time: Deprecate the library in the distribution

This commit deprecates the entire libtime library in favor of the
externally-provided libtime in the rust-lang organization. Users of the
`libtime` crate as-is today should add this to their Cargo manifests:

    [dependencies.time]
    git = "https://github.com/rust-lang/time"

To implement this transition, a new function `Duration::span` was added to the
`std::time::Duration` time. This function takes a closure and then returns the
duration of time it took that closure to execute. This interface will likely
improve with `FnOnce` unboxed closures as moving in and out will be a little
easier.

Due to the deprecation of the in-tree crate, this is a:

[breaking-change]

cc #18855, some of the conversions in the `src/test/bench` area may have been a
little nicer with that implemented

src/librustc/lib.rs

@@ -41,7 +41,6 @@ extern crate rustc_llvm;
 extern crate rustc_back;
 extern crate serialize;
 extern crate rbml;
-extern crate time;
 #[phase(plugin, link)] extern crate log;
 #[phase(plugin, link)] extern crate syntax;
 

src/librustc/metadata/loader.rs

@@ -228,16 +228,16 @@ use util::fs;
 
 use std::c_str::ToCStr;
 use std::cmp;
+use std::collections::hash_map::{Occupied, Vacant};
+use std::collections::{HashMap, HashSet};
 use std::io::fs::PathExtensions;
 use std::io;
 use std::ptr;
 use std::slice;
 use std::string;
+use std::time::Duration;
 
-use std::collections::{HashMap, HashSet};
-use std::collections::hash_map::{Occupied, Vacant};
 use flate;
-use time;
 
 pub struct CrateMismatch {
     path: Path,
@@ -691,11 +691,13 @@ impl ArchiveMetadata {
 
 // Just a small wrapper to time how long reading metadata takes.
 fn get_metadata_section(is_osx: bool, filename: &Path) -> Result<MetadataBlob, String> {
-    let start = time::precise_time_ns();
-    let ret = get_metadata_section_imp(is_osx, filename);
+    let mut ret = None;
+    let dur = Duration::span(|| {
+        ret = Some(get_metadata_section_imp(is_osx, filename));
+    });
     info!("reading {} => {}ms", filename.filename_display(),
-           (time::precise_time_ns() - start) / 1000000);
-    return ret;
+          dur.num_milliseconds());
+    return ret.unwrap();;
 }
 
 fn get_metadata_section_imp(is_osx: bool, filename: &Path) -> Result<MetadataBlob, String> {

src/librustc/middle/trans/base.rs

@@ -97,8 +97,6 @@ use syntax::visit::Visitor;
 use syntax::visit;
 use syntax::{ast, ast_util, ast_map};
 
-use time;
-
 local_data_key!(task_local_insn_key: RefCell<Vec<&'static str>>)
 
 pub fn with_insn_ctxt(blk: |&[&'static str]|) {
@@ -138,23 +136,16 @@ pub fn push_ctxt(s: &'static str) -> _InsnCtxt {
 pub struct StatRecorder<'a, 'tcx: 'a> {
     ccx: &'a CrateContext<'a, 'tcx>,
     name: Option<String>,
-    start: u64,
     istart: uint,
 }
 
 impl<'a, 'tcx> StatRecorder<'a, 'tcx> {
     pub fn new(ccx: &'a CrateContext<'a, 'tcx>, name: String)
                -> StatRecorder<'a, 'tcx> {
-        let start = if ccx.sess().trans_stats() {
-            time::precise_time_ns()
-        } else {
-            0
-        };
         let istart = ccx.stats().n_llvm_insns.get();
         StatRecorder {
             ccx: ccx,
             name: Some(name),
-            start: start,
             istart: istart,
         }
     }
@@ -164,11 +155,8 @@ impl<'a, 'tcx> StatRecorder<'a, 'tcx> {
 impl<'a, 'tcx> Drop for StatRecorder<'a, 'tcx> {
     fn drop(&mut self) {
         if self.ccx.sess().trans_stats() {
-            let end = time::precise_time_ns();
-            let elapsed = ((end - self.start) / 1_000_000) as uint;
             let iend = self.ccx.stats().n_llvm_insns.get();
             self.ccx.stats().fn_stats.borrow_mut().push((self.name.take().unwrap(),
-                                                       elapsed,
                                                        iend - self.istart));
             self.ccx.stats().n_fns.set(self.ccx.stats().n_fns.get() + 1);
             // Reset LLVM insn count to avoid compound costs.
@@ -3097,13 +3085,13 @@ pub fn trans_crate<'tcx>(analysis: CrateAnalysis<'tcx>)
         println!("n_inlines: {}", stats.n_inlines.get());
         println!("n_closures: {}", stats.n_closures.get());
         println!("fn stats:");
-        stats.fn_stats.borrow_mut().sort_by(|&(_, _, insns_a), &(_, _, insns_b)| {
+        stats.fn_stats.borrow_mut().sort_by(|&(_, insns_a), &(_, insns_b)| {
             insns_b.cmp(&insns_a)
         });
         for tuple in stats.fn_stats.borrow().iter() {
             match *tuple {
-                (ref name, ms, insns) => {
-                    println!("{} insns, {} ms, {}", insns, ms, *name);
+                (ref name, insns) => {
+                    println!("{} insns, {}", insns, *name);
                 }
             }
         }

src/librustc/middle/trans/context.rs

@@ -47,8 +47,8 @@ pub struct Stats {
     pub n_closures: Cell<uint>,
     pub n_llvm_insns: Cell<uint>,
     pub llvm_insns: RefCell<FnvHashMap<String, uint>>,
-    // (ident, time-in-ms, llvm-instructions)
-    pub fn_stats: RefCell<Vec<(String, uint, uint)> >,
+    // (ident, llvm-instructions)
+    pub fn_stats: RefCell<Vec<(String, uint)> >,
 }
 
 /// The shared portion of a `CrateContext`.  There is one `SharedCrateContext`

src/librustc/util/common.rs

@@ -12,26 +12,30 @@
 
 use std::cell::RefCell;
 use std::collections::HashMap;
-use std::hash::{Hash, Hasher};
 use std::fmt::Show;
+use std::hash::{Hash, Hasher};
+use std::time::Duration;
+
 use syntax::ast;
 use syntax::visit;
 use syntax::visit::Visitor;
 
-use time;
-
 pub fn time<T, U>(do_it: bool, what: &str, u: U, f: |U| -> T) -> T {
     local_data_key!(depth: uint);
     if !do_it { return f(u); }
 
     let old = depth.get().map(|d| *d).unwrap_or(0);
     depth.replace(Some(old + 1));
 
-    let start = time::precise_time_s();
-    let rv = f(u);
-    let end = time::precise_time_s();
+    let mut u = Some(u);
+    let mut rv = None;
+    let dur = Duration::span(|| {
+        rv = Some(f(u.take().unwrap()))
+    });
+    let rv = rv.unwrap();
 
-    println!("{}time: {:3.3f} s\t{}", "  ".repeat(old), end - start, what);
+    println!("{}time: {}.{:03} \t{}", "  ".repeat(old),
+             dur.num_seconds(), dur.num_milliseconds(), what);
     depth.replace(Some(old));
 
     rv

src/librustdoc/lib.rs

@@ -25,7 +25,6 @@ extern crate rustc;
 extern crate serialize;
 extern crate syntax;
 extern crate "test" as testing;
-extern crate time;
 #[phase(plugin, link)] extern crate log;
 
 use std::io;
@@ -238,7 +237,6 @@ pub fn main_args(args: &[String]) -> int {
     };
 
     info!("going to format");
-    let started = time::precise_time_ns();
     match matches.opt_str("w").as_ref().map(|s| s.as_slice()) {
         Some("html") | None => {
             match html::render::run(krate, &external_html, output.unwrap_or(Path::new("doc"))) {
@@ -257,8 +255,6 @@ pub fn main_args(args: &[String]) -> int {
             return 1;
         }
     }
-    let ended = time::precise_time_ns();
-    info!("Took {:.03f}s", (ended as f64 - started as f64) / 1e9f64);
 
     return 0;
 }

src/libstd/time/duration.rs

@@ -135,6 +135,14 @@ impl Duration {
         Duration { secs: secs, nanos: nanos as i32 }
     }
 
+    /// Runs a closure, returning the duration of time it took to run the
+    /// closure.
+    pub fn span(f: ||) -> Duration {
+        let before = super::precise_time_ns();
+        f();
+        Duration::nanoseconds((before - super::precise_time_ns()) as i64)
+    }
+
     /// Returns the total number of whole weeks in the duration.
     #[inline]
     pub fn num_weeks(&self) -> i64 {

src/libstd/time/mod.rs

@@ -10,6 +10,79 @@
 
 //! Temporal quantification.
 
+use libc;
+
 pub use self::duration::Duration;
 
 pub mod duration;
+
+/// Returns the current value of a high-resolution performance counter
+/// 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.doit(|| {
+                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;
+    }
+}