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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
commit698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch)
tree173a775858bd501c378080a10dca74132f05bc50 /library/std/src/sys/unix/time.rs
parentInitial commit. (diff)
downloadrustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz
rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'library/std/src/sys/unix/time.rs')
-rw-r--r--library/std/src/sys/unix/time.rs346
1 files changed, 346 insertions, 0 deletions
diff --git a/library/std/src/sys/unix/time.rs b/library/std/src/sys/unix/time.rs
new file mode 100644
index 000000000..dff973f59
--- /dev/null
+++ b/library/std/src/sys/unix/time.rs
@@ -0,0 +1,346 @@
+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)]
+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: i64,
+}
+
+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)
+ .finish()
+ }
+}
+
+impl Timespec {
+ pub const fn zero() -> Timespec {
+ Timespec { tv_sec: 0, tv_nsec: 0 }
+ }
+
+ fn new(tv_sec: i64, tv_nsec: i64) -> Timespec {
+ Timespec { tv_sec, tv_nsec }
+ }
+
+ 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 >= other.tv_nsec {
+ ((self.tv_sec - other.tv_sec) as u64, (self.tv_nsec - other.tv_nsec) as u32)
+ } else {
+ (
+ (self.tv_sec - other.tv_sec - 1) as u64,
+ self.tv_nsec as u32 + (NSEC_PER_SEC as u32) - other.tv_nsec as u32,
+ )
+ };
+
+ 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 as u32;
+ 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 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.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(target_os = "macos", 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(target_os = "macos", 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 {
+ Instant { t: Timespec::now(libc::CLOCK_MONOTONIC) }
+ }
+
+ 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)
+ .finish()
+ }
+ }
+
+ impl SystemTime {
+ pub fn now() -> SystemTime {
+ SystemTime { t: Timespec::now(libc::CLOCK_REALTIME) }
+ }
+ }
+
+ #[cfg(not(any(target_os = "dragonfly", target_os = "espidf", target_os = "horizon")))]
+ pub type clock_t = libc::c_int;
+ #[cfg(any(target_os = "dragonfly", target_os = "espidf", target_os = "horizon"))]
+ pub type clock_t = libc::c_ulong;
+
+ impl Timespec {
+ pub fn now(clock: clock_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 { tv_sec: t.tv_sec, tv_nsec: 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() })
+ }
+ }
+}