| use crate::fmt; |
| use crate::time::Duration; |
| |
| pub use self::inner::Instant; |
| |
| const NSEC_PER_SEC: u64 = 1_000_000_000; |
| pub const UNIX_EPOCH: SystemTime = SystemTime { t: Timespec::zero() }; |
| |
| #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)] |
| #[repr(transparent)] |
| #[rustc_layout_scalar_valid_range_start(0)] |
| #[rustc_layout_scalar_valid_range_end(999_999_999)] |
| struct Nanoseconds(u32); |
| |
| #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)] |
| pub struct SystemTime { |
| pub(in crate::sys::unix) t: Timespec, |
| } |
| |
| #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)] |
| pub(in crate::sys::unix) struct Timespec { |
| tv_sec: i64, |
| tv_nsec: Nanoseconds, |
| } |
| |
| impl SystemTime { |
| #[cfg_attr(target_os = "horizon", allow(unused))] |
| pub fn new(tv_sec: i64, tv_nsec: i64) -> SystemTime { |
| SystemTime { t: Timespec::new(tv_sec, tv_nsec) } |
| } |
| |
| pub fn sub_time(&self, other: &SystemTime) -> Result<Duration, Duration> { |
| self.t.sub_timespec(&other.t) |
| } |
| |
| pub fn checked_add_duration(&self, other: &Duration) -> Option<SystemTime> { |
| Some(SystemTime { t: self.t.checked_add_duration(other)? }) |
| } |
| |
| pub fn checked_sub_duration(&self, other: &Duration) -> Option<SystemTime> { |
| Some(SystemTime { t: self.t.checked_sub_duration(other)? }) |
| } |
| } |
| |
| impl From<libc::timespec> for SystemTime { |
| fn from(t: libc::timespec) -> SystemTime { |
| SystemTime { t: Timespec::from(t) } |
| } |
| } |
| |
| impl fmt::Debug for SystemTime { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| f.debug_struct("SystemTime") |
| .field("tv_sec", &self.t.tv_sec) |
| .field("tv_nsec", &self.t.tv_nsec.0) |
| .finish() |
| } |
| } |
| |
| impl Timespec { |
| pub const fn zero() -> Timespec { |
| Timespec::new(0, 0) |
| } |
| |
| const fn new(tv_sec: i64, tv_nsec: i64) -> Timespec { |
| assert!(tv_nsec >= 0 && tv_nsec < NSEC_PER_SEC as i64); |
| // SAFETY: The assert above checks tv_nsec is within the valid range |
| Timespec { tv_sec, tv_nsec: unsafe { Nanoseconds(tv_nsec as u32) } } |
| } |
| |
| pub fn sub_timespec(&self, other: &Timespec) -> Result<Duration, Duration> { |
| if self >= other { |
| // NOTE(eddyb) two aspects of this `if`-`else` are required for LLVM |
| // to optimize it into a branchless form (see also #75545): |
| // |
| // 1. `self.tv_sec - other.tv_sec` shows up as a common expression |
| // in both branches, i.e. the `else` must have its `- 1` |
| // subtraction after the common one, not interleaved with it |
| // (it used to be `self.tv_sec - 1 - other.tv_sec`) |
| // |
| // 2. the `Duration::new` call (or any other additional complexity) |
| // is outside of the `if`-`else`, not duplicated in both branches |
| // |
| // Ideally this code could be rearranged such that it more |
| // directly expresses the lower-cost behavior we want from it. |
| let (secs, nsec) = if self.tv_nsec.0 >= other.tv_nsec.0 { |
| ((self.tv_sec - other.tv_sec) as u64, self.tv_nsec.0 - other.tv_nsec.0) |
| } else { |
| ( |
| (self.tv_sec - other.tv_sec - 1) as u64, |
| self.tv_nsec.0 + (NSEC_PER_SEC as u32) - other.tv_nsec.0, |
| ) |
| }; |
| |
| Ok(Duration::new(secs, nsec)) |
| } else { |
| match other.sub_timespec(self) { |
| Ok(d) => Err(d), |
| Err(d) => Ok(d), |
| } |
| } |
| } |
| |
| pub fn checked_add_duration(&self, other: &Duration) -> Option<Timespec> { |
| let mut secs = other |
| .as_secs() |
| .try_into() // <- target type would be `i64` |
| .ok() |
| .and_then(|secs| self.tv_sec.checked_add(secs))?; |
| |
| // Nano calculations can't overflow because nanos are <1B which fit |
| // in a u32. |
| let mut nsec = other.subsec_nanos() + self.tv_nsec.0; |
| if nsec >= NSEC_PER_SEC as u32 { |
| nsec -= NSEC_PER_SEC as u32; |
| secs = secs.checked_add(1)?; |
| } |
| Some(Timespec::new(secs, nsec as i64)) |
| } |
| |
| pub fn checked_sub_duration(&self, other: &Duration) -> Option<Timespec> { |
| let mut secs = other |
| .as_secs() |
| .try_into() // <- target type would be `i64` |
| .ok() |
| .and_then(|secs| self.tv_sec.checked_sub(secs))?; |
| |
| // Similar to above, nanos can't overflow. |
| let mut nsec = self.tv_nsec.0 as i32 - other.subsec_nanos() as i32; |
| if nsec < 0 { |
| nsec += NSEC_PER_SEC as i32; |
| secs = secs.checked_sub(1)?; |
| } |
| Some(Timespec::new(secs, nsec as i64)) |
| } |
| |
| #[allow(dead_code)] |
| pub fn to_timespec(&self) -> Option<libc::timespec> { |
| Some(libc::timespec { |
| tv_sec: self.tv_sec.try_into().ok()?, |
| tv_nsec: self.tv_nsec.0.try_into().ok()?, |
| }) |
| } |
| } |
| |
| impl From<libc::timespec> for Timespec { |
| fn from(t: libc::timespec) -> Timespec { |
| Timespec::new(t.tv_sec as i64, t.tv_nsec as i64) |
| } |
| } |
| |
| #[cfg(any( |
| all(target_os = "macos", any(not(target_arch = "aarch64"))), |
| target_os = "ios", |
| target_os = "watchos" |
| ))] |
| mod inner { |
| use crate::sync::atomic::{AtomicU64, Ordering}; |
| use crate::sys::cvt; |
| use crate::sys_common::mul_div_u64; |
| use crate::time::Duration; |
| |
| use super::{SystemTime, Timespec, NSEC_PER_SEC}; |
| |
| #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Debug, Hash)] |
| pub struct Instant { |
| t: u64, |
| } |
| |
| #[repr(C)] |
| #[derive(Copy, Clone)] |
| struct mach_timebase_info { |
| numer: u32, |
| denom: u32, |
| } |
| type mach_timebase_info_t = *mut mach_timebase_info; |
| type kern_return_t = libc::c_int; |
| |
| impl Instant { |
| pub fn now() -> Instant { |
| extern "C" { |
| fn mach_absolute_time() -> u64; |
| } |
| Instant { t: unsafe { mach_absolute_time() } } |
| } |
| |
| pub fn checked_sub_instant(&self, other: &Instant) -> Option<Duration> { |
| let diff = self.t.checked_sub(other.t)?; |
| let info = info(); |
| let nanos = mul_div_u64(diff, info.numer as u64, info.denom as u64); |
| Some(Duration::new(nanos / NSEC_PER_SEC, (nanos % NSEC_PER_SEC) as u32)) |
| } |
| |
| pub fn checked_add_duration(&self, other: &Duration) -> Option<Instant> { |
| Some(Instant { t: self.t.checked_add(checked_dur2intervals(other)?)? }) |
| } |
| |
| pub fn checked_sub_duration(&self, other: &Duration) -> Option<Instant> { |
| Some(Instant { t: self.t.checked_sub(checked_dur2intervals(other)?)? }) |
| } |
| } |
| |
| impl SystemTime { |
| pub fn now() -> SystemTime { |
| use crate::ptr; |
| |
| let mut s = libc::timeval { tv_sec: 0, tv_usec: 0 }; |
| cvt(unsafe { libc::gettimeofday(&mut s, ptr::null_mut()) }).unwrap(); |
| return SystemTime::from(s); |
| } |
| } |
| |
| impl From<libc::timeval> for Timespec { |
| fn from(t: libc::timeval) -> Timespec { |
| Timespec::new(t.tv_sec as i64, 1000 * t.tv_usec as i64) |
| } |
| } |
| |
| impl From<libc::timeval> for SystemTime { |
| fn from(t: libc::timeval) -> SystemTime { |
| SystemTime { t: Timespec::from(t) } |
| } |
| } |
| |
| fn checked_dur2intervals(dur: &Duration) -> Option<u64> { |
| let nanos = |
| dur.as_secs().checked_mul(NSEC_PER_SEC)?.checked_add(dur.subsec_nanos() as u64)?; |
| let info = info(); |
| Some(mul_div_u64(nanos, info.denom as u64, info.numer as u64)) |
| } |
| |
| fn info() -> mach_timebase_info { |
| // INFO_BITS conceptually is an `Option<mach_timebase_info>`. We can do |
| // this in 64 bits because we know 0 is never a valid value for the |
| // `denom` field. |
| // |
| // Encoding this as a single `AtomicU64` allows us to use `Relaxed` |
| // operations, as we are only interested in the effects on a single |
| // memory location. |
| static INFO_BITS: AtomicU64 = AtomicU64::new(0); |
| |
| // If a previous thread has initialized `INFO_BITS`, use it. |
| let info_bits = INFO_BITS.load(Ordering::Relaxed); |
| if info_bits != 0 { |
| return info_from_bits(info_bits); |
| } |
| |
| // ... otherwise learn for ourselves ... |
| extern "C" { |
| fn mach_timebase_info(info: mach_timebase_info_t) -> kern_return_t; |
| } |
| |
| let mut info = info_from_bits(0); |
| unsafe { |
| mach_timebase_info(&mut info); |
| } |
| INFO_BITS.store(info_to_bits(info), Ordering::Relaxed); |
| info |
| } |
| |
| #[inline] |
| fn info_to_bits(info: mach_timebase_info) -> u64 { |
| ((info.denom as u64) << 32) | (info.numer as u64) |
| } |
| |
| #[inline] |
| fn info_from_bits(bits: u64) -> mach_timebase_info { |
| mach_timebase_info { numer: bits as u32, denom: (bits >> 32) as u32 } |
| } |
| } |
| |
| #[cfg(not(any( |
| all(target_os = "macos", any(not(target_arch = "aarch64"))), |
| target_os = "ios", |
| target_os = "watchos" |
| )))] |
| mod inner { |
| use crate::fmt; |
| use crate::mem::MaybeUninit; |
| use crate::sys::cvt; |
| use crate::time::Duration; |
| |
| use super::{SystemTime, Timespec}; |
| |
| #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)] |
| pub struct Instant { |
| t: Timespec, |
| } |
| |
| impl Instant { |
| pub fn now() -> Instant { |
| #[cfg(target_os = "macos")] |
| const clock_id: libc::clockid_t = libc::CLOCK_UPTIME_RAW; |
| #[cfg(not(target_os = "macos"))] |
| const clock_id: libc::clockid_t = libc::CLOCK_MONOTONIC; |
| Instant { t: Timespec::now(clock_id) } |
| } |
| |
| pub fn checked_sub_instant(&self, other: &Instant) -> Option<Duration> { |
| self.t.sub_timespec(&other.t).ok() |
| } |
| |
| pub fn checked_add_duration(&self, other: &Duration) -> Option<Instant> { |
| Some(Instant { t: self.t.checked_add_duration(other)? }) |
| } |
| |
| pub fn checked_sub_duration(&self, other: &Duration) -> Option<Instant> { |
| Some(Instant { t: self.t.checked_sub_duration(other)? }) |
| } |
| } |
| |
| impl fmt::Debug for Instant { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| f.debug_struct("Instant") |
| .field("tv_sec", &self.t.tv_sec) |
| .field("tv_nsec", &self.t.tv_nsec.0) |
| .finish() |
| } |
| } |
| |
| impl SystemTime { |
| pub fn now() -> SystemTime { |
| SystemTime { t: Timespec::now(libc::CLOCK_REALTIME) } |
| } |
| } |
| |
| impl Timespec { |
| pub fn now(clock: libc::clockid_t) -> Timespec { |
| // Try to use 64-bit time in preparation for Y2038. |
| #[cfg(all(target_os = "linux", target_env = "gnu", target_pointer_width = "32"))] |
| { |
| use crate::sys::weak::weak; |
| |
| // __clock_gettime64 was added to 32-bit arches in glibc 2.34, |
| // and it handles both vDSO calls and ENOSYS fallbacks itself. |
| weak!(fn __clock_gettime64(libc::clockid_t, *mut __timespec64) -> libc::c_int); |
| |
| #[repr(C)] |
| struct __timespec64 { |
| tv_sec: i64, |
| #[cfg(target_endian = "big")] |
| _padding: i32, |
| tv_nsec: i32, |
| #[cfg(target_endian = "little")] |
| _padding: i32, |
| } |
| |
| if let Some(clock_gettime64) = __clock_gettime64.get() { |
| let mut t = MaybeUninit::uninit(); |
| cvt(unsafe { clock_gettime64(clock, t.as_mut_ptr()) }).unwrap(); |
| let t = unsafe { t.assume_init() }; |
| return Timespec::new(t.tv_sec, t.tv_nsec as i64); |
| } |
| } |
| |
| let mut t = MaybeUninit::uninit(); |
| cvt(unsafe { libc::clock_gettime(clock, t.as_mut_ptr()) }).unwrap(); |
| Timespec::from(unsafe { t.assume_init() }) |
| } |
| } |
| } |
