Auto merge of #41735 - frewsxcv:rollup, r=frewsxcv

Rollup of 6 pull requests

- Successful merges: #41543, #41600, #41715, #41720, #41721, #41730
- Failed merges:

Author: bors

.mailmap

@@ -139,6 +139,7 @@ Margaret Meyerhofer <[email protected]> <mmeyerho@andrew>
 Mark Sinclair <[email protected]>
 Mark Sinclair <[email protected]> =Mark Sinclair <[email protected]>
 Markus Westerlind <[email protected]> Markus <[email protected]>
+Martin Hafskjold Thoresen <[email protected]>
 Matej Lach <[email protected]> Matej Ľach <[email protected]>
 Matt Brubeck <[email protected]> <[email protected]>
 Matthew Auld <[email protected]>

.travis.yml

@@ -95,7 +95,10 @@ matrix:
         MACOSX_DEPLOYMENT_TARGET=10.7
       os: osx
       osx_image: xcode7
-      install: *osx_install_sccache
+      install:
+        - travis_retry brew update
+        - travis_retry brew install xz
+        - *osx_install_sccache
     - env: >
         RUST_CHECK_TARGET=dist
         RUST_CONFIGURE_ARGS="--target=aarch64-apple-ios,armv7-apple-ios,armv7s-apple-ios,i386-apple-ios,x86_64-apple-ios --enable-extended --enable-sanitizers"
@@ -106,7 +109,10 @@ matrix:
         MACOSX_DEPLOYMENT_TARGET=10.7
       os: osx
       osx_image: xcode7
-      install: *osx_install_sccache
+      install:
+        - travis_retry brew update
+        - travis_retry brew install xz
+        - *osx_install_sccache
 
     # "alternate" deployments, these are "nightlies" but don't have assertions
     # turned on, they're deployed to a different location primarily for projects
@@ -123,7 +129,10 @@ matrix:
         MACOSX_DEPLOYMENT_TARGET=10.7
       os: osx
       osx_image: xcode7
-      install: *osx_install_sccache
+      install:
+        - travis_retry brew update
+        - travis_retry brew install xz
+        - *osx_install_sccache
 
 env:
   global:

src/liballoc/arc.rs

@@ -767,7 +767,18 @@ unsafe impl<#[may_dangle] T: ?Sized> Drop for Arc<T> {
         // > through this reference must obviously happened before), and an
         // > "acquire" operation before deleting the object.
         //
+        // In particular, while the contents of an Arc are usually immutable, it's
+        // possible to have interior writes to something like a Mutex<T>. Since a
+        // Mutex is not acquired when it is deleted, we can't rely on its
+        // synchronization logic to make writes in thread A visible to a destructor
+        // running in thread B.
+        //
+        // Also note that the Acquire fence here could probably be replaced with an
+        // Acquire load, which could improve performance in highly-contended
+        // situations. See [2].
+        //
         // [1]: (www.boost.org/doc/libs/1_55_0/doc/html/atomic/usage_examples.html)
+        // [2]: (https://github.com/rust-lang/rust/pull/41714)
         atomic::fence(Acquire);
 
         unsafe {

src/libstd/process.rs

@@ -148,8 +148,9 @@ impl fmt::Debug for Child {
     }
 }
 
-/// A handle to a child process's stdin. This struct is used in the [`stdin`]
-/// field on [`Child`].
+/// A handle to a child process's stdin.
+///
+/// This struct is used in the [`stdin`] field on [`Child`].
 ///
 /// [`Child`]: struct.Child.html
 /// [`stdin`]: struct.Child.html#structfield.stdin
@@ -190,8 +191,9 @@ impl fmt::Debug for ChildStdin {
     }
 }
 
-/// A handle to a child process's stdout. This struct is used in the [`stdout`]
-/// field on [`Child`].
+/// A handle to a child process's stdout.
+///
+/// This struct is used in the [`stdout`] field on [`Child`].
 ///
 /// [`Child`]: struct.Child.html
 /// [`stdout`]: struct.Child.html#structfield.stdout

src/libstd/thread/mod.rs

@@ -715,21 +715,32 @@ struct Inner {
 #[stable(feature = "rust1", since = "1.0.0")]
 /// A handle to a thread.
 ///
+/// You can use it to identify a thread (by name, for example). Most of the
+/// time, there is no need to directly create a `Thread` struct using the
+/// constructor, instead you should use a function like `spawn` to create
+/// new threads, see the docs of [`Builder`] and [`spawn`] for more.
+///
 /// # Examples
 ///
 /// ```
-/// use std::thread;
-///
-/// let handler = thread::Builder::new()
-///     .name("foo".into())
-///     .spawn(|| {
-///         let thread = thread::current();
-///         println!("thread name: {}", thread.name().unwrap());
-///     })
-///     .unwrap();
-///
-/// handler.join().unwrap();
+/// use std::thread::Builder;
+///
+/// for i in 0..5 {
+///     let thread_name = format!("thread_{}", i);
+///     Builder::new()
+///         .name(thread_name) // Now you can identify which thread panicked
+///                            // thanks to the handle's name
+///         .spawn(move || {
+///             if i == 3 {
+///                  panic!("I'm scared!!!");
+///             }
+///         })
+///         .unwrap();
+/// }
 /// ```
+/// [`Builder`]: ../../std/thread/struct.Builder.html
+/// [`spawn`]: ../../std/thread/fn.spawn.html
+
 pub struct Thread {
     inner: Arc<Inner>,
 }

src/libstd/time/duration.rs

@@ -84,7 +84,10 @@ impl Duration {
     /// ```
     /// use std::time::Duration;
     ///
-    /// let five_seconds = Duration::from_secs(5);
+    /// let duration = Duration::from_secs(5);
+    ///
+    /// assert_eq!(5, duration.as_secs());
+    /// assert_eq!(0, duration.subsec_nanos());
     /// ```
     #[stable(feature = "duration", since = "1.3.0")]
     #[inline]
@@ -99,7 +102,10 @@ impl Duration {
     /// ```
     /// use std::time::Duration;
     ///
-    /// let five_seconds = Duration::from_millis(5000);
+    /// let duration = Duration::from_millis(2569);
+    ///
+    /// assert_eq!(2, duration.as_secs());
+    /// assert_eq!(569000000, duration.subsec_nanos());
     /// ```
     #[stable(feature = "duration", since = "1.3.0")]
     #[inline]
@@ -119,9 +125,24 @@ impl Duration {
     /// ```
     /// use std::time::Duration;
     ///
-    /// let five_seconds = Duration::new(5, 0);
-    /// assert_eq!(five_seconds.as_secs(), 5);
+    /// let duration = Duration::new(5, 730023852);
+    /// assert_eq!(duration.as_secs(), 5);
+    /// ```
+    ///
+    /// To determine the total number of seconds represented by the `Duration`,
+    /// use `as_secs` in combination with [`subsec_nanos`]:
+    ///
     /// ```
+    /// use std::time::Duration;
+    ///
+    /// let duration = Duration::new(5, 730023852);
+    ///
+    /// assert_eq!(5.730023852,
+    ///            duration.as_secs() as f64
+    ///            + duration.subsec_nanos() as f64 * 1e-9);
+    /// ```
+    ///
+    /// [`subsec_nanos`]: #method.subsec_nanos
     #[stable(feature = "duration", since = "1.3.0")]
     #[inline]
     pub fn as_secs(&self) -> u64 { self.secs }

src/rust-installer

@@ -116,10 +116,26 @@ struct Target {
     available: bool,
     url: Option<String>,
     hash: Option<String>,
+    xz_url: Option<String>,
+    xz_hash: Option<String>,
     components: Option<Vec<Component>>,
     extensions: Option<Vec<Component>>,
 }
 
+impl Target {
+    fn unavailable() -> Target {
+        Target {
+            available: false,
+            url: None,
+            hash: None,
+            xz_url: None,
+            xz_hash: None,
+            components: None,
+            extensions: None,
+        }
+    }
+}
+
 #[derive(RustcEncodable)]
 struct Component {
     pkg: String,
@@ -242,16 +258,12 @@ impl Builder {
             let digest = match self.digests.remove(&filename) {
                 Some(digest) => digest,
                 None => {
-                    pkg.target.insert(host.to_string(), Target {
-                        available: false,
-                        url: None,
-                        hash: None,
-                        components: None,
-                        extensions: None,
-                    });
+                    pkg.target.insert(host.to_string(), Target::unavailable());
                     continue
                 }
             };
+            let xz_filename = filename.replace(".tar.gz", ".tar.xz");
+            let xz_digest = self.digests.remove(&xz_filename);
             let mut components = Vec::new();
             let mut extensions = Vec::new();
 
@@ -293,8 +305,10 @@ impl Builder {
 
             pkg.target.insert(host.to_string(), Target {
                 available: true,
-                url: Some(self.url("rust", host)),
+                url: Some(self.url(&filename)),
                 hash: Some(digest),
+                xz_url: xz_digest.as_ref().map(|_| self.url(&xz_filename)),
+                xz_hash: xz_digest,
                 components: Some(components),
                 extensions: Some(extensions),
             });
@@ -312,21 +326,17 @@ impl Builder {
             let filename = self.filename(pkgname, name);
             let digest = match self.digests.remove(&filename) {
                 Some(digest) => digest,
-                None => {
-                    return (name.to_string(), Target {
-                        available: false,
-                        url: None,
-                        hash: None,
-                        components: None,
-                        extensions: None,
-                    })
-                }
+                None => return (name.to_string(), Target::unavailable()),
             };
+            let xz_filename = filename.replace(".tar.gz", ".tar.xz");
+            let xz_digest = self.digests.remove(&xz_filename);
 
             (name.to_string(), Target {
                 available: true,
-                url: Some(self.url(pkgname, name)),
+                url: Some(self.url(&filename)),
                 hash: Some(digest),
+                xz_url: xz_digest.as_ref().map(|_| self.url(&xz_filename)),
+                xz_hash: xz_digest,
                 components: None,
                 extensions: None,
             })
@@ -338,11 +348,11 @@ impl Builder {
         });
     }
 
-    fn url(&self, component: &str, target: &str) -> String {
+    fn url(&self, filename: &str) -> String {
         format!("{}/{}/{}",
                 self.s3_address,
                 self.date,
-                self.filename(component, target))
+                filename)
     }
 
     fn filename(&self, component: &str, target: &str) -> String {