Added clock_gettime, clock_getres, clock_settime, clock_getcpuclockid

CHANGELOG.md

@@ -5,6 +5,9 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased] - ReleaseDate
 ### Added
+- Added `clock_gettime`, `clock_settime`, `clock_getres`,
+  `clock_getcpuclockid` functions and `ClockId` struct.
+  (#[1281](https://github.com/nix-rust/nix/pull/1281))
 ### Changed
 ### Fixed
 ### Removed

Cargo.toml

@@ -17,7 +17,7 @@ exclude     = [
 ]
 
 [dependencies]
-libc = { version = "0.2.73", features = [ "extra_traits" ] }
+libc = { version = "0.2.74", features = [ "extra_traits" ] }
 bitflags = "1.1"
 cfg-if = "0.1.10"
 

src/lib.rs

@@ -61,6 +61,7 @@ pub mod poll;
 pub mod pty;
 pub mod sched;
 pub mod sys;
+pub mod time;
 // This can be implemented for other platforms as soon as libc
 // provides bindings for them.
 #[cfg(all(target_os = "linux",

src/time.rs

@@ -0,0 +1,239 @@
+use crate::sys::time::TimeSpec;
+use crate::unistd::Pid;
+use crate::{Errno, Error, Result};
+use libc::{self, clockid_t};
+use std::mem::MaybeUninit;
+
+/// Clock identifier
+///
+/// Newtype pattern around `clockid_t` (which is just alias). It pervents bugs caused by
+/// accidentally passing wrong value.
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
+pub struct ClockId(clockid_t);
+
+impl ClockId {
+    /// Creates `ClockId` from raw `clockid_t`
+    pub fn from_raw(clk_id: clockid_t) -> Self {
+        ClockId(clk_id)
+    }
+
+    /// Returns `ClockId` of a `pid` CPU-time clock
+    #[cfg(target_os = "linux")]
+    pub fn pid_cpu_clock_id(pid: Pid) -> Result<Self> {
+        clock_getcpuclockid(pid)
+    }
+
+    /// Returns resolution of the clock id
+    pub fn res(self) -> Result<TimeSpec> {
+        clock_getres(self)
+    }
+
+    /// Returns time on the clock id
+    pub fn time(self) -> Result<TimeSpec> {
+        clock_gettime(self)
+    }
+
+    /// Sets time to `timespec` on the clock id
+    #[cfg(not(any(
+        target_os = "macos",
+        target_os = "ios",
+        all(
+            not(any(target_env = "uclibc", target_env = "newlibc")),
+            any(target_os = "redox", target_os = "hermit",),
+        ),
+    )))]
+    pub fn set_time(self, timespec: TimeSpec) -> Result<()> {
+        clock_settime(self, timespec)
+    }
+
+    /// Gets the raw `clockid_t` wrapped by `self`
+    pub fn as_raw(self) -> clockid_t {
+        self.0
+    }
+
+    #[cfg(any(
+        target_os = "fuchsia",
+        all(
+            not(any(target_env = "uclibc", target_env = "newlib")),
+            any(target_os = "linux", target_os = "android", target_os = "emscripten"),
+        )
+    ))]
+    pub const CLOCK_BOOTTIME: ClockId = ClockId(libc::CLOCK_BOOTTIME);
+    #[cfg(any(
+        target_os = "fuchsia",
+        all(
+            not(any(target_env = "uclibc", target_env = "newlib")),
+            any(target_os = "linux", target_os = "android", target_os = "emscripten")
+        )
+    ))]
+    pub const CLOCK_BOOTTIME_ALARM: ClockId = ClockId(libc::CLOCK_BOOTTIME_ALARM);
+    pub const CLOCK_MONOTONIC: ClockId = ClockId(libc::CLOCK_MONOTONIC);
+    #[cfg(any(
+        target_os = "fuchsia",
+        all(
+            not(any(target_env = "uclibc", target_env = "newlib")),
+            any(target_os = "linux", target_os = "android", target_os = "emscripten")
+        )
+    ))]
+    pub const CLOCK_MONOTONIC_COARSE: ClockId = ClockId(libc::CLOCK_MONOTONIC_COARSE);
+    #[cfg(any(target_os = "freebsd", target_os = "dragonfly"))]
+    pub const CLOCK_MONOTONIC_FAST: ClockId = ClockId(libc::CLOCK_MONOTONIC_FAST);
+    #[cfg(any(target_os = "freebsd", target_os = "dragonfly"))]
+    pub const CLOCK_MONOTONIC_PRECISE: ClockId = ClockId(libc::CLOCK_MONOTONIC_PRECISE);
+    #[cfg(any(
+        target_os = "fuchsia",
+        all(
+            not(any(target_env = "uclibc", target_env = "newlib")),
+            any(target_os = "linux", target_os = "android", target_os = "emscripten")
+        )
+    ))]
+    pub const CLOCK_MONOTONIC_RAW: ClockId = ClockId(libc::CLOCK_MONOTONIC_RAW);
+    #[cfg(any(
+        target_os = "fuchsia",
+        target_env = "uclibc",
+        target_os = "macos",
+        target_os = "ios",
+        target_os = "freebsd",
+        target_os = "dragonfly",
+        all(
+            not(target_env = "newlib"),
+            any(target_os = "linux", target_os = "android", target_os = "emscripten")
+        )
+    ))]
+    pub const CLOCK_PROCESS_CPUTIME_ID: ClockId = ClockId(libc::CLOCK_PROCESS_CPUTIME_ID);
+    #[cfg(any(target_os = "freebsd", target_os = "dragonfly"))]
+    pub const CLOCK_PROF: ClockId = ClockId(libc::CLOCK_PROF);
+    pub const CLOCK_REALTIME: ClockId = ClockId(libc::CLOCK_REALTIME);
+    #[cfg(any(
+        target_os = "fuchsia",
+        all(
+            not(any(target_env = "uclibc", target_env = "newlib")),
+            any(target_os = "linux", target_os = "android", target_os = "emscripten")
+        )
+    ))]
+    pub const CLOCK_REALTIME_ALARM: ClockId = ClockId(libc::CLOCK_REALTIME_ALARM);
+    #[cfg(any(
+        target_os = "fuchsia",
+        all(
+            not(any(target_env = "uclibc", target_env = "newlib")),
+            any(target_os = "linux", target_os = "android", target_os = "emscripten")
+        )
+    ))]
+    pub const CLOCK_REALTIME_COARSE: ClockId = ClockId(libc::CLOCK_REALTIME_COARSE);
+    #[cfg(any(target_os = "freebsd", target_os = "dragonfly"))]
+    pub const CLOCK_REALTIME_FAST: ClockId = ClockId(libc::CLOCK_REALTIME_FAST);
+    #[cfg(any(target_os = "freebsd", target_os = "dragonfly"))]
+    pub const CLOCK_REALTIME_PRECISE: ClockId = ClockId(libc::CLOCK_REALTIME_PRECISE);
+    #[cfg(any(target_os = "freebsd", target_os = "dragonfly"))]
+    pub const CLOCK_SECOND: ClockId = ClockId(libc::CLOCK_SECOND);
+    #[cfg(any(
+        target_os = "fuchsia",
+        all(
+            not(any(target_env = "uclibc", target_env = "newlib")),
+            any(
+                target_os = "emscripten",
+                all(target_os = "linux", target_env = "musl")
+            )
+        )
+    ))]
+    pub const CLOCK_SGI_CYCLE: ClockId = ClockId(libc::CLOCK_SGI_CYCLE);
+    #[cfg(any(
+        target_os = "fuchsia",
+        all(
+            not(any(target_env = "uclibc", target_env = "newlib")),
+            any(
+                target_os = "emscripten",
+                all(target_os = "linux", target_env = "musl")
+            )
+        )
+    ))]
+    pub const CLOCK_TAI: ClockId = ClockId(libc::CLOCK_TAI);
+    #[cfg(any(
+        target_env = "uclibc",
+        target_os = "fuchsia",
+        target_os = "ios",
+        target_os = "macos",
+        target_os = "freebsd",
+        target_os = "dragonfly",
+        all(
+            not(target_env = "newlib"),
+            any(target_os = "linux", target_os = "android", target_os = "emscripten",),
+        ),
+    ))]
+    pub const CLOCK_THREAD_CPUTIME_ID: ClockId = ClockId(libc::CLOCK_THREAD_CPUTIME_ID);
+    #[cfg(any(target_os = "freebsd", target_os = "dragonfly"))]
+    pub const CLOCK_UPTIME: ClockId = ClockId(libc::CLOCK_UPTIME);
+    #[cfg(any(target_os = "freebsd", target_os = "dragonfly"))]
+    pub const CLOCK_UPTIME_FAST: ClockId = ClockId(libc::CLOCK_UPTIME_FAST);
+    #[cfg(any(target_os = "freebsd", target_os = "dragonfly"))]
+    pub const CLOCK_UPTIME_PRECISE: ClockId = ClockId(libc::CLOCK_UPTIME_PRECISE);
+    #[cfg(any(target_os = "freebsd", target_os = "dragonfly"))]
+    pub const CLOCK_VIRTUAL: ClockId = ClockId(libc::CLOCK_VIRTUAL);
+}
+
+impl Into<clockid_t> for ClockId {
+    fn into(self) -> clockid_t {
+        self.as_raw()
+    }
+}
+
+impl From<clockid_t> for ClockId {
+    fn from(clk_id: clockid_t) -> Self {
+        ClockId::from_raw(clk_id)
+    }
+}
+
+impl std::fmt::Display for ClockId {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Display::fmt(&self.0, f)
+    }
+}
+
+/// Get the resolution of the specified clock, (see
+/// [clock_getres(2)](https://www.man7.org/linux/man-pages/man2/clock_getres.2.html)).
+pub fn clock_getres(clock_id: ClockId) -> Result<TimeSpec> {
+    let mut c_time: MaybeUninit<libc::timespec> = MaybeUninit::uninit();
+    let ret = unsafe { libc::clock_getres(clock_id.as_raw(), c_time.as_mut_ptr()) };
+    Errno::result(ret)?;
+    let res = unsafe { c_time.assume_init() };
+    Ok(TimeSpec::from(res))
+}
+
+/// Get the time of the specified clock, (see
+/// [clock_gettime(2)](https://www.man7.org/linux/man-pages/man2/clock_gettime.2.html)).
+pub fn clock_gettime(clock_id: ClockId) -> Result<TimeSpec> {
+    let mut c_time: MaybeUninit<libc::timespec> = MaybeUninit::uninit();
+    let ret = unsafe { libc::clock_gettime(clock_id.as_raw(), c_time.as_mut_ptr()) };
+    Errno::result(ret)?;
+    let res = unsafe { c_time.assume_init() };
+    Ok(TimeSpec::from(res))
+}
+
+/// Set the time of the specified clock, (see
+/// [clock_settime(2)](https://www.man7.org/linux/man-pages/man2/clock_settime.2.html)).
+#[cfg(not(any(
+    target_os = "macos",
+    target_os = "ios",
+    all(
+        not(any(target_env = "uclibc", target_env = "newlibc")),
+        any(target_os = "redox", target_os = "hermit",),
+    ),
+)))]
+pub fn clock_settime(clock_id: ClockId, timespec: TimeSpec) -> Result<()> {
+    let ret = unsafe { libc::clock_settime(clock_id.as_raw(), timespec.as_ref()) };
+    Errno::result(ret).map(drop)
+}
+
+/// Get the clock id of the specified process id, (see
+/// [clock_getcpuclockid(3)](https://www.man7.org/linux/man-pages/man3/clock_getcpuclockid.3.html)).
+#[cfg(target_os = "linux")]
+pub fn clock_getcpuclockid(pid: Pid) -> Result<ClockId> {
+    let mut clk_id: MaybeUninit<libc::clockid_t> = MaybeUninit::uninit();
+    let ret = unsafe { libc::clock_getcpuclockid(pid.into(), clk_id.as_mut_ptr()) };
+    if ret == 0 {
+        let res = unsafe { clk_id.assume_init() };
+        Ok(ClockId::from(res))
+    } else {
+        Err(Error::Sys(Errno::from_i32(ret)))
+    }
+}

test/test.rs

@@ -139,6 +139,7 @@ mod test_sched;
           target_os = "macos"))]
 mod test_sendfile;
 mod test_stat;
+mod test_time;
 mod test_unistd;
 
 use std::os::unix::io::RawFd;

test/test_time.rs

@@ -0,0 +1,38 @@
+#[cfg(target_os = "linux")]
+use nix::time::clock_getcpuclockid;
+use nix::time::{clock_getres, clock_gettime, ClockId};
+
+#[test]
+pub fn test_clock_getres() {
+    assert!(clock_getres(ClockId::CLOCK_REALTIME).is_ok());
+}
+
+#[test]
+pub fn test_clock_gettime() {
+    assert!(clock_gettime(ClockId::CLOCK_REALTIME).is_ok());
+}
+
+#[cfg(target_os = "linux")]
+#[test]
+pub fn test_clock_getcpuclockid() {
+    let clock_id = clock_getcpuclockid(nix::unistd::Pid::this()).unwrap();
+    assert!(clock_gettime(clock_id).is_ok());
+}
+
+#[test]
+pub fn test_clock_id_res() {
+    assert!(ClockId::CLOCK_REALTIME.res().is_ok());
+}
+
+#[test]
+pub fn test_clock_id_time() {
+    assert!(ClockId::CLOCK_REALTIME.time().is_ok());
+}
+
+#[cfg(target_os = "linux")]
+#[test]
+pub fn test_clock_id_pid_cpu_clock_id() {
+    assert!(ClockId::pid_cpu_clock_id(nix::unistd::Pid::this())
+        .map(ClockId::time)
+        .is_ok());
+}