Rename Sleep to Delay (#270)

This patch renames `Sleep` from tokio-timer and the tokio facade to
`Delay`. Given that the future does not actually put anything to sleep,
the `Delay` name feels more appropriate.

Fixes #263

tokio-timer/src/deadline.rs

@@ -1,6 +1,4 @@
-//! Docs
-
-use Sleep;
+use Delay;
 
 use futures::{Future, Poll, Async};
 
@@ -19,7 +17,7 @@ use std::time::Instant;
 #[derive(Debug)]
 pub struct Deadline<T> {
     future: T,
-    sleep: Sleep,
+    delay: Delay,
 }
 
 /// Error returned by `Deadline` future.
@@ -43,13 +41,13 @@ impl<T> Deadline<T> {
     /// Create a new `Deadline` that completes when `future` completes or when
     /// `deadline` is reached.
     pub fn new(future: T, deadline: Instant) -> Deadline<T> {
-        Deadline::new_with_sleep(future, Sleep::new(deadline))
+        Deadline::new_with_delay(future, Delay::new(deadline))
     }
 
-    pub(crate) fn new_with_sleep(future: T, sleep: Sleep) -> Deadline<T> {
+    pub(crate) fn new_with_delay(future: T, delay: Delay) -> Deadline<T> {
         Deadline {
             future,
-            sleep,
+            delay,
         }
     }
 
@@ -84,7 +82,7 @@ where T: Future,
         }
 
         // Now check the timer
-        match self.sleep.poll() {
+        match self.delay.poll() {
             Ok(Async::NotReady) => Ok(Async::NotReady),
             Ok(Async::Ready(_)) => {
                 Err(DeadlineError::elapsed())

tokio-timer/src/delay.rs

@@ -7,40 +7,38 @@ use std::time::Instant;
 
 /// A future that completes at a specified instant in time.
 ///
-/// Instances of `Sleep` perform no work and complete with `()` once the
+/// Instances of `Delay` perform no work and complete with `()` once the
 /// specified deadline has been reached.
 ///
-/// `Sleep` has a resolution of one millisecond and should not be used for tasks
+/// `Delay` has a resolution of one millisecond and should not be used for tasks
 /// that require high-resolution timers.
 ///
 /// [`new`]: #method.new
 #[derive(Debug)]
-pub struct Sleep {
+pub struct Delay {
     /// The instant at which the future completes.
     deadline: Instant,
 
-    /// The link between the `Sleep` instance at the timer that drives it.
+    /// The link between the `Delay` instance at the timer that drives it.
     ///
-    /// When `Sleep` is created with `new`, this is initialized to `None` and is
+    /// When `Delay` is created with `new`, this is initialized to `None` and is
     /// lazily set in `poll`. When `poll` is called, the default for the current
     /// execution context is used (obtained via `Handle::current`).
     ///
-    /// When `sleep` is created with `new_with_registration`, the value is set.
+    /// When `delay` is created with `new_with_registration`, the value is set.
     ///
     /// Once `registration` is set to `Some`, it is never changed.
     registration: Option<Registration>,
 }
 
-// ===== impl Sleep =====
-
-impl Sleep {
-    /// Create a new `Sleep` instance that elapses at `deadline`.
+impl Delay {
+    /// Create a new `Delay` instance that elapses at `deadline`.
     ///
     /// Only millisecond level resolution is guaranteed. There is no guarantee
     /// as to how the sub-millisecond portion of `deadline` will be handled.
-    /// `Sleep` should not be used for high-resolution timer use cases.
-    pub fn new(deadline: Instant) -> Sleep {
-        Sleep {
+    /// `Delay` should not be used for high-resolution timer use cases.
+    pub fn new(deadline: Instant) -> Delay {
+        Delay {
             deadline,
             registration: None,
         }
@@ -48,9 +46,9 @@ impl Sleep {
 
     pub(crate) fn new_with_registration(
         deadline: Instant,
-        registration: Registration) -> Sleep
+        registration: Registration) -> Delay
     {
-        Sleep {
+        Delay {
             deadline,
             registration: Some(registration),
         }
@@ -61,18 +59,18 @@ impl Sleep {
         self.deadline
     }
 
-    /// Returns true if the `Sleep` has elapsed
+    /// Returns true if the `Delay` has elapsed
     ///
-    /// A `Sleep` is elapsed when the requested duration has elapsed.
+    /// A `Delay` is elapsed when the requested duration has elapsed.
     pub fn is_elapsed(&self) -> bool {
         self.registration.as_ref()
             .map(|r| r.is_elapsed())
             .unwrap_or(false)
     }
 
-    /// Reset the `Sleep` instance to a new deadline.
+    /// Reset the `Delay` instance to a new deadline.
     ///
-    /// Calling this function allows changing the instant at which the `Sleep`
+    /// Calling this function allows changing the instant at which the `Delay`
     /// future completes without having to create new associated state.
     ///
     /// This function can be called both before and after the future has
@@ -85,7 +83,7 @@ impl Sleep {
         }
     }
 
-    /// Register the sleep with the timer instance for the current execution
+    /// Register the delay with the timer instance for the current execution
     /// context.
     fn register(&mut self) {
         if self.registration.is_some() {
@@ -96,12 +94,12 @@ impl Sleep {
     }
 }
 
-impl Future for Sleep {
+impl Future for Delay {
     type Item = ();
     type Error = Error;
 
     fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
-        // Ensure the `Sleep` instance is associated with a timer.
+        // Ensure the `Delay` instance is associated with a timer.
         self.register();
 
         self.registration.as_ref().unwrap()

tokio-timer/src/interval.rs

@@ -1,4 +1,4 @@
-use Sleep;
+use Delay;
 
 use futures::{Future, Stream, Poll};
 
@@ -8,7 +8,7 @@ use std::time::{Instant, Duration};
 #[derive(Debug)]
 pub struct Interval {
     /// Future that completes the next time the `Interval` yields a value.
-    sleep: Sleep,
+    delay: Delay,
 
     /// The duration between values yielded by `Interval`.
     duration: Duration,
@@ -26,12 +26,12 @@ impl Interval {
     pub fn new(at: Instant, duration: Duration) -> Interval {
         assert!(duration > Duration::new(0, 0), "`duration` must be non-zero.");
 
-        Interval::new_with_sleep(Sleep::new(at), duration)
+        Interval::new_with_delay(Delay::new(at), duration)
     }
 
-    pub(crate) fn new_with_sleep(sleep: Sleep, duration: Duration) -> Interval {
+    pub(crate) fn new_with_delay(delay: Delay, duration: Duration) -> Interval {
         Interval {
-            sleep,
+            delay,
             duration,
         }
     }
@@ -42,15 +42,15 @@ impl Stream for Interval {
     type Error = ::Error;
 
     fn poll(&mut self) -> Poll<Option<Self::Item>, Self::Error> {
-        // Wait for the sleep to be done
-        let _ = try_ready!(self.sleep.poll());
+        // Wait for the delay to be done
+        let _ = try_ready!(self.delay.poll());
 
-        // Get the `now` by looking at the `sleep` deadline
-        let now = self.sleep.deadline();
+        // Get the `now` by looking at the `delay` deadline
+        let now = self.delay.deadline();
 
         // The next interval value is `duration` after the one that just
         // yielded.
-        self.sleep.reset(now + self.duration);
+        self.delay.reset(now + self.duration);
 
         // Return the current instant
         Ok(Some(now).into())

tokio-timer/src/lib.rs

@@ -2,7 +2,7 @@
 //!
 //! This crate provides a number of utilities for working with periods of time:
 //!
-//! * [`Sleep`]: A future that completes at a specified instant in time.
+//! * [`Delay`]: A future that completes at a specified instant in time.
 //!
 //! * [`Interval`] A stream that yields at fixed time intervals.
 //!
@@ -10,10 +10,10 @@
 //!   instant in time, erroring if the future takes too long.
 //!
 //! These three types are backed by a [`Timer`] instance. In order for
-//! [`Sleep`], [`Interval`], and [`Deadline`] to function, the associated
+//! [`Delay`], [`Interval`], and [`Deadline`] to function, the associated
 //! [`Timer`] instance must be running on some thread.
 //!
-//! [`Sleep`]: struct.Sleep.html
+//! [`Delay`]: struct.Delay.html
 //! [`Deadline`]: struct.Deadline.html
 //! [`Interval`]: struct.Interval.html
 //! [`Timer`]: timer/struct.Timer.html
@@ -30,12 +30,12 @@ pub mod timer;
 
 mod atomic;
 mod deadline;
+mod delay;
 mod error;
 mod interval;
-mod sleep;
 
 pub use self::deadline::{Deadline, DeadlineError};
+pub use self::delay::Delay;
 pub use self::error::Error;
 pub use self::interval::Interval;
 pub use self::timer::{Timer, with_default};
-pub use self::sleep::Sleep;

tokio-timer/src/timer/entry.rs

@@ -13,7 +13,7 @@ use std::sync::atomic::Ordering::SeqCst;
 use std::time::Instant;
 use std::u64;
 
-/// Internal state shared between a `Sleep` instance and the timer.
+/// Internal state shared between a `Delay` instance and the timer.
 ///
 /// This struct is used as a node in two intrusive data structures:
 ///
@@ -27,7 +27,7 @@ use std::u64;
 #[derive(Debug)]
 pub(crate) struct Entry {
     /// Timer internals. Using a weak pointer allows the timer to shutdown
-    /// without all `Sleep` instances having completed.
+    /// without all `Delay` instances having completed.
     inner: Weak<Inner>,
 
     /// Task to notify once the deadline is reached.
@@ -49,7 +49,7 @@ pub(crate) struct Entry {
     /// counter.
     ///
     /// One might think that it would be easier to just not create the `Entry`.
-    /// The problem is that `Sleep` expects creating a `Registration` to always
+    /// The problem is that `Delay` expects creating a `Registration` to always
     /// return a `Registration` instance. This simplifying factor allows it to
     /// improve the struct layout. To do this, we must always allocate the node.
     counted: bool,
@@ -66,8 +66,8 @@ pub(crate) struct Entry {
     /// When the entry expires, relative to the `start` of the timer
     /// (Inner::start). This is only used by the timer.
     ///
-    /// A `Sleep` instance can be reset to a different deadline by the thread
-    /// that owns the `Sleep` instance. In this case, the timer thread will not
+    /// A `Delay` instance can be reset to a different deadline by the thread
+    /// that owns the `Delay` instance. In this case, the timer thread will not
     /// immediately know that this has happened. The timer thread must know the
     /// last deadline that it saw as it uses this value to locate the entry in
     /// its wheel.

tokio-timer/src/timer/handle.rs

@@ -1,4 +1,4 @@
-use {Error, Sleep, Deadline, Interval};
+use {Error, Delay, Deadline, Interval};
 use timer::{Registration, Inner};
 
 use tokio_executor::Enter;
@@ -9,7 +9,7 @@ use std::time::{Duration, Instant};
 
 /// Handle to timer instance.
 ///
-/// The `Handle` allows creating `Sleep` instances that are driven by the
+/// The `Handle` allows creating `Delay` instances that are driven by the
 /// associated timer.
 ///
 /// A `Handle` is obtained by calling [`Timer::handle`].
@@ -25,14 +25,14 @@ thread_local!(static CURRENT_TIMER: RefCell<Option<Handle>> = RefCell::new(None)
 
 /// Set the default timer for the duration of the closure.
 ///
-/// From within the closure, [`Sleep`] instances that are created via
-/// [`Sleep::new`] can be used.
+/// From within the closure, [`Delay`] instances that are created via
+/// [`Delay::new`] can be used.
 ///
 /// # Panics
 ///
 /// This function panics if there already is a default timer set.
 ///
-/// [`Sleep`]: ../struct.Sleep.html
+/// [`Delay`]: ../struct.Delay.html
 pub fn with_default<F, R>(handle: &Handle, enter: &mut Enter, f: F) -> R
 where F: FnOnce(&mut Enter) -> R
 {
@@ -77,7 +77,7 @@ impl Handle {
     ///
     /// This function should only be called from within the context of
     /// [`with_default`]. Calling this function from outside of this context
-    /// will return a `Handle` that does not reference a timer. `Sleep`
+    /// will return a `Handle` that does not reference a timer. `Delay`
     /// instances created with this handle will error.
     ///
     /// [`with_default`]: ../fn.with_default.html
@@ -86,21 +86,21 @@ impl Handle {
             .unwrap_or(Handle { inner: Weak::new() })
     }
 
-    /// Create a `Sleep` driven by this handle's associated `Timer`.
-    pub fn sleep(&self, deadline: Instant) -> Sleep {
+    /// Create a `Delay` driven by this handle's associated `Timer`.
+    pub fn delay(&self, deadline: Instant) -> Delay {
         let registration = Registration::new_with_handle(deadline, self.clone());
-        Sleep::new_with_registration(deadline, registration)
+        Delay::new_with_registration(deadline, registration)
     }
 
     /// Create a `Deadline` driven by this handle's associated `Timer`.
     pub fn deadline<T>(&self, future: T, deadline: Instant) -> Deadline<T> {
-        Deadline::new_with_sleep(future, self.sleep(deadline))
+        Deadline::new_with_delay(future, self.delay(deadline))
     }
 
     /// Create a new `Interval` that starts at `at` and yields every `duration`
     /// interval after that.
     pub fn interval(&self, at: Instant, duration: Duration) -> Interval {
-        Interval::new_with_sleep(self.sleep(at), duration)
+        Interval::new_with_delay(self.delay(at), duration)
     }
 
     /// Try to get a handle to the current timer.

tokio-timer/src/timer/mod.rs

@@ -3,12 +3,12 @@
 //! This module contains the types needed to run a timer.
 //!
 //! The [`Timer`] type runs the timer logic. It holds all the necessary state
-//! to track all associated [`Sleep`] instances and delivering notifications
+//! to track all associated [`Delay`] instances and delivering notifications
 //! once the deadlines are reached.
 //!
 //! The [`Handle`] type is a reference to a [`Timer`] instance. This type is
 //! `Clone`, `Send`, and `Sync`. This type is used to create instances of
-//! [`Sleep`].
+//! [`Delay`].
 //!
 //! The [`Now`] trait describes how to get an `Instance` representing the
 //! current moment in time. [`SystemNow`] is the default implementation, where
@@ -23,7 +23,7 @@
 //!
 //! [`Timer`]: struct.Timer.html
 //! [`Handle`]: struct.Handle.html
-//! [`Sleep`]: ../struct.Sleep.html
+//! [`Delay`]: ../struct.Delay.html
 //! [`Now`]: trait.Now.html
 //! [`Now::now`]: trait.Now.html#method.now
 
@@ -52,16 +52,16 @@ use std::sync::atomic::AtomicUsize;
 use std::sync::atomic::Ordering::SeqCst;
 use std::usize;
 
-/// Timer implementation that drives [`Sleep`], [`Interval`], and [`Deadline`].
+/// Timer implementation that drives [`Delay`], [`Interval`], and [`Deadline`].
 ///
 /// A `Timer` instance tracks the state necessary for managing time and
-/// notifying the [`Sleep`] instances once their deadlines are reached.
+/// notifying the [`Delay`] instances once their deadlines are reached.
 ///
 /// It is expected that a single `Timer` instance manages many individual
-/// `Sleep` instances. The `Timer` implementation is thread-safe and, as such,
+/// `Delay` instances. The `Timer` implementation is thread-safe and, as such,
 /// is able to handle callers from across threads.
 ///
-/// Callers do not use `Timer` directly to create `Sleep` instances.  Instead,
+/// Callers do not use `Timer` directly to create `Delay` instances.  Instead,
 /// [`Handle`] is used. A handle for the timer instance is obtained by calling
 /// [`handle`]. [`Handle`] is the type that implements `Clone` and is `Send +
 /// Sync`.
@@ -73,9 +73,9 @@ use std::usize;
 /// The `Timer` has a resolution of one millisecond. Any unit of time that falls
 /// between milliseconds are rounded up to the next millisecond.
 ///
-/// When the `Timer` instance is dropped, any outstanding `Sleep` instance that
+/// When the `Timer` instance is dropped, any outstanding `Delay` instance that
 /// has not elapsed will be notified with an error. At this point, calling
-/// `poll` on the sleep instance will result in `Err` being returned.
+/// `poll` on the `Delay` instance will result in `Err` being returned.
 ///
 /// # Implementation
 ///
@@ -102,13 +102,13 @@ use std::usize;
 /// * Level 5: 64 x ~12 day slots.
 ///
 /// When the timer processes entries at level zero, it will notify all the
-/// [`Sleep`] instances as their deadlines have been reached. For all higher
+/// [`Delay`] instances as their deadlines have been reached. For all higher
 /// levels, all entries will be redistributed across the wheel at the next level
-/// down. Eventually, as time progresses, entries will `Sleep` instances will
+/// down. Eventually, as time progresses, entries will `Delay` instances will
 /// either be canceled (dropped) or their associated entries will reach level
 /// zero and be notified.
 ///
-/// [`Sleep`]: ../struct.Sleep.html
+/// [`Delay`]: ../struct.Delay.html
 /// [`Interval`]: ../struct.Interval.html
 /// [`Deadline`]: ../struct.Deadline.html
 /// [paper]: http://www.cs.columbia.edu/~nahum/w6998/papers/ton97-timing-wheels.pdf
@@ -172,7 +172,7 @@ pub(crate) struct Inner {
 /// precision of 1 millisecond.
 const NUM_LEVELS: usize = 6;
 
-/// The maximum duration of a sleep
+/// The maximum duration of a delay
 const MAX_DURATION: u64 = 1 << (6 * NUM_LEVELS);
 
 /// Maximum number of timeouts the system can handle concurrently.
@@ -187,7 +187,7 @@ where T: Park
     /// thread.
     ///
     /// Once the timer has been created, a handle can be obtained using
-    /// [`handle`]. The handle is used to create `Sleep` instances.
+    /// [`handle`]. The handle is used to create `Delay` instances.
     ///
     /// Use `default` when constructing a `Timer` using the default `park`
     /// instance.
@@ -236,7 +236,7 @@ where T: Park,
 
     /// Returns a handle to the timer.
     ///
-    /// The `Handle` is how `Sleep` instances are created. The `Sleep` instances
+    /// The `Handle` is how `Delay` instances are created. The `Delay` instances
     /// can either be created directly or the `Handle` instance can be passed to
     /// `with_default`, setting the timer as the default timer for the execution
     /// context.
@@ -250,7 +250,7 @@ where T: Park,
     /// instance to make progress. This is where the work happens.
     ///
     /// The `Timer` will use the `Park` instance that was specified in [`new`]
-    /// to block the current thread until the next `Sleep` instance elapses. One
+    /// to block the current thread until the next `Delay` instance elapses. One
     /// call to `turn` results in at most one call to `park.park()`.
     ///
     /// # Return

tokio-timer/src/timer/registration.rs

@@ -8,7 +8,7 @@ use std::time::Instant;
 
 /// Registration with a timer.
 ///
-/// The association between a `Sleep` instance and a timer is done lazily in
+/// The association between a `Delay` instance and a timer is done lazily in
 /// `poll`
 #[derive(Debug)]
 pub(crate) struct Registration {