auto merge of #21132 : sfackler/rust/wait_timeout, r=alexcrichton

**The implementation is a direct adaptation of libcxx's condition_variable implementation.**

I also added a wait_timeout_with method, which matches the second overload in C++'s condition_variable. The implementation right now is kind of dumb but it works. There is an outstanding issue with it: as is it doesn't support the use case where a user doesn't care about poisoning and wants to continue through poison.

r? @alexcrichton @aturon 

1 files changed, 2 insertions, 66 deletions

diff --git a/src/libstd/time/mod.rs b/src/libstd/time/mod.rs
index d6c94f27a8b..f62571942a7 100644
--- a/src/libstd/time/mod.rs
+++ b/src/libstd/time/mod.rs
@@ -10,7 +10,7 @@
 
 //! Temporal quantification.
 
-use libc;
+use sys::time::SteadyTime;
 
 pub use self::duration::Duration;
 
@@ -20,69 +20,5 @@ pub mod duration;
 /// in nanoseconds since an unspecified epoch.
 // NB: this is intentionally not public, this is not ready to stabilize its api.
 fn precise_time_ns() -> u64 {
-    return os_precise_time_ns();
-
-    #[cfg(windows)]
-    fn os_precise_time_ns() -> u64 {
-        let mut ticks_per_s = 0;
-        assert_eq!(unsafe {
-            libc::QueryPerformanceFrequency(&mut ticks_per_s)
-        }, 1);
-        let ticks_per_s = if ticks_per_s == 0 {1} else {ticks_per_s};
-        let mut ticks = 0;
-        assert_eq!(unsafe {
-            libc::QueryPerformanceCounter(&mut ticks)
-        }, 1);
-
-        return (ticks as u64 * 1000000000) / (ticks_per_s as u64);
-    }
-
-    #[cfg(any(target_os = "macos", target_os = "ios"))]
-    fn os_precise_time_ns() -> u64 {
-        use sync;
-
-        static mut TIMEBASE: libc::mach_timebase_info = libc::mach_timebase_info { numer: 0,
-                                                                                   denom: 0 };
-        static ONCE: sync::Once = sync::ONCE_INIT;
-        unsafe {
-            ONCE.call_once(|| {
-                imp::mach_timebase_info(&mut TIMEBASE);
-            });
-            let time = imp::mach_absolute_time();
-            time * TIMEBASE.numer as u64 / TIMEBASE.denom as u64
-        }
-    }
-
-    #[cfg(not(any(windows, target_os = "macos", target_os = "ios")))]
-    fn os_precise_time_ns() -> u64 {
-        let mut ts = libc::timespec { tv_sec: 0, tv_nsec: 0 };
-        unsafe {
-            imp::clock_gettime(libc::CLOCK_MONOTONIC, &mut ts);
-        }
-        return (ts.tv_sec as u64) * 1000000000 + (ts.tv_nsec as u64)
-    }
-}
-
-#[cfg(all(unix, not(target_os = "macos"), not(target_os = "ios")))]
-mod imp {
-    use libc::{c_int, timespec};
-
-    // Apparently android provides this in some other library?
-    #[cfg(not(target_os = "android"))]
-    #[link(name = "rt")]
-    extern {}
-
-    extern {
-        pub fn clock_gettime(clk_id: c_int, tp: *mut timespec) -> c_int;
-    }
-
-}
-#[cfg(any(target_os = "macos", target_os = "ios"))]
-mod imp {
-    use libc::{c_int, mach_timebase_info};
-
-    extern {
-        pub fn mach_absolute_time() -> u64;
-        pub fn mach_timebase_info(info: *mut mach_timebase_info) -> c_int;
-    }
+    SteadyTime::now().ns()
 }