfg(CONFIG_64BIT)] { self.as_nanos() / NSEC_PER_MSEC } #[cfg(not(CONFIG_64BIT))] // SAFETY: It is always safe to call `ktime_to_ms()` with any value. unsafe { bindings::ktime_to_ms(self.as_nanos()) } } /// Return `self % dividend` where `dividend` is in nanoseconds. /// /// The kernel doesn't have any emulation for `s64 % s64` on 32 bit platforms, so this is /// limited to 32 bit dividends. #[inline] pub fn rem_nanos(self, dividend: i32) -> Self { #[cfg(CONFIG_64BIT)] { Self { nanos: self.as_nanos() % i64::from(dividend), } } #[cfg(not(CONFIG_64BIT))] { let mut rem = 0; // SAFETY: `rem` is in the stack, so we can always provide a valid pointer to it. unsafe { bindings::div_s64_rem(self.as_nanos(), dividend, &mut rem) }; Self { nanos: i64::from(rem), } } }}
// SPDX-License-Identifier: GPL-2.0
//! Time related primitives.
//!
//! This module contains the kernel APIs related to time and timers that
//! have been ported or wrapped for usage by Rust code in the kernel.
//!
//! There are two types in this module:
//!
//! - The [`Instant`] type represents a specific point in time.
//! - The [`Delta`] type represents a span of time.
//!
//! Note that the C side uses `ktime_t` type to represent both. However, timestamp
//! and timedelta are different. To avoid confusion, we use two different types.
//!
//! A [`Instant`] object can be created by calling the [`Instant::now()`] function.
//! It represents a point in time at which the object was created.
//! By calling the [`Instant::elapsed()`] method, a [`Delta`] object representing
//! the elapsed time can be created. The [`Delta`] object can also be created
//! by subtracting two [`Instant`] objects.
//!
//! A [`Delta`] type supports methods to retrieve the duration in various units.
//!
//! C header: [`include/linux/jiffies.h`](srctree/include/linux/jiffies.h).
//! C header: [`include/linux/ktime.h`](srctree/include/linux/ktime.h).
use core::marker::PhantomData;
use core::ops;
pub mod delay;
pub mod hrtimer;
/// The number of nanoseconds per microsecond.
pub const NSEC_PER_USEC: i64 = bindings::NSEC_PER_USEC as i64;
/// The number of nanoseconds per millisecond.
pub const NSEC_PER_MSEC: i64 = bindings::NSEC_PER_MSEC as i64;
/// The number of nanoseconds per second.
pub const NSEC_PER_SEC: i64 = bindings::NSEC_PER_SEC as i64;
/// The time unit of Linux kernel. One jiffy equals (1/HZ) second.
pub type Jiffies = crate::ffi::c_ulong;
/// The millisecond time unit.
pub type Msecs = crate::ffi::c_uint;
/// Converts milliseconds to jiffies.
#[inline]
pub fn msecs_to_jiffies(msecs: Msecs) -> Jiffies {
// SAFETY: The `__msecs_to_jiffies` function is always safe to call no
// matter what the argument is.
unsafe { bindings::__msecs_to_jiffies(msecs) }
}
/// Trait for clock sources.
///
/// Selection of the clock source depends on the use case. In some cases the usage of a
/// particular clock is mandatory, e.g. in network protocols, filesystems. In other
/// cases the user of the clock has to decide which clock is best suited for the
/// purpose. In most scenarios clock [`Monotonic`] is the best choice as it
/// provides a accurate monotonic notion of time (leap second smearing ignored).
pub trait ClockSource {
/// The kernel clock ID associated with this clock source.
///
/// This constant corresponds to the C side `clockid_t` value.
const ID: bindings::clockid_t;
/// Get the current time from the clock source.
///
/// The function must return a value in the range from 0 to `KTIME_MAX`.
fn ktime_get() -> bindings::ktime_t;
}
/// A monotonically increasing clock.
///
/// A nonsettable system-wide clock that represents monotonic time since as
/// described by POSIX, "some unspecified point in the past". On Linux, that
/// point corresponds to the number of seconds that the system has been
/// running since it was booted.
///
/// The CLOCK_MONOTONIC clock is not affected by discontinuous jumps in the
/// CLOCK_REAL (e.g., if the system administrator manually changes the
/// clock), but is affected by frequency adjustments. This clock does not
/// count time that the system is suspended.
pub struct Monotonic;
impl ClockSource for Monotonic {
const ID: bindings::clockid_t = bindings::CLOCK_MONOTONIC as bindings::clockid_t;
fn ktime_get() -> bindings::ktime_t {
// SAFETY: It is always safe to call `ktime_get()` outside of NMI context.
unsafe { bindings::ktime_get() }
}
}
/// A settable system-wide clock that measures real (i.e., wall-clock) time.
///
/// Setting this clock requires appropriate privileges. This clock is
/// affected by discontinuous jumps in the system time (e.g., if the system
/// administrator manually changes the clock), and by frequency adjustments
/// performed by NTP and similar applications via adjtime(3), adjtimex(2),
/// clock_adjtime(2), and ntp_adjtime(3). This clock normally counts the
/// number of seconds since 1970-01-01 00:00:00 Coordinated Universal Time
/// (UTC) except that it ignores leap seconds; near a leap second it may be
/// adjusted by leap second smearing to stay roughly in sync with UTC. Leap
/// second smearing applies frequency adjustments to the clock to speed up
/// or slow down the clock to account for the leap second without
/// discontinuities in the clock. If leap second smearing is not applied,
/// the clock will experience discontinuity around leap second adjustment.
pub struct RealTime;
impl ClockSource for RealTime {
const ID: bindings::clockid_t = bindings::CLOCK_REALTIME as bindings::clockid_t;
fn ktime_get() -> bindings::ktime_t {
// SAFETY: It is always safe to call `ktime_get_real()` outside of NMI context.
unsafe { bindings::ktime_get_real() }
}
}
/// A monotonic that ticks while system is suspended.
///
/// A nonsettable system-wide clock that is identical to CLOCK_MONOTONIC,
/// except that it also includes any time that the system is suspended. This
/// allows applications to get a suspend-aware monotonic clock without
/// having to deal with the complications of CLOCK_REALTIME, which may have
/// discontinuities if the time is changed using settimeofday(2) or similar.
pub struct BootTime;
impl ClockSource for BootTime {
const ID: bindings::clockid_t = bindings::CLOCK_BOOTTIME as bindings::clockid_t;
fn ktime_get() -> bindings::ktime_t {
// SAFETY: It is always safe to call `ktime_get_boottime()` outside of NMI context.
unsafe { bindings::ktime_get_boottime() }
}
}
/// International Atomic Time.
///
/// A system-wide clock derived from wall-clock time but counting leap seconds.
///
/// This clock is coupled to CLOCK_REALTIME and will be set when CLOCK_REALTIME is
/// set, or when the offset to CLOCK_REALTIME is changed via adjtimex(2). This
/// usually happens during boot and **should** not happen during normal operations.
/// However, if NTP or another application adjusts CLOCK_REALTIME by leap second
/// smearing, this clock will not be precise during leap second smearing.
///
/// The acronym TAI refers to International Atomic Time.
pub struct Tai;
impl ClockSource for Tai {
const ID: bindings::clockid_t = bindings::CLOCK_TAI as bindings::clockid_t;
fn ktime_get() -> bindings::ktime_t {
// SAFETY: It is always safe to call `ktime_get_tai()` outside of NMI context.
unsafe { bindings::ktime_get_clocktai() }
}
}
/// A specific point in time.
///
/// # Invariants
///
/// The `inner` value is in the range from 0 to `KTIME_MAX`.
#[repr(transparent)]
#[derive(PartialEq, PartialOrd, Eq, Ord)]
pub struct Instant<C: ClockSource> {
inner: bindings::ktime_t,
_c: PhantomData<C>,
}
impl<C: ClockSource> Clone for Instant<C> {
fn clone(&self) -> Self {
*self
}
}
impl<C: ClockSource> Copy for Instant<C> {}
impl<C: ClockSource> Instant<C> {
/// Get the current time from the clock source.
#[inline]
pub fn now() -> Self {
// INVARIANT: The `ClockSource::ktime_get()` function returns a value in the range
// from 0 to `KTIME_MAX`.
Self {
inner: C::ktime_get(),
_c: PhantomData,
}
}
/// Return the amount of time elapsed since the [`Instant`].
#[inline]
pub fn elapsed(&self) -> Delta {
Self::now() - *self
}
#[inline]
pub(crate) fn as_nanos(&self) -> i64 {
self.inner
}
/// Create an [`Instant`] from a `ktime_t` without checking if it is non-negative.
///
/// # Panics
///
/// On debug builds, this function will panic if `ktime` is not in the range from 0 to
/// `KTIME_MAX`.
///
/// # Safety
///
/// The caller promises that `ktime` is in the range from 0 to `KTIME_MAX`.
#[inline]
pub(crate) unsafe fn from_ktime(ktime: bindings::ktime_t) -> Self {
debug_assert!(ktime >= 0);
// INVARIANT: Our safety contract ensures that `ktime` is in the range from 0 to
// `KTIME_MAX`.
Self {
inner: ktime,
_c: PhantomData,
}
}
}
impl<C: ClockSource> ops::Sub for Instant<C> {
type Output = Delta;
// By the type invariant, it never overflows.
#[inline]
fn sub(self, other: Instant<C>) -> Delta {
Delta {
nanos: self.inner - other.inner,
}
}
}
impl<T: ClockSource> ops::Add<Delta> for Instant<T> {
type Output = Self;
#[inline]
fn add(self, rhs: Delta) -> Self::Output {
// INVARIANT: With arithmetic over/underflow checks enabled, this will panic if we overflow
// (e.g. go above `KTIME_MAX`)
let res = self.inner + rhs.nanos;
// INVARIANT: With overflow checks enabled, we verify here that the value is >= 0
#[cfg(CONFIG_RUST_OVERFLOW_CHECKS)]
assert!(res >= 0);
Self {
inner: res,
_c: PhantomData,
}
}
}
impl<T: ClockSource> ops::Sub<Delta> for Instant<T> {
type Output = Self;
#[inline]
fn sub(self, rhs: Delta) -> Self::Output {
// INVARIANT: With arithmetic over/underflow checks enabled, this will panic if we overflow
// (e.g. go above `KTIME_MAX`)
let res = self.inner - rhs.nanos;
// INVARIANT: With overflow checks enabled, we verify here that the value is >= 0
#[cfg(CONFIG_RUST_OVERFLOW_CHECKS)]
assert!(res >= 0);
Self {
inner: res,
_c: PhantomData,
}
}
}
/// A span of time.
///
/// This struct represents a span of time, with its value stored as nanoseconds.
/// The value can represent any valid i64 value, including negative, zero, and
/// positive numbers.
#[derive(Copy, Clone, PartialEq, PartialOrd, Eq, Ord, Debug)]
pub struct Delta {
nanos: i64,
}
impl ops::Add for Delta {
type Output = Self;
#[inline]
fn add(self, rhs: Self) -> Self {
Self {
nanos: self.nanos + rhs.nanos,
}
}
}
impl ops::AddAssign for Delta {
#[inline]
fn add_assign(&mut self, rhs: Self) {
self.nanos += rhs.nanos;
}
}
impl ops::Sub for Delta {
type Output = Self;
#[inline]
fn sub(self, rhs: Self) -> Self::Output {
Self {
nanos: self.nanos - rhs.nanos,
}
}
}
impl ops::SubAssign for Delta {
#[inline]
fn sub_assign(&mut self, rhs: Self) {
self.nanos -= rhs.nanos;
}
}
impl ops::Mul<i64> for Delta {
type Output = Self;
#[inline]
fn mul(self, rhs: i64) -> Self::Output {
Self {
nanos: self.nanos * rhs,
}
}
}
impl ops::MulAssign<i64> for Delta {
#[inline]
fn mul_assign(&mut self, rhs: i64) {
self.nanos *= rhs;
}
}
impl ops::Div for Delta {
type Output = i64;
#[inline]
fn div(self, rhs: Self) -> Self::Output {
#[cfg(CONFIG_64BIT)]
{
self.nanos / rhs.nanos
}
#[cfg(not(CONFIG_64BIT))]
{
// SAFETY: This function is always safe to call regardless of the input values
unsafe { bindings::div64_s64(self.nanos, rhs.nanos) }
}
}
}
impl Delta {
/// A span of time equal to zero.
pub const ZERO: Self = Self { nanos: 0 };
/// Create a new [`Delta`] from a number of microseconds.
///
/// The `micros` can range from -9_223_372_036_854_775 to 9_223_372_036_854_775.
/// If `micros` is outside this range, `i64::MIN` is used for negative values,
/// and `i64::MAX` is used for positive values due to saturation.
#[inline]
pub const fn from_micros(micros: i64) -> Self {
Self {
nanos: micros.saturating_mul(NSEC_PER_USEC),
}
}
/// Create a new [`Delta`] from a number of milliseconds.
///
/// The `millis` can range from -9_223_372_036_854 to 9_223_372_036_854.
/// If `millis` is outside this range, `i64::MIN` is used for negative values,
/// and `i64::MAX` is used for positive values due to saturation.
#[inline]
pub const fn from_millis(millis: i64) -> Self {
Self {
nanos: millis.saturating_mul(NSEC_PER_MSEC),
}
}
/// Create a new [`Delta`] from a number of seconds.
///
/// The `secs` can range from -9_223_372_036 to 9_223_372_036.
/// If `secs` is outside this range, `i64::MIN` is used for negative values,
/// and `i64::MAX` is used for positive values due to saturation.
#[inline]
pub const fn from_secs(secs: i64) -> Self {
Self {
nanos: secs.saturating_mul(NSEC_PER_SEC),
}
}
/// Return `true` if the [`Delta`] spans no time.
#[inline]
pub fn is_zero(self) -> bool {
self.as_nanos() == 0
}
/// Return `true` if the [`Delta`] spans a negative amount of time.
#[inline]
pub fn is_negative(self) -> bool {
self.as_nanos() < 0
}
/// Return the number of nanoseconds in the [`Delta`].
#[inline]
pub const fn as_nanos(self) -> i64 {
self.nanos
}
/// Return the smallest number of microseconds greater than or equal
/// to the value in the [`Delta`].
#[inline]
pub fn as_micros_ceil(self) -> i64 {
#[cfg(CONFIG_64BIT)]
{
self.as_nanos().saturating_add(NSEC_PER_USEC - 1) / NSEC_PER_USEC
}
#[cfg(not(CONFIG_64BIT))]
// SAFETY: It is always safe to call `ktime_to_us()` with any value.
unsafe {
bindings::ktime_to_us(self.as_nanos().saturating_add(NSEC_PER_USEC - 1))
}
}
/// Return the number of milliseconds in the [`Delta`].
#[inline]
pub fn as_millis(self) -> i64 {
#[cfg(CONFIG_64BIT)]
{
self.as_nanos() / NSEC_PER_MSEC
}
#[cfg(not(CONFIG_64BIT))]
// SAFETY: It is always safe to call `ktime_to_ms()` with any value.
unsafe {
bindings::ktime_to_ms(self.as_nanos())
}
}
/// Return `self % dividend` where `dividend` is in nanoseconds.
///
/// The kernel doesn't have any emulation for `s64 % s64` on 32 bit platforms, so this is
/// limited to 32 bit dividends.
#[inline]
pub fn rem_nanos(self, dividend: i32) -> Self {
#[cfg(CONFIG_64BIT)]
{
Self {
nanos: self.as_nanos() % i64::from(dividend),
}
}
#[cfg(not(CONFIG_64BIT))]
{
let mut rem = 0;
// SAFETY: `rem` is in the stack, so we can always provide a valid pointer to it.
unsafe { bindings::div_s64_rem(self.as_nanos(), dividend, &mut rem) };
Self {
nanos: i64::from(rem),
}
}
}
}