Add lifetime to `FutureObj`

3 files changed, 4 insertions, 154 deletions

diff --git a/src/libcore/task/executor.rs b/src/libcore/task/executor.rs
index 55ea5e724c1..f1db5093e98 100644
--- a/src/libcore/task/executor.rs
+++ b/src/libcore/task/executor.rs
@@ -13,7 +13,7 @@
             issue = "50547")]
 
 use fmt;
-use super::{FutureObj, LocalFutureObj};
+use future::{FutureObj, LocalFutureObj};
 
 /// A task executor.
 ///
@@ -29,7 +29,7 @@ pub trait Executor {
     ///
     /// The executor may be unable to spawn tasks, either because it has
     /// been shut down or is resource-constrained.
-    fn spawn_obj(&mut self, task: FutureObj<()>) -> Result<(), SpawnObjError>;
+    fn spawn_obj(&mut self, task: FutureObj<'static, ()>) -> Result<(), SpawnObjError>;
 
     /// Determine whether the executor is able to spawn new tasks.
     ///
@@ -76,7 +76,7 @@ pub struct SpawnObjError {
     pub kind: SpawnErrorKind,
 
     /// The task for which spawning was attempted
-    pub task: FutureObj<()>,
+    pub task: FutureObj<'static, ()>,
 }
 
 /// The result of a failed spawn
@@ -86,5 +86,5 @@ pub struct SpawnLocalObjError {
     pub kind: SpawnErrorKind,
 
     /// The task for which spawning was attempted
-    pub task: LocalFutureObj<()>,
+    pub task: LocalFutureObj<'static, ()>,
 }
diff --git a/src/libcore/task/future_obj.rs b/src/libcore/task/future_obj.rs
deleted file mode 100644
index 3ed3bd51cf6..00000000000
--- a/src/libcore/task/future_obj.rs
+++ /dev/null
@@ -1,147 +0,0 @@
-// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-#![unstable(feature = "futures_api",
-            reason = "futures in libcore are unstable",
-            issue = "50547")]
-
-use fmt;
-use future::Future;
-use marker::PhantomData;
-use mem::PinMut;
-use task::{Context, Poll};
-
-/// A custom trait object for polling futures, roughly akin to
-/// `Box<dyn Future<Output = T>>`.
-/// Contrary to `FutureObj`, `LocalFutureObj` does not have a `Send` bound.
-pub struct LocalFutureObj<T> {
-    ptr: *mut (),
-    poll_fn: unsafe fn(*mut (), &mut Context) -> Poll<T>,
-    drop_fn: unsafe fn(*mut ()),
-    _marker: PhantomData<T>,
-}
-
-impl<T> LocalFutureObj<T> {
-    /// Create a `LocalFutureObj` from a custom trait object representation.
-    #[inline]
-    pub fn new<F: UnsafeFutureObj<T>>(f: F) -> LocalFutureObj<T> {
-        LocalFutureObj {
-            ptr: f.into_raw(),
-            poll_fn: F::poll,
-            drop_fn: F::drop,
-            _marker: PhantomData,
-        }
-    }
-
-    /// Converts the `LocalFutureObj` into a `FutureObj`
-    /// To make this operation safe one has to ensure that the `UnsafeFutureObj`
-    /// instance from which this `LocalFutureObj` was created actually
-    /// implements `Send`.
-    #[inline]
-    pub unsafe fn as_future_obj(self) -> FutureObj<T> {
-        FutureObj(self)
-    }
-}
-
-impl<T> fmt::Debug for LocalFutureObj<T> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        f.debug_struct("LocalFutureObj")
-            .finish()
-    }
-}
-
-impl<T> From<FutureObj<T>> for LocalFutureObj<T> {
-    #[inline]
-    fn from(f: FutureObj<T>) -> LocalFutureObj<T> {
-        f.0
-    }
-}
-
-impl<T> Future for LocalFutureObj<T> {
-    type Output = T;
-
-    #[inline]
-    fn poll(self: PinMut<Self>, cx: &mut Context) -> Poll<T> {
-        unsafe {
-            (self.poll_fn)(self.ptr, cx)
-        }
-    }
-}
-
-impl<T> Drop for LocalFutureObj<T> {
-    fn drop(&mut self) {
-        unsafe {
-            (self.drop_fn)(self.ptr)
-        }
-    }
-}
-
-/// A custom trait object for polling futures, roughly akin to
-/// `Box<dyn Future<Output = T>> + Send`.
-pub struct FutureObj<T>(LocalFutureObj<T>);
-
-unsafe impl<T> Send for FutureObj<T> {}
-
-impl<T> FutureObj<T> {
-    /// Create a `FutureObj` from a custom trait object representation.
-    #[inline]
-    pub fn new<F: UnsafeFutureObj<T> + Send>(f: F) -> FutureObj<T> {
-        FutureObj(LocalFutureObj::new(f))
-    }
-}
-
-impl<T> fmt::Debug for FutureObj<T> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        f.debug_struct("FutureObj")
-            .finish()
-    }
-}
-
-impl<T> Future for FutureObj<T> {
-    type Output = T;
-
-    #[inline]
-    fn poll(self: PinMut<Self>, cx: &mut Context) -> Poll<T> {
-        let pinned_field = unsafe { PinMut::map_unchecked(self, |x| &mut x.0) };
-        pinned_field.poll(cx)
-    }
-}
-
-/// A custom implementation of a future trait object for `FutureObj`, providing
-/// a hand-rolled vtable.
-///
-/// This custom representation is typically used only in `no_std` contexts,
-/// where the default `Box`-based implementation is not available.
-///
-/// The implementor must guarantee that it is safe to call `poll` repeatedly (in
-/// a non-concurrent fashion) with the result of `into_raw` until `drop` is
-/// called.
-pub unsafe trait UnsafeFutureObj<T>: 'static {
-    /// Convert a owned instance into a (conceptually owned) void pointer.
-    fn into_raw(self) -> *mut ();
-
-    /// Poll the future represented by the given void pointer.
-    ///
-    /// # Safety
-    ///
-    /// The trait implementor must guarantee that it is safe to repeatedly call
-    /// `poll` with the result of `into_raw` until `drop` is called; such calls
-    /// are not, however, allowed to race with each other or with calls to `drop`.
-    unsafe fn poll(future: *mut (), cx: &mut Context) -> Poll<T>;
-
-    /// Drops the future represented by the given void pointer.
-    ///
-    /// # Safety
-    ///
-    /// The trait implementor must guarantee that it is safe to call this
-    /// function once per `into_raw` invocation; that call cannot race with
-    /// other calls to `drop` or `poll`.
-    unsafe fn drop(future: *mut ());
-}
diff --git a/src/libcore/task/mod.rs b/src/libcore/task/mod.rs
index 06cd7a9dd77..c4f07536164 100644
--- a/src/libcore/task/mod.rs
+++ b/src/libcore/task/mod.rs
@@ -25,8 +25,5 @@ pub use self::executor::{
 mod poll;
 pub use self::poll::Poll;
 
-mod future_obj;
-pub use self::future_obj::{FutureObj, LocalFutureObj, UnsafeFutureObj};
-
 mod wake;
 pub use self::wake::{Waker, LocalWaker, UnsafeWake};