fix: patch coarsetime with portable-atomic for MIPS AtomicU64 support

Cargo.lock

@@ -559,10 +559,9 @@ checksum = "c3e64b0cc0439b12df2fa678eae89a1c56a529fd067a9115f7827f1fffd22b32"
 [[package]]
 name = "coarsetime"
 version = "0.1.37"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e58eb270476aa4fc7843849f8a35063e8743b4dbcdf6dd0f8ea0886980c204c2"
 dependencies = [
  "libc",
+ "portable-atomic",
  "wasix",
  "wasm-bindgen",
 ]

Cargo.toml

@@ -16,3 +16,6 @@ strip = true
 # Artık (incremental) build'i kapat ki optimizasyon tam olsun
 incremental = false
 
+[patch.crates-io]
+coarsetime = { path = "patches/coarsetime" }
+

patches/coarsetime/Cargo.toml

@@ -0,0 +1,30 @@
+[package]
+edition = "2018"
+name = "coarsetime"
+version = "0.1.37"
+description = "Time and duration crate optimized for speed (patched for MIPS)"
+license = "BSD-2-Clause"
+
+[features]
+wasi-abi2 = ["dep:wasi-abi2"]
+
+[lib]
+name = "coarsetime"
+path = "src/lib.rs"
+
+[dependencies]
+portable-atomic = { version = "1", default-features = false, features = ["fallback"] }
+
+[target.'cfg(all(any(target_arch = "wasm32", target_arch = "wasm64"), target_os = "unknown"))'.dependencies.wasm-bindgen]
+version = "0.2"
+
+[target.'cfg(any(target_os = "wasix", target_os = "wasi"))'.dependencies.wasix]
+version = "0.13"
+
+[target.'cfg(not(any(target_os = "wasix", target_os = "wasi")))'.dependencies.libc]
+version = "0.2"
+
+[target.'cfg(target_os = "wasi")'.dependencies.wasi-abi2]
+version = "0.14.7"
+optional = true
+package = "wasi"

patches/coarsetime/src/clock.rs

@@ -0,0 +1,90 @@
+#[cfg(not(all(
+    any(target_arch = "wasm32", target_arch = "wasm64"),
+    target_os = "unknown"
+)))]
+use std::time;
+
+use portable_atomic::{AtomicU64, Ordering};
+
+use super::Duration;
+
+static RECENT: AtomicU64 = AtomicU64::new(0);
+
+#[cfg(all(
+    any(target_arch = "wasm32", target_arch = "wasm64"),
+    target_os = "unknown"
+))]
+mod js_imports {
+    use wasm_bindgen::prelude::*;
+
+    #[wasm_bindgen]
+    extern "C" {
+        pub type Date;
+
+        #[wasm_bindgen(static_method_of = Date)]
+        pub fn now() -> f64;
+    }
+}
+
+/// System time
+#[derive(Debug)]
+pub struct Clock;
+
+/// Alias for `Duration`.
+pub type UnixTimeStamp = Duration;
+
+impl Clock {
+    /// Returns the elapsed time since the UNIX epoch
+    #[inline]
+    pub fn now_since_epoch() -> UnixTimeStamp {
+        Duration::from_u64(unix_ts())
+    }
+
+    /// Returns the elapsed time since the UNIX epoch, based on the latest
+    /// explicit time update
+    #[inline]
+    pub fn recent_since_epoch() -> UnixTimeStamp {
+        Duration::from_u64(RECENT.load(Ordering::Relaxed))
+    }
+
+    /// Updates the cached system time.
+    ///
+    /// This function should be called frequently, for example in an event loop
+    /// or using an `Updater` task.
+    #[inline]
+    pub fn update() {
+        let now = unix_ts();
+        RECENT.store(now, Ordering::Relaxed)
+    }
+
+    /// Sets the cached system time to the specified timestamp.
+    /// This function is intended for testing purposes only.
+    /// It should not be used in production code.
+    pub fn set_recent_since_epoch(recent: UnixTimeStamp) {
+        RECENT.store(recent.as_u64(), Ordering::Relaxed)
+    }
+}
+
+#[cfg(all(
+    any(target_arch = "wasm32", target_arch = "wasm64"),
+    target_os = "unknown"
+))]
+#[inline]
+fn unix_ts() -> u64 {
+    let unix_ts_now_sys = (js_imports::Date::now() / 1000.0).round() as u64;
+    let unix_ts_now = Duration::from_secs(unix_ts_now_sys);
+    unix_ts_now.as_u64()
+}
+
+#[cfg(not(all(
+    any(target_arch = "wasm32", target_arch = "wasm64"),
+    target_os = "unknown"
+)))]
+#[inline]
+fn unix_ts() -> u64 {
+    let unix_ts_now_sys = time::SystemTime::now()
+        .duration_since(time::UNIX_EPOCH)
+        .expect("The system clock is not properly set");
+    let unix_ts_now = Duration::from(unix_ts_now_sys);
+    unix_ts_now.as_u64()
+}

patches/coarsetime/src/duration.rs

@@ -0,0 +1,270 @@
+use std::convert::From;
+use std::ops::*;
+use std::time;
+
+use super::helpers::*;
+
+/// A duration type to represent an approximate span of time
+#[derive(Copy, Clone, Debug, Hash, Ord, Eq, PartialOrd, PartialEq, Default)]
+pub struct Duration(u64);
+
+impl Duration {
+    /// Creates a new `Duration` from the specified number of seconds and
+    /// additional nanosecond precision
+    #[inline]
+    pub const fn new(sec: u64, nanos: u32) -> Duration {
+        Duration(_timespec_to_u64(sec, nanos))
+    }
+
+    /// Creates a new Duration from the specified number of days
+    #[inline]
+    pub const fn from_days(days: u64) -> Duration {
+        Duration(_sec_to_u64(days * 86400))
+    }
+
+    /// Creates a new Duration from the specified number of hours
+    #[inline]
+    pub const fn from_hours(hours: u64) -> Duration {
+        Duration(_sec_to_u64(hours * 3600))
+    }
+
+    /// Creates a new Duration from the specified number of minutes
+    #[inline]
+    pub const fn from_mins(mins: u64) -> Duration {
+        Duration(_sec_to_u64(mins * 60))
+    }
+
+    /// Creates a new Duration from the specified number of seconds
+    #[inline]
+    pub const fn from_secs(secs: u64) -> Duration {
+        Duration(_sec_to_u64(secs))
+    }
+
+    /// Creates a new Duration from the specified number of milliseconds
+    #[inline]
+    pub const fn from_millis(millis: u64) -> Duration {
+        Duration(_millis_to_u64(millis))
+    }
+
+    /// Returns the number of days represented by this duration
+    #[inline]
+    pub const fn as_days(&self) -> u64 {
+        self.as_secs() / 86400
+    }
+
+    /// Returns the number of hours represented by this duration
+    #[inline]
+    pub const fn as_hours(&self) -> u64 {
+        self.as_secs() / 3600
+    }
+
+    /// Returns the number of minutes represented by this duration
+    #[inline]
+    pub const fn as_mins(&self) -> u64 {
+        self.as_secs() / 60
+    }
+
+    /// Returns the number of whole seconds represented by this duration
+    #[inline]
+    pub const fn as_secs(&self) -> u64 {
+        self.0 >> 32
+    }
+
+    /// Returns the number of whole milliseconds represented by this duration
+    #[inline]
+    pub const fn as_millis(&self) -> u64 {
+        ((self.0 as u128 * 125) >> 29) as u64
+    }
+
+    /// Returns the number of whole microseconds represented by this duration
+    #[inline]
+    pub const fn as_micros(&self) -> u64 {
+        ((self.0 as u128 * 125_000) >> 29) as u64
+    }
+
+    /// Returns the number of whole nanoseconds represented by this duration
+    #[inline]
+    pub const fn as_nanos(&self) -> u64 {
+        ((self.0 as u128 * 125_000_000) >> 29) as u64
+    }
+
+    /// Returns the nanosecond precision represented by this duration
+    #[inline]
+    pub const fn subsec_nanos(&self) -> u32 {
+        ((self.0 as u32 as u64 * 125_000_000) >> 29) as u32
+    }
+
+    /// Return this duration as a number of "ticks".
+    ///
+    /// Note that length of a 'tick' is not guaranteed to represent
+    /// the same amount of time across different platforms, or from
+    /// one version of `coarsetime` to another.
+    #[inline]
+    pub const fn as_ticks(&self) -> u64 {
+        self.as_u64()
+    }
+
+    /// Creates a new Duration from the specified number of "ticks".
+    ///
+    /// Note that length of a 'tick' is not guaranteed to represent
+    /// the same amount of time across different platforms, or from
+    /// one version of `coarsetime` to another.
+    #[inline]
+    pub const fn from_ticks(ticks: u64) -> Duration {
+        Self::from_u64(ticks)
+    }
+
+    #[doc(hidden)]
+    #[inline]
+    pub const fn as_u64(&self) -> u64 {
+        self.0
+    }
+
+    #[doc(hidden)]
+    #[inline]
+    pub const fn from_u64(ts: u64) -> Duration {
+        Duration(ts)
+    }
+
+    /// Returns the duration as a floating point number, representing the number
+    /// of seconds
+    #[inline]
+    pub fn as_f64(&self) -> f64 {
+        (self.0 as f64) / ((1u64 << 32) as f64)
+    }
+
+    /// Returns the absolute difference between two `Duration`s
+    #[inline]
+    pub const fn abs_diff(&self, other: Duration) -> Duration {
+        Duration(self.0.abs_diff(other.0))
+    }
+
+    /// Add two durations, saturating on overflow
+    #[inline]
+    pub const fn saturating_add(self, rhs: Duration) -> Duration {
+        Duration(self.0.saturating_add(rhs.0))
+    }
+
+    /// Add two durations, returning `None` on overflow
+    #[inline]
+    pub fn checked_add(self, rhs: Duration) -> Option<Duration> {
+        self.0.checked_add(rhs.0).map(Duration)
+    }
+
+    /// Subtract two durations, saturating on underflow/overflow
+    #[inline]
+    pub const fn saturating_sub(self, rhs: Duration) -> Duration {
+        Duration(self.0.saturating_sub(rhs.0))
+    }
+
+    /// Subtract two durations, returning `None` on underflow/overflow
+    #[inline]
+    pub fn checked_sub(self, rhs: Duration) -> Option<Duration> {
+        self.0.checked_sub(rhs.0).map(Duration)
+    }
+
+    /// Multiply a duration by a scalar, saturating on overflow
+    #[inline]
+    pub const fn saturating_mul(self, rhs: u32) -> Duration {
+        Duration(self.0.saturating_mul(rhs as u64))
+    }
+
+    /// Multiply a duration by a scalar, returning `None` on overflow
+    #[inline]
+    pub fn checked_mul(self, rhs: u32) -> Option<Duration> {
+        self.0.checked_mul(rhs as u64).map(Duration)
+    }
+
+    /// Divide a duration by a scalar, returning `None` for division by zero
+    #[inline]
+    pub fn checked_div(self, rhs: u32) -> Option<Duration> {
+        self.0.checked_div(rhs as u64).map(Duration)
+    }
+}
+
+#[doc(hidden)]
+impl From<u64> for Duration {
+    #[doc(hidden)]
+    #[inline]
+    fn from(ts: u64) -> Duration {
+        Duration::from_u64(ts)
+    }
+}
+
+impl Add for Duration {
+    type Output = Duration;
+
+    #[inline]
+    fn add(self, rhs: Duration) -> Duration {
+        Duration(self.0 + rhs.0)
+    }
+}
+
+impl AddAssign for Duration {
+    #[inline]
+    fn add_assign(&mut self, rhs: Duration) {
+        *self = *self + rhs;
+    }
+}
+
+impl Sub for Duration {
+    type Output = Duration;
+
+    #[inline]
+    fn sub(self, rhs: Duration) -> Duration {
+        Duration(self.0 - rhs.0)
+    }
+}
+
+impl SubAssign for Duration {
+    #[inline]
+    fn sub_assign(&mut self, rhs: Duration) {
+        *self = *self - rhs;
+    }
+}
+
+impl Mul<u32> for Duration {
+    type Output = Duration;
+
+    #[inline]
+    fn mul(self, rhs: u32) -> Duration {
+        Duration(self.0 * rhs as u64)
+    }
+}
+
+impl MulAssign<u32> for Duration {
+    #[inline]
+    fn mul_assign(&mut self, rhs: u32) {
+        *self = *self * rhs;
+    }
+}
+
+impl Div<u32> for Duration {
+    type Output = Duration;
+
+    #[inline]
+    fn div(self, rhs: u32) -> Duration {
+        Duration(self.0 / rhs as u64)
+    }
+}
+
+impl DivAssign<u32> for Duration {
+    #[inline]
+    fn div_assign(&mut self, rhs: u32) {
+        *self = *self / rhs;
+    }
+}
+
+impl From<Duration> for time::Duration {
+    #[inline]
+    fn from(duration: Duration) -> time::Duration {
+        time::Duration::new(duration.as_secs(), duration.subsec_nanos())
+    }
+}
+
+impl From<time::Duration> for Duration {
+    #[inline]
+    fn from(duration_sys: time::Duration) -> Duration {
+        Duration::new(duration_sys.as_secs(), duration_sys.subsec_nanos())
+    }
+}

patches/coarsetime/src/helpers.rs

@@ -0,0 +1,26 @@
+#[inline]
+pub const fn _sec_to_u64(sec: u64) -> u64 {
+    sec.saturating_mul(1 << 32)
+}
+
+#[inline]
+pub const fn _millis_to_u64(millis: u64) -> u64 {
+    let secs = millis / 1_000;
+    secs.saturating_mul(1 << 32) | ((millis - secs * 1_000) << 22)
+}
+
+#[inline]
+pub const fn _nsecs_to_u64(nsecs: u64) -> u64 {
+    let secs = nsecs / 1_000_000_000;
+    _timespec_to_u64(secs, (nsecs - secs * 1_000_000_000) as u32)
+}
+
+#[inline]
+pub const fn _timespec_to_u64(tp_sec: u64, tp_nsec: u32) -> u64 {
+    tp_sec.saturating_mul(1 << 32) | ((tp_nsec as u64 * 9_223_372_037) >> 31)
+}
+
+#[inline]
+pub const fn _timeval_to_u64(tv_sec: u64, tv_usec: u32) -> u64 {
+    tv_sec.saturating_mul(1 << 32) | ((tv_usec as u64 * 9_223_372_036_855) >> 31)
+}

patches/coarsetime/src/instant.rs

@@ -0,0 +1,332 @@
+#[allow(unused_imports)]
+use std::mem::MaybeUninit;
+use std::ops::*;
+#[allow(unused_imports)]
+use std::ptr::*;
+use portable_atomic::{AtomicU64, Ordering};
+
+use super::duration::*;
+#[allow(unused_imports)]
+use super::helpers::*;
+
+/// A measurement of a *monotonically* increasing clock.
+/// Opaque and useful only with `Duration`.
+///
+/// Resulting durations are actual durations; they do not get affected by
+/// clock adjustments, leap seconds, or similar.
+/// In order to get a measurement of the *wall clock*, use `Date` instead.
+#[derive(Copy, Clone, Debug, Hash, Ord, Eq, PartialOrd, PartialEq)]
+pub struct Instant(u64);
+
+static RECENT: AtomicU64 = AtomicU64::new(0);
+
+#[cfg(windows)]
+extern "system" {
+    pub fn GetTickCount64() -> libc::c_ulonglong;
+}
+
+#[cfg(any(target_os = "macos", target_os = "freebsd"))]
+#[allow(non_camel_case_types)]
+type clockid_t = libc::c_int;
+
+#[cfg(target_os = "macos")]
+const CLOCK_MONOTONIC_RAW_APPROX: clockid_t = 5;
+
+#[cfg(target_os = "macos")]
+extern "system" {
+    fn clock_gettime_nsec_np(clk_id: clockid_t) -> u64;
+}
+
+#[cfg(target_os = "freebsd")]
+const CLOCK_MONOTONIC_FAST: clockid_t = 12;
+
+#[cfg(all(
+    any(target_arch = "wasm32", target_arch = "wasm64"),
+    target_os = "unknown"
+))]
+mod js_imports {
+    use wasm_bindgen::prelude::*;
+
+    #[wasm_bindgen]
+    extern "C" {
+        #[allow(non_camel_case_types)]
+        pub type performance;
+
+        #[wasm_bindgen(static_method_of = performance)]
+        pub fn now() -> f64;
+    }
+}
+
+impl Instant {
+    /// Returns an instant corresponding to "now"
+    ///
+    /// This function also updates the stored instant.
+    pub fn now() -> Instant {
+        let now = Self::_now();
+        Self::_update(now);
+        Instant(now)
+    }
+
+    /// Returns an instant corresponding to "now" without updating the cached value.
+    /// After this, `recent()` will still return the old instant.
+    ///
+    /// `now()` is generally preferred over this function.
+    pub fn now_without_cache_update() -> Instant {
+        let now = Self::_now();
+        Instant(now)
+    }
+
+    /// Returns an instant corresponding to the latest update
+    pub fn recent() -> Instant {
+        match Self::_recent() {
+            0 => Instant::now(),
+            recent => Instant(recent),
+        }
+    }
+
+    /// Update the stored instant
+    ///
+    /// This function should be called frequently, for example in an event loop
+    /// or using an `Updater` task.
+    pub fn update() {
+        let now = Self::_now();
+        Self::_update(now);
+    }
+
+    /// Returns the amount of time elapsed from another instant to this one
+    #[inline]
+    pub fn duration_since(&self, earlier: Instant) -> Duration {
+        *self - earlier
+    }
+
+    /// Returns the amount of time elapsed between the this instant was created
+    /// and the latest update
+    #[inline]
+    pub fn elapsed_since_recent(&self) -> Duration {
+        Self::recent() - *self
+    }
+
+    /// Returns the amount of time elapsed since this instant was created
+    ///
+    /// This function also updates the stored instant.
+    #[inline]
+    pub fn elapsed(&self) -> Duration {
+        Self::now() - *self
+    }
+
+    /// Return a representation of this instant as a number of "ticks".
+    ///
+    /// Note that length of a 'tick' is not guaranteed to represent
+    /// the same amount of time across different platforms, or from
+    /// one version of `coarsetime` to another.
+    ///
+    /// Note also that the instant represented by "0" ticks is
+    /// unspecified.  It is not guaranteed to be the same time across
+    /// different platforms, or from one version of `coarsetime` to
+    /// another.
+    ///
+    /// This API is mainly intended for applications that need to
+    /// store the value of an `Instant` in an
+    /// [`AtomicU64`](std::sync::atomic::AtomicU64).
+    #[inline]
+    pub const fn as_ticks(&self) -> u64 {
+        self.as_u64()
+    }
+
+    /// Create an `Instant` from a number of "ticks".
+    ///
+    /// Note that length of a 'tick' is not guaranteed to represent
+    /// the same amount of time across different platforms, or from
+    /// one version of `coarsetime` to another.
+    ///
+    /// Note also that the instant represented by "0" ticks is
+    /// unspecified.  It is not guaranteed to be the same time across
+    /// different platforms, or from one version of `coarsetime` to
+    /// another.
+    #[inline]
+    pub const fn from_ticks(ticks: u64) -> Instant {
+        Self::from_u64(ticks)
+    }
+
+    #[doc(hidden)]
+    #[inline]
+    pub const fn as_u64(&self) -> u64 {
+        self.0
+    }
+
+    #[doc(hidden)]
+    #[inline]
+    pub const fn from_u64(ts: u64) -> Instant {
+        Instant(ts)
+    }
+
+    /// Calculate an `Instant` that is a `Duration` later, saturating on overflow
+    #[inline]
+    pub const fn saturating_add(self, rhs: Duration) -> Instant {
+        Instant(self.0.saturating_add(rhs.as_u64()))
+    }
+
+    /// Calculate an `Instant` that is a `Duration` later, returning `None` on overflow
+    #[inline]
+    pub fn checked_add(self, rhs: Duration) -> Option<Instant> {
+        self.0.checked_add(rhs.as_u64()).map(Instant)
+    }
+
+    /// Calculate an `Instant` that is a `Duration` earlier, saturating on underflow
+    #[inline]
+    pub const fn saturating_sub(self, rhs: Duration) -> Instant {
+        Instant(self.0.saturating_sub(rhs.as_u64()))
+    }
+
+    /// Calculate an `Instant` that is a `Duration` earlier, returning `None` on underflow
+    #[inline]
+    pub fn checked_sub(self, rhs: Duration) -> Option<Instant> {
+        self.0.checked_sub(rhs.as_u64()).map(Instant)
+    }
+
+    #[cfg(any(target_os = "linux", target_os = "android"))]
+    fn _now() -> u64 {
+        let mut tp = MaybeUninit::<libc::timespec>::uninit();
+        let tp = unsafe {
+            libc::clock_gettime(libc::CLOCK_MONOTONIC_COARSE, tp.as_mut_ptr());
+            tp.assume_init()
+        };
+        _timespec_to_u64(tp.tv_sec as u64, tp.tv_nsec as u32)
+    }
+
+    #[cfg(target_os = "macos")]
+    fn _now() -> u64 {
+        let nsec = unsafe { clock_gettime_nsec_np(CLOCK_MONOTONIC_RAW_APPROX) };
+        _nsecs_to_u64(nsec)
+    }
+
+    #[cfg(any(target_os = "freebsd", target_os = "dragonfly"))]
+    fn _now() -> u64 {
+        let mut tp = MaybeUninit::<libc::timespec>::uninit();
+        let tp = unsafe {
+            libc::clock_gettime(libc::CLOCK_MONOTONIC_FAST, tp.as_mut_ptr());
+            tp.assume_init()
+        };
+        _timespec_to_u64(tp.tv_sec as u64, tp.tv_nsec as u32)
+    }
+
+    #[cfg(all(
+        unix,
+        not(any(
+            target_os = "macos",
+            target_os = "linux",
+            target_os = "android",
+            target_os = "freebsd",
+            target_os = "dragonfly"
+        ))
+    ))]
+    fn _now() -> u64 {
+        let mut tv = MaybeUninit::<libc::timeval>::uninit();
+        let tv = unsafe {
+            libc::gettimeofday(tv.as_mut_ptr(), null_mut());
+            tv.assume_init()
+        };
+        _timeval_to_u64(tv.tv_sec as u64, tv.tv_usec as u32)
+    }
+
+    #[cfg(windows)]
+    fn _now() -> u64 {
+        let tc = unsafe { GetTickCount64() } as u64;
+        _millis_to_u64(tc)
+    }
+
+    #[cfg(all(target_os = "wasi", not(feature = "wasi-abi2")))]
+    fn _now() -> u64 {
+        use wasix::{clock_time_get, CLOCKID_MONOTONIC, CLOCKID_REALTIME};
+        let nsec = unsafe { clock_time_get(CLOCKID_MONOTONIC, 1_000_000) }
+            .or_else(|_| unsafe { clock_time_get(CLOCKID_REALTIME, 1_000_000) })
+            .expect("Clock not available");
+        _nsecs_to_u64(nsec)
+    }
+
+    #[cfg(all(target_os = "wasi", feature = "wasi-abi2"))]
+    fn _now() -> u64 {
+        let nsec = wasi_abi2::clocks::monotonic_clock::now();
+        _nsecs_to_u64(nsec)
+    }
+
+    #[cfg(all(
+        any(target_arch = "wasm32", target_arch = "wasm64"),
+        target_os = "unknown"
+    ))]
+    fn _now() -> u64 {
+        _millis_to_u64(js_imports::performance::now() as u64)
+    }
+
+    #[cfg(all(target_arch = "x86_64", target_env = "sgx", target_vendor = "fortanix"))]
+    fn _now() -> u64 {
+        let timestamp = std::time::SystemTime::now()
+            .duration_since(std::time::UNIX_EPOCH)
+            .unwrap();
+        timestamp.as_secs() * 1_000_000_000 + (timestamp.subsec_nanos() as u64)
+    }
+
+    #[inline]
+    fn _update(now: u64) {
+        RECENT.store(now, Ordering::Relaxed)
+    }
+
+    #[inline]
+    fn _recent() -> u64 {
+        let recent = RECENT.load(Ordering::Relaxed);
+        if recent != 0 {
+            recent
+        } else {
+            let now = Self::_now();
+            Self::_update(now);
+            Self::_recent()
+        }
+    }
+}
+
+impl Default for Instant {
+    fn default() -> Instant {
+        Self::now()
+    }
+}
+
+impl Sub<Instant> for Instant {
+    type Output = Duration;
+
+    #[inline]
+    fn sub(self, other: Instant) -> Duration {
+        Duration::from_u64(self.0.saturating_sub(other.0))
+    }
+}
+
+impl Sub<Duration> for Instant {
+    type Output = Instant;
+
+    #[inline]
+    fn sub(self, rhs: Duration) -> Instant {
+        Instant(self.0 - rhs.as_u64())
+    }
+}
+
+impl SubAssign<Duration> for Instant {
+    #[inline]
+    fn sub_assign(&mut self, rhs: Duration) {
+        *self = *self - rhs;
+    }
+}
+
+impl Add<Duration> for Instant {
+    type Output = Instant;
+
+    #[inline]
+    fn add(self, rhs: Duration) -> Instant {
+        Instant(self.0 + rhs.as_u64())
+    }
+}
+
+impl AddAssign<Duration> for Instant {
+    #[inline]
+    fn add_assign(&mut self, rhs: Duration) {
+        *self = *self + rhs;
+    }
+}

patches/coarsetime/src/lib.rs

@@ -0,0 +1,37 @@
+//! A crate to make time measurements that focuses on speed.
+//!
+//! This crate is a partial replacement for the `Time` and `Duration` structures
+//! from the standard library, with the following differences:
+//!
+//! * Speed is privileged over accuracy. In particular, `CLOCK_MONOTONIC_COARSE`
+//!   is used to retrieve the clock value on Linux systems, and transformations avoid
+//!   operations that can be slow on non-Intel systems.
+//! * The number of system calls can be kept to a minimum. The "most recent
+//!   timestamp" is always kept in memory.
+//!   It can be read with just a load operation, and can be
+//!   updated only as frequently as necessary.
+//!
+//! # Installation
+//!
+//! `coarsetime` is available on [crates.io](https://crates.io/crates/coarsetime) and works on
+//! Rust stable, beta, and nightly.
+//!
+//! Windows and Unix-like systems are supported.
+
+#![allow(clippy::trivially_copy_pass_by_ref)]
+
+mod clock;
+mod duration;
+mod helpers;
+mod instant;
+#[cfg(not(any(target_arch = "wasm32", target_arch = "wasm64")))]
+mod updater;
+
+#[cfg(test)]
+mod tests;
+
+pub use self::clock::*;
+pub use self::duration::*;
+pub use self::instant::*;
+#[cfg(not(any(target_arch = "wasm32", target_arch = "wasm64")))]
+pub use self::updater::*;

patches/coarsetime/src/updater.rs

@@ -0,0 +1,58 @@
+use std::io;
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::Arc;
+use std::thread;
+use std::time;
+
+use super::clock::*;
+use super::instant::*;
+
+/// A service to periodically call `Instant::update()`
+#[derive(Debug)]
+pub struct Updater {
+    period: time::Duration,
+    running: Arc<AtomicBool>,
+    th: Option<thread::JoinHandle<()>>,
+}
+
+impl Updater {
+    /// Spawns a background task to call `Instant::update()` periodically
+    pub fn start(mut self) -> Result<Self, io::Error> {
+        let period = self.period;
+        let running = self.running.clone();
+        running.store(true, Ordering::Relaxed);
+        let th: thread::JoinHandle<()> = thread::Builder::new()
+            .name("coarsetime".to_string())
+            .spawn(move || {
+                while running.load(Ordering::Relaxed) {
+                    thread::sleep(period);
+                    Instant::update();
+                    Clock::update();
+                }
+            })?;
+        self.th = Some(th);
+        Instant::update();
+        Clock::update();
+        Ok(self)
+    }
+
+    /// Stops the periodic updates
+    pub fn stop(mut self) -> Result<(), io::Error> {
+        self.running.store(false, Ordering::Relaxed);
+        self.th
+            .take()
+            .expect("updater is not running")
+            .join()
+            .map_err(|_| io::Error::other("failed to properly stop the updater"))
+    }
+
+    /// Creates a new `Updater` with the specified update period, in
+    /// milliseconds.
+    pub fn new(period_millis: u64) -> Updater {
+        Updater {
+            period: time::Duration::from_millis(period_millis),
+            running: Arc::new(AtomicBool::new(false)),
+            th: None,
+        }
+    }
+}