std: Implement `thread::sleep`

This function is the current replacement for `std::old_io::timer` which will
soon be deprecated. This function is unstable and has its own feature gate as it
does not yet have an RFC nor has it existed for very long.

3 files changed, 50 insertions, 1 deletions

diff --git a/src/libstd/sys/unix/thread.rs b/src/libstd/sys/unix/thread.rs
index c5c86d8301d..04508294981 100644
--- a/src/libstd/sys/unix/thread.rs
+++ b/src/libstd/sys/unix/thread.rs
@@ -287,10 +287,24 @@ pub fn sleep(dur: Duration) {
         };
         // If we're awoken with a signal then the return value will be -1 and
         // nanosleep will fill in `ts` with the remaining time.
-        while libc::nanosleep(&ts, &mut ts) == -1 {
+        while dosleep(&mut ts) == -1 {
             assert_eq!(os::errno(), libc::EINTR);
         }
     }
+
+    #[cfg(target_os = "linux")]
+    unsafe fn dosleep(ts: *mut libc::timespec) -> libc::c_int {
+        extern {
+            fn clock_nanosleep(clock_id: libc::c_int, flags: libc::c_int,
+                               request: *const libc::timespec,
+                               remain: *mut libc::timespec) -> libc::c_int;
+        }
+        clock_nanosleep(libc::CLOCK_MONOTONIC, 0, ts, ts)
+    }
+    #[cfg(not(target_os = "linux"))]
+    unsafe fn dosleep(ts: *mut libc::timespec) -> libc::c_int {
+        libc::nanosleep(ts, ts)
+    }
 }
 
 // glibc >= 2.15 has a __pthread_get_minstack() function that returns
diff --git a/src/libstd/sys/windows/thread.rs b/src/libstd/sys/windows/thread.rs
index b361faba0f6..d1d4ad90081 100644
--- a/src/libstd/sys/windows/thread.rs
+++ b/src/libstd/sys/windows/thread.rs
@@ -20,6 +20,7 @@ use ptr;
 use sys_common::stack::RED_ZONE;
 use sys_common::thread::*;
 use thunk::Thunk;
+use time::Duration;
 
 pub type rust_thread = HANDLE;
 
@@ -82,6 +83,20 @@ pub unsafe fn yield_now() {
     SwitchToThread();
 }
 
+pub fn sleep(dur: Duration) {
+    unsafe {
+        if dur < Duration::zero() {
+            return yield_now()
+        }
+        let ms = dur.num_milliseconds();
+        // if we have a fractional number of milliseconds then add an extra
+        // millisecond to sleep for
+        let extra = dur - Duration::milliseconds(ms);
+        let ms = ms + if extra.is_zero() {0} else {1};
+        Sleep(ms as DWORD);
+    }
+}
+
 #[allow(non_snake_case)]
 extern "system" {
     fn CreateThread(lpThreadAttributes: LPSECURITY_ATTRIBUTES,
@@ -92,4 +107,5 @@ extern "system" {
                     lpThreadId: LPDWORD) -> HANDLE;
     fn WaitForSingleObject(hHandle: HANDLE, dwMilliseconds: DWORD) -> DWORD;
     fn SwitchToThread() -> BOOL;
+    fn Sleep(dwMilliseconds: DWORD);
 }
diff --git a/src/libstd/thread.rs b/src/libstd/thread.rs
index adc3b77407a..0216f324fdb 100644
--- a/src/libstd/thread.rs
+++ b/src/libstd/thread.rs
@@ -379,6 +379,19 @@ pub fn panicking() -> bool {
     unwind::panicking()
 }
 
+/// Put the current thread to sleep for the specified amount of time.
+///
+/// The thread may sleep longer than the duration specified due to scheduling
+/// specifics or platform-dependent functionality. Note that on unix platforms
+/// this function will not return early due to a signal being received or a
+/// spurious wakeup.
+#[unstable(feature = "thread_sleep",
+           reason = "recently added, needs an RFC, and `Duration` itself is \
+                     unstable")]
+pub fn sleep(dur: Duration) {
+    imp::sleep(dur)
+}
+
 /// Block unless or until the current thread's token is made available (may wake spuriously).
 ///
 /// See the module doc for more detail.
@@ -935,6 +948,12 @@ mod test {
         }
     }
 
+    #[test]
+    fn sleep_smoke() {
+        thread::sleep(Duration::milliseconds(2));
+        thread::sleep(Duration::milliseconds(-2));
+    }
+
     // NOTE: the corresponding test for stderr is in run-pass/task-stderr, due
     // to the test harness apparently interfering with stderr configuration.
 }