---

yaml
---
r: 152137
b: refs/heads/try2
c: 7889c95
h: refs/heads/master
i:
  152135: 11de71b
v: v3

Author: aturon

[refs]

@@ -5,7 +5,7 @@ refs/heads/snap-stage3: 78a7676898d9f80ab540c6df5d4c9ce35bb50463
 refs/heads/try: 519addf6277dbafccbb4159db4b710c37eaa2ec5
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b
-refs/heads/try2: 3a105464fbdf5ba9df7c97eaecffe9f8479f91b0
+refs/heads/try2: 7889c951240624b22cc4c9b87f2852322b0b716c
 refs/heads/dist-snap: ba4081a5a8573875fed17545846f6f6902c8ba8d
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596
 refs/tags/release-0.3: b5f0d0f648d9a6153664837026ba1be43d3e2503

branches/try2/.gitignore

@@ -60,6 +60,7 @@ config.mk
 /rt/
 /rustllvm/
 /test/
+/build
 /inst/
 /mingw-build/
 src/.DS_Store

branches/try2/mk/crates.mk

@@ -60,9 +60,9 @@ DEPS_core :=
 DEPS_rlibc :=
 DEPS_alloc := core libc native:jemalloc
 DEPS_debug := std
-DEPS_std := core rand libc alloc native:rustrt native:backtrace
+DEPS_std := core libc alloc native:rustrt native:backtrace
 DEPS_graphviz := std
-DEPS_green := std native:context_switch
+DEPS_green := std rand native:context_switch
 DEPS_rustuv := std native:uv native:uv_support
 DEPS_native := std
 DEPS_syntax := std term serialize collections log fmt_macros debug
@@ -77,16 +77,16 @@ DEPS_glob := std
 DEPS_serialize := std collections log
 DEPS_term := std collections log
 DEPS_semver := std
-DEPS_uuid := std serialize
+DEPS_uuid := std serialize rand
 DEPS_sync := std alloc
 DEPS_getopts := std
-DEPS_collections := std debug
+DEPS_collections := std rand debug
 DEPS_fourcc := syntax std
 DEPS_hexfloat := syntax std
-DEPS_num := std
+DEPS_num := std rand
 DEPS_test := std collections getopts serialize term time regex
 DEPS_time := std serialize sync
-DEPS_rand := core
+DEPS_rand := std
 DEPS_url := std collections
 DEPS_workcache := std serialize collections log
 DEPS_log := std sync
@@ -104,7 +104,6 @@ TOOL_SOURCE_rustc := $(S)src/driver/driver.rs
 ONLY_RLIB_core := 1
 ONLY_RLIB_rlibc := 1
 ONLY_RLIB_alloc := 1
-ONLY_RLIB_rand := 1
 
 ################################################################################
 # You should not need to edit below this line

branches/try2/src/doc/guide-tasks.md

@@ -329,10 +329,10 @@ Here is a small example showing how to use Arcs. We wish to run concurrently sev
 a single large vector of floats. Each task needs the full vector to perform its duty.
 
 ~~~
+extern crate rand;
 extern crate sync;
 
 use sync::Arc;
-use std::rand;
 
 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))
@@ -358,7 +358,7 @@ created by the line
 
 ~~~
 # extern crate sync;
-# use std::rand;
+# extern crate rand;
 # use sync::Arc;
 # fn main() {
 # let numbers = Vec::from_fn(1000000, |_| rand::random::<f64>());
@@ -372,7 +372,7 @@ reference to the underlying vector as if it were local.
 
 ~~~
 # extern crate sync;
-# use std::rand;
+# extern crate rand;
 # use sync::Arc;
 # fn pnorm(nums: &[f64], p: uint) -> f64 { 4.0 }
 # fn main() {

branches/try2/src/doc/tutorial.md

@@ -1112,7 +1112,7 @@ let ys = xs;
 
 xs = Nil;
 
-// `xs` can be used again
+// `xs` can't be used again
 ~~~
 
 A destructor call will only occur for a variable that has not been moved from,

branches/try2/src/liballoc/arc.rs

@@ -152,7 +152,11 @@ impl<T: Send + Share + Clone> Arc<T> {
     #[inline]
     #[experimental]
     pub fn make_unique<'a>(&'a mut self) -> &'a mut T {
-        if self.inner().strong.load(atomics::SeqCst) != 1 {
+        // Note that we hold a strong reference, which also counts as
+        // a weak reference, so we only clone if there is an
+        // additional reference of either kind.
+        if self.inner().strong.load(atomics::SeqCst) != 1 ||
+           self.inner().weak.load(atomics::SeqCst) != 1 {
             *self = Arc::new(self.deref().clone())
         }
         // This unsafety is ok because we're guaranteed that the pointer
@@ -356,6 +360,20 @@ mod tests {
         assert!(*cow1 == *cow2);
     }
 
+    #[test]
+    fn test_cowarc_clone_weak() {
+        let mut cow0 = Arc::new(75u);
+        let cow1_weak = cow0.downgrade();
+
+        assert!(75 == *cow0);
+        assert!(75 == *cow1_weak.upgrade().unwrap());
+
+        *cow0.make_unique() += 1;
+
+        assert!(76 == *cow0);
+        assert!(cow1_weak.upgrade().is_none());
+    }
+
     #[test]
     fn test_live() {
         let x = Arc::new(5);

branches/try2/src/liballoc/rc.rs

@@ -86,6 +86,31 @@ impl<T> Rc<T> {
     }
 }
 
+impl<T: Clone> Rc<T> {
+    /// Acquires a mutable pointer to the inner contents by guaranteeing that
+    /// the reference count is one (no sharing is possible).
+    ///
+    /// This is also referred to as a copy-on-write operation because the inner
+    /// data is cloned if the reference count is greater than one.
+    #[inline]
+    #[experimental]
+    pub fn make_unique<'a>(&'a mut self) -> &'a mut T {
+        // Note that we hold a strong reference, which also counts as
+        // a weak reference, so we only clone if there is an
+        // additional reference of either kind.
+        if self.strong() != 1 || self.weak() != 1 {
+            *self = Rc::new(self.deref().clone())
+        }
+        // This unsafety is ok because we're guaranteed that the pointer
+        // returned is the *only* pointer that will ever be returned to T. Our
+        // reference count is guaranteed to be 1 at this point, and we required
+        // the Rc itself to be `mut`, so we're returning the only possible
+        // reference to the inner data.
+        let inner = unsafe { &mut *self._ptr };
+        &mut inner.value
+    }
+}
+
 impl<T> Deref<T> for Rc<T> {
     /// Borrow the value contained in the reference-counted box
     #[inline(always)]
@@ -234,6 +259,7 @@ impl<T> RcBoxPtr<T> for Weak<T> {
 }
 
 #[cfg(test)]
+#[allow(experimental)]
 mod tests {
     use super::{Rc, Weak};
     use std::cell::RefCell;
@@ -304,4 +330,66 @@ mod tests {
 
         // hopefully we don't double-free (or leak)...
     }
+
+    #[test]
+    fn test_cowrc_clone_make_unique() {
+        let mut cow0 = Rc::new(75u);
+        let mut cow1 = cow0.clone();
+        let mut cow2 = cow1.clone();
+
+        assert!(75 == *cow0.make_unique());
+        assert!(75 == *cow1.make_unique());
+        assert!(75 == *cow2.make_unique());
+
+        *cow0.make_unique() += 1;
+        *cow1.make_unique() += 2;
+        *cow2.make_unique() += 3;
+
+        assert!(76 == *cow0);
+        assert!(77 == *cow1);
+        assert!(78 == *cow2);
+
+        // none should point to the same backing memory
+        assert!(*cow0 != *cow1);
+        assert!(*cow0 != *cow2);
+        assert!(*cow1 != *cow2);
+    }
+
+    #[test]
+    fn test_cowrc_clone_unique2() {
+        let mut cow0 = Rc::new(75u);
+        let cow1 = cow0.clone();
+        let cow2 = cow1.clone();
+
+        assert!(75 == *cow0);
+        assert!(75 == *cow1);
+        assert!(75 == *cow2);
+
+        *cow0.make_unique() += 1;
+
+        assert!(76 == *cow0);
+        assert!(75 == *cow1);
+        assert!(75 == *cow2);
+
+        // cow1 and cow2 should share the same contents
+        // cow0 should have a unique reference
+        assert!(*cow0 != *cow1);
+        assert!(*cow0 != *cow2);
+        assert!(*cow1 == *cow2);
+    }
+
+    #[test]
+    fn test_cowrc_clone_weak() {
+        let mut cow0 = Rc::new(75u);
+        let cow1_weak = cow0.downgrade();
+
+        assert!(75 == *cow0);
+        assert!(75 == *cow1_weak.upgrade().unwrap());
+
+        *cow0.make_unique() += 1;
+
+        assert!(76 == *cow0);
+        assert!(cow1_weak.upgrade().is_none());
+    }
+
 }

branches/try2/src/libcollections/bitv.rs

@@ -980,8 +980,8 @@ mod tests {
     use bitv;
 
     use std::uint;
-    use std::rand;
-    use std::rand::Rng;
+    use rand;
+    use rand::Rng;
 
     static BENCH_BITS : uint = 1 << 14;
 

branches/try2/src/libcollections/deque.rs

@@ -44,8 +44,8 @@ pub mod bench {
     extern crate test;
     use self::test::Bencher;
     use std::container::MutableMap;
-    use std::rand;
-    use std::rand::Rng;
+    use rand;
+    use rand::Rng;
 
     pub fn insert_rand_n<M:MutableMap<uint,uint>>(n: uint,
                                                   map: &mut M,

branches/try2/src/libcollections/dlist.rs

@@ -610,7 +610,7 @@ mod tests {
     extern crate test;
     use self::test::Bencher;
     use deque::Deque;
-    use std::rand;
+    use rand;
     use super::{DList, Node, ListInsertion};
 
     pub fn check_links<T>(list: &DList<T>) {

branches/try2/src/libcollections/hashmap.rs

@@ -24,8 +24,8 @@ use std::iter::{range, range_inclusive};
 use std::mem::replace;
 use std::num;
 use std::option::{Option, Some, None};
-use std::rand;
-use std::rand::Rng;
+use rand;
+use rand::Rng;
 use std::result::{Ok, Err};
 use std::slice::ImmutableVector;
 

branches/try2/src/libcollections/lib.rs

@@ -24,6 +24,7 @@
 
 #![deny(deprecated_owned_vector)]
 
+extern crate rand;
 extern crate debug;
 
 #[cfg(test)] extern crate test;

branches/try2/src/libcollections/treemap.rs

@@ -1000,8 +1000,8 @@ impl<T: TotalOrd> Extendable<T> for TreeSet<T> {
 mod test_treemap {
     use super::{TreeMap, TreeNode};
 
-    use std::rand::Rng;
-    use std::rand;
+    use rand::Rng;
+    use rand;
 
     #[test]
     fn find_empty() {

branches/try2/src/libcollections/trie.rs

@@ -915,7 +915,7 @@ mod test_map {
 mod bench_map {
     extern crate test;
     use super::TrieMap;
-    use std::rand::{weak_rng, Rng};
+    use rand::{weak_rng, Rng};
     use self::test::Bencher;
 
     #[bench]

branches/try2/src/libcore/any.rs

@@ -119,7 +119,7 @@ mod tests {
     use prelude::*;
     use super::*;
     use realstd::owned::{Box, AnyOwnExt};
-    use realstd::str::Str;
+    use realstd::str::{Str, StrAllocating};
 
     #[deriving(Eq, Show)]
     struct Test;

branches/try2/src/libcore/char.rs

@@ -607,7 +607,7 @@ mod test {
     use slice::ImmutableVector;
     use option::{Some, None};
     use realstd::string::String;
-    use realstd::str::Str;
+    use realstd::str::{Str, StrAllocating};
 
     #[test]
     fn test_is_lowercase() {

branches/try2/src/libcore/fmt/mod.rs

@@ -596,6 +596,7 @@ pub fn argument<'a, T>(f: extern "Rust" fn(&T, &mut Formatter) -> Result,
 #[cfg(test)]
 pub fn format(args: &Arguments) -> ::realstd::string::String {
     use str;
+    use realstd::str::StrAllocating;
     use realstd::io::MemWriter;
 
     fn mywrite<T: ::realstd::io::Writer>(t: &mut T, b: &[u8]) {