Merge remote-tracking branch 'upstream/master' into fast-swap

31 files changed, 619 insertions, 325 deletions

diff --git a/src/libstd/sys/redox/fast_thread_local.rs b/src/libstd/sys/redox/fast_thread_local.rs
index 6eeae2d90ea..7dc61ce6654 100644
--- a/src/libstd/sys/redox/fast_thread_local.rs
+++ b/src/libstd/sys/redox/fast_thread_local.rs
@@ -12,9 +12,10 @@
 #![unstable(feature = "thread_local_internals", issue = "0")]
 
 use cell::{Cell, UnsafeCell};
-use intrinsics;
+use mem;
 use ptr;
 
+
 pub struct Key<T> {
     inner: UnsafeCell<Option<T>>,
 
@@ -37,7 +38,7 @@ impl<T> Key<T> {
 
     pub fn get(&'static self) -> Option<&'static UnsafeCell<Option<T>>> {
         unsafe {
-            if intrinsics::needs_drop::<T>() && self.dtor_running.get() {
+            if mem::needs_drop::<T>() && self.dtor_running.get() {
                 return None
             }
             self.register_dtor();
@@ -46,7 +47,7 @@ impl<T> Key<T> {
     }
 
     unsafe fn register_dtor(&self) {
-        if !intrinsics::needs_drop::<T>() || self.dtor_registered.get() {
+        if !mem::needs_drop::<T>() || self.dtor_registered.get() {
             return
         }
 
@@ -96,17 +97,17 @@ pub unsafe extern fn destroy_value<T>(ptr: *mut u8) {
     // `None`.
     (*ptr).dtor_running.set(true);
 
-    // The OSX implementation of TLS apparently had an odd aspect to it
+    // The macOS implementation of TLS apparently had an odd aspect to it
     // where the pointer we have may be overwritten while this destructor
     // is running. Specifically if a TLS destructor re-accesses TLS it may
     // trigger a re-initialization of all TLS variables, paving over at
     // least some destroyed ones with initial values.
     //
-    // This means that if we drop a TLS value in place on OSX that we could
+    // This means that if we drop a TLS value in place on macOS that we could
     // revert the value to its original state halfway through the
     // destructor, which would be bad!
     //
-    // Hence, we use `ptr::read` on OSX (to move to a "safe" location)
+    // Hence, we use `ptr::read` on macOS (to move to a "safe" location)
     // instead of drop_in_place.
     if cfg!(target_os = "macos") {
         ptr::read((*ptr).inner.get());
diff --git a/src/libstd/sys/redox/os_str.rs b/src/libstd/sys/redox/os_str.rs
index 474d59eed83..c2bba07f68c 100644
--- a/src/libstd/sys/redox/os_str.rs
+++ b/src/libstd/sys/redox/os_str.rs
@@ -104,6 +104,12 @@ impl Buf {
     pub fn into_box(self) -> Box<Slice> {
         unsafe { mem::transmute(self.inner.into_boxed_slice()) }
     }
+
+    #[inline]
+    pub fn from_box(boxed: Box<Slice>) -> Buf {
+        let inner: Box<[u8]> = unsafe { mem::transmute(boxed) };
+        Buf { inner: inner.into_vec() }
+    }
 }
 
 impl Slice {
diff --git a/src/libstd/sys/redox/process.rs b/src/libstd/sys/redox/process.rs
index 60dc03fcf47..95e9438cd71 100644
--- a/src/libstd/sys/redox/process.rs
+++ b/src/libstd/sys/redox/process.rs
@@ -249,7 +249,7 @@ impl Command {
     // mutex, and then after the fork they unlock it.
     //
     // Despite this information, libnative's spawn has been witnessed to
-    // deadlock on both OSX and FreeBSD. I'm not entirely sure why, but
+    // deadlock on both macOS and FreeBSD. I'm not entirely sure why, but
     // all collected backtraces point at malloc/free traffic in the
     // child spawned process.
     //
@@ -270,19 +270,22 @@ impl Command {
         }
 
         if let Some(fd) = stdio.stderr.fd() {
-            let _ = syscall::close(2);
-            t!(cvt(syscall::dup(fd, &[])));
-            let _ = syscall::close(fd);
+            t!(cvt(syscall::dup2(fd, 2, &[])));
+            let mut flags = t!(cvt(syscall::fcntl(2, syscall::F_GETFL, 0)));
+            flags &= ! syscall::O_CLOEXEC;
+            t!(cvt(syscall::fcntl(2, syscall::F_SETFL, flags)));
         }
         if let Some(fd) = stdio.stdout.fd() {
-            let _ = syscall::close(1);
-            t!(cvt(syscall::dup(fd, &[])));
-            let _ = syscall::close(fd);
+            t!(cvt(syscall::dup2(fd, 1, &[])));
+            let mut flags = t!(cvt(syscall::fcntl(1, syscall::F_GETFL, 0)));
+            flags &= ! syscall::O_CLOEXEC;
+            t!(cvt(syscall::fcntl(1, syscall::F_SETFL, flags)));
         }
         if let Some(fd) = stdio.stdin.fd() {
-            let _ = syscall::close(0);
-            t!(cvt(syscall::dup(fd, &[])));
-            let _ = syscall::close(fd);
+            t!(cvt(syscall::dup2(fd, 0, &[])));
+            let mut flags = t!(cvt(syscall::fcntl(0, syscall::F_GETFL, 0)));
+            flags &= ! syscall::O_CLOEXEC;
+            t!(cvt(syscall::fcntl(0, syscall::F_SETFL, flags)));
         }
 
         if let Some(g) = self.gid {
diff --git a/src/libstd/sys/redox/syscall/call.rs b/src/libstd/sys/redox/syscall/call.rs
index f58c240f31e..fadf7325d75 100644
--- a/src/libstd/sys/redox/syscall/call.rs
+++ b/src/libstd/sys/redox/syscall/call.rs
@@ -71,6 +71,11 @@ pub fn dup(fd: usize, buf: &[u8]) -> Result<usize> {
     unsafe { syscall3(SYS_DUP, fd, buf.as_ptr() as usize, buf.len()) }
 }
 
+/// Copy and transform a file descriptor
+pub fn dup2(fd: usize, newfd: usize, buf: &[u8]) -> Result<usize> {
+    unsafe { syscall4(SYS_DUP2, fd, newfd, buf.as_ptr() as usize, buf.len()) }
+}
+
 /// Replace the current process with a new executable
 pub fn execve(path: &str, args: &[[usize; 2]]) -> Result<usize> {
     unsafe { syscall4(SYS_EXECVE, path.as_ptr() as usize, path.len(),
diff --git a/src/libstd/sys/redox/syscall/number.rs b/src/libstd/sys/redox/syscall/number.rs
index 358746cd20a..98f8b73e4e1 100644
--- a/src/libstd/sys/redox/syscall/number.rs
+++ b/src/libstd/sys/redox/syscall/number.rs
@@ -28,6 +28,7 @@ pub const SYS_UNLINK: usize =   SYS_CLASS_PATH | 10;
 
 pub const SYS_CLOSE: usize =    SYS_CLASS_FILE | 6;
 pub const SYS_DUP: usize =      SYS_CLASS_FILE | SYS_RET_FILE | 41;
+pub const SYS_DUP2: usize =     SYS_CLASS_FILE | SYS_RET_FILE | 63;
 pub const SYS_READ: usize =     SYS_CLASS_FILE | SYS_ARG_MSLICE | 3;
 pub const SYS_WRITE: usize =    SYS_CLASS_FILE | SYS_ARG_SLICE | 4;
 pub const SYS_LSEEK: usize =    SYS_CLASS_FILE | 19;
diff --git a/src/libstd/sys/redox/thread_local.rs b/src/libstd/sys/redox/thread_local.rs
index abdd9ace795..cacd84e2102 100644
--- a/src/libstd/sys/redox/thread_local.rs
+++ b/src/libstd/sys/redox/thread_local.rs
@@ -64,3 +64,8 @@ pub unsafe fn set(key: Key, value: *mut u8) {
 pub unsafe fn destroy(key: Key) {
     keys().remove(&key);
 }
+
+#[inline]
+pub fn requires_synchronized_create() -> bool {
+    false
+}
diff --git a/src/libstd/sys/unix/backtrace/mod.rs b/src/libstd/sys/unix/backtrace/mod.rs
index 29d4012dcdf..bf52da2ed4a 100644
--- a/src/libstd/sys/unix/backtrace/mod.rs
+++ b/src/libstd/sys/unix/backtrace/mod.rs
@@ -13,7 +13,7 @@
 /// Some methods of getting a backtrace:
 ///
 /// * The backtrace() functions on unix. It turns out this doesn't work very
-///   well for green threads on OSX, and the address to symbol portion of it
+///   well for green threads on macOS, and the address to symbol portion of it
 ///   suffers problems that are described below.
 ///
 /// * Using libunwind. This is more difficult than it sounds because libunwind
@@ -51,9 +51,9 @@
 ///
 /// * Use dladdr(). The original backtrace()-based idea actually uses dladdr()
 ///   behind the scenes to translate, and this is why backtrace() was not used.
-///   Conveniently, this method works fantastically on OSX. It appears dladdr()
+///   Conveniently, this method works fantastically on macOS. It appears dladdr()
 ///   uses magic to consult the local symbol table, or we're putting everything
-///   in the dynamic symbol table anyway. Regardless, for OSX, this is the
+///   in the dynamic symbol table anyway. Regardless, for macOS, this is the
 ///   method used for translation. It's provided by the system and easy to do.o
 ///
 ///   Sadly, all other systems have a dladdr() implementation that does not
@@ -75,7 +75,7 @@
 /// * Use `libbacktrace`. It turns out that this is a small library bundled in
 ///   the gcc repository which provides backtrace and symbol translation
 ///   functionality. All we really need from it is the backtrace functionality,
-///   and we only really need this on everything that's not OSX, so this is the
+///   and we only really need this on everything that's not macOS, so this is the
 ///   chosen route for now.
 ///
 /// In summary, the current situation uses libgcc_s to get a trace of stack
diff --git a/src/libstd/sys/unix/ext/net.rs b/src/libstd/sys/unix/ext/net.rs
index 1ba4a104e51..d688f2fa504 100644
--- a/src/libstd/sys/unix/ext/net.rs
+++ b/src/libstd/sys/unix/ext/net.rs
@@ -204,7 +204,7 @@ impl SocketAddr {
         let len = self.len as usize - sun_path_offset();
         let path = unsafe { mem::transmute::<&[libc::c_char], &[u8]>(&self.addr.sun_path) };
 
-        // OSX seems to return a len of 16 and a zeroed sun_path for unnamed addresses
+        // macOS seems to return a len of 16 and a zeroed sun_path for unnamed addresses
         if len == 0 || (cfg!(not(target_os = "linux")) && self.addr.sun_path[0] == 0) {
             AddressKind::Unnamed
         } else if self.addr.sun_path[0] == 0 {
@@ -375,12 +375,12 @@ impl UnixStream {
 
     /// Sets the read timeout for the socket.
     ///
-    /// If the provided value is [`None`], then [`read()`] calls will block
+    /// If the provided value is [`None`], then [`read`] calls will block
     /// indefinitely. It is an error to pass the zero [`Duration`] to this
     /// method.
     ///
     /// [`None`]: ../../../../std/option/enum.Option.html#variant.None
-    /// [`read()`]: ../../../../std/io/trait.Read.html#tymethod.read
+    /// [`read`]: ../../../../std/io/trait.Read.html#tymethod.read
     /// [`Duration`]: ../../../../std/time/struct.Duration.html
     ///
     /// # Examples
@@ -399,12 +399,12 @@ impl UnixStream {
 
     /// Sets the write timeout for the socket.
     ///
-    /// If the provided value is [`None`], then [`write()`] calls will block
+    /// If the provided value is [`None`], then [`write`] calls will block
     /// indefinitely. It is an error to pass the zero [`Duration`] to this
     /// method.
     ///
     /// [`None`]: ../../../../std/option/enum.Option.html#variant.None
-    /// [`read()`]: ../../../../std/io/trait.Write.html#tymethod.write
+    /// [`read`]: ../../../../std/io/trait.Write.html#tymethod.write
     /// [`Duration`]: ../../../../std/time/struct.Duration.html
     ///
     /// # Examples
@@ -641,7 +641,7 @@ impl UnixListener {
                 let inner = Socket::new_raw(libc::AF_UNIX, libc::SOCK_STREAM)?;
                 let (addr, len) = sockaddr_un(path)?;
 
-                cvt(libc::bind(*inner.as_inner(), &addr as *const _ as *const _, len))?;
+                cvt(libc::bind(*inner.as_inner(), &addr as *const _ as *const _, len as _))?;
                 cvt(libc::listen(*inner.as_inner(), 128))?;
 
                 Ok(UnixListener(inner))
@@ -920,7 +920,7 @@ impl UnixDatagram {
                 let socket = UnixDatagram::unbound()?;
                 let (addr, len) = sockaddr_un(path)?;
 
-                cvt(libc::bind(*socket.0.as_inner(), &addr as *const _ as *const _, len))?;
+                cvt(libc::bind(*socket.0.as_inner(), &addr as *const _ as *const _, len as _))?;
 
                 Ok(socket)
             }
@@ -974,12 +974,12 @@ impl UnixDatagram {
 
     /// Connects the socket to the specified address.
     ///
-    /// The [`send()`] method may be used to send data to the specified address.
-    /// [`recv()`] and [`recv_from()`] will only receive data from that address.
+    /// The [`send`] method may be used to send data to the specified address.
+    /// [`recv`] and [`recv_from`] will only receive data from that address.
     ///
-    /// [`send()`]: #method.send
-    /// [`recv()`]: #method.recv
-    /// [`recv_from()`]: #method.recv_from
+    /// [`send`]: #method.send
+    /// [`recv`]: #method.recv
+    /// [`recv_from`]: #method.recv_from
     ///
     /// # Examples
     ///
@@ -1047,9 +1047,9 @@ impl UnixDatagram {
 
     /// Returns the address of this socket's peer.
     ///
-    /// The [`connect()`] method will connect the socket to a peer.
+    /// The [`connect`] method will connect the socket to a peer.
     ///
-    /// [`connect()`]: #method.connect
+    /// [`connect`]: #method.connect
     ///
     /// # Examples
     ///
@@ -1178,13 +1178,13 @@ impl UnixDatagram {
 
     /// Sets the read timeout for the socket.
     ///
-    /// If the provided value is [`None`], then [`recv()`] and [`recv_from()`] calls will
+    /// If the provided value is [`None`], then [`recv`] and [`recv_from`] calls will
     /// block indefinitely. It is an error to pass the zero [`Duration`] to this
     /// method.
     ///
     /// [`None`]: ../../../../std/option/enum.Option.html#variant.None
-    /// [`recv()`]: #method.recv
-    /// [`recv_from()`]: #method.recv_from
+    /// [`recv`]: #method.recv
+    /// [`recv_from`]: #method.recv_from
     /// [`Duration`]: ../../../../std/time/struct.Duration.html
     ///
     /// # Examples
@@ -1203,13 +1203,13 @@ impl UnixDatagram {
 
     /// Sets the write timeout for the socket.
     ///
-    /// If the provided value is [`None`], then [`send()`] and [`send_to()`] calls will
+    /// If the provided value is [`None`], then [`send`] and [`send_to`] calls will
     /// block indefinitely. It is an error to pass the zero [`Duration`] to this
     /// method.
     ///
     /// [`None`]: ../../../../std/option/enum.Option.html#variant.None
-    /// [`send()`]: #method.send
-    /// [`send_to()`]: #method.send_to
+    /// [`send`]: #method.send
+    /// [`send_to`]: #method.send_to
     /// [`Duration`]: ../../../../std/time/struct.Duration.html
     ///
     /// # Examples
diff --git a/src/libstd/sys/unix/fast_thread_local.rs b/src/libstd/sys/unix/fast_thread_local.rs
index f4f73646e1b..6b3973de84c 100644
--- a/src/libstd/sys/unix/fast_thread_local.rs
+++ b/src/libstd/sys/unix/fast_thread_local.rs
@@ -13,7 +13,7 @@
 
 use cell::{Cell, UnsafeCell};
 use fmt;
-use intrinsics;
+use mem;
 use ptr;
 
 pub struct Key<T> {
@@ -44,7 +44,7 @@ impl<T> Key<T> {
 
     pub fn get(&'static self) -> Option<&'static UnsafeCell<Option<T>>> {
         unsafe {
-            if intrinsics::needs_drop::<T>() && self.dtor_running.get() {
+            if mem::needs_drop::<T>() && self.dtor_running.get() {
                 return None
             }
             self.register_dtor();
@@ -53,7 +53,7 @@ impl<T> Key<T> {
     }
 
     unsafe fn register_dtor(&self) {
-        if !intrinsics::needs_drop::<T>() || self.dtor_registered.get() {
+        if !mem::needs_drop::<T>() || self.dtor_registered.get() {
             return
         }
 
@@ -128,7 +128,7 @@ unsafe fn register_dtor(t: *mut u8, dtor: unsafe extern fn(*mut u8)) {
     register_dtor_fallback(t, dtor);
 }
 
-// OSX's analog of the above linux function is this _tlv_atexit function.
+// macOS's analog of the above linux function is this _tlv_atexit function.
 // The disassembly of thread_local globals in C++ (at least produced by
 // clang) will have this show up in the output.
 #[cfg(target_os = "macos")]
@@ -154,17 +154,17 @@ pub unsafe extern fn destroy_value<T>(ptr: *mut u8) {
     // `None`.
     (*ptr).dtor_running.set(true);
 
-    // The OSX implementation of TLS apparently had an odd aspect to it
+    // The macOS implementation of TLS apparently had an odd aspect to it
     // where the pointer we have may be overwritten while this destructor
     // is running. Specifically if a TLS destructor re-accesses TLS it may
     // trigger a re-initialization of all TLS variables, paving over at
     // least some destroyed ones with initial values.
     //
-    // This means that if we drop a TLS value in place on OSX that we could
+    // This means that if we drop a TLS value in place on macOS that we could
     // revert the value to its original state halfway through the
     // destructor, which would be bad!
     //
-    // Hence, we use `ptr::read` on OSX (to move to a "safe" location)
+    // Hence, we use `ptr::read` on macOS (to move to a "safe" location)
     // instead of drop_in_place.
     if cfg!(target_os = "macos") {
         ptr::read((*ptr).inner.get());
diff --git a/src/libstd/sys/unix/fd.rs b/src/libstd/sys/unix/fd.rs
index c690fd467ee..405fac2b9d7 100644
--- a/src/libstd/sys/unix/fd.rs
+++ b/src/libstd/sys/unix/fd.rs
@@ -29,7 +29,7 @@ fn max_len() -> usize {
     // with the man page quoting that if the count of bytes to read is
     // greater than `SSIZE_MAX` the result is "unspecified".
     //
-    // On OSX, however, apparently the 64-bit libc is either buggy or
+    // On macOS, however, apparently the 64-bit libc is either buggy or
     // intentionally showing odd behavior by rejecting any read with a size
     // larger than or equal to INT_MAX. To handle both of these the read
     // size is capped on both platforms.
diff --git a/src/libstd/sys/unix/fs.rs b/src/libstd/sys/unix/fs.rs
index d0fb96b1ff1..e893a139094 100644
--- a/src/libstd/sys/unix/fs.rs
+++ b/src/libstd/sys/unix/fs.rs
@@ -439,7 +439,7 @@ impl File {
         // Linux kernel then the flag is just ignored by the OS, so we continue
         // to explicitly ask for a CLOEXEC fd here.
         //
-        // The CLOEXEC flag, however, is supported on versions of OSX/BSD/etc
+        // The CLOEXEC flag, however, is supported on versions of macOS/BSD/etc
         // that we support, so we only do this on Linux currently.
         if cfg!(target_os = "linux") {
             fd.set_cloexec()?;
@@ -573,7 +573,7 @@ impl fmt::Debug for File {
         #[cfg(target_os = "macos")]
         fn get_path(fd: c_int) -> Option<PathBuf> {
             // FIXME: The use of PATH_MAX is generally not encouraged, but it
-            // is inevitable in this case because OS X defines `fcntl` with
+            // is inevitable in this case because macOS defines `fcntl` with
             // `F_GETPATH` in terms of `MAXPATHLEN`, and there are no
             // alternatives. If a better method is invented, it should be used
             // instead.
diff --git a/src/libstd/sys/unix/mod.rs b/src/libstd/sys/unix/mod.rs
index c57751a01d7..854d380d128 100644
--- a/src/libstd/sys/unix/mod.rs
+++ b/src/libstd/sys/unix/mod.rs
@@ -92,7 +92,7 @@ pub fn init() {
 
     #[cfg(not(any(target_os = "nacl", target_os = "emscripten", target_os="fuchsia")))]
     unsafe fn reset_sigpipe() {
-        assert!(signal(libc::SIGPIPE, libc::SIG_IGN) != !0);
+        assert!(signal(libc::SIGPIPE, libc::SIG_IGN) != libc::SIG_ERR);
     }
     #[cfg(any(target_os = "nacl", target_os = "emscripten", target_os="fuchsia"))]
     unsafe fn reset_sigpipe() {}
diff --git a/src/libstd/sys/unix/os.rs b/src/libstd/sys/unix/os.rs
index 36928696c40..8e41fd009be 100644
--- a/src/libstd/sys/unix/os.rs
+++ b/src/libstd/sys/unix/os.rs
@@ -253,7 +253,12 @@ pub fn current_exe() -> io::Result<PathBuf> {
 
 #[cfg(any(target_os = "linux", target_os = "android", target_os = "emscripten"))]
 pub fn current_exe() -> io::Result<PathBuf> {
-    ::fs::read_link("/proc/self/exe")
+    let selfexe = PathBuf::from("/proc/self/exe");
+    if selfexe.exists() {
+        ::fs::read_link(selfexe)
+    } else {
+        Err(io::Error::new(io::ErrorKind::Other, "no /proc/self/exe available. Is /proc mounted?"))
+    }
 }
 
 #[cfg(any(target_os = "macos", target_os = "ios"))]
diff --git a/src/libstd/sys/unix/os_str.rs b/src/libstd/sys/unix/os_str.rs
index c27599ec020..f5b942d3343 100644
--- a/src/libstd/sys/unix/os_str.rs
+++ b/src/libstd/sys/unix/os_str.rs
@@ -104,6 +104,12 @@ impl Buf {
     pub fn into_box(self) -> Box<Slice> {
         unsafe { mem::transmute(self.inner.into_boxed_slice()) }
     }
+
+    #[inline]
+    pub fn from_box(boxed: Box<Slice>) -> Buf {
+        let inner: Box<[u8]> = unsafe { mem::transmute(boxed) };
+        Buf { inner: inner.into_vec() }
+    }
 }
 
 impl Slice {
diff --git a/src/libstd/sys/unix/pipe.rs b/src/libstd/sys/unix/pipe.rs
index 51e00fc1ab9..706256ff10e 100644
--- a/src/libstd/sys/unix/pipe.rs
+++ b/src/libstd/sys/unix/pipe.rs
@@ -8,11 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use cmp;
 use io;
 use libc::{self, c_int};
 use mem;
-use ptr;
 use sys::{cvt, cvt_r};
 use sys::fd::FileDesc;
 
@@ -80,16 +78,14 @@ pub fn read2(p1: AnonPipe,
     p1.set_nonblocking(true)?;
     p2.set_nonblocking(true)?;
 
-    let max = cmp::max(p1.raw(), p2.raw());
+    let mut fds: [libc::pollfd; 2] = unsafe { mem::zeroed() };
+    fds[0].fd = p1.raw();
+    fds[0].events = libc::POLLIN;
+    fds[1].fd = p2.raw();
+    fds[1].events = libc::POLLIN;
     loop {
-        // wait for either pipe to become readable using `select`
-        cvt_r(|| unsafe {
-            let mut read: libc::fd_set = mem::zeroed();
-            libc::FD_SET(p1.raw(), &mut read);
-            libc::FD_SET(p2.raw(), &mut read);
-            libc::select(max + 1, &mut read, ptr::null_mut(), ptr::null_mut(),
-                         ptr::null_mut())
-        })?;
+        // wait for either pipe to become readable using `poll`
+        cvt_r(|| unsafe { libc::poll(fds.as_mut_ptr(), 2, -1) })?;
 
         // Read as much as we can from each pipe, ignoring EWOULDBLOCK or
         // EAGAIN. If we hit EOF, then this will happen because the underlying
@@ -109,11 +105,11 @@ pub fn read2(p1: AnonPipe,
                 }
             }
         };
-        if read(&p1, v1)? {
+        if fds[0].revents != 0 && read(&p1, v1)? {
             p2.set_nonblocking(false)?;
             return p2.read_to_end(v2).map(|_| ());
         }
-        if read(&p2, v2)? {
+        if fds[1].revents != 0 && read(&p2, v2)? {
             p1.set_nonblocking(false)?;
             return p1.read_to_end(v1).map(|_| ());
         }
diff --git a/src/libstd/sys/unix/process/magenta.rs b/src/libstd/sys/unix/process/magenta.rs
index 07f29784df6..5b5e29c0374 100644
--- a/src/libstd/sys/unix/process/magenta.rs
+++ b/src/libstd/sys/unix/process/magenta.rs
@@ -202,7 +202,7 @@ pub const LP_CLONE_MXIO_CWD: u32 = 0x0002;
 
 // ERR_NO_RESOURCES: The system was not able to allocate some resource
 // needed for the operation.
-#[allow(unused)] pub const ERR_NO_RESOURCES: mx_status_t = -5;
+#[allow(unused)] pub const ERR_NO_RESOURCES: mx_status_t = -3;
 
 // ERR_NO_MEMORY: The system was not able to allocate memory needed
 // for the operation.
@@ -210,30 +210,34 @@ pub const LP_CLONE_MXIO_CWD: u32 = 0x0002;
 
 // ERR_CALL_FAILED: The second phase of mx_channel_call(; did not complete
 // successfully.
-#[allow(unused)] pub const ERR_CALL_FAILED: mx_status_t = -53;
+#[allow(unused)] pub const ERR_CALL_FAILED: mx_status_t = -5;
+
+// ERR_INTERRUPTED_RETRY: The system call was interrupted, but should be
+// retried.  This should not be seen outside of the VDSO.
+#[allow(unused)] pub const ERR_INTERRUPTED_RETRY: mx_status_t = -6;
 
 // ======= Parameter errors =======
 // ERR_INVALID_ARGS: an argument is invalid, ex. null pointer
 #[allow(unused)] pub const ERR_INVALID_ARGS: mx_status_t = -10;
 
+// ERR_BAD_HANDLE: A specified handle value does not refer to a handle.
+#[allow(unused)] pub const ERR_BAD_HANDLE: mx_status_t = -11;
+
 // ERR_WRONG_TYPE: The subject of the operation is the wrong type to
 // perform the operation.
 // Example: Attempting a message_read on a thread handle.
-#[allow(unused)] pub const ERR_WRONG_TYPE: mx_status_t = -54;
+#[allow(unused)] pub const ERR_WRONG_TYPE: mx_status_t = -12;
 
 // ERR_BAD_SYSCALL: The specified syscall number is invalid.
-#[allow(unused)] pub const ERR_BAD_SYSCALL: mx_status_t = -11;
-
-// ERR_BAD_HANDLE: A specified handle value does not refer to a handle.
-#[allow(unused)] pub const ERR_BAD_HANDLE: mx_status_t = -12;
+#[allow(unused)] pub const ERR_BAD_SYSCALL: mx_status_t = -13;
 
 // ERR_OUT_OF_RANGE: An argument is outside the valid range for this
 // operation.
-#[allow(unused)] pub const ERR_OUT_OF_RANGE: mx_status_t = -13;
+#[allow(unused)] pub const ERR_OUT_OF_RANGE: mx_status_t = -14;
 
 // ERR_BUFFER_TOO_SMALL: A caller provided buffer is too small for
 // this operation.
-#[allow(unused)] pub const ERR_BUFFER_TOO_SMALL: mx_status_t = -14;
+#[allow(unused)] pub const ERR_BUFFER_TOO_SMALL: mx_status_t = -15;
 
 // ======= Precondition or state errors =======
 // ERR_BAD_STATE: operation failed because the current state of the
@@ -241,47 +245,48 @@ pub const LP_CLONE_MXIO_CWD: u32 = 0x0002;
 // not satisfied
 #[allow(unused)] pub const ERR_BAD_STATE: mx_status_t = -20;
 
+// ERR_TIMED_OUT: The time limit for the operation elapsed before
+// the operation completed.
+#[allow(unused)] pub const ERR_TIMED_OUT: mx_status_t = -21;
+
+// ERR_SHOULD_WAIT: The operation cannot be performed currently but
+// potentially could succeed if the caller waits for a prerequisite
+// to be satisfied, for example waiting for a handle to be readable
+// or writable.
+// Example: Attempting to read from a message pipe that has no
+// messages waiting but has an open remote will return ERR_SHOULD_WAIT.
+// Attempting to read from a message pipe that has no messages waiting
+// and has a closed remote end will return ERR_REMOTE_CLOSED.
+#[allow(unused)] pub const ERR_SHOULD_WAIT: mx_status_t = -22;
+
+// ERR_CANCELED: The in-progress operation (e.g. a wait) has been
+// // canceled.
+#[allow(unused)] pub const ERR_CANCELED: mx_status_t = -23;
+
+// ERR_PEER_CLOSED: The operation failed because the remote end
+// of the subject of the operation was closed.
+#[allow(unused)] pub const ERR_PEER_CLOSED: mx_status_t = -24;
+
 // ERR_NOT_FOUND: The requested entity is not found.
-#[allow(unused)] pub const ERR_NOT_FOUND: mx_status_t = -3;
+#[allow(unused)] pub const ERR_NOT_FOUND: mx_status_t = -25;
 
 // ERR_ALREADY_EXISTS: An object with the specified identifier
 // already exists.
 // Example: Attempting to create a file when a file already exists
 // with that name.
-#[allow(unused)] pub const ERR_ALREADY_EXISTS: mx_status_t = -15;
+#[allow(unused)] pub const ERR_ALREADY_EXISTS: mx_status_t = -26;
 
 // ERR_ALREADY_BOUND: The operation failed because the named entity
 // is already owned or controlled by another entity. The operation
 // could succeed later if the current owner releases the entity.
-#[allow(unused)] pub const ERR_ALREADY_BOUND: mx_status_t = -16;
-
-// ERR_TIMED_OUT: The time limit for the operation elapsed before
-// the operation completed.
-#[allow(unused)] pub const ERR_TIMED_OUT: mx_status_t = -23;
-
-// ERR_HANDLE_CLOSED: a handle being waited on was closed
-#[allow(unused)] pub const ERR_HANDLE_CLOSED: mx_status_t = -24;
-
-// ERR_REMOTE_CLOSED: The operation failed because the remote end
-// of the subject of the operation was closed.
-#[allow(unused)] pub const ERR_REMOTE_CLOSED: mx_status_t = -25;
+#[allow(unused)] pub const ERR_ALREADY_BOUND: mx_status_t = -27;
 
 // ERR_UNAVAILABLE: The subject of the operation is currently unable
 // to perform the operation.
 // Note: This is used when there's no direct way for the caller to
 // observe when the subject will be able to perform the operation
 // and should thus retry.
-#[allow(unused)] pub const ERR_UNAVAILABLE: mx_status_t = -26;
-
-// ERR_SHOULD_WAIT: The operation cannot be performed currently but
-// potentially could succeed if the caller waits for a prerequisite
-// to be satisfied, for example waiting for a handle to be readable
-// or writable.
-// Example: Attempting to read from a message pipe that has no
-// messages waiting but has an open remote will return ERR_SHOULD_WAIT.
-// Attempting to read from a message pipe that has no messages waiting
-// and has a closed remote end will return ERR_REMOTE_CLOSED.
-#[allow(unused)] pub const ERR_SHOULD_WAIT: mx_status_t = -27;
+#[allow(unused)] pub const ERR_UNAVAILABLE: mx_status_t = -28;
 
 // ======= Permission check errors =======
 // ERR_ACCESS_DENIED: The caller did not have permission to perform
@@ -312,3 +317,7 @@ pub const LP_CLONE_MXIO_CWD: u32 = 0x0002;
 #[allow(unused)] pub const ERR_BAD_PATH: mx_status_t = -50;
 #[allow(unused)] pub const ERR_NOT_DIR: mx_status_t = -51;
 #[allow(unused)] pub const ERR_NOT_FILE: mx_status_t = -52;
+// ERR_FILE_BIG: A file exceeds a filesystem-specific size limit.
+#[allow(unused)] pub const ERR_FILE_BIG: mx_status_t = -53;
+// ERR_NO_SPACE: Filesystem or device space is exhausted.
+#[allow(unused)] pub const ERR_NO_SPACE: mx_status_t = -54;
diff --git a/src/libstd/sys/unix/process/process_common.rs b/src/libstd/sys/unix/process/process_common.rs
index a4536520376..e9f41009064 100644
--- a/src/libstd/sys/unix/process/process_common.rs
+++ b/src/libstd/sys/unix/process/process_common.rs
@@ -417,13 +417,27 @@ mod tests {
         }
     }
 
+    // Android with api less than 21 define sig* functions inline, so it is not
+    // available for dynamic link. Implementing sigemptyset and sigaddset allow us
+    // to support older Android version (independent of libc version).
+    // The following implementations are based on https://git.io/vSkNf
+
     #[cfg(not(target_os = "android"))]
     extern {
+        #[cfg_attr(target_os = "netbsd", link_name = "__sigemptyset14")]
+        fn sigemptyset(set: *mut libc::sigset_t) -> libc::c_int;
+
         #[cfg_attr(target_os = "netbsd", link_name = "__sigaddset14")]
         fn sigaddset(set: *mut libc::sigset_t, signum: libc::c_int) -> libc::c_int;
     }
 
     #[cfg(target_os = "android")]
+    unsafe fn sigemptyset(set: *mut libc::sigset_t) -> libc::c_int {
+        libc::memset(set as *mut _, 0, mem::size_of::<libc::sigset_t>());
+        return 0;
+    }
+
+    #[cfg(target_os = "android")]
     unsafe fn sigaddset(set: *mut libc::sigset_t, signum: libc::c_int) -> libc::c_int {
         use slice;
 
@@ -434,8 +448,8 @@ mod tests {
     }
 
     // See #14232 for more information, but it appears that signal delivery to a
-    // newly spawned process may just be raced in the OSX, so to prevent this
-    // test from being flaky we ignore it on OSX.
+    // newly spawned process may just be raced in the macOS, so to prevent this
+    // test from being flaky we ignore it on macOS.
     #[test]
     #[cfg_attr(target_os = "macos", ignore)]
     #[cfg_attr(target_os = "nacl", ignore)] // no signals on NaCl.
@@ -450,7 +464,7 @@ mod tests {
 
             let mut set: libc::sigset_t = mem::uninitialized();
             let mut old_set: libc::sigset_t = mem::uninitialized();
-            t!(cvt(libc::sigemptyset(&mut set)));
+            t!(cvt(sigemptyset(&mut set)));
             t!(cvt(sigaddset(&mut set, libc::SIGINT)));
             t!(cvt(libc::pthread_sigmask(libc::SIG_SETMASK, &set, &mut old_set)));
 
diff --git a/src/libstd/sys/unix/process/process_unix.rs b/src/libstd/sys/unix/process/process_unix.rs
index bbc987209e3..edd322ca6fa 100644
--- a/src/libstd/sys/unix/process/process_unix.rs
+++ b/src/libstd/sys/unix/process/process_unix.rs
@@ -129,7 +129,7 @@ impl Command {
     // mutex, and then after the fork they unlock it.
     //
     // Despite this information, libnative's spawn has been witnessed to
-    // deadlock on both OSX and FreeBSD. I'm not entirely sure why, but
+    // deadlock on both macOS and FreeBSD. I'm not entirely sure why, but
     // all collected backtraces point at malloc/free traffic in the
     // child spawned process.
     //
@@ -193,7 +193,16 @@ impl Command {
             // need to clean things up now to avoid confusing the program
             // we're about to run.
             let mut set: libc::sigset_t = mem::uninitialized();
-            t!(cvt(libc::sigemptyset(&mut set)));
+            if cfg!(target_os = "android") {
+                // Implementing sigemptyset allow us to support older Android
+                // versions. See the comment about Android and sig* functions in
+                // process_common.rs
+                libc::memset(&mut set as *mut _ as *mut _,
+                             0,
+                             mem::size_of::<libc::sigset_t>());
+            } else {
+                t!(cvt(libc::sigemptyset(&mut set)));
+            }
             t!(cvt(libc::pthread_sigmask(libc::SIG_SETMASK, &set,
                                          ptr::null_mut())));
             let ret = sys::signal(libc::SIGPIPE, libc::SIG_DFL);
diff --git a/src/libstd/sys/unix/stack_overflow.rs b/src/libstd/sys/unix/stack_overflow.rs
index 22d47ba0f62..51adbc24ae0 100644
--- a/src/libstd/sys/unix/stack_overflow.rs
+++ b/src/libstd/sys/unix/stack_overflow.rs
@@ -187,7 +187,7 @@ mod imp {
             let stack =  libc::stack_t {
                 ss_sp: ptr::null_mut(),
                 ss_flags: SS_DISABLE,
-                // Workaround for bug in MacOS implementation of sigaltstack
+                // Workaround for bug in macOS implementation of sigaltstack
                 // UNIX2003 which returns ENOMEM when disabling a stack while
                 // passing ss_size smaller than MINSIGSTKSZ. According to POSIX
                 // both ss_sp and ss_size should be ignored in this case.
diff --git a/src/libstd/sys/unix/thread_local.rs b/src/libstd/sys/unix/thread_local.rs
index d22118d4d79..2487f6bcaf7 100644
--- a/src/libstd/sys/unix/thread_local.rs
+++ b/src/libstd/sys/unix/thread_local.rs
@@ -38,3 +38,8 @@ pub unsafe fn destroy(key: Key) {
     let r = libc::pthread_key_delete(key);
     debug_assert_eq!(r, 0);
 }
+
+#[inline]
+pub fn requires_synchronized_create() -> bool {
+    false
+}
diff --git a/src/libstd/sys/unix/time.rs b/src/libstd/sys/unix/time.rs
index a08cec38f73..a1ad94872de 100644
--- a/src/libstd/sys/unix/time.rs
+++ b/src/libstd/sys/unix/time.rs
@@ -157,7 +157,7 @@ mod inner {
         pub fn sub_duration(&self, other: &Duration) -> Instant {
             Instant {
                 t: self.t.checked_sub(dur2intervals(other))
-                       .expect("overflow when adding duration to instant"),
+                       .expect("overflow when subtracting duration from instant"),
             }
         }
     }
diff --git a/src/libstd/sys/windows/c.rs b/src/libstd/sys/windows/c.rs
index 4daab31c28f..1646f8cce72 100644
--- a/src/libstd/sys/windows/c.rs
+++ b/src/libstd/sys/windows/c.rs
@@ -14,8 +14,9 @@
 #![cfg_attr(test, allow(dead_code))]
 #![unstable(issue = "0", feature = "windows_c")]
 
-use os::raw::{c_int, c_uint, c_ulong, c_long, c_longlong, c_ushort,};
-use os::raw::{c_char, c_ulonglong};
+use os::raw::{c_int, c_uint, c_ulong, c_long, c_longlong, c_ushort, c_char};
+#[cfg(target_arch = "x86_64")]
+use os::raw::c_ulonglong;
 use libc::{wchar_t, size_t, c_void};
 use ptr;
 
@@ -45,7 +46,7 @@ pub type SIZE_T = usize;
 pub type WORD = u16;
 pub type CHAR = c_char;
 pub type HCRYPTPROV = LONG_PTR;
-pub type ULONG_PTR = c_ulonglong;
+pub type ULONG_PTR = usize;
 pub type ULONG = c_ulong;
 #[cfg(target_arch = "x86_64")]
 pub type ULONGLONG = u64;
@@ -198,7 +199,10 @@ pub const ERROR_TIMEOUT: DWORD = 0x5B4;
 
 pub const INVALID_HANDLE_VALUE: HANDLE = !0 as HANDLE;
 
+pub const FACILITY_NT_BIT: DWORD = 0x1000_0000;
+
 pub const FORMAT_MESSAGE_FROM_SYSTEM: DWORD = 0x00001000;
+pub const FORMAT_MESSAGE_FROM_HMODULE: DWORD = 0x00000800;
 pub const FORMAT_MESSAGE_IGNORE_INSERTS: DWORD = 0x00000200;
 
 pub const TLS_OUT_OF_INDEXES: DWORD = 0xFFFFFFFF;
@@ -935,7 +939,6 @@ extern "system" {
                           args: *const c_void)
                           -> DWORD;
     pub fn TlsAlloc() -> DWORD;
-    pub fn TlsFree(dwTlsIndex: DWORD) -> BOOL;
     pub fn TlsGetValue(dwTlsIndex: DWORD) -> LPVOID;
     pub fn TlsSetValue(dwTlsIndex: DWORD, lpTlsvalue: LPVOID) -> BOOL;
     pub fn GetLastError() -> DWORD;
diff --git a/src/libstd/sys/windows/ext/ffi.rs b/src/libstd/sys/windows/ext/ffi.rs
index 253787546c1..3f6c2827a3f 100644
--- a/src/libstd/sys/windows/ext/ffi.rs
+++ b/src/libstd/sys/windows/ext/ffi.rs
@@ -26,8 +26,22 @@ pub trait OsStringExt {
     /// Creates an `OsString` from a potentially ill-formed UTF-16 slice of
     /// 16-bit code units.
     ///
-    /// This is lossless: calling `.encode_wide()` on the resulting string
+    /// This is lossless: calling [`encode_wide`] on the resulting string
     /// will always return the original code units.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::ffi::OsString;
+    /// use std::os::windows::prelude::*;
+    ///
+    /// // UTF-16 encoding for "Unicode".
+    /// let source = [0x0055, 0x006E, 0x0069, 0x0063, 0x006F, 0x0064, 0x0065];
+    ///
+    /// let string = OsString::from_wide(&source[..]);
+    /// ```
+    ///
+    /// [`encode_wide`]: ./trait.OsStrExt.html#tymethod.encode_wide
     #[stable(feature = "rust1", since = "1.0.0")]
     fn from_wide(wide: &[u16]) -> Self;
 }
@@ -42,11 +56,29 @@ impl OsStringExt for OsString {
 /// Windows-specific extensions to `OsStr`.
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait OsStrExt {
-    /// Re-encodes an `OsStr` as a wide character sequence,
-    /// i.e. potentially ill-formed UTF-16.
+    /// Re-encodes an `OsStr` as a wide character sequence, i.e. potentially
+    /// ill-formed UTF-16.
+    ///
+    /// This is lossless: calling [`OsString::from_wide`] and then
+    /// `encode_wide` on the result will yield the original code units.
+    /// Note that the encoding does not add a final null terminator.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::ffi::OsString;
+    /// use std::os::windows::prelude::*;
+    ///
+    /// // UTF-16 encoding for "Unicode".
+    /// let source = [0x0055, 0x006E, 0x0069, 0x0063, 0x006F, 0x0064, 0x0065];
+    ///
+    /// let string = OsString::from_wide(&source[..]);
+    ///
+    /// let result: Vec<u16> = string.encode_wide().collect();
+    /// assert_eq!(&source[..], &result[..]);
+    /// ```
     ///
-    /// This is lossless. Note that the encoding does not include a final
-    /// null.
+    /// [`OsString::from_wide`]: ./trait.OsStringExt.html#tymethod.from_wide
     #[stable(feature = "rust1", since = "1.0.0")]
     fn encode_wide(&self) -> EncodeWide;
 }
diff --git a/src/libstd/sys/windows/ext/fs.rs b/src/libstd/sys/windows/ext/fs.rs
index c63dd8a47ca..2d00cb38ec4 100644
--- a/src/libstd/sys/windows/ext/fs.rs
+++ b/src/libstd/sys/windows/ext/fs.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-//! Windows-specific extensions for the primitives in `std::fs`
+//! Windows-specific extensions for the primitives in the `std::fs` module.
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
@@ -18,7 +18,9 @@ use path::Path;
 use sys;
 use sys_common::{AsInnerMut, AsInner};
 
-/// Windows-specific extensions to `File`
+/// Windows-specific extensions to [`File`].
+///
+/// [`File`]: ../../../fs/struct.File.html
 #[stable(feature = "file_offset", since = "1.15.0")]
 pub trait FileExt {
     /// Seeks to a given position and reads a number of bytes.
@@ -35,6 +37,24 @@ pub trait FileExt {
     /// Note that similar to `File::read`, it is not an error to return with a
     /// short read. When returning from such a short read, the file pointer is
     /// still updated.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::io;
+    /// use std::fs::File;
+    /// use std::os::windows::prelude::*;
+    ///
+    /// # fn foo() -> io::Result<()> {
+    /// let mut file = File::open("foo.txt")?;
+    /// let mut buffer = [0; 10];
+    ///
+    /// // Read 10 bytes, starting 72 bytes from the
+    /// // start of the file.
+    /// file.seek_read(&mut buffer[..], 72)?;
+    /// # Ok(())
+    /// # }
+    /// ```
     #[stable(feature = "file_offset", since = "1.15.0")]
     fn seek_read(&self, buf: &mut [u8], offset: u64) -> io::Result<usize>;
 
@@ -52,6 +72,22 @@ pub trait FileExt {
     /// Note that similar to `File::write`, it is not an error to return a
     /// short write. When returning from such a short write, the file pointer
     /// is still updated.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs::File;
+    /// use std::os::windows::prelude::*;
+    ///
+    /// # fn foo() -> std::io::Result<()> {
+    /// let mut buffer = File::create("foo.txt")?;
+    ///
+    /// // Write a byte string starting 72 bytes from
+    /// // the start of the file.
+    /// buffer.seek_write(b"some bytes", 72)?;
+    /// # Ok(())
+    /// # }
+    /// ```
     #[stable(feature = "file_offset", since = "1.15.0")]
     fn seek_write(&self, buf: &[u8], offset: u64) -> io::Result<usize>;
 }
@@ -67,84 +103,97 @@ impl FileExt for fs::File {
     }
 }
 
-/// Windows-specific extensions to `OpenOptions`
+/// Windows-specific extensions to [`OpenOptions`].
+///
+/// [`OpenOptions`]: ../../../fs/struct.OpenOptions.html
 #[stable(feature = "open_options_ext", since = "1.10.0")]
 pub trait OpenOptionsExt {
-    /// Overrides the `dwDesiredAccess` argument to the call to `CreateFile`
+    /// Overrides the `dwDesiredAccess` argument to the call to [`CreateFile`]
     /// with the specified value.
     ///
     /// This will override the `read`, `write`, and `append` flags on the
     /// `OpenOptions` structure. This method provides fine-grained control over
     /// the permissions to read, write and append data, attributes (like hidden
-    /// and system) and extended attributes.
+    /// and system), and extended attributes.
     ///
     /// # Examples
     ///
     /// ```no_run
     /// use std::fs::OpenOptions;
-    /// use std::os::windows::fs::OpenOptionsExt;
+    /// use std::os::windows::prelude::*;
     ///
     /// // Open without read and write permission, for example if you only need
-    /// // to call `stat()` on the file
+    /// // to call `stat` on the file
     /// let file = OpenOptions::new().access_mode(0).open("foo.txt");
     /// ```
+    ///
+    /// [`CreateFile`]: https://msdn.microsoft.com/en-us/library/windows/desktop/aa363858.aspx
     #[stable(feature = "open_options_ext", since = "1.10.0")]
     fn access_mode(&mut self, access: u32) -> &mut Self;
 
-    /// Overrides the `dwShareMode` argument to the call to `CreateFile` with
+    /// Overrides the `dwShareMode` argument to the call to [`CreateFile`] with
     /// the specified value.
     ///
     /// By default `share_mode` is set to
-    /// `FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE`. Specifying
-    /// less permissions denies others to read from, write to and/or delete the
-    /// file while it is open.
+    /// `FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE`. This allows
+    /// other processes to to read, write, and delete/rename the same file
+    /// while it is open. Removing any of the flags will prevent other
+    /// processes from performing the corresponding operation until the file
+    /// handle is closed.
     ///
     /// # Examples
     ///
     /// ```no_run
     /// use std::fs::OpenOptions;
-    /// use std::os::windows::fs::OpenOptionsExt;
+    /// use std::os::windows::prelude::*;
     ///
     /// // Do not allow others to read or modify this file while we have it open
-    /// // for writing
-    /// let file = OpenOptions::new().write(true)
-    ///                              .share_mode(0)
-    ///                              .open("foo.txt");
+    /// // for writing.
+    /// let file = OpenOptions::new()
+    ///     .write(true)
+    ///     .share_mode(0)
+    ///     .open("foo.txt");
     /// ```
+    ///
+    /// [`CreateFile`]: https://msdn.microsoft.com/en-us/library/windows/desktop/aa363858.aspx
     #[stable(feature = "open_options_ext", since = "1.10.0")]
     fn share_mode(&mut self, val: u32) -> &mut Self;
 
     /// Sets extra flags for the `dwFileFlags` argument to the call to
-    /// `CreateFile2` (or combines it with `attributes` and `security_qos_flags`
-    /// to set the `dwFlagsAndAttributes` for `CreateFile`).
+    /// [`CreateFile2`] to the specified value (or combines it with
+    /// `attributes` and `security_qos_flags` to set the `dwFlagsAndAttributes`
+    /// for [`CreateFile`]).
     ///
-    /// Custom flags can only set flags, not remove flags set by Rusts options.
-    /// This options overwrites any previously set custom flags.
+    /// Custom flags can only set flags, not remove flags set by Rust's options.
+    /// This option overwrites any previously set custom flags.
     ///
     /// # Examples
     ///
-    /// ```rust,ignore
+    /// ```ignore
     /// extern crate winapi;
+    ///
     /// use std::fs::OpenOptions;
-    /// use std::os::windows::fs::OpenOptionsExt;
-    ///
-    /// let mut options = OpenOptions::new();
-    /// options.create(true).write(true);
-    /// if cfg!(windows) {
-    ///     options.custom_flags(winapi::FILE_FLAG_DELETE_ON_CLOSE);
-    /// }
-    /// let file = options.open("foo.txt");
+    /// use std::os::windows::prelude::*;
+    ///
+    /// let file = OpenOptions::new()
+    ///     .create(true)
+    ///     .write(true)
+    ///     .custom_flags(winapi::FILE_FLAG_DELETE_ON_CLOSE)
+    ///     .open("foo.txt");
     /// ```
+    ///
+    /// [`CreateFile`]: https://msdn.microsoft.com/en-us/library/windows/desktop/aa363858.aspx
+    /// [`CreateFile2`]: https://msdn.microsoft.com/en-us/library/windows/desktop/hh449422.aspx
     #[stable(feature = "open_options_ext", since = "1.10.0")]
     fn custom_flags(&mut self, flags: u32) -> &mut Self;
 
-    /// Sets the `dwFileAttributes` argument to the call to `CreateFile2` to
+    /// Sets the `dwFileAttributes` argument to the call to [`CreateFile2`] to
     /// the specified value (or combines it with `custom_flags` and
     /// `security_qos_flags` to set the `dwFlagsAndAttributes` for
-    /// `CreateFile`).
+    /// [`CreateFile`]).
     ///
     /// If a _new_ file is created because it does not yet exist and
-    ///`.create(true)` or `.create_new(true)` are specified, the new file is
+    /// `.create(true)` or `.create_new(true)` are specified, the new file is
     /// given the attributes declared with `.attributes()`.
     ///
     /// If an _existing_ file is opened with `.create(true).truncate(true)`, its
@@ -155,21 +204,52 @@ pub trait OpenOptionsExt {
     ///
     /// # Examples
     ///
-    /// ```rust,ignore
+    /// ```ignore
     /// extern crate winapi;
+    ///
     /// use std::fs::OpenOptions;
-    /// use std::os::windows::fs::OpenOptionsExt;
+    /// use std::os::windows::prelude::*;
     ///
-    /// let file = OpenOptions::new().write(true).create(true)
-    ///                              .attributes(winapi::FILE_ATTRIBUTE_HIDDEN)
-    ///                              .open("foo.txt");
+    /// let file = OpenOptions::new()
+    ///     .write(true)
+    ///     .create(true)
+    ///     .attributes(winapi::FILE_ATTRIBUTE_HIDDEN)
+    ///     .open("foo.txt");
     /// ```
+    ///
+    /// [`CreateFile`]: https://msdn.microsoft.com/en-us/library/windows/desktop/aa363858.aspx
+    /// [`CreateFile2`]: https://msdn.microsoft.com/en-us/library/windows/desktop/hh449422.aspx
     #[stable(feature = "open_options_ext", since = "1.10.0")]
     fn attributes(&mut self, val: u32) -> &mut Self;
 
-    /// Sets the `dwSecurityQosFlags` argument to the call to `CreateFile2` to
+    /// Sets the `dwSecurityQosFlags` argument to the call to [`CreateFile2`] to
     /// the specified value (or combines it with `custom_flags` and `attributes`
-    /// to set the `dwFlagsAndAttributes` for `CreateFile`).
+    /// to set the `dwFlagsAndAttributes` for [`CreateFile`]).
+    ///
+    /// By default, `security_qos_flags` is set to `SECURITY_ANONYMOUS`. For
+    /// information about possible values, see [Impersonation Levels] on the
+    /// Windows Dev Center site.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs::OpenOptions;
+    /// use std::os::windows::prelude::*;
+    ///
+    /// let file = OpenOptions::new()
+    ///     .write(true)
+    ///     .create(true)
+    ///
+    ///     // Sets the flag value to `SecurityIdentification`.
+    ///     .security_qos_flags(1)
+    ///
+    ///     .open("foo.txt");
+    /// ```
+    ///
+    /// [`CreateFile`]: https://msdn.microsoft.com/en-us/library/windows/desktop/aa363858.aspx
+    /// [`CreateFile2`]: https://msdn.microsoft.com/en-us/library/windows/desktop/hh449422.aspx
+    /// [Impersonation Levels]:
+    ///     https://msdn.microsoft.com/en-us/library/windows/desktop/aa379572.aspx
     #[stable(feature = "open_options_ext", since = "1.10.0")]
     fn security_qos_flags(&mut self, flags: u32) -> &mut OpenOptions;
 }
@@ -197,35 +277,136 @@ impl OpenOptionsExt for OpenOptions {
     }
 }
 
-/// Extension methods for `fs::Metadata` to access the raw fields contained
+/// Extension methods for [`fs::Metadata`] to access the raw fields contained
 /// within.
+///
+/// The data members that this trait exposes correspond to the members
+/// of the [`BY_HANDLE_FILE_INFORMATION`] structure.
+///
+/// [`fs::Metadata`]: ../../../fs/struct.Metadata.html
+/// [`BY_HANDLE_FILE_INFORMATION`]:
+///     https://msdn.microsoft.com/en-us/library/windows/desktop/aa363788.aspx
 #[stable(feature = "metadata_ext", since = "1.1.0")]
 pub trait MetadataExt {
     /// Returns the value of the `dwFileAttributes` field of this metadata.
     ///
     /// This field contains the file system attribute information for a file
-    /// or directory.
+    /// or directory. For possible values and their descriptions, see
+    /// [File Attribute Constants] in the Windows Dev Center.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::io;
+    /// use std::fs;
+    /// use std::os::windows::prelude::*;
+    ///
+    /// # fn foo() -> io::Result<()> {
+    /// let metadata = fs::metadata("foo.txt")?;
+    /// let attributes = metadata.file_attributes();
+    /// # Ok(())
+    /// # }
+    /// ```
+    ///
+    /// [File Attribute Constants]:
+    ///     https://msdn.microsoft.com/en-us/library/windows/desktop/gg258117.aspx
     #[stable(feature = "metadata_ext", since = "1.1.0")]
     fn file_attributes(&self) -> u32;
 
     /// Returns the value of the `ftCreationTime` field of this metadata.
     ///
-    /// The returned 64-bit value represents the number of 100-nanosecond
-    /// intervals since January 1, 1601 (UTC).
+    /// The returned 64-bit value is equivalent to a [`FILETIME`] struct,
+    /// which represents the number of 100-nanosecond intervals since
+    /// January 1, 1601 (UTC). The struct is automatically
+    /// converted to a `u64` value, as that is the recommended way
+    /// to use it.
+    ///
+    /// If the underlying filesystem does not support creation time, the
+    /// returned value is 0.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::io;
+    /// use std::fs;
+    /// use std::os::windows::prelude::*;
+    ///
+    /// # fn foo() -> io::Result<()> {
+    /// let metadata = fs::metadata("foo.txt")?;
+    /// let creation_time = metadata.creation_time();
+    /// # Ok(())
+    /// # }
+    /// ```
+    ///
+    /// [`FILETIME`]: https://msdn.microsoft.com/en-us/library/windows/desktop/ms724284.aspx
     #[stable(feature = "metadata_ext", since = "1.1.0")]
     fn creation_time(&self) -> u64;
 
     /// Returns the value of the `ftLastAccessTime` field of this metadata.
     ///
-    /// The returned 64-bit value represents the number of 100-nanosecond
-    /// intervals since January 1, 1601 (UTC).
+    /// The returned 64-bit value is equivalent to a [`FILETIME`] struct,
+    /// which represents the number of 100-nanosecond intervals since
+    /// January 1, 1601 (UTC). The struct is automatically
+    /// converted to a `u64` value, as that is the recommended way
+    /// to use it.
+    ///
+    /// For a file, the value specifies the last time that a file was read
+    /// from or written to. For a directory, the value specifies when
+    /// the directory was created. For both files and directories, the
+    /// specified date is correct, but the time of day is always set to
+    /// midnight.
+    ///
+    /// If the underlying filesystem does not support last access time, the
+    /// returned value is 0.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::io;
+    /// use std::fs;
+    /// use std::os::windows::prelude::*;
+    ///
+    /// # fn foo() -> io::Result<()> {
+    /// let metadata = fs::metadata("foo.txt")?;
+    /// let last_access_time = metadata.last_access_time();
+    /// # Ok(())
+    /// # }
+    /// ```
+    ///
+    /// [`FILETIME`]: https://msdn.microsoft.com/en-us/library/windows/desktop/ms724284.aspx
     #[stable(feature = "metadata_ext", since = "1.1.0")]
     fn last_access_time(&self) -> u64;
 
     /// Returns the value of the `ftLastWriteTime` field of this metadata.
     ///
-    /// The returned 64-bit value represents the number of 100-nanosecond
-    /// intervals since January 1, 1601 (UTC).
+    /// The returned 64-bit value is equivalent to a [`FILETIME`] struct,
+    /// which represents the number of 100-nanosecond intervals since
+    /// January 1, 1601 (UTC). The struct is automatically
+    /// converted to a `u64` value, as that is the recommended way
+    /// to use it.
+    ///
+    /// For a file, the value specifies the last time that a file was written
+    /// to. For a directory, the structure specifies when the directory was
+    /// created.
+    ///
+    /// If the underlying filesystem does not support the last write time
+    /// time, the returned value is 0.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::io;
+    /// use std::fs;
+    /// use std::os::windows::prelude::*;
+    ///
+    /// # fn foo() -> io::Result<()> {
+    /// let metadata = fs::metadata("foo.txt")?;
+    /// let last_write_time = metadata.last_write_time();
+    /// # Ok(())
+    /// # }
+    /// ```
+    ///
+    /// [`FILETIME`]: https://msdn.microsoft.com/en-us/library/windows/desktop/ms724284.aspx
     #[stable(feature = "metadata_ext", since = "1.1.0")]
     fn last_write_time(&self) -> u64;
 
@@ -233,6 +414,20 @@ pub trait MetadataExt {
     /// metadata.
     ///
     /// The returned value does not have meaning for directories.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::io;
+    /// use std::fs;
+    /// use std::os::windows::prelude::*;
+    ///
+    /// # fn foo() -> io::Result<()> {
+    /// let metadata = fs::metadata("foo.txt")?;
+    /// let file_size = metadata.file_size();
+    /// # Ok(())
+    /// # }
+    /// ```
     #[stable(feature = "metadata_ext", since = "1.1.0")]
     fn file_size(&self) -> u64;
 }
@@ -253,7 +448,7 @@ impl MetadataExt for Metadata {
 ///
 /// # Examples
 ///
-/// ```ignore
+/// ```no_run
 /// use std::os::windows::fs;
 ///
 /// # fn foo() -> std::io::Result<()> {
@@ -274,7 +469,7 @@ pub fn symlink_file<P: AsRef<Path>, Q: AsRef<Path>>(src: P, dst: Q)
 ///
 /// # Examples
 ///
-/// ```ignore
+/// ```no_run
 /// use std::os::windows::fs;
 ///
 /// # fn foo() -> std::io::Result<()> {
diff --git a/src/libstd/sys/windows/ext/mod.rs b/src/libstd/sys/windows/ext/mod.rs
index f12e50cc923..11b1337a8ae 100644
--- a/src/libstd/sys/windows/ext/mod.rs
+++ b/src/libstd/sys/windows/ext/mod.rs
@@ -8,11 +8,13 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-//! Experimental extensions to `std` for Windows.
+//! Platform-specific extensions to `std` for Windows.
 //!
-//! For now, this module is limited to extracting handles, file
-//! descriptors, and sockets, but its functionality will grow over
-//! time.
+//! Provides access to platform-level information for Windows, and exposes
+//! Windows-specific idioms that would otherwise be inappropriate as part
+//! the core `std` library. These extensions allow developers to use
+//! `std` types and idioms with Windows in a way that the normal
+//! platform-agnostic idioms would not normally support.
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
diff --git a/src/libstd/sys/windows/ext/process.rs b/src/libstd/sys/windows/ext/process.rs
index 1419a4af427..759f055c4b1 100644
--- a/src/libstd/sys/windows/ext/process.rs
+++ b/src/libstd/sys/windows/ext/process.rs
@@ -104,6 +104,7 @@ pub trait CommandExt {
     /// Sets the [process creation flags][1] to be passed to `CreateProcess`.
     ///
     /// These will always be ORed with `CREATE_UNICODE_ENVIRONMENT`.
+    ///
     /// [1]: https://msdn.microsoft.com/en-us/library/windows/desktop/ms684863(v=vs.85).aspx
     #[stable(feature = "windows_process_extensions", since = "1.16.0")]
     fn creation_flags(&mut self, flags: u32) -> &mut process::Command;
diff --git a/src/libstd/sys/windows/os.rs b/src/libstd/sys/windows/os.rs
index 7e28dd1e259..a51b458451e 100644
--- a/src/libstd/sys/windows/os.rs
+++ b/src/libstd/sys/windows/os.rs
@@ -32,7 +32,7 @@ pub fn errno() -> i32 {
 }
 
 /// Gets a detailed string description for the given error number.
-pub fn error_string(errnum: i32) -> String {
+pub fn error_string(mut errnum: i32) -> String {
     // This value is calculated from the macro
     // MAKELANGID(LANG_SYSTEM_DEFAULT, SUBLANG_SYS_DEFAULT)
     let langId = 0x0800 as c::DWORD;
@@ -40,9 +40,27 @@ pub fn error_string(errnum: i32) -> String {
     let mut buf = [0 as c::WCHAR; 2048];
 
     unsafe {
-        let res = c::FormatMessageW(c::FORMAT_MESSAGE_FROM_SYSTEM |
+        let mut module = ptr::null_mut();
+        let mut flags = 0;
+
+        // NTSTATUS errors may be encoded as HRESULT, which may returned from
+        // GetLastError. For more information about Windows error codes, see
+        // `[MS-ERREF]`: https://msdn.microsoft.com/en-us/library/cc231198.aspx
+        if (errnum & c::FACILITY_NT_BIT as i32) != 0 {
+            // format according to https://support.microsoft.com/en-us/help/259693
+            const NTDLL_DLL: &'static [u16] = &['N' as _, 'T' as _, 'D' as _, 'L' as _, 'L' as _,
+                                                '.' as _, 'D' as _, 'L' as _, 'L' as _, 0];
+            module = c::GetModuleHandleW(NTDLL_DLL.as_ptr());
+
+            if module != ptr::null_mut() {
+                errnum ^= c::FACILITY_NT_BIT as i32;
+                flags = c::FORMAT_MESSAGE_FROM_HMODULE;
+            }
+        }
+
+        let res = c::FormatMessageW(flags | c::FORMAT_MESSAGE_FROM_SYSTEM |
                                         c::FORMAT_MESSAGE_IGNORE_INSERTS,
-                                    ptr::null_mut(),
+                                    module,
                                     errnum as c::DWORD,
                                     langId,
                                     buf.as_mut_ptr(),
@@ -299,3 +317,17 @@ pub fn home_dir() -> Option<PathBuf> {
 pub fn exit(code: i32) -> ! {
     unsafe { c::ExitProcess(code as c::UINT) }
 }
+
+#[cfg(test)]
+mod tests {
+    use io::Error;
+    use sys::c;
+
+    // tests `error_string` above
+    #[test]
+    fn ntstatus_error() {
+        const STATUS_UNSUCCESSFUL: u32 = 0xc000_0001;
+        assert!(!Error::from_raw_os_error((STATUS_UNSUCCESSFUL | c::FACILITY_NT_BIT) as _)
+            .to_string().contains("FormatMessageW() returned error"));
+    }
+}
diff --git a/src/libstd/sys/windows/os_str.rs b/src/libstd/sys/windows/os_str.rs
index b02b06e1ef2..f401e7b35c8 100644
--- a/src/libstd/sys/windows/os_str.rs
+++ b/src/libstd/sys/windows/os_str.rs
@@ -97,6 +97,12 @@ impl Buf {
     pub fn into_box(self) -> Box<Slice> {
         unsafe { mem::transmute(self.inner.into_box()) }
     }
+
+    #[inline]
+    pub fn from_box(boxed: Box<Slice>) -> Buf {
+        let inner: Box<Wtf8> = unsafe { mem::transmute(boxed) };
+        Buf { inner: Wtf8Buf::from_box(inner) }
+    }
 }
 
 impl Slice {
diff --git a/src/libstd/sys/windows/process.rs b/src/libstd/sys/windows/process.rs
index 1afb3728c9d..dfbc1b581ee 100644
--- a/src/libstd/sys/windows/process.rs
+++ b/src/libstd/sys/windows/process.rs
@@ -257,8 +257,13 @@ impl Stdio {
             // INVALID_HANDLE_VALUE.
             Stdio::Inherit => {
                 match stdio::get(stdio_id) {
-                    Ok(io) => io.handle().duplicate(0, true,
-                                                    c::DUPLICATE_SAME_ACCESS),
+                    Ok(io) => {
+                        let io = Handle::new(io.handle());
+                        let ret = io.duplicate(0, true,
+                                               c::DUPLICATE_SAME_ACCESS);
+                        io.into_raw();
+                        return ret
+                    }
                     Err(..) => Ok(Handle::new(c::INVALID_HANDLE_VALUE)),
                 }
             }
diff --git a/src/libstd/sys/windows/stdio.rs b/src/libstd/sys/windows/stdio.rs
index b1a57c349fb..d72e4b4438b 100644
--- a/src/libstd/sys/windows/stdio.rs
+++ b/src/libstd/sys/windows/stdio.rs
@@ -22,42 +22,43 @@ use sys::cvt;
 use sys::handle::Handle;
 use sys_common::io::read_to_end_uninitialized;
 
-pub struct NoClose(Option<Handle>);
-
 pub enum Output {
-    Console(NoClose),
-    Pipe(NoClose),
+    Console(c::HANDLE),
+    Pipe(c::HANDLE),
 }
 
 pub struct Stdin {
-    handle: Output,
     utf8: Mutex<io::Cursor<Vec<u8>>>,
 }
-pub struct Stdout(Output);
-pub struct Stderr(Output);
+pub struct Stdout;
+pub struct Stderr;
 
 pub fn get(handle: c::DWORD) -> io::Result<Output> {
     let handle = unsafe { c::GetStdHandle(handle) };
     if handle == c::INVALID_HANDLE_VALUE {
         Err(io::Error::last_os_error())
     } else if handle.is_null() {
-        Err(io::Error::new(io::ErrorKind::Other,
-                           "no stdio handle available for this process"))
+        Err(io::Error::from_raw_os_error(c::ERROR_INVALID_HANDLE as i32))
     } else {
-        let ret = NoClose::new(handle);
         let mut out = 0;
         match unsafe { c::GetConsoleMode(handle, &mut out) } {
-            0 => Ok(Output::Pipe(ret)),
-            _ => Ok(Output::Console(ret)),
+            0 => Ok(Output::Pipe(handle)),
+            _ => Ok(Output::Console(handle)),
         }
     }
 }
 
-fn write(out: &Output, data: &[u8]) -> io::Result<usize> {
-    let handle = match *out {
-        Output::Console(ref c) => c.get().raw(),
-        Output::Pipe(ref p) => return p.get().write(data),
+fn write(handle: c::DWORD, data: &[u8]) -> io::Result<usize> {
+    let handle = match try!(get(handle)) {
+        Output::Console(c) => c,
+        Output::Pipe(p) => {
+            let handle = Handle::new(p);
+            let ret = handle.write(data);
+            handle.into_raw();
+            return ret
+        }
     };
+
     // As with stdin on windows, stdout often can't handle writes of large
     // sizes. For an example, see #14940. For this reason, don't try to
     // write the entire output buffer on windows.
@@ -93,18 +94,20 @@ fn write(out: &Output, data: &[u8]) -> io::Result<usize> {
 
 impl Stdin {
     pub fn new() -> io::Result<Stdin> {
-        get(c::STD_INPUT_HANDLE).map(|handle| {
-            Stdin {
-                handle: handle,
-                utf8: Mutex::new(Cursor::new(Vec::new())),
-            }
+        Ok(Stdin {
+            utf8: Mutex::new(Cursor::new(Vec::new())),
         })
     }
 
     pub fn read(&self, buf: &mut [u8]) -> io::Result<usize> {
-        let handle = match self.handle {
-            Output::Console(ref c) => c.get().raw(),
-            Output::Pipe(ref p) => return p.get().read(buf),
+        let handle = match try!(get(c::STD_INPUT_HANDLE)) {
+            Output::Console(c) => c,
+            Output::Pipe(p) => {
+                let handle = Handle::new(p);
+                let ret = handle.read(buf);
+                handle.into_raw();
+                return ret
+            }
         };
         let mut utf8 = self.utf8.lock().unwrap();
         // Read more if the buffer is empty
@@ -125,11 +128,9 @@ impl Stdin {
                 Ok(utf8) => utf8.into_bytes(),
                 Err(..) => return Err(invalid_encoding()),
             };
-            if let Output::Console(_) = self.handle {
-                if let Some(&last_byte) = data.last() {
-                    if last_byte == CTRL_Z {
-                        data.pop();
-                    }
+            if let Some(&last_byte) = data.last() {
+                if last_byte == CTRL_Z {
+                    data.pop();
                 }
             }
             *utf8 = Cursor::new(data);
@@ -158,11 +159,11 @@ impl<'a> Read for &'a Stdin {
 
 impl Stdout {
     pub fn new() -> io::Result<Stdout> {
-        get(c::STD_OUTPUT_HANDLE).map(Stdout)
+        Ok(Stdout)
     }
 
     pub fn write(&self, data: &[u8]) -> io::Result<usize> {
-        write(&self.0, data)
+        write(c::STD_OUTPUT_HANDLE, data)
     }
 
     pub fn flush(&self) -> io::Result<()> {
@@ -172,11 +173,11 @@ impl Stdout {
 
 impl Stderr {
     pub fn new() -> io::Result<Stderr> {
-        get(c::STD_ERROR_HANDLE).map(Stderr)
+        Ok(Stderr)
     }
 
     pub fn write(&self, data: &[u8]) -> io::Result<usize> {
-        write(&self.0, data)
+        write(c::STD_ERROR_HANDLE, data)
     }
 
     pub fn flush(&self) -> io::Result<()> {
@@ -197,27 +198,12 @@ impl io::Write for Stderr {
     }
 }
 
-impl NoClose {
-    fn new(handle: c::HANDLE) -> NoClose {
-        NoClose(Some(Handle::new(handle)))
-    }
-
-    fn get(&self) -> &Handle { self.0.as_ref().unwrap() }
-}
-
-impl Drop for NoClose {
-    fn drop(&mut self) {
-        self.0.take().unwrap().into_raw();
-    }
-}
-
 impl Output {
-    pub fn handle(&self) -> &Handle {
-        let nc = match *self {
-            Output::Console(ref c) => c,
-            Output::Pipe(ref c) => c,
-        };
-        nc.0.as_ref().unwrap()
+    pub fn handle(&self) -> c::HANDLE {
+        match *self {
+            Output::Console(c) => c,
+            Output::Pipe(c) => c,
+        }
     }
 }
 
diff --git a/src/libstd/sys/windows/thread_local.rs b/src/libstd/sys/windows/thread_local.rs
index 597f05622a5..ad57f87dc1f 100644
--- a/src/libstd/sys/windows/thread_local.rs
+++ b/src/libstd/sys/windows/thread_local.rs
@@ -8,10 +8,11 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+use mem;
 use ptr;
+use sync::atomic::AtomicPtr;
+use sync::atomic::Ordering::SeqCst;
 use sys::c;
-use sys_common::mutex::Mutex;
-use sys_common;
 
 pub type Key = c::DWORD;
 pub type Dtor = unsafe extern fn(*mut u8);
@@ -34,8 +35,6 @@ pub type Dtor = unsafe extern fn(*mut u8);
 // * All TLS destructors are tracked by *us*, not the windows runtime. This
 //   means that we have a global list of destructors for each TLS key that
 //   we know about.
-// * When a TLS key is destroyed, we're sure to remove it from the dtor list
-//   if it's in there.
 // * When a thread exits, we run over the entire list and run dtors for all
 //   non-null keys. This attempts to match Unix semantics in this regard.
 //
@@ -50,13 +49,6 @@ pub type Dtor = unsafe extern fn(*mut u8);
 // [2]: https://github.com/ChromiumWebApps/chromium/blob/master/base
 //                        /threading/thread_local_storage_win.cc#L42
 
-// NB these are specifically not types from `std::sync` as they currently rely
-// on poisoning and this module needs to operate at a lower level than requiring
-// the thread infrastructure to be in place (useful on the borders of
-// initialization/destruction).
-static DTOR_LOCK: Mutex = Mutex::new();
-static mut DTORS: *mut Vec<(Key, Dtor)> = ptr::null_mut();
-
 // -------------------------------------------------------------------------
 // Native bindings
 //
@@ -85,81 +77,64 @@ pub unsafe fn get(key: Key) -> *mut u8 {
 }
 
 #[inline]
-pub unsafe fn destroy(key: Key) {
-    if unregister_dtor(key) {
-        // FIXME: Currently if a key has a destructor associated with it we
-        // can't actually ever unregister it. If we were to
-        // unregister it, then any key destruction would have to be
-        // serialized with respect to actually running destructors.
-        //
-        // We want to avoid a race where right before run_dtors runs
-        // some destructors TlsFree is called. Allowing the call to
-        // TlsFree would imply that the caller understands that *all
-        // known threads* are not exiting, which is quite a difficult
-        // thing to know!
-        //
-        // For now we just leak all keys with dtors to "fix" this.
-        // Note that source [2] above shows precedent for this sort
-        // of strategy.
-    } else {
-        let r = c::TlsFree(key);
-        debug_assert!(r != 0);
-    }
+pub unsafe fn destroy(_key: Key) {
+    rtabort!("can't destroy tls keys on windows")
+}
+
+#[inline]
+pub fn requires_synchronized_create() -> bool {
+    true
 }
 
 // -------------------------------------------------------------------------
 // Dtor registration
 //
-// These functions are associated with registering and unregistering
-// destructors. They're pretty simple, they just push onto a vector and scan
-// a vector currently.
+// Windows has no native support for running destructors so we manage our own
+// list of destructors to keep track of how to destroy keys. We then install a
+// callback later to get invoked whenever a thread exits, running all
+// appropriate destructors.
 //
-// FIXME: This could probably be at least a little faster with a BTree.
-
-unsafe fn init_dtors() {
-    if !DTORS.is_null() { return }
+// Currently unregistration from this list is not supported. A destructor can be
+// registered but cannot be unregistered. There's various simplifying reasons
+// for doing this, the big ones being:
+//
+// 1. Currently we don't even support deallocating TLS keys, so normal operation
+//    doesn't need to deallocate a destructor.
+// 2. There is no point in time where we know we can unregister a destructor
+//    because it could always be getting run by some remote thread.
+//
+// Typically processes have a statically known set of TLS keys which is pretty
+// small, and we'd want to keep this memory alive for the whole process anyway
+// really.
+//
+// Perhaps one day we can fold the `Box` here into a static allocation,
+// expanding the `StaticKey` structure to contain not only a slot for the TLS
+// key but also a slot for the destructor queue on windows. An optimization for
+// another day!
 
-    let dtors = box Vec::<(Key, Dtor)>::new();
+static DTORS: AtomicPtr<Node> = AtomicPtr::new(ptr::null_mut());
 
-    let res = sys_common::at_exit(move|| {
-        DTOR_LOCK.lock();
-        let dtors = DTORS;
-        DTORS = 1 as *mut _;
-        Box::from_raw(dtors);
-        assert!(DTORS as usize == 1); // can't re-init after destructing
-        DTOR_LOCK.unlock();
-    });
-    if res.is_ok() {
-        DTORS = Box::into_raw(dtors);
-    } else {
-        DTORS = 1 as *mut _;
-    }
+struct Node {
+    dtor: Dtor,
+    key: Key,
+    next: *mut Node,
 }
 
 unsafe fn register_dtor(key: Key, dtor: Dtor) {
-    DTOR_LOCK.lock();
-    init_dtors();
-    assert!(DTORS as usize != 0);
-    assert!(DTORS as usize != 1,
-            "cannot create new TLS keys after the main thread has exited");
-    (*DTORS).push((key, dtor));
-    DTOR_LOCK.unlock();
-}
+    let mut node = Box::new(Node {
+        key: key,
+        dtor: dtor,
+        next: ptr::null_mut(),
+    });
 
-unsafe fn unregister_dtor(key: Key) -> bool {
-    DTOR_LOCK.lock();
-    init_dtors();
-    assert!(DTORS as usize != 0);
-    assert!(DTORS as usize != 1,
-            "cannot unregister destructors after the main thread has exited");
-    let ret = {
-        let dtors = &mut *DTORS;
-        let before = dtors.len();
-        dtors.retain(|&(k, _)| k != key);
-        dtors.len() != before
-    };
-    DTOR_LOCK.unlock();
-    ret
+    let mut head = DTORS.load(SeqCst);
+    loop {
+        node.next = head;
+        match DTORS.compare_exchange(head, &mut *node, SeqCst, SeqCst) {
+            Ok(_) => return mem::forget(node),
+            Err(cur) => head = cur,
+        }
+    }
 }
 
 // -------------------------------------------------------------------------
@@ -196,16 +171,12 @@ unsafe fn unregister_dtor(key: Key) -> bool {
 // # Ok, what's up with running all these destructors?
 //
 // This will likely need to be improved over time, but this function
-// attempts a "poor man's" destructor callback system. To do this we clone a
-// local copy of the dtor list to start out with. This is our fudgy attempt
-// to not hold the lock while destructors run and not worry about the list
-// changing while we're looking at it.
-//
-// Once we've got a list of what to run, we iterate over all keys, check
-// their values, and then run destructors if the values turn out to be non
-// null (setting them to null just beforehand). We do this a few times in a
-// loop to basically match Unix semantics. If we don't reach a fixed point
-// after a short while then we just inevitably leak something most likely.
+// attempts a "poor man's" destructor callback system. Once we've got a list
+// of what to run, we iterate over all keys, check their values, and then run
+// destructors if the values turn out to be non null (setting them to null just
+// beforehand). We do this a few times in a loop to basically match Unix
+// semantics. If we don't reach a fixed point after a short while then we just
+// inevitably leak something most likely.
 //
 // # The article mentions weird stuff about "/INCLUDE"?
 //
@@ -259,25 +230,21 @@ unsafe extern "system" fn on_tls_callback(h: c::LPVOID,
 unsafe fn run_dtors() {
     let mut any_run = true;
     for _ in 0..5 {
-        if !any_run { break }
+        if !any_run {
+            break
+        }
         any_run = false;
-        let dtors = {
-            DTOR_LOCK.lock();
-            let ret = if DTORS as usize <= 1 {
-                Vec::new()
-            } else {
-                (*DTORS).iter().map(|s| *s).collect()
-            };
-            DTOR_LOCK.unlock();
-            ret
-        };
-        for &(key, dtor) in &dtors {
-            let ptr = c::TlsGetValue(key);
+        let mut cur = DTORS.load(SeqCst);
+        while !cur.is_null() {
+            let ptr = c::TlsGetValue((*cur).key);
+
             if !ptr.is_null() {
-                c::TlsSetValue(key, ptr::null_mut());
-                dtor(ptr as *mut _);
+                c::TlsSetValue((*cur).key, ptr::null_mut());
+                ((*cur).dtor)(ptr as *mut _);
                 any_run = true;
             }
+
+            cur = (*cur).next;
         }
     }
 }