move concurrent stuff from libextra to libsync

48 files changed, 224 insertions, 145 deletions

diff --git a/mk/crates.mk b/mk/crates.mk
index e02e4fb8706..dd94d268bec 100644
--- a/mk/crates.mk
+++ b/mk/crates.mk
@@ -49,25 +49,26 @@
 # automatically generated for all stage/host/target combinations.
 ################################################################################
 
-TARGET_CRATES := std extra green rustuv native flate arena glob term semver uuid
+TARGET_CRATES := std extra green rustuv native flate arena glob term semver uuid sync
 HOST_CRATES := syntax rustc rustdoc
 CRATES := $(TARGET_CRATES) $(HOST_CRATES)
 TOOLS := compiletest rustdoc rustc
 
 DEPS_std := native:rustrt
-DEPS_extra := std term
+DEPS_extra := std term sync
 DEPS_green := std
 DEPS_rustuv := std native:uv native:uv_support
 DEPS_native := std
 DEPS_syntax := std extra term
-DEPS_rustc := syntax native:rustllvm flate arena
-DEPS_rustdoc := rustc native:sundown
+DEPS_rustc := syntax native:rustllvm flate arena sync
+DEPS_rustdoc := rustc native:sundown sync
 DEPS_flate := std native:miniz
 DEPS_arena := std extra
 DEPS_glob := std
 DEPS_term := std
 DEPS_semver := std
 DEPS_uuid := std extra
+DEPS_sync := std
 
 TOOL_DEPS_compiletest := extra green rustuv
 TOOL_DEPS_rustdoc := rustdoc green rustuv
diff --git a/src/doc/guide-tasks.md b/src/doc/guide-tasks.md
index c3bdbe3a3ee..387f481025d 100644
--- a/src/doc/guide-tasks.md
+++ b/src/doc/guide-tasks.md
@@ -39,7 +39,7 @@ data through the global _exchange heap_.
 
 While Rust's type system provides the building blocks needed for safe
 and efficient tasks, all of the task functionality itself is implemented
-in the standard and extra libraries, which are still under development
+in the standard and sync libraries, which are still under development
 and do not always present a consistent or complete interface.
 
 For your reference, these are the standard modules involved in Rust
@@ -47,18 +47,43 @@ concurrency at this writing:
 
 * [`std::task`] - All code relating to tasks and task scheduling,
 * [`std::comm`] - The message passing interface,
-* [`extra::comm`] - Additional messaging types based on `std::comm`,
-* [`extra::sync`] - More exotic synchronization tools, including locks,
-* [`extra::arc`] - The Arc (atomically reference counted) type,
-  for safely sharing immutable data,
-* [`extra::future`] - A type representing values that may be computed concurrently and retrieved at a later time.
+* [`sync::DuplexStream`] - An extension of `pipes::stream` that allows both sending and receiving,
+* [`sync::SyncChan`] - An extension of `pipes::stream` that provides synchronous message sending,
+* [`sync::SyncPort`] - An extension of `pipes::stream` that acknowledges each message received,
+* [`sync::rendezvous`] - Creates a stream whose channel, upon sending a message, blocks until the 
+    message is received.
+* [`sync::Arc`] - The Arc (atomically reference counted) type, for safely sharing immutable data,
+* [`sync::RWArc`] - A dual-mode Arc protected by a reader-writer lock,
+* [`sync::MutexArc`] - An Arc with mutable data protected by a blocking mutex,
+* [`sync::Semaphore`] - A counting, blocking, bounded-waiting semaphore,
+* [`sync::Mutex`] - A blocking, bounded-waiting, mutual exclusion lock with an associated 
+    FIFO condition variable,
+* [`sync::RWLock`] - A blocking, no-starvation, reader-writer lock with an associated condvar,
+* [`sync::Barrier`] - A barrier enables multiple tasks to synchronize the beginning
+    of some computation,
+* [`sync::TaskPool`] - A task pool abstraction,
+* [`sync::Future`] - A type encapsulating the result of a computation which may not be complete,
+* [`sync::one`] - A "once initialization" primitive
+* [`sync::mutex`] - A proper mutex implementation regardless of the "flavor of task" which is
+    acquiring the lock.
 
 [`std::task`]: std/task/index.html
 [`std::comm`]: std/comm/index.html
-[`extra::comm`]: extra/comm/index.html
-[`extra::sync`]: extra/sync/index.html
-[`extra::arc`]: extra/arc/index.html
-[`extra::future`]: extra/future/index.html
+[`sync::DuplexStream`]: sync/struct.DuplexStream.html
+[`sync::SyncChan`]: sync/struct.SyncChan.html
+[`sync::SyncPort`]: sync/struct.SyncPort.html
+[`sync::rendezvous`]: sync/fn.rendezvous.html
+[`sync::Arc`]: sync/struct.Arc.html
+[`sync::RWArc`]: sync/struct.RWArc.html
+[`sync::MutexArc`]: sync/struct.MutexArc.html
+[`sync::Semaphore`]: sync/struct.Semaphore.html
+[`sync::Mutex`]: sync/struct.Mutex.html
+[`sync::RWLock`]: sync/struct.RWLock.html
+[`sync::Barrier`]: sync/struct.Barrier.html
+[`sync::TaskPool`]: sync/struct.TaskPool.html
+[`sync::Future`]: sync/struct.Future.html
+[`sync::one`]: sync/one/index.html
+[`sync::mutex`]: sync/mutex/index.html
 
 # Basics
 
@@ -254,21 +279,25 @@ let result = ports.iter().fold(0, |accum, port| accum + port.recv() );
 ~~~
 
 ## Backgrounding computations: Futures
-With `extra::future`, rust has a mechanism for requesting a computation and getting the result
+With `sync::Future`, rust has a mechanism for requesting a computation and getting the result
 later.
 
 The basic example below illustrates this.
 
 ~~~
+# extern mod sync;
+
+# fn main() {
 # fn make_a_sandwich() {};
 fn fib(n: u64) -> u64 {
     // lengthy computation returning an uint
     12586269025
 }
 
-let mut delayed_fib = extra::future::Future::spawn(proc() fib(50));
+let mut delayed_fib = sync::Future::spawn(proc() fib(50));
 make_a_sandwich();
 println!("fib(50) = {:?}", delayed_fib.get())
+# }
 ~~~
 
 The call to `future::spawn` returns immediately a `future` object regardless of how long it
@@ -281,6 +310,7 @@ Here is another example showing how futures allow you to background computations
 be distributed on the available cores.
 
 ~~~
+# extern mod sync;
 # use std::vec;
 fn partial_sum(start: uint) -> f64 {
     let mut local_sum = 0f64;
@@ -291,7 +321,7 @@ fn partial_sum(start: uint) -> f64 {
 }
 
 fn main() {
-    let mut futures = vec::from_fn(1000, |ind| extra::future::Future::spawn( proc() { partial_sum(ind) }));
+    let mut futures = vec::from_fn(1000, |ind| sync::Future::spawn( proc() { partial_sum(ind) }));
 
     let mut final_res = 0f64;
     for ft in futures.mut_iter()  {
@@ -309,16 +339,17 @@ add up to a significant amount of wasted memory and would require copying the sa
 necessary.
 
 To tackle this issue, one can use an Atomically Reference Counted wrapper (`Arc`) as implemented in
-the `extra` library of Rust. With an Arc, the data will no longer be copied for each task. The Arc
+the `sync` library of Rust. With an Arc, the data will no longer be copied for each task. The Arc
 acts as a reference to the shared data and only this reference is shared and cloned.
 
 Here is a small example showing how to use Arcs. We wish to run concurrently several computations on
 a single large vector of floats. Each task needs the full vector to perform its duty.
 
 ~~~
+# extern mod sync;
 # use std::vec;
 # use std::rand;
-use extra::arc::Arc;
+use sync::Arc;
 
 fn pnorm(nums: &~[f64], p: uint) -> f64 {
     nums.iter().fold(0.0, |a,b| a+(*b).powf(&(p as f64)) ).powf(&(1.0 / (p as f64)))
@@ -348,23 +379,29 @@ at the power given as argument and takes the inverse power of this value). The A
 created by the line
 
 ~~~
-# use extra::arc::Arc;
+# extern mod sync;
+# use sync::Arc;
 # use std::vec;
 # use std::rand;
+# fn main() {
 # let numbers = vec::from_fn(1000000, |_| rand::random::<f64>());
 let numbers_arc=Arc::new(numbers);
+# }
 ~~~
 
 and a clone of it is sent to each task
 
 ~~~
-# use extra::arc::Arc;
+# extern mod sync;
+# use sync::Arc;
 # use std::vec;
 # use std::rand;
+# fn main() {
 # let numbers=vec::from_fn(1000000, |_| rand::random::<f64>());
 # let numbers_arc = Arc::new(numbers);
 # let (port, chan)  = Chan::new();
 chan.send(numbers_arc.clone());
+# }
 ~~~
 
 copying only the wrapper and not its contents.
@@ -372,15 +409,18 @@ copying only the wrapper and not its contents.
 Each task recovers the underlying data by
 
 ~~~
-# use extra::arc::Arc;
+# extern mod sync;
+# use sync::Arc;
 # use std::vec;
 # use std::rand;
+# fn main() {
 # let numbers=vec::from_fn(1000000, |_| rand::random::<f64>());
 # let numbers_arc=Arc::new(numbers);
 # let (port, chan)  = Chan::new();
 # chan.send(numbers_arc.clone());
 # let local_arc : Arc<~[f64]> = port.recv();
 let task_numbers = local_arc.get();
+# }
 ~~~
 
 and can use it as if it were local.
@@ -450,7 +490,7 @@ proceed).
 
 A very common thing to do is to spawn a child task where the parent
 and child both need to exchange messages with each other. The
-function `extra::comm::DuplexStream()` supports this pattern.  We'll
+function `sync::comm::DuplexStream()` supports this pattern.  We'll
 look briefly at how to use it.
 
 To see how `DuplexStream()` works, we will create a child task
@@ -458,17 +498,19 @@ that repeatedly receives a `uint` message, converts it to a string, and sends
 the string in response.  The child terminates when it receives `0`.
 Here is the function that implements the child task:
 
-~~~{.ignore .linked-failure}
-# use extra::comm::DuplexStream;
-# use std::uint;
-fn stringifier(channel: &DuplexStream<~str, uint>) {
-    let mut value: uint;
-    loop {
-        value = channel.recv();
-        channel.send(uint::to_str(value));
-        if value == 0 { break; }
+~~~
+# extern mod sync;
+# fn main() {
+# use sync::DuplexStream;
+    fn stringifier(channel: &DuplexStream<~str, uint>) {
+        let mut value: uint;
+        loop {
+            value = channel.recv();
+            channel.send(value.to_str());
+            if value == 0 { break; }
+        }
     }
-}
+# }
 ~~~~
 
 The implementation of `DuplexStream` supports both sending and
@@ -481,15 +523,15 @@ response itself is simply the stringified version of the received value,
 
 Here is the code for the parent task:
 
-~~~{.ignore .linked-failure}
+~~~
+# extern mod sync;
 # use std::task::spawn;
-# use std::uint;
-# use extra::comm::DuplexStream;
+# use sync::DuplexStream;
 # fn stringifier(channel: &DuplexStream<~str, uint>) {
 #     let mut value: uint;
 #     loop {
 #         value = channel.recv();
-#         channel.send(uint::to_str(value));
+#         channel.send(value.to_str());
 #         if value == 0u { break; }
 #     }
 # }
diff --git a/src/doc/index.md b/src/doc/index.md
index 9915d67bfca..5aa92c9fec4 100644
--- a/src/doc/index.md
+++ b/src/doc/index.md
@@ -43,6 +43,7 @@ li {list-style-type: none; }
 * [The `semver` version collation library](semver/index.html)
 * [The `term` terminal-handling library](term/index.html)
 * [The UUID library](uuid/index.html)
+* [The `sync` library for concurrency-enabled mechanisms and primitives](sync/index.html)
 
 # Tooling
 
diff --git a/src/etc/licenseck.py b/src/etc/licenseck.py
index afbf34d0753..e214a40e3d1 100644
--- a/src/etc/licenseck.py
+++ b/src/etc/licenseck.py
@@ -41,7 +41,7 @@ exceptions = [
     "libstd/sync/mpsc_queue.rs", # BSD
     "libstd/sync/spsc_queue.rs", # BSD
     "libstd/sync/mpmc_bounded_queue.rs", # BSD
-    "libextra/sync/mpsc_intrusive.rs", # BSD
+    "libsync/sync/mpsc_intrusive.rs", # BSD
 ]
 
 def check_license(name, contents):
diff --git a/src/libextra/lib.rs b/src/libextra/lib.rs
index d198fd44450..401ece64a5d 100644
--- a/src/libextra/lib.rs
+++ b/src/libextra/lib.rs
@@ -34,17 +34,16 @@ Rust extras are part of the standard Rust distribution.
 #[deny(non_camel_case_types)];
 #[deny(missing_doc)];
 
-// Utility modules
+extern mod sync;
 
-pub mod c_vec;
+#[cfg(stage0)]
+macro_rules! if_ok (
+    ($e:expr) => (match $e { Ok(e) => e, Err(e) => return Err(e) })
+)
 
-// Concurrency
+// Utility modules
 
-pub mod sync;
-pub mod arc;
-pub mod comm;
-pub mod future;
-pub mod task_pool;
+pub mod c_vec;
 
 // Collections
 
diff --git a/src/libextra/workcache.rs b/src/libextra/workcache.rs
index 4d8e7e50dcf..d16edb7aa1e 100644
--- a/src/libextra/workcache.rs
+++ b/src/libextra/workcache.rs
@@ -13,7 +13,7 @@
 use json;
 use json::ToJson;
 use serialize::{Encoder, Encodable, Decoder, Decodable};
-use arc::{Arc,RWArc};
+use sync::{Arc,RWArc};
 use treemap::TreeMap;
 use std::str;
 use std::io;
diff --git a/src/librustc/back/link.rs b/src/librustc/back/link.rs
index e224a06818a..aea9b65087d 100644
--- a/src/librustc/back/link.rs
+++ b/src/librustc/back/link.rs
@@ -331,7 +331,7 @@ pub mod write {
     }
 
     unsafe fn configure_llvm(sess: Session) {
-        use extra::sync::one::{Once, ONCE_INIT};
+        use sync::one::{Once, ONCE_INIT};
         static mut INIT: Once = ONCE_INIT;
 
         // Copy what clang does by turning on loop vectorization at O2 and
diff --git a/src/librustc/lib.rs b/src/librustc/lib.rs
index 8e722fae13a..d4a6c29752d 100644
--- a/src/librustc/lib.rs
+++ b/src/librustc/lib.rs
@@ -35,6 +35,7 @@ extern mod extra;
 extern mod flate;
 extern mod arena;
 extern mod syntax;
+extern mod sync;
 
 use back::link;
 use driver::session;
diff --git a/src/librustc/middle/trans/base.rs b/src/librustc/middle/trans/base.rs
index 1ebe4a03cfd..5b4a9617612 100644
--- a/src/librustc/middle/trans/base.rs
+++ b/src/librustc/middle/trans/base.rs
@@ -2660,7 +2660,7 @@ pub fn trans_crate(sess: session::Session,
                    output: &Path) -> CrateTranslation {
     // Before we touch LLVM, make sure that multithreading is enabled.
     unsafe {
-        use extra::sync::one::{Once, ONCE_INIT};
+        use sync::one::{Once, ONCE_INIT};
         static mut INIT: Once = ONCE_INIT;
         static mut POISONED: bool = false;
         INIT.doit(|| {
diff --git a/src/librustdoc/html/render.rs b/src/librustdoc/html/render.rs
index 65696528a6f..f01e420030f 100644
--- a/src/librustdoc/html/render.rs
+++ b/src/librustdoc/html/render.rs
@@ -41,7 +41,7 @@ use std::io::{fs, File, BufferedWriter};
 use std::str;
 use std::vec;
 
-use extra::arc::Arc;
+use sync::Arc;
 use extra::json::ToJson;
 use syntax::ast;
 use syntax::attr;
diff --git a/src/librustdoc/lib.rs b/src/librustdoc/lib.rs
index fe989279e71..bf096a7e49b 100644
--- a/src/librustdoc/lib.rs
+++ b/src/librustdoc/lib.rs
@@ -18,6 +18,7 @@
 extern mod syntax;
 extern mod rustc;
 extern mod extra;
+extern mod sync;
 
 use std::local_data;
 use std::io;
diff --git a/src/libextra/arc.rs b/src/libsync/arc.rs
index 7f8d64053d5..0e53ecd416a 100644
--- a/src/libextra/arc.rs
+++ b/src/libsync/arc.rs
@@ -18,7 +18,7 @@
  * With simple pipes, without Arc, a copy would have to be made for each task.
  *
  * ```rust
- * use extra::arc::Arc;
+ * use sync::Arc;
  * use std::{rand, vec};
  *
  * let numbers = vec::from_fn(100, |i| (i as f32) * rand::random());
@@ -38,7 +38,7 @@
  * ```
  */
 
-#[allow(missing_doc)];
+#[allow(missing_doc, dead_code)];
 
 
 use sync;
@@ -424,7 +424,7 @@ impl<T:Freeze + Send> RWArc<T> {
      * # Example
      *
      * ```rust
-     * use extra::arc::RWArc;
+     * use sync::RWArc;
      *
      * let arc = RWArc::new(1);
      * arc.write_downgrade(|mut write_token| {
@@ -605,7 +605,7 @@ impl<T:Clone+Send+Freeze> Clone for CowArc<T> {
 #[cfg(test)]
 mod tests {
 
-    use arc::*;
+    use super::{Arc, RWArc, MutexArc, CowArc};
 
     use std::task;
 
diff --git a/src/libextra/comm.rs b/src/libsync/comm.rs
index c7d55076254..c7d55076254 100644
--- a/src/libextra/comm.rs
+++ b/src/libsync/comm.rs
diff --git a/src/libextra/future.rs b/src/libsync/future.rs
index b9121290f33..479174d17af 100644
--- a/src/libextra/future.rs
+++ b/src/libsync/future.rs
@@ -15,7 +15,7 @@
  * # Example
  *
  * ```rust
- * use extra::future::Future;
+ * use sync::Future;
  * # fn fib(n: uint) -> uint {42};
  * # fn make_a_sandwich() {};
  * let mut delayed_fib = Future::spawn(proc() { fib(5000) });
diff --git a/src/libsync/lib.rs b/src/libsync/lib.rs
new file mode 100644
index 00000000000..de1b0f91d6d
--- /dev/null
+++ b/src/libsync/lib.rs
@@ -0,0 +1,31 @@
+// Copyright 2012-2013 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.
+
+/*!
+ * Concurrency-enabled mechanisms and primitives.
+ */
+
+#[crate_id = "sync#0.10-pre"];
+#[crate_type = "rlib"];
+#[crate_type = "dylib"];
+#[license = "MIT/ASL2"];
+
+pub use arc::{Arc, MutexArc, RWArc, RWWriteMode, RWReadMode, Condvar};
+pub use sync::{Mutex, RWLock, Condvar, Semaphore, RWLockWriteMode,
+    RWLockReadMode, Barrier, one, mutex};
+pub use comm::{DuplexStream, SyncChan, SyncPort, rendezvous};
+pub use task_pool::TaskPool;
+pub use future::Future;
+
+mod arc;
+mod sync;
+mod comm;
+mod task_pool;
+mod future;
diff --git a/src/libextra/sync/mod.rs b/src/libsync/sync/mod.rs
index 03bf1101f1f..cfff31e08d4 100644
--- a/src/libextra/sync/mod.rs
+++ b/src/libsync/sync/mod.rs
@@ -588,7 +588,7 @@ impl RWLock {
      * # Example
      *
      * ```rust
-     * use extra::sync::RWLock;
+     * use sync::RWLock;
      *
      * let lock = RWLock::new();
      * lock.write_downgrade(|mut write_token| {
@@ -695,7 +695,7 @@ impl<'a> RWLockReadMode<'a> {
 /// of some computation.
 ///
 /// ```rust
-/// use extra::sync::Barrier;
+/// use sync::Barrier;
 ///
 /// let barrier = Barrier::new(10);
 /// for _ in range(0, 10) {
@@ -759,7 +759,7 @@ impl Barrier {
 
 #[cfg(test)]
 mod tests {
-    use sync::*;
+    use sync::{Semaphore, Mutex, RWLock, Barrier, Condvar};
 
     use std::cast;
     use std::result;
diff --git a/src/libextra/sync/mpsc_intrusive.rs b/src/libsync/sync/mpsc_intrusive.rs
index 0f13a4980d9..0f13a4980d9 100644
--- a/src/libextra/sync/mpsc_intrusive.rs
+++ b/src/libsync/sync/mpsc_intrusive.rs
diff --git a/src/libextra/sync/mutex.rs b/src/libsync/sync/mutex.rs
index 7ea98c0741a..f1a81d65c1d 100644
--- a/src/libextra/sync/mutex.rs
+++ b/src/libsync/sync/mutex.rs
@@ -83,7 +83,7 @@ pub static NATIVE_BLOCKED: uint = 1 << 2;
 /// # Example
 ///
 /// ```rust
-/// use extra::sync::mutex::Mutex;
+/// use sync::mutex::Mutex;
 ///
 /// let mut m = Mutex::new();
 /// let guard = m.lock();
@@ -113,7 +113,7 @@ enum Flavor {
 /// # Example
 ///
 /// ```rust
-/// use extra::sync::mutex::{StaticMutex, MUTEX_INIT};
+/// use sync::mutex::{StaticMutex, MUTEX_INIT};
 ///
 /// static mut LOCK: StaticMutex = MUTEX_INIT;
 ///
diff --git a/src/libextra/sync/one.rs b/src/libsync/sync/one.rs
index 826955d93e8..93d818b704d 100644
--- a/src/libextra/sync/one.rs
+++ b/src/libsync/sync/one.rs
@@ -30,7 +30,7 @@ use sync::mutex::{StaticMutex, MUTEX_INIT};
 /// # Example
 ///
 /// ```rust
-/// use extra::sync::one::{Once, ONCE_INIT};
+/// use sync::one::{Once, ONCE_INIT};
 ///
 /// static mut START: Once = ONCE_INIT;
 /// unsafe {
diff --git a/src/libextra/task_pool.rs b/src/libsync/task_pool.rs
index 0d8cccfe2b9..0d8cccfe2b9 100644
--- a/src/libextra/task_pool.rs
+++ b/src/libsync/task_pool.rs
diff --git a/src/test/bench/msgsend-ring-mutex-arcs.rs b/src/test/bench/msgsend-ring-mutex-arcs.rs
index b1b2300466a..4b505ec8117 100644
--- a/src/test/bench/msgsend-ring-mutex-arcs.rs
+++ b/src/test/bench/msgsend-ring-mutex-arcs.rs
@@ -16,15 +16,17 @@
 // This also serves as a pipes test, because Arcs are implemented with pipes.
 
 extern mod extra;
+extern mod sync;
 
-use extra::arc;
-use extra::future::Future;
+use sync::Arc;
+use sync::MutexArc;
+use sync::Future;
 use extra::time;
 use std::os;
 use std::uint;
 
 // A poor man's pipe.
-type pipe = arc::MutexArc<~[uint]>;
+type pipe = MutexArc<~[uint]>;
 
 fn send(p: &pipe, msg: uint) {
     unsafe {
@@ -46,7 +48,7 @@ fn recv(p: &pipe) -> uint {
 }
 
 fn init() -> (pipe,pipe) {
-    let m = arc::MutexArc::new(~[]);
+    let m = MutexArc::new(~[]);
     ((&m).clone(), m)
 }
 
diff --git a/src/test/bench/msgsend-ring-rw-arcs.rs b/src/test/bench/msgsend-ring-rw-arcs.rs
index d7bd0f2f6bd..23b4f00b280 100644
--- a/src/test/bench/msgsend-ring-rw-arcs.rs
+++ b/src/test/bench/msgsend-ring-rw-arcs.rs
@@ -16,15 +16,16 @@
 // This also serves as a pipes test, because Arcs are implemented with pipes.
 
 extern mod extra;
+extern mod sync;
 
-use extra::arc;
-use extra::future::Future;
+use sync::RWArc;
+use sync::Future;
 use extra::time;
 use std::os;
 use std::uint;
 
 // A poor man's pipe.
-type pipe = arc::RWArc<~[uint]>;
+type pipe = RWArc<~[uint]>;
 
 fn send(p: &pipe, msg: uint) {
     p.write_cond(|state, cond| {
@@ -42,7 +43,7 @@ fn recv(p: &pipe) -> uint {
 }
 
 fn init() -> (pipe,pipe) {
-    let x = arc::RWArc::new(~[]);
+    let x = RWArc::new(~[]);
     ((&x).clone(), x)
 }
 
diff --git a/src/test/bench/shootout-binarytrees.rs b/src/test/bench/shootout-binarytrees.rs
index da658e6d041..c0e22f207b8 100644
--- a/src/test/bench/shootout-binarytrees.rs
+++ b/src/test/bench/shootout-binarytrees.rs
@@ -8,11 +8,11 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-extern mod extra;
+extern mod sync;
 extern mod arena;
 
 use std::iter::range_step;
-use extra::future::Future;
+use sync::Future;
 use arena::TypedArena;
 
 enum Tree<'a> {
diff --git a/src/test/bench/shootout-spectralnorm.rs b/src/test/bench/shootout-spectralnorm.rs
index d68ca4e0abb..9de62aaf960 100644
--- a/src/test/bench/shootout-spectralnorm.rs
+++ b/src/test/bench/shootout-spectralnorm.rs
@@ -10,15 +10,15 @@
 
 // xfail-test arcs no longer unwrap
 
-extern mod extra;
+extern mod sync;
 
 use std::from_str::FromStr;
 use std::iter::count;
 use std::num::min;
 use std::os;
 use std::vec::from_elem;
-use extra::arc::Arc;
-use extra::arc::RWArc;
+use sync::Arc;
+use sync::RWArc;
 
 fn A(i: uint, j: uint) -> f64 {
     ((i + j) * (i + j + 1) / 2 + i + 1) as f64
diff --git a/src/test/compile-fail/arc-cant-nest-rw-arc-3177.rs b/src/test/compile-fail/arc-cant-nest-rw-arc-3177.rs
index 49412b3aafd..5c55f10ab4f 100644
--- a/src/test/compile-fail/arc-cant-nest-rw-arc-3177.rs
+++ b/src/test/compile-fail/arc-cant-nest-rw-arc-3177.rs
@@ -8,8 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-extern mod extra;
-use extra::arc::RWArc;
+extern mod sync;
+use sync::RWArc;
 
 fn main() {
     let arc1  = RWArc::new(true);
diff --git a/src/test/compile-fail/arc-rw-cond-shouldnt-escape.rs b/src/test/compile-fail/arc-rw-cond-shouldnt-escape.rs
index c31a7bb244c..c9cd1327882 100644
--- a/src/test/compile-fail/arc-rw-cond-shouldnt-escape.rs
+++ b/src/test/compile-fail/arc-rw-cond-shouldnt-escape.rs
@@ -9,10 +9,10 @@
 // except according to those terms.
 
 // error-pattern: lifetime of return value does not outlive the function call
-extern mod extra;
-use extra::arc;
+extern mod sync;
+use sync::RWArc;
 fn main() {
-    let x = ~arc::RWArc::new(1);
+    let x = ~RWArc::new(1);
     let mut y = None;
     x.write_cond(|_one, cond| y = Some(cond));
     y.unwrap().wait();
diff --git a/src/test/compile-fail/arc-rw-read-mode-shouldnt-escape.rs b/src/test/compile-fail/arc-rw-read-mode-shouldnt-escape.rs
index 716dfe2c8b5..dfdbd882acf 100644
--- a/src/test/compile-fail/arc-rw-read-mode-shouldnt-escape.rs
+++ b/src/test/compile-fail/arc-rw-read-mode-shouldnt-escape.rs
@@ -8,10 +8,10 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-extern mod extra;
-use extra::arc;
+extern mod sync;
+use sync::RWArc;
 fn main() {
-    let x = ~arc::RWArc::new(1);
+    let x = ~RWArc::new(1);
     let mut y = None;
     x.write_downgrade(|write_mode| {
         y = Some(x.downgrade(write_mode));
diff --git a/src/test/compile-fail/arc-rw-state-shouldnt-escape.rs b/src/test/compile-fail/arc-rw-state-shouldnt-escape.rs
index 7c129ae0dca..4bb7653d23e 100644
--- a/src/test/compile-fail/arc-rw-state-shouldnt-escape.rs
+++ b/src/test/compile-fail/arc-rw-state-shouldnt-escape.rs
@@ -8,10 +8,10 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-extern mod extra;
-use extra::arc;
+extern mod sync;
+use sync::RWArc;
 fn main() {
-    let x = ~arc::RWArc::new(1);
+    let x = ~RWArc::new(1);
     let mut y = None; //~ ERROR lifetime of variable does not enclose its declaration
     x.write(|one| y = Some(one));
     *y.unwrap() = 2;
diff --git a/src/test/compile-fail/arc-rw-write-mode-cond-shouldnt-escape.rs b/src/test/compile-fail/arc-rw-write-mode-cond-shouldnt-escape.rs
index 674cd570888..1410308107e 100644
--- a/src/test/compile-fail/arc-rw-write-mode-cond-shouldnt-escape.rs
+++ b/src/test/compile-fail/arc-rw-write-mode-cond-shouldnt-escape.rs
@@ -9,10 +9,10 @@
 // except according to those terms.
 
 // error-pattern: lifetime of variable does not enclose its declaration
-extern mod extra;
-use extra::arc;
+extern mod sync;
+use sync::RWArc;
 fn main() {
-    let x = ~arc::RWArc::new(1);
+    let x = ~RWArc::new(1);
     let mut y = None;
     x.write_downgrade(|write_mode| {
         (&write_mode).write_cond(|_one, cond| {
diff --git a/src/test/compile-fail/arc-rw-write-mode-shouldnt-escape.rs b/src/test/compile-fail/arc-rw-write-mode-shouldnt-escape.rs
index 213bf48a087..68226d96a18 100644
--- a/src/test/compile-fail/arc-rw-write-mode-shouldnt-escape.rs
+++ b/src/test/compile-fail/arc-rw-write-mode-shouldnt-escape.rs
@@ -9,10 +9,10 @@
 // except according to those terms.
 
 // error-pattern: lifetime of variable does not enclose its declaration
-extern mod extra;
-use extra::arc;
+extern mod sync;
+use sync::RWArc;
 fn main() {
-    let x = ~arc::RWArc::new(1);
+    let x = ~RWArc::new(1);
     let mut y = None;
     x.write_downgrade(|write_mode| y = Some(write_mode));
     y.unwrap();
diff --git a/src/test/compile-fail/functional-struct-update-noncopyable.rs b/src/test/compile-fail/functional-struct-update-noncopyable.rs
index 00945ea8469..f2c9ba58228 100644
--- a/src/test/compile-fail/functional-struct-update-noncopyable.rs
+++ b/src/test/compile-fail/functional-struct-update-noncopyable.rs
@@ -11,8 +11,8 @@
 // issue 7327
 
 // xfail-fast #7103
-extern mod extra;
-use extra::arc::Arc;
+extern mod sync;
+use sync::Arc;
 
 struct A { y: Arc<int>, x: Arc<int> }
 
diff --git a/src/test/compile-fail/future_not_copyable.rs b/src/test/compile-fail/future_not_copyable.rs
index aef5d0f9b04..69a90275ec7 100644
--- a/src/test/compile-fail/future_not_copyable.rs
+++ b/src/test/compile-fail/future_not_copyable.rs
@@ -8,9 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-extern mod extra;
+extern mod sync;
 
-use extra::future::Future;
+use sync::Future;
 
 fn main() {
     let f = Future::from_value(());
diff --git a/src/test/compile-fail/mutex-arc-nested.rs b/src/test/compile-fail/mutex-arc-nested.rs
index 24a141c4799..cdfdd29410e 100644
--- a/src/test/compile-fail/mutex-arc-nested.rs
+++ b/src/test/compile-fail/mutex-arc-nested.rs
@@ -8,10 +8,10 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-extern mod extra;
+extern mod sync;
 
 use std::task;
-use extra::arc::{MutexArc};
+use sync::MutexArc;
 
 fn test_mutex_arc_nested() {
     let arc = ~MutexArc::new(1);
diff --git a/src/test/compile-fail/no-capture-arc.rs b/src/test/compile-fail/no-capture-arc.rs
index 5ae38e69ec0..cc529abd6f9 100644
--- a/src/test/compile-fail/no-capture-arc.rs
+++ b/src/test/compile-fail/no-capture-arc.rs
@@ -10,14 +10,14 @@
 
 // error-pattern: use of moved value
 
-extern mod extra;
-use extra::arc;
+extern mod sync;
+use sync::Arc;
 
 use std::task;
 
 fn main() {
     let v = ~[1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
-    let arc_v = arc::Arc::new(v);
+    let arc_v = Arc::new(v);
 
     task::spawn(proc() {
         let v = arc_v.get();
diff --git a/src/test/compile-fail/no-reuse-move-arc.rs b/src/test/compile-fail/no-reuse-move-arc.rs
index c6c0ba41ab9..204a0e1cdd4 100644
--- a/src/test/compile-fail/no-reuse-move-arc.rs
+++ b/src/test/compile-fail/no-reuse-move-arc.rs
@@ -8,14 +8,14 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-extern mod extra;
-use extra::arc;
+extern mod sync;
+use sync::Arc;
 
 use std::task;
 
 fn main() {
     let v = ~[1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
-    let arc_v = arc::Arc::new(v);
+    let arc_v = Arc::new(v);
 
     task::spawn(proc() {
         let v = arc_v.get();
diff --git a/src/test/compile-fail/once-cant-call-twice-on-heap.rs b/src/test/compile-fail/once-cant-call-twice-on-heap.rs
index 8d5e2229b2e..a7e4f8de437 100644
--- a/src/test/compile-fail/once-cant-call-twice-on-heap.rs
+++ b/src/test/compile-fail/once-cant-call-twice-on-heap.rs
@@ -12,8 +12,8 @@
 // This program would segfault if it were legal.
 
 #[feature(once_fns)];
-extern mod extra;
-use extra::arc;
+extern mod sync;
+use sync::Arc;
 
 fn foo(blk: proc()) {
     blk();
@@ -21,7 +21,7 @@ fn foo(blk: proc()) {
 }
 
 fn main() {
-    let x = arc::Arc::new(true);
+    let x = Arc::new(true);
     foo(proc() {
         assert!(*x.get());
         drop(x);
diff --git a/src/test/compile-fail/once-cant-call-twice-on-stack.rs b/src/test/compile-fail/once-cant-call-twice-on-stack.rs
index 71293555d49..8b168dd6787 100644
--- a/src/test/compile-fail/once-cant-call-twice-on-stack.rs
+++ b/src/test/compile-fail/once-cant-call-twice-on-stack.rs
@@ -12,8 +12,8 @@
 // This program would segfault if it were legal.
 
 #[feature(once_fns)];
-extern mod extra;
-use extra::arc;
+extern mod sync;
+use sync::Arc;
 
 fn foo(blk: once ||) {
     blk();
@@ -21,7 +21,7 @@ fn foo(blk: once ||) {
 }
 
 fn main() {
-    let x = arc::Arc::new(true);
+    let x = Arc::new(true);
     foo(|| {
         assert!(*x.get());
         drop(x);
diff --git a/src/test/compile-fail/once-cant-move-out-of-non-once-on-stack.rs b/src/test/compile-fail/once-cant-move-out-of-non-once-on-stack.rs
index 7206b9bdb88..4fa6b6af794 100644
--- a/src/test/compile-fail/once-cant-move-out-of-non-once-on-stack.rs
+++ b/src/test/compile-fail/once-cant-move-out-of-non-once-on-stack.rs
@@ -11,8 +11,8 @@
 // Testing guarantees provided by once functions.
 // This program would segfault if it were legal.
 
-extern mod extra;
-use extra::arc;
+extern mod sync;
+use sync::Arc;
 
 fn foo(blk: ||) {
     blk();
@@ -20,7 +20,7 @@ fn foo(blk: ||) {
 }
 
 fn main() {
-    let x = arc::Arc::new(true);
+    let x = Arc::new(true);
     foo(|| {
         assert!(*x.get());
         drop(x); //~ ERROR cannot move out of captured outer variable
diff --git a/src/test/compile-fail/sync-cond-shouldnt-escape.rs b/src/test/compile-fail/sync-cond-shouldnt-escape.rs
index 4df08b28eb8..06b8ad6259b 100644
--- a/src/test/compile-fail/sync-cond-shouldnt-escape.rs
+++ b/src/test/compile-fail/sync-cond-shouldnt-escape.rs
@@ -9,8 +9,8 @@
 // except according to those terms.
 
 // error-pattern: lifetime of variable does not enclose its declaration
-extern mod extra;
-use extra::sync;
+extern mod sync;
+use sync::Mutex;
 
 fn main() {
     let m = ~sync::Mutex::new();
diff --git a/src/test/compile-fail/sync-rwlock-cond-shouldnt-escape.rs b/src/test/compile-fail/sync-rwlock-cond-shouldnt-escape.rs
index d59eaf62abf..52466c122dd 100644
--- a/src/test/compile-fail/sync-rwlock-cond-shouldnt-escape.rs
+++ b/src/test/compile-fail/sync-rwlock-cond-shouldnt-escape.rs
@@ -9,10 +9,10 @@
 // except according to those terms.
 
 // error-pattern: lifetime of method receiver does not outlive the method call
-extern mod extra;
-use extra::sync;
+extern mod sync;
+use sync::RWLock;
 fn main() {
-    let x = ~sync::RWLock::new();
+    let x = ~RWLock::new();
     let mut y = None;
     x.write_cond(|cond| {
         y = Some(cond);
diff --git a/src/test/compile-fail/sync-rwlock-read-mode-shouldnt-escape.rs b/src/test/compile-fail/sync-rwlock-read-mode-shouldnt-escape.rs
index 0078841acb1..0201f9dd51c 100644
--- a/src/test/compile-fail/sync-rwlock-read-mode-shouldnt-escape.rs
+++ b/src/test/compile-fail/sync-rwlock-read-mode-shouldnt-escape.rs
@@ -9,10 +9,10 @@
 // except according to those terms.
 
 // error-pattern: cannot infer an appropriate lifetime
-extern mod extra;
-use extra::sync;
+extern mod sync;
+use sync::RWLock;
 fn main() {
-    let x = ~sync::RWLock::new();
+    let x = ~RWLock::new();
     let mut y = None;
     x.write_downgrade(|write_mode| {
         y = Some(x.downgrade(write_mode));
diff --git a/src/test/compile-fail/sync-rwlock-write-mode-cond-shouldnt-escape.rs b/src/test/compile-fail/sync-rwlock-write-mode-cond-shouldnt-escape.rs
index cbe5181d46f..71a9dd100c3 100644
--- a/src/test/compile-fail/sync-rwlock-write-mode-cond-shouldnt-escape.rs
+++ b/src/test/compile-fail/sync-rwlock-write-mode-cond-shouldnt-escape.rs
@@ -9,10 +9,10 @@
 // except according to those terms.
 
 // error-pattern: lifetime of variable does not enclose its declaration
-extern mod extra;
-use extra::sync;
+extern mod sync;
+use sync::RWLock;
 fn main() {
-    let x = ~sync::RWLock::new();
+    let x = ~RWLock::new();
     let mut y = None;
     x.write_downgrade(|write_mode| {
         (&write_mode).write_cond(|cond| {
diff --git a/src/test/compile-fail/sync-rwlock-write-mode-shouldnt-escape.rs b/src/test/compile-fail/sync-rwlock-write-mode-shouldnt-escape.rs
index 6e921683075..53966bf48a4 100644
--- a/src/test/compile-fail/sync-rwlock-write-mode-shouldnt-escape.rs
+++ b/src/test/compile-fail/sync-rwlock-write-mode-shouldnt-escape.rs
@@ -9,10 +9,10 @@
 // except according to those terms.
 
 // error-pattern: lifetime of variable does not enclose its declaration
-extern mod extra;
-use extra::sync;
+extern mod sync;
+use sync::RWLock;
 fn main() {
-    let x = ~sync::RWLock::new();
+    let x = ~RWLock::new();
     let mut y = None;
     x.write_downgrade(|write_mode| {
         y = Some(write_mode);
diff --git a/src/test/run-fail/issue-2444.rs b/src/test/run-fail/issue-2444.rs
index c1357988f7d..16f54e92923 100644
--- a/src/test/run-fail/issue-2444.rs
+++ b/src/test/run-fail/issue-2444.rs
@@ -10,10 +10,10 @@
 
 // error-pattern:explicit failure
 
-extern mod extra;
-use extra::arc;
+extern mod sync;
+use sync::Arc;
 
-enum e<T> { e(arc::Arc<T>) }
+enum e<T> { e(Arc<T>) }
 
 fn foo() -> e<int> {fail!();}
 
diff --git a/src/test/run-pass/bind-by-move.rs b/src/test/run-pass/bind-by-move.rs
index a7a4aa9885e..3a86357bdaa 100644
--- a/src/test/run-pass/bind-by-move.rs
+++ b/src/test/run-pass/bind-by-move.rs
@@ -9,12 +9,12 @@
 // except according to those terms.
 
 // xfail-fast
-extern mod extra;
-use extra::arc;
-fn dispose(_x: arc::Arc<bool>) { }
+extern mod sync;
+use sync::Arc;
+fn dispose(_x: Arc<bool>) { }
 
 pub fn main() {
-    let p = arc::Arc::new(true);
+    let p = Arc::new(true);
     let x = Some(p);
     match x {
         Some(z) => { dispose(z); },
diff --git a/src/test/run-pass/once-move-out-on-heap.rs b/src/test/run-pass/once-move-out-on-heap.rs
index bc56712ee3b..0ccf7b8f8a3 100644
--- a/src/test/run-pass/once-move-out-on-heap.rs
+++ b/src/test/run-pass/once-move-out-on-heap.rs
@@ -13,15 +13,15 @@
 // xfail-fast
 
 #[feature(once_fns)];
-extern mod extra;
-use extra::arc;
+extern mod sync;
+use sync::Arc;
 
 fn foo(blk: proc()) {
     blk();
 }
 
 pub fn main() {
-    let x = arc::Arc::new(true);
+    let x = Arc::new(true);
     foo(proc() {
         assert!(*x.get());
         drop(x);
diff --git a/src/test/run-pass/once-move-out-on-stack.rs b/src/test/run-pass/once-move-out-on-stack.rs
index 07dd5175a0f..e732d0c76a6 100644
--- a/src/test/run-pass/once-move-out-on-stack.rs
+++ b/src/test/run-pass/once-move-out-on-stack.rs
@@ -13,15 +13,15 @@
 // xfail-fast
 
 #[feature(once_fns)];
-extern mod extra;
-use extra::arc;
+extern mod sync;
+use sync::Arc;
 
 fn foo(blk: once ||) {
     blk();
 }
 
 pub fn main() {
-    let x = arc::Arc::new(true);
+    let x = Arc::new(true);
     foo(|| {
         assert!(*x.get());
         drop(x);
diff --git a/src/test/run-pass/trait-bounds-in-arc.rs b/src/test/run-pass/trait-bounds-in-arc.rs
index 2bf18e1ae1d..454da6d2aaa 100644
--- a/src/test/run-pass/trait-bounds-in-arc.rs
+++ b/src/test/run-pass/trait-bounds-in-arc.rs
@@ -15,9 +15,9 @@
 
 // xfail-fast
 
-extern mod extra;
+extern mod sync;
 
-use extra::arc;
+use sync::Arc;
 use std::task;
 
 trait Pet {
@@ -65,7 +65,7 @@ pub fn main() {
     let dogge1 = Dogge { bark_decibels: 100, tricks_known: 42, name: ~"alan_turing" };
     let dogge2 = Dogge { bark_decibels: 55,  tricks_known: 11, name: ~"albert_einstein" };
     let fishe = Goldfyshe { swim_speed: 998, name: ~"alec_guinness" };
-    let arc = arc::Arc::new(~[~catte  as ~Pet:Freeze+Send,
+    let arc = Arc::new(~[~catte  as ~Pet:Freeze+Send,
                          ~dogge1 as ~Pet:Freeze+Send,
                          ~fishe  as ~Pet:Freeze+Send,
                          ~dogge2 as ~Pet:Freeze+Send]);
@@ -83,21 +83,21 @@ pub fn main() {
     p3.recv();
 }
 
-fn check_legs(arc: arc::Arc<~[~Pet:Freeze+Send]>) {
+fn check_legs(arc: Arc<~[~Pet:Freeze+Send]>) {
     let mut legs = 0;
     for pet in arc.get().iter() {
         legs += pet.num_legs();
     }
     assert!(legs == 12);
 }
-fn check_names(arc: arc::Arc<~[~Pet:Freeze+Send]>) {
+fn check_names(arc: Arc<~[~Pet:Freeze+Send]>) {
     for pet in arc.get().iter() {
         pet.name(|name| {
             assert!(name[0] == 'a' as u8 && name[1] == 'l' as u8);
         })
     }
 }
-fn check_pedigree(arc: arc::Arc<~[~Pet:Freeze+Send]>) {
+fn check_pedigree(arc: Arc<~[~Pet:Freeze+Send]>) {
     for pet in arc.get().iter() {
         assert!(pet.of_good_pedigree());
     }