implement clock_gettime, clock_getres, clock_settime

Author: kevinwern

CHANGELOG.md

@@ -21,6 +21,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
   ([#1058](https://github.com/nix-rust/nix/pull/1058))
 - Add `renameat`.
   ([#1097](https://github.com/nix-rust/nix/pull/1097))
+- Add `clock_gettime`, `clock_settime`, `clock_getres`
+  ([#1100](https://github.com/nix-rust/nix/pull/1100))
 
 ### Changed
 - Support for `ifaddrs` now present when building for Android.

src/lib.rs

@@ -66,6 +66,7 @@ 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/sys/time.rs

@@ -67,6 +67,12 @@ impl AsRef<timespec> for TimeSpec {
     }
 }
 
+impl From<timespec> for TimeSpec {
+    fn from(ts: timespec) -> Self {
+        TimeSpec(ts)
+    }
+}
+
 impl Ord for TimeSpec {
     // The implementation of cmp is simplified by assuming that the struct is
     // normalized.  That is, tv_nsec must always be within [0, 1_000_000_000)

src/time.rs

@@ -0,0 +1,118 @@
+use sys::time::TimeSpec;
+use {Result, Errno};
+use libc;
+
+libc_enum! {
+    #[repr(i32)]
+    pub enum ClockId {
+        #[cfg(any(target_os = "fuchsia",
+                  target_os = "linux",
+                  target_os = "android",
+                  target_os = "emscripten"))]
+        CLOCK_BOOTTIME,
+        #[cfg(any(target_os = "fuchsia",
+                  target_os = "linux",
+                  target_os = "android",
+                  target_os = "emscripten"))]
+        CLOCK_BOOTTIME_ALARM,
+        CLOCK_MONOTONIC,
+        #[cfg(any(target_os = "fuchsia",
+                  target_os = "linux",
+                  target_os = "android",
+                  target_os = "emscripten"))]
+        CLOCK_MONOTONIC_COARSE,
+        #[cfg(any(target_os = "freebsd",
+                  target_os = "dragonfly"))]
+        CLOCK_MONOTONIC_FAST,
+        #[cfg(any(target_os = "freebsd",
+                  target_os = "dragonfly"))]
+        CLOCK_MONOTONIC_PRECISE,
+        #[cfg(any(target_os = "fuchsia",
+                  target_os = "linux",
+                  target_os = "android",
+                  target_os = "emscripten"))]
+        CLOCK_MONOTONIC_RAW,
+        #[cfg(any(target_os = "fuchsia",
+                  target_env = "uclibc",
+                  target_os = "macos",
+                  target_os = "ios",
+                  target_os = "freebsd",
+                  target_os = "dragonfly",
+                  target_os = "linux",
+                  target_os = "android",
+                  target_os = "emscripten"))]
+        CLOCK_PROCESS_CPUTIME_ID,
+        #[cfg(any(target_os = "freebsd",
+                  target_os = "dragonfly"))]
+        CLOCK_PROF,
+        CLOCK_REALTIME,
+        #[cfg(any(target_os = "fuchsia",
+                  target_os = "linux",
+                  target_os = "android",
+                  target_os = "emscripten"))]
+        CLOCK_REALTIME_ALARM,
+        #[cfg(any(target_os = "fuchsia",
+                  target_os = "linux",
+                  target_os = "android",
+                  target_os = "emscripten"))]
+        CLOCK_REALTIME_COARSE,
+        #[cfg(any(target_os = "freebsd",
+                  target_os = "dragonfly"))]
+        CLOCK_REALTIME_FAST,
+        #[cfg(any(target_os = "freebsd",
+                  target_os = "dragonfly"))]
+        CLOCK_REALTIME_PRECISE,
+        #[cfg(any(target_os = "freebsd",
+                  target_os = "dragonfly"))]
+        CLOCK_SECOND,
+        #[cfg(any(target_os = "fuchsia",
+                  target_os = "emscripten",
+                  all(target_os = "linux", target_env = "musl")))]
+        CLOCK_SGI_CYCLE,
+        #[cfg(any(target_os = "fuchsia",
+                  target_os = "emscripten",
+                  all(target_os = "linux", target_env = "musl")))]
+        CLOCK_TAI,
+        #[cfg(any(target_os = "fuchsia",
+                  target_os = "ios",
+                  target_os = "macos",
+                  target_os = "freebsd",
+                  target_os = "dragonfly",
+                  target_os = "linux",
+                  target_os = "android",
+                  target_os = "emscripten",
+                  target_env = "uclibc"))]
+        CLOCK_THREAD_CPUTIME_ID,
+        #[cfg(any(target_os = "freebsd",
+                  target_os = "dragonfly"))]
+        CLOCK_UPTIME,
+        #[cfg(any(target_os = "freebsd",
+                  target_os = "dragonfly"))]
+        CLOCK_UPTIME_FAST,
+        #[cfg(any(target_os = "freebsd",
+                  target_os = "dragonfly"))]
+        CLOCK_UPTIME_PRECISE,
+        #[cfg(any(target_os = "freebsd",
+                  target_os = "dragonfly"))]
+        CLOCK_VIRTUAL,
+    }
+}
+
+pub fn clock_getres(clk_id: ClockId) -> Result<TimeSpec> {
+    let mut c_time = libc::timespec {tv_sec: 0, tv_nsec: 0};
+    let res = unsafe { libc::clock_getres(clk_id as libc::c_int, &mut c_time) };
+    Errno::result(res)?;
+    Ok(TimeSpec::from(c_time))
+}
+
+pub fn clock_gettime(clk_id: ClockId) -> Result<TimeSpec> {
+    let mut c_time = libc::timespec {tv_sec: 0, tv_nsec: 0};
+    let res = unsafe { libc::clock_gettime(clk_id as libc::c_int, &mut c_time) };
+    Errno::result(res)?;
+    Ok(TimeSpec::from(c_time))
+}
+
+pub fn clock_settime(clk_id: ClockId, timespec: TimeSpec) -> Result<()> {
+    let res = unsafe { libc::clock_settime(clk_id as libc::c_int, timespec.as_ref()) };
+    Errno::result(res).map(drop)
+}

test/test.rs

@@ -86,6 +86,7 @@ mod test_pty;
           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 +1,32 @@
+use nix::time::{clock_getres, clock_gettime, clock_settime, ClockId};
+use nix::Error;
+use nix::errno::Errno;
+use nix::sys::time::TimeSpec;
+use libc::timespec;
+
+#[test]
+pub fn test_clock_getres() {
+    clock_getres(ClockId::CLOCK_REALTIME).unwrap();
+}
+
+#[test]
+pub fn test_clock_gettime() {
+    let res1 = clock_gettime(ClockId::CLOCK_REALTIME).unwrap();
+    let res2 = clock_gettime(ClockId::CLOCK_REALTIME).unwrap();
+    assert!(res1 < res2);
+}
+
+#[test]
+pub fn test_clock_settime() {
+    require_capability!(CAP_SYS_TIME);
+    let ts = TimeSpec::from(timespec{tv_sec: 10000000, tv_nsec: 100});
+    let res = clock_settime(ClockId::CLOCK_REALTIME, ts).unwrap();
+}
+
+#[test]
+pub fn test_clock_settime_err() {
+    require_capability!(CAP_SYS_TIME);
+    let ts = TimeSpec::from(timespec{tv_sec: 10000000, tv_nsec: 100});
+    let err = clock_settime(ClockId::CLOCK_MONOTONIC, ts).unwrap_err();
+    assert_eq!(err, Error::Sys(Errno::EINVAL));
+}