Add more clocks to ClockId under linux_4_11 (#911)

* Add more clocks to `ClockId` under `linux_4_11`

Add several more clocks to `ClockId` for use with the infallible
`clock_gettiem` when the `linux_4_11` feature is enabled.

* Don't test `test_boottime_alarm_clock` on platforms that don't have it.

Author: sunfishcode

src/backend/linux_raw/c.rs

@@ -266,6 +266,14 @@ pub(crate) const CLOCK_THREAD_CPUTIME_ID: c_int =
     linux_raw_sys::general::CLOCK_THREAD_CPUTIME_ID as _;
 pub(crate) const CLOCK_PROCESS_CPUTIME_ID: c_int =
     linux_raw_sys::general::CLOCK_PROCESS_CPUTIME_ID as _;
+#[cfg(all(feature = "time", feature = "linux_4_11"))]
+pub(crate) const CLOCK_BOOTTIME: c_int = linux_raw_sys::general::CLOCK_BOOTTIME as _;
+#[cfg(all(feature = "time", feature = "linux_4_11"))]
+pub(crate) const CLOCK_BOOTTIME_ALARM: c_int = linux_raw_sys::general::CLOCK_BOOTTIME_ALARM as _;
+#[cfg(all(feature = "time", feature = "linux_4_11"))]
+pub(crate) const CLOCK_TAI: c_int = linux_raw_sys::general::CLOCK_TAI as _;
+#[cfg(all(feature = "time", feature = "linux_4_11"))]
+pub(crate) const CLOCK_REALTIME_ALARM: c_int = linux_raw_sys::general::CLOCK_REALTIME_ALARM as _;
 
 #[cfg(feature = "system")]
 mod reboot_symbols {

src/backend/linux_raw/fs/syscalls.rs

@@ -8,9 +8,11 @@
 
 use crate::backend::c;
 use crate::backend::conv::fs::oflags_for_open_how;
+#[cfg(not(feature = "linux_4_11"))]
+use crate::backend::conv::zero;
 use crate::backend::conv::{
     by_ref, c_int, c_uint, dev_t, opt_mut, pass_usize, raw_fd, ret, ret_c_int, ret_c_uint,
-    ret_infallible, ret_owned_fd, ret_usize, size_of, slice, slice_mut, zero,
+    ret_infallible, ret_owned_fd, ret_usize, size_of, slice, slice_mut,
 };
 #[cfg(target_pointer_width = "64")]
 use crate::backend::conv::{loff_t, loff_t_from_u64, ret_u64};
@@ -839,6 +841,7 @@ pub(crate) fn statx(
     }
 }
 
+#[cfg(not(feature = "linux_4_11"))]
 #[inline]
 pub(crate) fn is_statx_available() -> bool {
     unsafe {

src/clockid.rs

@@ -54,6 +54,33 @@ pub enum ClockId {
     /// `CLOCK_MONOTONIC_RAW`
     #[cfg(linux_kernel)]
     MonotonicRaw = c::CLOCK_MONOTONIC_RAW,
+
+    /// `CLOCK_REALTIME_ALARM`, available on Linux >= 3.0
+    #[cfg(all(linux_kernel, feature = "linux_4_11"))]
+    #[doc(alias = "CLOCK_REALTIME_ALARM")]
+    RealtimeAlarm = bitcast!(c::CLOCK_REALTIME_ALARM),
+
+    /// `CLOCK_TAI`, available on Linux >= 3.10
+    #[cfg(all(linux_kernel, feature = "linux_4_11"))]
+    #[doc(alias = "CLOCK_TAI")]
+    Tai = bitcast!(c::CLOCK_TAI),
+
+    /// `CLOCK_BOOTTIME`, available on Linux >= 2.6.39
+    ///
+    /// On FreeBSD, use [`Self::Uptime`], as `CLOCK_BOOTTIME` is an alias for
+    /// `CLOCK_UPTIME`.
+    #[cfg(any(
+        all(linux_kernel, feature = "linux_4_11"),
+        target_os = "fuchsia",
+        target_os = "openbsd"
+    ))]
+    #[doc(alias = "CLOCK_BOOTTIME")]
+    Boottime = bitcast!(c::CLOCK_BOOTTIME),
+
+    /// `CLOCK_BOOTTIME_ALARM`, available on Linux >= 2.6.39
+    #[cfg(any(all(linux_kernel, feature = "linux_4_11"), target_os = "fuchsia"))]
+    #[doc(alias = "CLOCK_BOOTTIME_ALARM")]
+    BoottimeAlarm = bitcast!(c::CLOCK_BOOTTIME_ALARM),
 }
 
 /// `CLOCK_*` constants for use with [`clock_gettime`].

tests/time/clocks.rs

@@ -17,6 +17,8 @@ use rustix::time::{clock_gettime, ClockId};
 fn test_boottime_clock() {
     use rustix::time::{clock_gettime_dynamic, DynamicClockId};
 
+    let monotonic = clock_gettime(ClockId::Monotonic);
+
     if let Ok(a) = clock_gettime_dynamic(DynamicClockId::Boottime) {
         if let Ok(b) = clock_gettime_dynamic(DynamicClockId::Boottime) {
             if b.tv_sec == a.tv_sec {
@@ -25,6 +27,78 @@ fn test_boottime_clock() {
                 assert!(b.tv_sec > a.tv_sec);
             }
         }
+
+        // Test that boot time is after monotonic.
+        if a.tv_sec == monotonic.tv_sec {
+            assert!(a.tv_nsec >= monotonic.tv_nsec);
+        } else {
+            assert!(a.tv_sec > monotonic.tv_sec);
+        }
+    }
+
+    #[cfg(feature = "linux_4_11")]
+    {
+        let a = clock_gettime(ClockId::Boottime);
+        let b = clock_gettime(ClockId::Boottime);
+
+        if b.tv_sec == a.tv_sec {
+            assert!(b.tv_nsec >= a.tv_nsec);
+        } else {
+            assert!(b.tv_sec > a.tv_sec);
+        }
+
+        // Test that boot time is after monotonic.
+        if a.tv_sec == monotonic.tv_sec {
+            assert!(a.tv_nsec >= monotonic.tv_nsec);
+        } else {
+            assert!(a.tv_sec > monotonic.tv_sec);
+        }
+    }
+}
+
+/// Attempt to test that the boot alarm clock is monotonic. Time may or may not
+/// advance, but it shouldn't regress.
+#[cfg(any(linux_kernel, target_os = "fuchsia"))]
+#[test]
+fn test_boottime_alarm_clock() {
+    use rustix::time::{clock_gettime_dynamic, DynamicClockId};
+
+    let monotonic = clock_gettime(ClockId::Monotonic);
+
+    if let Ok(a) = clock_gettime_dynamic(DynamicClockId::BoottimeAlarm) {
+        if let Ok(b) = clock_gettime_dynamic(DynamicClockId::BoottimeAlarm) {
+            if b.tv_sec == a.tv_sec {
+                assert!(b.tv_nsec >= a.tv_nsec);
+            } else {
+                assert!(b.tv_sec > a.tv_sec);
+            }
+        }
+
+        // Test that boot alarm time is after monotonic.
+        if a.tv_sec == monotonic.tv_sec {
+            assert!(a.tv_nsec >= monotonic.tv_nsec);
+        } else {
+            assert!(a.tv_sec > monotonic.tv_sec);
+        }
+    }
+
+    #[cfg(feature = "linux_4_11")]
+    {
+        let a = clock_gettime(ClockId::BoottimeAlarm);
+        let b = clock_gettime(ClockId::BoottimeAlarm);
+
+        if b.tv_sec == a.tv_sec {
+            assert!(b.tv_nsec >= a.tv_nsec);
+        } else {
+            assert!(b.tv_sec > a.tv_sec);
+        }
+
+        // Test that boot alarm time is after monotonic.
+        if a.tv_sec == monotonic.tv_sec {
+            assert!(a.tv_nsec >= monotonic.tv_nsec);
+        } else {
+            assert!(a.tv_sec > monotonic.tv_sec);
+        }
     }
 }
 
@@ -79,6 +153,71 @@ fn test_realtime_coarse_clock() {
     assert!(a.tv_nsec < 1_000_000_000);
 }
 
+#[cfg(linux_kernel)]
+#[test]
+fn test_realtime_alarm_clock() {
+    use rustix::time::{clock_gettime_dynamic, DynamicClockId};
+
+    if let Ok(a) = clock_gettime_dynamic(DynamicClockId::RealtimeAlarm) {
+        // Test that the timespec is valid; there's not much else we can say.
+        assert!(a.tv_nsec < 1_000_000_000);
+    }
+
+    #[cfg(feature = "linux_4_11")]
+    {
+        let a = clock_gettime(ClockId::RealtimeAlarm);
+
+        // Test that the timespec is valid; there's not much else we can say.
+        assert!(a.tv_nsec < 1_000_000_000);
+    }
+}
+
+/// Attempt to test that the TAI clock is monotonic. Time may or may not
+/// advance, but it shouldn't regress.
+#[cfg(linux_kernel)]
+#[test]
+fn test_tai_clock() {
+    use rustix::time::{clock_gettime_dynamic, DynamicClockId};
+
+    let realtime = clock_gettime(ClockId::Realtime);
+
+    if let Ok(a) = clock_gettime_dynamic(DynamicClockId::Tai) {
+        if let Ok(b) = clock_gettime_dynamic(DynamicClockId::Tai) {
+            if b.tv_sec == a.tv_sec {
+                assert!(b.tv_nsec >= a.tv_nsec);
+            } else {
+                assert!(b.tv_sec > a.tv_sec);
+            }
+        }
+
+        // Test that TAI time is after realtime.
+        if a.tv_sec == realtime.tv_sec {
+            assert!(a.tv_nsec >= realtime.tv_nsec);
+        } else {
+            assert!(a.tv_sec > realtime.tv_sec);
+        }
+    }
+
+    #[cfg(feature = "linux_4_11")]
+    {
+        let a = clock_gettime(ClockId::Tai);
+        let b = clock_gettime(ClockId::Tai);
+
+        if b.tv_sec == a.tv_sec {
+            assert!(b.tv_nsec >= a.tv_nsec);
+        } else {
+            assert!(b.tv_sec > a.tv_sec);
+        }
+
+        // Test that TAI time is after realtime.
+        if a.tv_sec == realtime.tv_sec {
+            assert!(a.tv_nsec >= realtime.tv_nsec);
+        } else {
+            assert!(a.tv_sec > realtime.tv_sec);
+        }
+    }
+}
+
 /// Attempt to test that the coarse monotonic clock is monotonic. Time may or
 /// may not advance, but it shouldn't regress.
 #[cfg(any(linux_kernel, target_os = "freebsd"))]