rollup merge of #20315: alexcrichton/std-sync

Conflicts:
	src/libstd/rt/exclusive.rs
	src/libstd/sync/barrier.rs
	src/libstd/sys/unix/pipe.rs
	src/test/bench/shootout-binarytrees.rs
	src/test/bench/shootout-fannkuch-redux.rs

src/doc/guide-tasks.md

@@ -206,6 +206,7 @@ getting the result later.
 The basic example below illustrates this.
 
 ```{rust,ignore}
+# #![allow(deprecated)]
 use std::sync::Future;
 
 # fn main() {
@@ -233,6 +234,7 @@ Here is another example showing how futures allow you to background
 computations. The workload will be distributed on the available cores.
 
 ```{rust,ignore}
+# #![allow(deprecated)]
 # use std::num::Float;
 # use std::sync::Future;
 fn partial_sum(start: uint) -> f64 {

src/doc/guide.md

@@ -5339,6 +5339,7 @@ example, if you wish to compute some value in the background, `Future` is
 a useful thing to use:
 
 ```{rust}
+# #![allow(deprecated)]
 use std::sync::Future;
 
 let mut delayed_value = Future::spawn(move || {

src/doc/reference.md

@@ -1480,9 +1480,9 @@ data are being stored, or single-address and mutability properties are required.
 ```
 use std::sync::atomic;
 
-// Note that INIT_ATOMIC_UINT is a *const*, but it may be used to initialize a
+// Note that ATOMIC_UINT_INIT is a *const*, but it may be used to initialize a
 // static. This static can be modified, so it is not placed in read-only memory.
-static COUNTER: atomic::AtomicUint = atomic::INIT_ATOMIC_UINT;
+static COUNTER: atomic::AtomicUint = atomic::ATOMIC_UINT_INIT;
 
 // This table is a candidate to be placed in read-only memory.
 static TABLE: &'static [uint] = &[1, 2, 3, /* ... */];

src/libcollections/vec.rs

@@ -2265,7 +2265,7 @@ mod tests {
             }
         }
         const NUM_ELEMENTS: uint = 2;
-        static DROP_COUNTER: AtomicUint = atomic::INIT_ATOMIC_UINT;
+        static DROP_COUNTER: AtomicUint = atomic::ATOMIC_UINT_INIT;
 
         let v = Vec::from_elem(NUM_ELEMENTS, Nothing);
 

src/libcore/atomic.rs

@@ -89,17 +89,27 @@ pub enum Ordering {
 
 /// An `AtomicBool` initialized to `false`.
 #[unstable = "may be renamed, pending conventions for static initalizers"]
-pub const INIT_ATOMIC_BOOL: AtomicBool =
+pub const ATOMIC_BOOL_INIT: AtomicBool =
         AtomicBool { v: UnsafeCell { value: 0 } };
 /// An `AtomicInt` initialized to `0`.
 #[unstable = "may be renamed, pending conventions for static initalizers"]
-pub const INIT_ATOMIC_INT: AtomicInt =
+pub const ATOMIC_INT_INIT: AtomicInt =
         AtomicInt { v: UnsafeCell { value: 0 } };
 /// An `AtomicUint` initialized to `0`.
 #[unstable = "may be renamed, pending conventions for static initalizers"]
-pub const INIT_ATOMIC_UINT: AtomicUint =
+pub const ATOMIC_UINT_INIT: AtomicUint =
         AtomicUint { v: UnsafeCell { value: 0, } };
 
+/// Deprecated
+#[deprecated = "renamed to ATOMIC_BOOL_INIT"]
+pub const INIT_ATOMIC_BOOL: AtomicBool = ATOMIC_BOOL_INIT;
+/// Deprecated
+#[deprecated = "renamed to ATOMIC_INT_INIT"]
+pub const INIT_ATOMIC_INT: AtomicInt = ATOMIC_INT_INIT;
+/// Deprecated
+#[deprecated = "renamed to ATOMIC_UINT_INIT"]
+pub const INIT_ATOMIC_UINT: AtomicUint = ATOMIC_UINT_INIT;
+
 // NB: Needs to be -1 (0b11111111...) to make fetch_nand work correctly
 const UINT_TRUE: uint = -1;
 

src/libcore/cell.rs

@@ -155,6 +155,8 @@
 // FIXME: Can't be shared between threads. Dynamic borrows
 // FIXME: Relationship to Atomic types and RWLock
 
+#![stable]
+
 use clone::Clone;
 use cmp::PartialEq;
 use default::Default;

src/libcoretest/atomic.rs

@@ -70,9 +70,9 @@ fn int_xor() {
     assert_eq!(x.load(SeqCst), 0xf731 ^ 0x137f);
 }
 
-static S_BOOL : AtomicBool = INIT_ATOMIC_BOOL;
+static S_BOOL : AtomicBool = ATOMIC_BOOL_INIT;
-static S_INT  : AtomicInt  = INIT_ATOMIC_INT;
+static S_INT  : AtomicInt  = ATOMIC_INT_INIT;
-static S_UINT : AtomicUint = INIT_ATOMIC_UINT;
+static S_UINT : AtomicUint = ATOMIC_UINT_INIT;
 
 #[test]
 fn static_init() {

src/liblog/lib.rs

@@ -352,7 +352,7 @@ pub struct LogLocation {
 #[doc(hidden)]
 pub fn mod_enabled(level: u32, module: &str) -> bool {
     static INIT: Once = ONCE_INIT;
-    INIT.doit(init);
+    INIT.call_once(init);
 
     // It's possible for many threads are in this function, only one of them
     // will perform the global initialization, but all of them will need to check

src/librustc/middle/infer/region_inference/graphviz.rs

@@ -73,7 +73,7 @@ pub fn maybe_print_constraints_for<'a, 'tcx>(region_vars: &RegionVarBindings<'a,
     let output_path = {
         let output_template = match requested_output {
             Some(ref s) if s.as_slice() == "help" => {
-                static PRINTED_YET : atomic::AtomicBool = atomic::INIT_ATOMIC_BOOL;
+                static PRINTED_YET : atomic::AtomicBool = atomic::ATOMIC_BOOL_INIT;
                 if !PRINTED_YET.load(atomic::SeqCst) {
                     print_help_message();
                     PRINTED_YET.store(true, atomic::SeqCst);

src/librustc_trans/back/write.rs

@@ -1011,7 +1011,7 @@ unsafe fn configure_llvm(sess: &Session) {
         }
     }
 
-    INIT.doit(|| {
+    INIT.call_once(|| {
         llvm::LLVMInitializePasses();
 
         // Only initialize the platforms supported by Rust here, because

src/librustc_trans/trans/base.rs

@@ -3097,7 +3097,7 @@ pub fn trans_crate<'tcx>(analysis: ty::CrateAnalysis<'tcx>)
         use std::sync::{Once, ONCE_INIT};
         static INIT: Once = ONCE_INIT;
         static mut POISONED: bool = false;
-        INIT.doit(|| {
+        INIT.call_once(|| {
             if llvm::LLVMStartMultithreaded() != 1 {
                 // use an extra bool to make sure that all future usage of LLVM
                 // cannot proceed despite the Once not running more than once.

src/libstd/io/buffered.rs

@@ -22,7 +22,6 @@ use result::Result::{Ok, Err};
 use slice::{SliceExt};
 use slice;
 use vec::Vec;
-use kinds::{Send,Sync};
 
 /// Wraps a Reader and buffers input from it
 ///
@@ -52,11 +51,6 @@ pub struct BufferedReader<R> {
     cap: uint,
 }
 
-
-unsafe impl<R: Send> Send for BufferedReader<R> {}
-unsafe impl<R: Send+Sync> Sync for BufferedReader<R> {}
-
-
 impl<R: Reader> BufferedReader<R> {
     /// Creates a new `BufferedReader` with the specified buffer capacity
     pub fn with_capacity(cap: uint, inner: R) -> BufferedReader<R> {

src/libstd/io/stdio.rs

@@ -218,7 +218,7 @@ pub fn stdin() -> StdinReader {
     static ONCE: Once = ONCE_INIT;
 
     unsafe {
-        ONCE.doit(|| {
+        ONCE.call_once(|| {
             // The default buffer capacity is 64k, but apparently windows doesn't like
             // 64k reads on stdin. See #13304 for details, but the idea is that on
             // windows we use a slightly smaller buffer that's been seen to be

src/libstd/io/tempfile.rs

@@ -90,7 +90,7 @@ impl TempDir {
             return TempDir::new_in(&abs_tmpdir, suffix);
         }
 
-        static CNT: atomic::AtomicUint = atomic::INIT_ATOMIC_UINT;
+        static CNT: atomic::AtomicUint = atomic::ATOMIC_UINT_INIT;
 
         let mut attempts = 0u;
         loop {

src/libstd/io/test.rs

@@ -17,17 +17,17 @@ use prelude::v1::*;
 use libc;
 use os;
 use std::io::net::ip::*;
-use sync::atomic::{AtomicUint, INIT_ATOMIC_UINT, Relaxed};
+use sync::atomic::{AtomicUint, ATOMIC_UINT_INIT, Relaxed};
 
 /// Get a port number, starting at 9600, for use in tests
 pub fn next_test_port() -> u16 {
-    static NEXT_OFFSET: AtomicUint = INIT_ATOMIC_UINT;
+    static NEXT_OFFSET: AtomicUint = ATOMIC_UINT_INIT;
     base_port() + NEXT_OFFSET.fetch_add(1, Relaxed) as u16
 }
 
 /// Get a temporary path which could be the location of a unix socket
 pub fn next_test_unix() -> Path {
-    static COUNT: AtomicUint = INIT_ATOMIC_UINT;
+    static COUNT: AtomicUint = ATOMIC_UINT_INIT;
     // base port and pid are an attempt to be unique between multiple
     // test-runners of different configurations running on one
     // buildbot, the count is to be unique within this executable.

src/libstd/os.rs

@@ -55,7 +55,7 @@ use slice::{AsSlice, SliceExt};
 use slice::CloneSliceExt;
 use str::{Str, StrExt};
 use string::{String, ToString};
-use sync::atomic::{AtomicInt, INIT_ATOMIC_INT, SeqCst};
+use sync::atomic::{AtomicInt, ATOMIC_INT_INIT, SeqCst};
 use vec::Vec;
 
 #[cfg(unix)] use c_str::ToCStr;
@@ -596,7 +596,7 @@ pub fn last_os_error() -> String {
     error_string(errno() as uint)
 }
 
-static EXIT_STATUS: AtomicInt = INIT_ATOMIC_INT;
+static EXIT_STATUS: AtomicInt = ATOMIC_INT_INIT;
 
 /// Sets the process exit code
 ///

src/libstd/rand/os.rs

@@ -84,10 +84,10 @@ mod imp {
     #[cfg(all(target_os = "linux",
               any(target_arch = "x86_64", target_arch = "x86", target_arch = "arm")))]
     fn is_getrandom_available() -> bool {
-        use sync::atomic::{AtomicBool, INIT_ATOMIC_BOOL, Relaxed};
+        use sync::atomic::{AtomicBool, ATOMIC_BOOL_INIT, Relaxed};
 
-        static GETRANDOM_CHECKED: AtomicBool = INIT_ATOMIC_BOOL;
+        static GETRANDOM_CHECKED: AtomicBool = ATOMIC_BOOL_INIT;
-        static GETRANDOM_AVAILABLE: AtomicBool = INIT_ATOMIC_BOOL;
+        static GETRANDOM_AVAILABLE: AtomicBool = ATOMIC_BOOL_INIT;
 
         if !GETRANDOM_CHECKED.load(Relaxed) {
             let mut buf: [u8; 0] = [];

src/libstd/rt/backtrace.rs

@@ -22,7 +22,7 @@ pub use sys::backtrace::write;
 // For now logging is turned off by default, and this function checks to see
 // whether the magical environment variable is present to see if it's turned on.
 pub fn log_enabled() -> bool {
-    static ENABLED: atomic::AtomicInt = atomic::INIT_ATOMIC_INT;
+    static ENABLED: atomic::AtomicInt = atomic::ATOMIC_INT_INIT;
     match ENABLED.load(atomic::SeqCst) {
         1 => return false,
         2 => return true,

src/libstd/rt/exclusive.rs

@@ -1,119 +0,0 @@
-// Copyright 2013 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.
-
-use core::prelude::*;
-
-use cell::UnsafeCell;
-use rt::mutex;
-
-/// An OS mutex over some data.
-///
-/// This is not a safe primitive to use, it is unaware of the libgreen
-/// scheduler, as well as being easily susceptible to misuse due to the usage of
-/// the inner NativeMutex.
-///
-/// > **Note**: This type is not recommended for general use. The mutex provided
-/// >           as part of `libsync` should almost always be favored.
-pub struct Exclusive<T> {
-    lock: mutex::NativeMutex,
-    data: UnsafeCell<T>,
-}
-
-unsafe impl<T:Send> Send for Exclusive<T> { }
-
-unsafe impl<T:Send> Sync for Exclusive<T> { }
-
-/// An RAII guard returned via `lock`
-pub struct ExclusiveGuard<'a, T:'a> {
-    // FIXME #12808: strange name to try to avoid interfering with
-    // field accesses of the contained type via Deref
-    _data: &'a mut T,
-    _guard: mutex::LockGuard<'a>,
-}
-
-impl<T: Send> Exclusive<T> {
-    /// Creates a new `Exclusive` which will protect the data provided.
-    pub fn new(user_data: T) -> Exclusive<T> {
-        Exclusive {
-            lock: unsafe { mutex::NativeMutex::new() },
-            data: UnsafeCell::new(user_data),
-        }
-    }
-
-    /// Acquires this lock, returning a guard which the data is accessed through
-    /// and from which that lock will be unlocked.
-    ///
-    /// This method is unsafe due to many of the same reasons that the
-    /// NativeMutex itself is unsafe.
-    pub unsafe fn lock<'a>(&'a self) -> ExclusiveGuard<'a, T> {
-        let guard = self.lock.lock();
-        let data = &mut *self.data.get();
-
-        ExclusiveGuard {
-            _data: data,
-            _guard: guard,
-        }
-    }
-}
-
-impl<'a, T: Send> ExclusiveGuard<'a, T> {
-    // The unsafety here should be ok because our loan guarantees that the lock
-    // itself is not moving
-    pub fn signal(&self) {
-        unsafe { self._guard.signal() }
-    }
-    pub fn wait(&self) {
-        unsafe { self._guard.wait() }
-    }
-}
-
-impl<'a, T: Send> Deref<T> for ExclusiveGuard<'a, T> {
-    fn deref(&self) -> &T { &*self._data }
-}
-impl<'a, T: Send> DerefMut<T> for ExclusiveGuard<'a, T> {
-    fn deref_mut(&mut self) -> &mut T { &mut *self._data }
-}
-
-#[cfg(test)]
-mod tests {
-    use prelude::v1::*;
-    use sync::Arc;
-    use super::Exclusive;
-    use task;
-
-    #[test]
-    fn exclusive_new_arc() {
-        unsafe {
-            let mut futures = Vec::new();
-
-            let num_tasks = 10;
-            let count = 10;
-
-            let total = Arc::new(Exclusive::new(box 0));
-
-            for _ in range(0u, num_tasks) {
-                let total = total.clone();
-                let (tx, rx) = channel();
-                futures.push(rx);
-
-                task::spawn(move || {
-                    for _ in range(0u, count) {
-                        **total.lock() += 1;
-                    }
-                    tx.send(());
-                });
-            };
-
-            for f in futures.iter_mut() { f.recv() }
-
-            assert_eq!(**total.lock(), num_tasks * count);
-        }
-    }
-}

src/libstd/rt/task.rs

@@ -1,554 +0,0 @@
-// Copyright 2013-2014 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.
-
-//! Language-level runtime services that should reasonably expected
-//! to be available 'everywhere'. Unwinding, local storage, and logging.
-//! Even a 'freestanding' Rust would likely want to implement this.
-
-pub use self::BlockedTask::*;
-use self::TaskState::*;
-
-use any::Any;
-use boxed::Box;
-use sync::Arc;
-use sync::atomic::{AtomicUint, SeqCst};
-use iter::{IteratorExt, Take};
-use kinds::marker;
-use mem;
-use ops::FnMut;
-use core::prelude::{Clone, Drop, Err, Iterator, None, Ok, Option, Send, Some};
-use core::prelude::{drop};
-use str::SendStr;
-use thunk::Thunk;
-
-use rt;
-use rt::mutex::NativeMutex;
-use rt::local::Local;
-use rt::thread::{mod, Thread};
-use sys_common::stack;
-use rt::unwind;
-use rt::unwind::Unwinder;
-
-/// State associated with Rust threads
-///
-/// This structure is currently undergoing major changes, and is
-/// likely to be move/be merged with a `Thread` structure.
-pub struct Task {
-    pub unwinder: Unwinder,
-    pub death: Death,
-    pub name: Option<SendStr>,
-
-    state: TaskState,
-    lock: NativeMutex,       // native synchronization
-    awoken: bool,            // used to prevent spurious wakeups
-
-    // This field holds the known bounds of the stack in (lo, hi) form. Not all
-    // native threads necessarily know their precise bounds, hence this is
-    // optional.
-    stack_bounds: (uint, uint),
-
-    stack_guard: uint
-}
-
-// Once a thread has entered the `Armed` state it must be destroyed via `drop`,
-// and no other method. This state is used to track this transition.
-#[deriving(PartialEq)]
-enum TaskState {
-    New,
-    Armed,
-    Destroyed,
-}
-
-pub struct TaskOpts {
-    /// Invoke this procedure with the result of the thread when it finishes.
-    pub on_exit: Option<Thunk<Result>>,
-    /// A name for the thread-to-be, for identification in panic messages
-    pub name: Option<SendStr>,
-    /// The size of the stack for the spawned thread
-    pub stack_size: Option<uint>,
-}
-
-/// Indicates the manner in which a thread exited.
-///
-/// A thread that completes without panicking is considered to exit successfully.
-///
-/// If you wish for this result's delivery to block until all
-/// children threads complete, recommend using a result future.
-pub type Result = ::core::result::Result<(), Box<Any + Send>>;
-
-/// A handle to a blocked thread. Usually this means having the Box<Task>
-/// pointer by ownership, but if the thread is killable, a killer can steal it
-/// at any time.
-pub enum BlockedTask {
-    Owned(Box<Task>),
-    Shared(Arc<AtomicUint>),
-}
-
-/// Per-thread state related to thread death, killing, panic, etc.
-pub struct Death {
-    pub on_exit: Option<Thunk<Result>>,
-}
-
-pub struct BlockedTasks {
-    inner: Arc<AtomicUint>,
-}
-
-impl Task {
-    /// Creates a new uninitialized thread.
-    pub fn new(stack_bounds: Option<(uint, uint)>, stack_guard: Option<uint>) -> Task {
-        Task {
-            unwinder: Unwinder::new(),
-            death: Death::new(),
-            state: New,
-            name: None,
-            lock: unsafe { NativeMutex::new() },
-            awoken: false,
-            // these *should* get overwritten
-            stack_bounds: stack_bounds.unwrap_or((0, 0)),
-            stack_guard: stack_guard.unwrap_or(0)
-        }
-    }
-
-    pub fn spawn<F>(opts: TaskOpts, f: F)
-        where F : FnOnce(), F : Send
-    {
-        Task::spawn_thunk(opts, Thunk::new(f))
-    }
-
-    fn spawn_thunk(opts: TaskOpts, f: Thunk) {
-        let TaskOpts { name, stack_size, on_exit } = opts;
-
-        let mut task = box Task::new(None, None);
-        task.name = name;
-        task.death.on_exit = on_exit;
-
-        let stack = stack_size.unwrap_or(rt::min_stack());
-
-        // Spawning a new OS thread guarantees that __morestack will never get
-        // triggered, but we must manually set up the actual stack bounds once
-        // this function starts executing. This raises the lower limit by a bit
-        // because by the time that this function is executing we've already
-        // consumed at least a little bit of stack (we don't know the exact byte
-        // address at which our stack started).
-        Thread::spawn_stack(stack, move|| {
-            let something_around_the_top_of_the_stack = 1;
-            let addr = &something_around_the_top_of_the_stack as *const int;
-            let my_stack = addr as uint;
-            unsafe {
-                stack::record_os_managed_stack_bounds(my_stack - stack + 1024,
-                                                      my_stack);
-            }
-            task.stack_guard = thread::current_guard_page();
-            task.stack_bounds = (my_stack - stack + 1024, my_stack);
-
-            let mut f = Some(f);
-            drop(task.run(|| { f.take().unwrap().invoke(()) }).destroy());
-        })
-    }
-
-    /// Consumes ownership of a thread, runs some code, and returns the thread back.
-    ///
-    /// This function can be used as an emulated "try/catch" to interoperate
-    /// with the rust runtime at the outermost boundary. It is not possible to
-    /// use this function in a nested fashion (a try/catch inside of another
-    /// try/catch). Invoking this function is quite cheap.
-    ///
-    /// If the closure `f` succeeds, then the returned thread can be used again
-    /// for another invocation of `run`. If the closure `f` panics then `self`
-    /// will be internally destroyed along with all of the other associated
-    /// resources of this thread. The `on_exit` callback is invoked with the
-    /// cause of panic (not returned here). This can be discovered by querying
-    /// `is_destroyed()`.
-    ///
-    /// Note that it is possible to view partial execution of the closure `f`
-    /// because it is not guaranteed to run to completion, but this function is
-    /// guaranteed to return if it panicks. Care should be taken to ensure that
-    /// stack references made by `f` are handled appropriately.
-    ///
-    /// It is invalid to call this function with a thread that has been previously
-    /// destroyed via a failed call to `run`.
-    pub fn run<F>(mut self: Box<Task>, f: F) -> Box<Task> where F: FnOnce() {
-        assert!(!self.is_destroyed(), "cannot re-use a destroyed thread");
-
-        // First, make sure that no one else is in TLS. This does not allow
-        // recursive invocations of run(). If there's no one else, then
-        // relinquish ownership of ourselves back into TLS.
-        if Local::exists(None::<Task>) {
-            panic!("cannot run a thread recursively inside another");
-        }
-        self.state = Armed;
-        Local::put(self);
-
-        // There are two primary reasons that general try/catch is unsafe. The
-        // first is that we do not support nested try/catch. The above check for
-        // an existing thread in TLS is sufficient for this invariant to be
-        // upheld. The second is that unwinding while unwinding is not defined.
-        // We take care of that by having an 'unwinding' flag in the thread
-        // itself. For these reasons, this unsafety should be ok.
-        let result = unsafe { unwind::try(f) };
-
-        // After running the closure given return the thread back out if it ran
-        // successfully, or clean up the thread if it panicked.
-        let task: Box<Task> = Local::take();
-        match result {
-            Ok(()) => task,
-            Err(cause) => { task.cleanup(Err(cause)) }
-        }
-    }
-
-    /// Destroy all associated resources of this thread.
-    ///
-    /// This function will perform any necessary clean up to prepare the thread
-    /// for destruction. It is required that this is called before a `Task`
-    /// falls out of scope.
-    ///
-    /// The returned thread cannot be used for running any more code, but it may
-    /// be used to extract the runtime as necessary.
-    pub fn destroy(self: Box<Task>) -> Box<Task> {
-        if self.is_destroyed() {
-            self
-        } else {
-            self.cleanup(Ok(()))
-        }
-    }
-
-    /// Cleans up a thread, processing the result of the thread as appropriate.
-    ///
-    /// This function consumes ownership of the thread, deallocating it once it's
-    /// done being processed. It is assumed that TLD and the local heap have
-    /// already been destroyed and/or annihilated.
-    fn cleanup(mut self: Box<Task>, result: Result) -> Box<Task> {
-        // After taking care of the data above, we need to transmit the result
-        // of this thread.
-        let what_to_do = self.death.on_exit.take();
-        Local::put(self);
-
-        // FIXME: this is running in a seriously constrained context. If this
-        //        allocates TLD then it will likely abort the runtime. Similarly,
-        //        if this panics, this will also likely abort the runtime.
-        //
-        //        This closure is currently limited to a channel send via the
-        //        standard library's thread interface, but this needs
-        //        reconsideration to whether it's a reasonable thing to let a
-        //        thread to do or not.
-        match what_to_do {
-            Some(f) => { f.invoke(result) }
-            None => { drop(result) }
-        }
-
-        // Now that we're done, we remove the thread from TLS and flag it for
-        // destruction.
-        let mut task: Box<Task> = Local::take();
-        task.state = Destroyed;
-        return task;
-    }
-
-    /// Queries whether this can be destroyed or not.
-    pub fn is_destroyed(&self) -> bool { self.state == Destroyed }
-
-    /// Deschedules the current thread, invoking `f` `amt` times. It is not
-    /// recommended to use this function directly, but rather communication
-    /// primitives in `std::comm` should be used.
-    //
-    // This function gets a little interesting. There are a few safety and
-    // ownership violations going on here, but this is all done in the name of
-    // shared state. Additionally, all of the violations are protected with a
-    // mutex, so in theory there are no races.
-    //
-    // The first thing we need to do is to get a pointer to the thread's internal
-    // mutex. This address will not be changing (because the thread is allocated
-    // on the heap). We must have this handle separately because the thread will
-    // have its ownership transferred to the given closure. We're guaranteed,
-    // however, that this memory will remain valid because *this* is the current
-    // thread's execution thread.
-    //
-    // The next weird part is where ownership of the thread actually goes. We
-    // relinquish it to the `f` blocking function, but upon returning this
-    // function needs to replace the thread back in TLS. There is no communication
-    // from the wakeup thread back to this thread about the thread pointer, and
-    // there's really no need to. In order to get around this, we cast the thread
-    // to a `uint` which is then used at the end of this function to cast back
-    // to a `Box<Task>` object. Naturally, this looks like it violates
-    // ownership semantics in that there may be two `Box<Task>` objects.
-    //
-    // The fun part is that the wakeup half of this implementation knows to
-    // "forget" the thread on the other end. This means that the awakening half of
-    // things silently relinquishes ownership back to this thread, but not in a
-    // way that the compiler can understand. The thread's memory is always valid
-    // for both threads because these operations are all done inside of a mutex.
-    //
-    // You'll also find that if blocking fails (the `f` function hands the
-    // BlockedTask back to us), we will `mem::forget` the handles. The
-    // reasoning for this is the same logic as above in that the thread silently
-    // transfers ownership via the `uint`, not through normal compiler
-    // semantics.
-    //
-    // On a mildly unrelated note, it should also be pointed out that OS
-    // condition variables are susceptible to spurious wakeups, which we need to
-    // be ready for. In order to accommodate for this fact, we have an extra
-    // `awoken` field which indicates whether we were actually woken up via some
-    // invocation of `reawaken`. This flag is only ever accessed inside the
-    // lock, so there's no need to make it atomic.
-    pub fn deschedule<F>(mut self: Box<Task>, times: uint, mut f: F) where
-        F: FnMut(BlockedTask) -> ::core::result::Result<(), BlockedTask>,
-    {
-        unsafe {
-            let me = &mut *self as *mut Task;
-            let task = BlockedTask::block(self);
-
-            if times == 1 {
-                let guard = (*me).lock.lock();
-                (*me).awoken = false;
-                match f(task) {
-                    Ok(()) => {
-                        while !(*me).awoken {
-                            guard.wait();
-                        }
-                    }
-                    Err(task) => { mem::forget(task.wake()); }
-                }
-            } else {
-                let iter = task.make_selectable(times);
-                let guard = (*me).lock.lock();
-                (*me).awoken = false;
-
-                // Apply the given closure to all of the "selectable threads",
-                // bailing on the first one that produces an error. Note that
-                // care must be taken such that when an error is occurred, we
-                // may not own the thread, so we may still have to wait for the
-                // thread to become available. In other words, if thread.wake()
-                // returns `None`, then someone else has ownership and we must
-                // wait for their signal.
-                match iter.map(f).filter_map(|a| a.err()).next() {
-                    None => {}
-                    Some(task) => {
-                        match task.wake() {
-                            Some(task) => {
-                                mem::forget(task);
-                                (*me).awoken = true;
-                            }
-                            None => {}
-                        }
-                    }
-                }
-                while !(*me).awoken {
-                    guard.wait();
-                }
-            }
-            // put the thread back in TLS, and everything is as it once was.
-            Local::put(mem::transmute(me));
-        }
-    }
-
-    /// Wakes up a previously blocked thread. This function can only be
-    /// called on threads that were previously blocked in `deschedule`.
-    //
-    // See the comments on `deschedule` for why the thread is forgotten here, and
-    // why it's valid to do so.
-    pub fn reawaken(mut self: Box<Task>) {
-        unsafe {
-            let me = &mut *self as *mut Task;
-            mem::forget(self);
-            let guard = (*me).lock.lock();
-            (*me).awoken = true;
-            guard.signal();
-        }
-    }
-
-    /// Yields control of this thread to another thread. This function will
-    /// eventually return, but possibly not immediately. This is used as an
-    /// opportunity to allow other threads a chance to run.
-    pub fn yield_now() {
-        Thread::yield_now();
-    }
-
-    /// Returns the stack bounds for this thread in (lo, hi) format. The stack
-    /// bounds may not be known for all threads, so the return value may be
-    /// `None`.
-    pub fn stack_bounds(&self) -> (uint, uint) {
-        self.stack_bounds
-    }
-
-    /// Returns the stack guard for this thread, if known.
-    pub fn stack_guard(&self) -> Option<uint> {
-        if self.stack_guard != 0 {
-            Some(self.stack_guard)
-        } else {
-            None
-        }
-    }
-
-    /// Consume this thread, flagging it as a candidate for destruction.
-    ///
-    /// This function is required to be invoked to destroy a thread. A thread
-    /// destroyed through a normal drop will abort.
-    pub fn drop(mut self) {
-        self.state = Destroyed;
-    }
-}
-
-impl Drop for Task {
-    fn drop(&mut self) {
-        rtdebug!("called drop for a thread: {}", self as *mut Task as uint);
-        rtassert!(self.state != Armed);
-    }
-}
-
-impl TaskOpts {
-    pub fn new() -> TaskOpts {
-        TaskOpts { on_exit: None, name: None, stack_size: None }
-    }
-}
-
-impl Iterator<BlockedTask> for BlockedTasks {
-    fn next(&mut self) -> Option<BlockedTask> {
-        Some(Shared(self.inner.clone()))
-    }
-}
-
-impl BlockedTask {
-    /// Returns Some if the thread was successfully woken; None if already killed.
-    pub fn wake(self) -> Option<Box<Task>> {
-        match self {
-            Owned(task) => Some(task),
-            Shared(arc) => {
-                match arc.swap(0, SeqCst) {
-                    0 => None,
-                    n => Some(unsafe { mem::transmute(n) }),
-                }
-            }
-        }
-    }
-
-    /// Reawakens this thread if ownership is acquired. If finer-grained control
-    /// is desired, use `wake` instead.
-    pub fn reawaken(self) {
-        self.wake().map(|t| t.reawaken());
-    }
-
-    // This assertion has two flavours because the wake involves an atomic op.
-    // In the faster version, destructors will panic dramatically instead.
-    #[cfg(not(test))] pub fn trash(self) { }
-    #[cfg(test)]      pub fn trash(self) { assert!(self.wake().is_none()); }
-
-    /// Create a blocked thread, unless the thread was already killed.
-    pub fn block(task: Box<Task>) -> BlockedTask {
-        Owned(task)
-    }
-
-    /// Converts one blocked thread handle to a list of many handles to the same.
-    pub fn make_selectable(self, num_handles: uint) -> Take<BlockedTasks> {
-        let arc = match self {
-            Owned(task) => {
-                let flag = unsafe { AtomicUint::new(mem::transmute(task)) };
-                Arc::new(flag)
-            }
-            Shared(arc) => arc.clone(),
-        };
-        BlockedTasks{ inner: arc }.take(num_handles)
-    }
-
-    /// Convert to an unsafe uint value. Useful for storing in a pipe's state
-    /// flag.
-    #[inline]
-    pub unsafe fn cast_to_uint(self) -> uint {
-        match self {
-            Owned(task) => {
-                let blocked_task_ptr: uint = mem::transmute(task);
-                rtassert!(blocked_task_ptr & 0x1 == 0);
-                blocked_task_ptr
-            }
-            Shared(arc) => {
-                let blocked_task_ptr: uint = mem::transmute(box arc);
-                rtassert!(blocked_task_ptr & 0x1 == 0);
-                blocked_task_ptr | 0x1
-            }
-        }
-    }
-
-    /// Convert from an unsafe uint value. Useful for retrieving a pipe's state
-    /// flag.
-    #[inline]
-    pub unsafe fn cast_from_uint(blocked_task_ptr: uint) -> BlockedTask {
-        if blocked_task_ptr & 0x1 == 0 {
-            Owned(mem::transmute(blocked_task_ptr))
-        } else {
-            let ptr: Box<Arc<AtomicUint>> =
-                mem::transmute(blocked_task_ptr & !1);
-            Shared(*ptr)
-        }
-    }
-}
-
-impl Death {
-    pub fn new() -> Death {
-        Death { on_exit: None }
-    }
-}
-
-#[cfg(test)]
-mod test {
-    use super::*;
-    use prelude::v1::*;
-    use task;
-    use rt::unwind;
-
-    #[test]
-    fn unwind() {
-        let result = task::try(move|| ());
-        rtdebug!("trying first assert");
-        assert!(result.is_ok());
-        let result = task::try(move|| -> () panic!());
-        rtdebug!("trying second assert");
-        assert!(result.is_err());
-    }
-
-    #[test]
-    fn rng() {
-        use rand::{StdRng, Rng};
-        let mut r = StdRng::new().ok().unwrap();
-        let _ = r.next_u32();
-    }
-
-    #[test]
-    fn comm_stream() {
-        let (tx, rx) = channel();
-        tx.send(10i);
-        assert!(rx.recv() == 10);
-    }
-
-    #[test]
-    fn comm_shared_chan() {
-        let (tx, rx) = channel();
-        tx.send(10i);
-        assert!(rx.recv() == 10);
-    }
-
-    #[test]
-    #[should_fail]
-    fn test_begin_unwind() {
-        use rt::unwind::begin_unwind;
-        begin_unwind("cause", &(file!(), line!()))
-    }
-
-    #[test]
-    fn drop_new_task_ok() {
-        drop(Task::new(None, None));
-    }
-
-    // Thread blocking tests
-
-    #[test]
-    fn block_and_wake() {
-        let task = box Task::new(None, None);
-        let task = BlockedTask::block(task).wake().unwrap();
-        task.drop();
-    }
-}

src/libstd/rt/unwind.rs

@@ -84,15 +84,15 @@ pub type Callback = fn(msg: &(Any + Send), file: &'static str, line: uint);
 // For more information, see below.
 const MAX_CALLBACKS: uint = 16;
 static CALLBACKS: [atomic::AtomicUint; MAX_CALLBACKS] =
-        [atomic::INIT_ATOMIC_UINT, atomic::INIT_ATOMIC_UINT,
+        [atomic::ATOMIC_UINT_INIT, atomic::ATOMIC_UINT_INIT,
-         atomic::INIT_ATOMIC_UINT, atomic::INIT_ATOMIC_UINT,
+         atomic::ATOMIC_UINT_INIT, atomic::ATOMIC_UINT_INIT,
-         atomic::INIT_ATOMIC_UINT, atomic::INIT_ATOMIC_UINT,
+         atomic::ATOMIC_UINT_INIT, atomic::ATOMIC_UINT_INIT,
-         atomic::INIT_ATOMIC_UINT, atomic::INIT_ATOMIC_UINT,
+         atomic::ATOMIC_UINT_INIT, atomic::ATOMIC_UINT_INIT,
-         atomic::INIT_ATOMIC_UINT, atomic::INIT_ATOMIC_UINT,
+         atomic::ATOMIC_UINT_INIT, atomic::ATOMIC_UINT_INIT,
-         atomic::INIT_ATOMIC_UINT, atomic::INIT_ATOMIC_UINT,
+         atomic::ATOMIC_UINT_INIT, atomic::ATOMIC_UINT_INIT,
-         atomic::INIT_ATOMIC_UINT, atomic::INIT_ATOMIC_UINT,
+         atomic::ATOMIC_UINT_INIT, atomic::ATOMIC_UINT_INIT,
-         atomic::INIT_ATOMIC_UINT, atomic::INIT_ATOMIC_UINT];
+         atomic::ATOMIC_UINT_INIT, atomic::ATOMIC_UINT_INIT];
-static CALLBACK_CNT: atomic::AtomicUint = atomic::INIT_ATOMIC_UINT;
+static CALLBACK_CNT: atomic::AtomicUint = atomic::ATOMIC_UINT_INIT;
 
 thread_local! { static PANICKING: Cell<bool> = Cell::new(false) }
 
@@ -533,7 +533,7 @@ fn begin_unwind_inner(msg: Box<Any + Send>, file_line: &(&'static str, uint)) ->
     // Make sure the default failure handler is registered before we look at the
     // callbacks.
     static INIT: Once = ONCE_INIT;
-    INIT.doit(|| unsafe { register(failure::on_fail); });
+    INIT.call_once(|| unsafe { register(failure::on_fail); });
 
     // First, invoke call the user-defined callbacks triggered on thread panic.
     //

src/libstd/rt/util.rs

@@ -46,7 +46,7 @@ pub fn limit_thread_creation_due_to_osx_and_valgrind() -> bool {
 }
 
 pub fn min_stack() -> uint {
-    static MIN: atomic::AtomicUint = atomic::INIT_ATOMIC_UINT;
+    static MIN: atomic::AtomicUint = atomic::ATOMIC_UINT_INIT;
     match MIN.load(atomic::SeqCst) {
         0 => {}
         n => return n - 1,

src/libstd/sync/atomic.rs

@@ -86,15 +86,15 @@
 //! Keep a global count of live tasks:
 //!
 //! ```
-//! use std::sync::atomic::{AtomicUint, SeqCst, INIT_ATOMIC_UINT};
+//! use std::sync::atomic::{AtomicUint, SeqCst, ATOMIC_UINT_INIT};
 //!
-//! static GLOBAL_TASK_COUNT: AtomicUint = INIT_ATOMIC_UINT;
+//! static GLOBAL_TASK_COUNT: AtomicUint = ATOMIC_UINT_INIT;
 //!
 //! let old_task_count = GLOBAL_TASK_COUNT.fetch_add(1, SeqCst);
 //! println!("live tasks: {}", old_task_count + 1);
 //! ```
 
-#![allow(deprecated)]
+#![stable]
 
 use alloc::boxed::Box;
 use core::mem;
@@ -102,6 +102,7 @@ use core::prelude::{Send, Drop, None, Option, Some};
 
 pub use core::atomic::{AtomicBool, AtomicInt, AtomicUint, AtomicPtr};
 pub use core::atomic::{INIT_ATOMIC_BOOL, INIT_ATOMIC_INT, INIT_ATOMIC_UINT};
+pub use core::atomic::{ATOMIC_BOOL_INIT, ATOMIC_INT_INIT, ATOMIC_UINT_INIT};
 pub use core::atomic::fence;
 pub use core::atomic::Ordering::{mod, Relaxed, Release, Acquire, AcqRel, SeqCst};
 
@@ -116,6 +117,7 @@ pub struct AtomicOption<T> {
     p: AtomicUint,
 }
 
+#[allow(deprecated)]
 impl<T: Send> AtomicOption<T> {
     /// Create a new `AtomicOption`
     pub fn new(p: Box<T>) -> AtomicOption<T> {

src/libstd/sync/barrier.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use kinds::{Send, Sync};
 use sync::{Mutex, Condvar};
 
 /// A barrier enables multiple tasks to synchronize the beginning
@@ -30,29 +29,32 @@ use sync::{Mutex, Condvar};
 ///     }).detach();
 /// }
 /// ```
+#[stable]
 pub struct Barrier {
     lock: Mutex<BarrierState>,
     cvar: Condvar,
     num_threads: uint,
 }
 
-unsafe impl Send for Barrier {}
-unsafe impl Sync for Barrier {}
-
 // The inner state of a double barrier
 struct BarrierState {
     count: uint,
     generation_id: uint,
 }
 
-unsafe impl Send for BarrierState {}
+/// A result returned from wait.
-unsafe impl Sync for BarrierState {}
+///
+/// Currently this opaque structure only has one method, `.is_leader()`. Only
+/// one thread will receive a result that will return `true` from this function.
+#[allow(missing_copy_implementations)]
+pub struct BarrierWaitResult(bool);
 
 impl Barrier {
     /// Create a new barrier that can block a given number of threads.
     ///
     /// A barrier will block `n`-1 threads which call `wait` and then wake up
     /// all threads at once when the `n`th thread calls `wait`.
+    #[stable]
     pub fn new(n: uint) -> Barrier {
         Barrier {
             lock: Mutex::new(BarrierState {
@@ -68,7 +70,13 @@ impl Barrier {
     ///
     /// Barriers are re-usable after all threads have rendezvoused once, and can
     /// be used continuously.
-    pub fn wait(&self) {
+    ///
+    /// A single (arbitrary) thread will receive a `BarrierWaitResult` that
+    /// returns `true` from `is_leader` when returning from this function, and
+    /// all other threads will receive a result that will return `false` from
+    /// `is_leader`
+    #[stable]
+    pub fn wait(&self) -> BarrierWaitResult {
         let mut lock = self.lock.lock().unwrap();
         let local_gen = lock.generation_id;
         lock.count += 1;
@@ -79,14 +87,25 @@ impl Barrier {
                   lock.count < self.num_threads {
                 lock = self.cvar.wait(lock).unwrap();
             }
+            BarrierWaitResult(false)
         } else {
             lock.count = 0;
             lock.generation_id += 1;
             self.cvar.notify_all();
+            BarrierWaitResult(true)
         }
     }
 }
 
+impl BarrierWaitResult {
+    /// Return whether this thread from `wait` is the "leader thread".
+    ///
+    /// Only one thread will have `true` returned from their result, all other
+    /// threads will have `false` returned.
+    #[stable]
+    pub fn is_leader(&self) -> bool { self.0 }
+}
+
 #[cfg(test)]
 mod tests {
     use prelude::v1::*;
@@ -97,15 +116,16 @@ mod tests {
 
     #[test]
     fn test_barrier() {
-        let barrier = Arc::new(Barrier::new(10));
+        const N: uint = 10;
+
+        let barrier = Arc::new(Barrier::new(N));
         let (tx, rx) = channel();
 
-        for _ in range(0u, 9) {
+        for _ in range(0u, N - 1) {
             let c = barrier.clone();
             let tx = tx.clone();
             Thread::spawn(move|| {
-                c.wait();
+                tx.send(c.wait().is_leader()).unwrap();
-                tx.send(true).unwrap();
             }).detach();
         }
 
@@ -116,10 +136,15 @@ mod tests {
             _ => false,
         });
 
-        barrier.wait();
+        let mut leader_found = barrier.wait().is_leader();
+
         // Now, the barrier is cleared and we should get data.
-        for _ in range(0u, 9) {
+        for _ in range(0u, N - 1) {
-            rx.recv().unwrap();
+            if rx.recv().unwrap() {
+                assert!(!leader_found);
+                leader_found = true;
+            }
         }
+        assert!(leader_found);
     }
 }

src/libstd/sync/condvar.rs

@@ -88,7 +88,7 @@ unsafe impl Sync for StaticCondvar {}
 #[unstable = "may be merged with Condvar in the future"]
 pub const CONDVAR_INIT: StaticCondvar = StaticCondvar {
     inner: sys::CONDVAR_INIT,
-    mutex: atomic::INIT_ATOMIC_UINT,
+    mutex: atomic::ATOMIC_UINT_INIT,
 };
 
 impl Condvar {

src/libstd/sync/future.rs

@@ -8,8 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-//! A type representing values that may be computed concurrently and operations for working with
+//! A type representing values that may be computed concurrently and operations
-//! them.
+//! for working with them.
 //!
 //! # Example
 //!
@@ -23,6 +23,9 @@
 //! ```
 
 #![allow(missing_docs)]
+#![unstable = "futures as-is have yet to be deeply reevaluated with recent \
+               core changes to Rust's synchronization story, and will likely \
+               become stable in the future but are unstable until that time"]
 
 use core::prelude::*;
 use core::mem::replace;

src/libstd/sync/mod.rs

@@ -26,7 +26,7 @@ pub use self::rwlock::{RWLockReadGuard, RWLockWriteGuard};
 pub use self::condvar::{Condvar, StaticCondvar, CONDVAR_INIT};
 pub use self::once::{Once, ONCE_INIT};
 pub use self::semaphore::{Semaphore, SemaphoreGuard};
-pub use self::barrier::Barrier;
+pub use self::barrier::{Barrier, BarrierWaitResult};
 pub use self::poison::{PoisonError, TryLockError, TryLockResult, LockResult};
 
 pub use self::future::Future;

src/libstd/sync/mpsc/blocking.rs

@@ -11,7 +11,7 @@
 //! Generic support for building blocking abstractions.
 
 use thread::Thread;
-use sync::atomic::{AtomicBool, INIT_ATOMIC_BOOL, Ordering};
+use sync::atomic::{AtomicBool, ATOMIC_BOOL_INIT, Ordering};
 use sync::Arc;
 use kinds::{Sync, Send};
 use kinds::marker::{NoSend, NoSync};
@@ -40,7 +40,7 @@ pub struct WaitToken {
 pub fn tokens() -> (WaitToken, SignalToken) {
     let inner = Arc::new(Inner {
         thread: Thread::current(),
-        woken: INIT_ATOMIC_BOOL,
+        woken: ATOMIC_BOOL_INIT,
     });
     let wait_token = WaitToken {
         inner: inner.clone(),

src/libstd/sync/once.rs

@@ -32,10 +32,11 @@ use sync::{StaticMutex, MUTEX_INIT};
 ///
 /// static START: Once = ONCE_INIT;
 ///
-/// START.doit(|| {
+/// START.call_once(|| {
 ///     // run initialization here
 /// });
 /// ```
+#[stable]
 pub struct Once {
     mutex: StaticMutex,
     cnt: atomic::AtomicInt,
@@ -45,23 +46,25 @@ pub struct Once {
 unsafe impl Sync for Once {}
 
 /// Initialization value for static `Once` values.
+#[stable]
 pub const ONCE_INIT: Once = Once {
     mutex: MUTEX_INIT,
-    cnt: atomic::INIT_ATOMIC_INT,
+    cnt: atomic::ATOMIC_INT_INIT,
-    lock_cnt: atomic::INIT_ATOMIC_INT,
+    lock_cnt: atomic::ATOMIC_INT_INIT,
 };
 
 impl Once {
     /// Perform an initialization routine once and only once. The given closure
-    /// will be executed if this is the first time `doit` has been called, and
+    /// will be executed if this is the first time `call_once` has been called,
-    /// otherwise the routine will *not* be invoked.
+    /// and otherwise the routine will *not* be invoked.
     ///
     /// This method will block the calling task if another initialization
     /// routine is currently running.
     ///
     /// When this function returns, it is guaranteed that some initialization
     /// has run and completed (it may not be the closure specified).
-    pub fn doit<F>(&'static self, f: F) where F: FnOnce() {
+    #[stable]
+    pub fn call_once<F>(&'static self, f: F) where F: FnOnce() {
         // Optimize common path: load is much cheaper than fetch_add.
         if self.cnt.load(atomic::SeqCst) < 0 {
             return
@@ -91,13 +94,13 @@ impl Once {
         //
         // It is crucial that the negative value is swapped in *after* the
         // initialization routine has completed because otherwise new threads
-        // calling `doit` will return immediately before the initialization has
+        // calling `call_once` will return immediately before the initialization
-        // completed.
+        // has completed.
 
         let prev = self.cnt.fetch_add(1, atomic::SeqCst);
         if prev < 0 {
             // Make sure we never overflow, we'll never have int::MIN
-            // simultaneous calls to `doit` to make this value go back to 0
+            // simultaneous calls to `call_once` to make this value go back to 0
             self.cnt.store(int::MIN, atomic::SeqCst);
             return
         }
@@ -118,6 +121,10 @@ impl Once {
             unsafe { self.mutex.destroy() }
         }
     }
+
+    /// Deprecated
+    #[deprecated = "renamed to `call_once`"]
+    pub fn doit<F>(&'static self, f: F) where F: FnOnce() { self.call_once(f) }
 }
 
 #[cfg(test)]
@@ -132,9 +139,9 @@ mod test {
     fn smoke_once() {
         static O: Once = ONCE_INIT;
         let mut a = 0i;
-        O.doit(|| a += 1);
+        O.call_once(|| a += 1);
         assert_eq!(a, 1);
-        O.doit(|| a += 1);
+        O.call_once(|| a += 1);
         assert_eq!(a, 1);
     }
 
@@ -149,7 +156,7 @@ mod test {
             Thread::spawn(move|| {
                 for _ in range(0u, 4) { Thread::yield_now() }
                 unsafe {
-                    O.doit(|| {
+                    O.call_once(|| {
                         assert!(!run);
                         run = true;
                     });
@@ -160,7 +167,7 @@ mod test {
         }
 
         unsafe {
-            O.doit(|| {
+            O.call_once(|| {
                 assert!(!run);
                 run = true;
             });

src/libstd/sync/semaphore.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![unstable = "the interaction between semaphores and the acquisition/release \
+               of resources is currently unclear"]
+
 use ops::Drop;
 use sync::{Mutex, Condvar};
 

src/libstd/sync/task_pool.rs

@@ -10,6 +10,11 @@
 
 //! Abstraction of a thread pool for basic parallelism.
 
+#![unstable = "the semantics of a failing task and whether a thread is \
+               re-attached to a thread pool are somewhat unclear, and the \
+               utility of this type in `std::sync` is questionable with \
+               respect to the jobs of other primitives"]
+
 use core::prelude::*;
 
 use sync::{Arc, Mutex};

src/libstd/sys/common/thread_local.rs

@@ -137,7 +137,7 @@ pub const INIT: StaticKey = StaticKey {
 ///
 /// This value allows specific configuration of the destructor for a TLS key.
 pub const INIT_INNER: StaticKeyInner = StaticKeyInner {
-    key: atomic::INIT_ATOMIC_UINT,
+    key: atomic::ATOMIC_UINT_INIT,
 };
 
 static INIT_KEYS: Once = ONCE_INIT;

src/libstd/sys/unix/os.rs

@@ -20,7 +20,7 @@ use libc::{mod, c_int, c_char, c_void};
 use os;
 use path::{BytesContainer};
 use ptr;
-use sync::atomic::{AtomicInt, INIT_ATOMIC_INT, SeqCst};
+use sync::atomic::{AtomicInt, SeqCst};
 use sys::fs::FileDesc;
 
 use os::TMPBUF_SZ;

src/libstd/sys/unix/pipe.rs

@@ -10,6 +10,8 @@
 
 use prelude::v1::*;
 
+use prelude::*;
+
 use libc;
 use c_str::CString;
 use mem;
@@ -117,9 +119,6 @@ pub struct UnixStream {
     write_deadline: u64,
 }
 
-unsafe impl Send for UnixStream {}
-unsafe impl Sync for UnixStream {}
-
 impl UnixStream {
     pub fn connect(addr: &CString,
                    timeout: Option<u64>) -> IoResult<UnixStream> {
@@ -218,6 +217,7 @@ pub struct UnixListener {
     path: CString,
 }
 
+// we currently own the CString, so these impls should be safe
 unsafe impl Send for UnixListener {}
 unsafe impl Sync for UnixListener {}
 
@@ -265,9 +265,6 @@ struct AcceptorInner {
     closed: atomic::AtomicBool,
 }
 
-unsafe impl Send for AcceptorInner {}
-unsafe impl Sync for AcceptorInner {}
-
 impl UnixAcceptor {
     pub fn fd(&self) -> fd_t { self.inner.listener.fd() }
 

src/libstd/sys/unix/timer.rs

@@ -211,7 +211,7 @@ impl Timer {
         // instead of ()
         HELPER.boot(|| {}, helper);
 
-        static ID: atomic::AtomicUint = atomic::INIT_ATOMIC_UINT;
+        static ID: atomic::AtomicUint = atomic::ATOMIC_UINT_INIT;
         let id = ID.fetch_add(1, atomic::Relaxed);
         Ok(Timer {
             id: id,

src/libstd/sys/windows/mod.rs

@@ -173,7 +173,7 @@ pub fn init_net() {
     unsafe {
         static START: Once = ONCE_INIT;
 
-        START.doit(|| {
+        START.call_once(|| {
             let mut data: c::WSADATA = mem::zeroed();
             let ret = c::WSAStartup(0x202, // version 2.2
                                     &mut data);

src/libstd/sys/windows/mutex.rs

@@ -20,7 +20,7 @@ const SPIN_COUNT: DWORD = 4000;
 
 pub struct Mutex { inner: atomic::AtomicUint }
 
-pub const MUTEX_INIT: Mutex = Mutex { inner: atomic::INIT_ATOMIC_UINT };
+pub const MUTEX_INIT: Mutex = Mutex { inner: atomic::ATOMIC_UINT_INIT };
 
 unsafe impl Sync for Mutex {}
 

src/libstd/time/mod.rs

@@ -45,7 +45,7 @@ fn precise_time_ns() -> u64 {
                                                                                    denom: 0 };
         static ONCE: sync::Once = sync::ONCE_INIT;
         unsafe {
-            ONCE.doit(|| {
+            ONCE.call_once(|| {
                 imp::mach_timebase_info(&mut TIMEBASE);
             });
             let time = imp::mach_absolute_time();

src/libtime/lib.rs

@@ -197,7 +197,7 @@ pub fn precise_time_ns() -> u64 {
                                                                                    denom: 0 };
         static ONCE: std::sync::Once = std::sync::ONCE_INIT;
         unsafe {
-            ONCE.doit(|| {
+            ONCE.call_once(|| {
                 imp::mach_timebase_info(&mut TIMEBASE);
             });
             let time = imp::mach_absolute_time();

src/test/auxiliary/issue-17718.rs

@@ -11,12 +11,12 @@
 use std::sync::atomic;
 
 pub const C1: uint = 1;
-pub const C2: atomic::AtomicUint = atomic::INIT_ATOMIC_UINT;
+pub const C2: atomic::AtomicUint = atomic::ATOMIC_UINT_INIT;
 pub const C3: fn() = foo;
 pub const C4: uint = C1 * C1 + C1 / C1;
 pub const C5: &'static uint = &C4;
 
 pub static S1: uint = 3;
-pub static S2: atomic::AtomicUint = atomic::INIT_ATOMIC_UINT;
+pub static S2: atomic::AtomicUint = atomic::ATOMIC_UINT_INIT;
 
 fn foo() {}

src/test/bench/shootout-binarytrees.rs

@@ -41,9 +41,7 @@
 extern crate arena;
 
 use std::iter::range_step;
-use std::str::from_str;
+use std::thread::Thread;
-use std::sync::Future;
-
 use arena::TypedArena;
 
 enum Tree<'a> {
@@ -97,7 +95,7 @@ fn main() {
     let mut messages = range_step(min_depth, max_depth + 1, 2).map(|depth| {
             use std::num::Int;
             let iterations = 2i.pow((max_depth - depth + min_depth) as uint);
-            Future::spawn(move|| {
+            Thread::spawn(move|| {
                 let mut chk = 0;
                 for i in range(1, iterations + 1) {
                     let arena = TypedArena::new();
@@ -108,10 +106,10 @@ fn main() {
                 format!("{}\t trees of depth {}\t check: {}",
                         iterations * 2, depth, chk)
             })
-        }).collect::<Vec<Future<String>>>();
+        }).collect::<Vec<_>>();
 
-    for message in messages.iter_mut() {
+    for message in messages.into_iter() {
-        println!("{}", *message.get_ref());
+        println!("{}", message.join().ok().unwrap());
     }
 
     println!("long lived tree of depth {}\t check: {}",

src/test/bench/shootout-fannkuch-redux.rs

@@ -40,9 +40,8 @@
 
 #![feature(slicing_syntax)]
 
-use std::str::from_str;
-use std::sync::Future;
 use std::{cmp, iter, mem};
+use std::thread::Thread;
 
 fn rotate(x: &mut [i32]) {
     let mut prev = x[0];
@@ -169,15 +168,15 @@ fn fannkuch(n: i32) -> (i32, i32) {
     for (i, j) in range(0, N).zip(iter::count(0, k)) {
         let max = cmp::min(j+k, perm.max());
 
-        futures.push(Future::spawn(move|| {
+        futures.push(Thread::spawn(move|| {
             work(perm, j as uint, max as uint)
         }))
     }
 
     let mut checksum = 0;
     let mut maxflips = 0;
-    for fut in futures.iter_mut() {
+    for fut in futures.into_iter() {
-        let (cs, mf) = fut.get();
+        let (cs, mf) = fut.join().ok().unwrap();
         checksum += cs;
         maxflips = cmp::max(maxflips, mf);
     }

src/test/compile-fail/std-uncopyable-atomics.rs

@@ -16,11 +16,11 @@ use std::sync::atomic::*;
 use std::ptr;
 
 fn main() {
-    let x = INIT_ATOMIC_BOOL;
+    let x = ATOMIC_BOOL_INIT;
     let x = *&x; //~ ERROR: cannot move out of dereference
-    let x = INIT_ATOMIC_INT;
+    let x = ATOMIC_INT_INIT;
     let x = *&x; //~ ERROR: cannot move out of dereference
-    let x = INIT_ATOMIC_UINT;
+    let x = ATOMIC_UINT_INIT;
     let x = *&x; //~ ERROR: cannot move out of dereference
     let x: AtomicPtr<uint> = AtomicPtr::new(ptr::null_mut());
     let x = *&x; //~ ERROR: cannot move out of dereference

src/test/run-pass/issue-17718.rs

@@ -15,7 +15,7 @@ extern crate "issue-17718" as other;
 use std::sync::atomic;
 
 const C1: uint = 1;
-const C2: atomic::AtomicUint = atomic::INIT_ATOMIC_UINT;
+const C2: atomic::AtomicUint = atomic::ATOMIC_UINT_INIT;
 const C3: fn() = foo;
 const C4: uint = C1 * C1 + C1 / C1;
 const C5: &'static uint = &C4;
@@ -25,7 +25,7 @@ const C6: uint = {
 };
 
 static S1: uint = 3;
-static S2: atomic::AtomicUint = atomic::INIT_ATOMIC_UINT;
+static S2: atomic::AtomicUint = atomic::ATOMIC_UINT_INIT;
 
 mod test {
     static A: uint = 4;

src/test/run-pass/vector-sort-panic-safe.rs

@@ -9,7 +9,7 @@
 // except according to those terms.
 
 use std::task;
-use std::sync::atomic::{AtomicUint, INIT_ATOMIC_UINT, Relaxed};
+use std::sync::atomic::{AtomicUint, ATOMIC_UINT_INIT, Relaxed};
 use std::rand::{thread_rng, Rng, Rand};
 
 const REPEATS: uint = 5;
@@ -17,18 +17,18 @@ const MAX_LEN: uint = 32;
 static drop_counts: [AtomicUint;  MAX_LEN] =
     // FIXME #5244: AtomicUint is not Copy.
     [
-        INIT_ATOMIC_UINT, INIT_ATOMIC_UINT, INIT_ATOMIC_UINT, INIT_ATOMIC_UINT,
+        ATOMIC_UINT_INIT, ATOMIC_UINT_INIT, ATOMIC_UINT_INIT, ATOMIC_UINT_INIT,
-        INIT_ATOMIC_UINT, INIT_ATOMIC_UINT, INIT_ATOMIC_UINT, INIT_ATOMIC_UINT,
+        ATOMIC_UINT_INIT, ATOMIC_UINT_INIT, ATOMIC_UINT_INIT, ATOMIC_UINT_INIT,
-        INIT_ATOMIC_UINT, INIT_ATOMIC_UINT, INIT_ATOMIC_UINT, INIT_ATOMIC_UINT,
+        ATOMIC_UINT_INIT, ATOMIC_UINT_INIT, ATOMIC_UINT_INIT, ATOMIC_UINT_INIT,
-        INIT_ATOMIC_UINT, INIT_ATOMIC_UINT, INIT_ATOMIC_UINT, INIT_ATOMIC_UINT,
+        ATOMIC_UINT_INIT, ATOMIC_UINT_INIT, ATOMIC_UINT_INIT, ATOMIC_UINT_INIT,
 
-        INIT_ATOMIC_UINT, INIT_ATOMIC_UINT, INIT_ATOMIC_UINT, INIT_ATOMIC_UINT,
+        ATOMIC_UINT_INIT, ATOMIC_UINT_INIT, ATOMIC_UINT_INIT, ATOMIC_UINT_INIT,
-        INIT_ATOMIC_UINT, INIT_ATOMIC_UINT, INIT_ATOMIC_UINT, INIT_ATOMIC_UINT,
+        ATOMIC_UINT_INIT, ATOMIC_UINT_INIT, ATOMIC_UINT_INIT, ATOMIC_UINT_INIT,
-        INIT_ATOMIC_UINT, INIT_ATOMIC_UINT, INIT_ATOMIC_UINT, INIT_ATOMIC_UINT,
+        ATOMIC_UINT_INIT, ATOMIC_UINT_INIT, ATOMIC_UINT_INIT, ATOMIC_UINT_INIT,
-        INIT_ATOMIC_UINT, INIT_ATOMIC_UINT, INIT_ATOMIC_UINT, INIT_ATOMIC_UINT,
+        ATOMIC_UINT_INIT, ATOMIC_UINT_INIT, ATOMIC_UINT_INIT, ATOMIC_UINT_INIT,
      ];
 
-static creation_count: AtomicUint = INIT_ATOMIC_UINT;
+static creation_count: AtomicUint = ATOMIC_UINT_INIT;
 
 #[deriving(Clone, PartialEq, PartialOrd, Eq, Ord)]
 struct DropCounter { x: uint, creation_id: uint }