Revert "std: Re-enable at_exit()"

This reverts commit 9e224c2b.

Conflicts:
	src/libstd/sys/windows/os.rs

src/liblog/lib.rs

@@ -177,7 +177,7 @@
 use std::os;
 use std::rt;
 use std::slice;
-use std::sync::{Once, ONCE_INIT, StaticMutex, MUTEX_INIT};
+use std::sync::{Once, ONCE_INIT};
 
 use regex::Regex;
 
@@ -193,8 +193,6 @@
 /// The default logging level of a crate if no other is specified.
 const DEFAULT_LOG_LEVEL: u32 = 1;
 
-static LOCK: StaticMutex = MUTEX_INIT;
-
 /// An unsafe constant that is the maximum logging level of any module
 /// specified. This is the first line of defense to determining whether a
 /// logging statement should be run.
@@ -281,18 +279,9 @@ fn drop(&mut self) {
 pub fn log(level: u32, loc: &'static LogLocation, args: fmt::Arguments) {
     // Test the literal string from args against the current filter, if there
     // is one.
-    unsafe {
-        let _g = LOCK.lock();
-        match FILTER as uint {
-            0 => {}
-            1 => panic!("cannot log after main thread has exited"),
-            n => {
-                let filter = mem::transmute::<_, &Regex>(n);
-                if !filter.is_match(args.to_string().as_slice()) {
-                    return
-                }
-            }
-        }
+    match unsafe { FILTER.as_ref() } {
+        Some(filter) if !filter.is_match(args.to_string()[]) => return,
+        _ => {}
     }
 
     // Completely remove the local logger from TLS in case anyone attempts to
@@ -374,15 +363,9 @@ pub fn mod_enabled(level: u32, module: &str) -> bool {
 
     // This assertion should never get tripped unless we're in an at_exit
     // handler after logging has been torn down and a logging attempt was made.
+    assert!(unsafe { !DIRECTIVES.is_null() });
 
-    let _g = LOCK.lock();
-    unsafe {
-        assert!(DIRECTIVES as uint != 0);
-        assert!(DIRECTIVES as uint != 1,
-                "cannot log after the main thread has exited");
-
-        enabled(level, module, (*DIRECTIVES).iter())
-    }
+    enabled(level, module, unsafe { (*DIRECTIVES).iter() })
 }
 
 fn enabled(level: u32,
@@ -438,15 +421,14 @@ fn init() {
 
         // Schedule the cleanup for the globals for when the runtime exits.
         rt::at_exit(move |:| {
-            let _g = LOCK.lock();
             assert!(!DIRECTIVES.is_null());
             let _directives: Box<Vec<directive::LogDirective>> =
                 mem::transmute(DIRECTIVES);
-            DIRECTIVES = 1 as *const Vec<directive::LogDirective>;
+            DIRECTIVES = 0 as *const Vec<directive::LogDirective>;
 
             if !FILTER.is_null() {
                 let _filter: Box<Regex> = mem::transmute(FILTER);
-                FILTER = 1 as *const _;
+                FILTER = 0 as *const _;
             }
         });
     }

src/libstd/io/stdio.rs

@@ -26,19 +26,29 @@
 //! ```
 
 use self::StdSource::*;
-use prelude::*;
 
+use boxed::Box;
 use cell::RefCell;
+use clone::Clone;
 use failure::LOCAL_STDERR;
 use fmt;
-use io::{IoResult, IoError, OtherIoError};
-use io::{standard_error, EndOfFile, LineBufferedWriter, BufferedReader};
+use io::{Reader, Writer, IoResult, IoError, OtherIoError, Buffer,
+         standard_error, EndOfFile, LineBufferedWriter, BufferedReader};
+use kinds::{Sync, Send};
 use libc;
 use mem;
+use option::Option;
+use option::Option::{Some, None};
+use ops::{Deref, DerefMut, FnOnce};
+use result::Result::{Ok, Err};
 use rt;
+use slice::SliceExt;
+use str::StrExt;
+use string::String;
 use sys::{fs, tty};
-use sync::{Arc, Mutex, MutexGuard, StaticMutex, MUTEX_INIT};
+use sync::{Arc, Mutex, MutexGuard, Once, ONCE_INIT};
 use uint;
+use vec::Vec;
 
 // And so begins the tale of acquiring a uv handle to a stdio stream on all
 // platforms in all situations. Our story begins by splitting the world into two
@@ -205,15 +215,14 @@ fn read_be_uint_n(&mut self, nbytes: uint) -> IoResult<u64> {
 pub fn stdin() -> StdinReader {
     // We're following the same strategy as kimundi's lazy_static library
     static mut STDIN: *const StdinReader = 0 as *const StdinReader;
-    static LOCK: StaticMutex = MUTEX_INIT;
+    static ONCE: Once = ONCE_INIT;
 
     unsafe {
-        let _g = LOCK.lock();
-        if STDIN as uint == 0 {
-            // The default buffer capacity is 64k, but apparently windows
-            // doesn't like 64k reads on stdin. See #13304 for details, but the
-            // idea is that on windows we use a slightly smaller buffer that's
-            // been seen to be acceptable.
+        ONCE.doit(|| {
+            // The default buffer capacity is 64k, but apparently windows doesn't like
+            // 64k reads on stdin. See #13304 for details, but the idea is that on
+            // windows we use a slightly smaller buffer that's been seen to be
+            // acceptable.
             let stdin = if cfg!(windows) {
                 BufferedReader::with_capacity(8 * 1024, stdin_raw())
             } else {
@@ -226,15 +235,11 @@ pub fn stdin() -> StdinReader {
 
             // Make sure to free it at exit
             rt::at_exit(|| {
-                let g = LOCK.lock();
-                let stdin = STDIN;
-                STDIN = 1 as *const _;
-                drop(g);
-                mem::transmute::<_, Box<StdinReader>>(stdin);
+                mem::transmute::<_, Box<StdinReader>>(STDIN);
+                STDIN = 0 as *const _;
             });
-        } else if STDIN as uint == 1 {
-            panic!("accessing stdin after the main thread has exited")
-        }
+        });
+
         (*STDIN).clone()
     }
 }

src/libstd/lib.rs

@@ -229,13 +229,13 @@
 pub mod sync;
 pub mod comm;
 
-#[path = "sys/common/mod.rs"] mod sys_common;
-
 #[cfg(unix)]
 #[path = "sys/unix/mod.rs"] mod sys;
 #[cfg(windows)]
 #[path = "sys/windows/mod.rs"] mod sys;
 
+#[path = "sys/common/mod.rs"] mod sys_common;
+
 pub mod rt;
 mod failure;
 

src/libstd/rt/at_exit_imp.rs

@@ -29,8 +29,6 @@
 static LOCK: Mutex = MUTEX_INIT;
 static mut QUEUE: *mut Queue = 0 as *mut Queue;
 
-const DTOR_RUN_ITERS: uint = 10;
-
 unsafe fn init() {
     if QUEUE.is_null() {
         let state: Box<Queue> = box Vec::new();
@@ -51,7 +49,7 @@ pub fn cleanup() {
     unsafe {
         LOCK.lock();
         let queue = QUEUE;
-        QUEUE = 1u as *mut _;
+        QUEUE = 1 as *mut _;
         LOCK.unlock();
 
         // make sure we're not recursively cleaning up

src/libstd/rt/mod.rs

@@ -92,7 +92,9 @@ fn lang_start(main: *const u8, argc: int, argv: *const *const u8) -> int {
         // but we just do this to name the main thread and to give it correct
         // info about the stack bounds.
         let thread: Thread = NewThread::new(Some("<main>".to_string()));
-        thread_info::set(sys::thread::guard::main(), thread);
+        thread_info::set((my_stack_bottom, my_stack_top),
+                         sys::thread::guard::main(),
+                         thread);
 
         // By default, some platforms will send a *signal* when a EPIPE error
         // would otherwise be delivered. This runtime doesn't install a SIGPIPE
@@ -131,14 +133,20 @@ fn lang_start(main: *const u8, argc: int, argv: *const *const u8) -> int {
     }
 }
 
-/// Enqueues a procedure to run when the main thread exits.
+/// Enqueues a procedure to run when the runtime is cleaned up
+///
+/// The procedure passed to this function will be executed as part of the
+/// runtime cleanup phase. For normal rust programs, this means that it will run
+/// after all other threads have exited.
+///
+/// The procedure is *not* executed with a local `Thread` available to it, so
+/// primitives like logging, I/O, channels, spawning, etc, are *not* available.
+/// This is meant for "bare bones" usage to clean up runtime details, this is
+/// not meant as a general-purpose "let's clean everything up" function.
 ///
 /// It is forbidden for procedures to register more `at_exit` handlers when they
 /// are running, and doing so will lead to a process abort.
-///
-/// Note that other threads may still be running when `at_exit` routines start
-/// running.
-pub fn at_exit<F: FnOnce() + Send>(f: F) {
+pub fn at_exit<F:FnOnce()+Send>(f: F) {
     at_exit_imp::push(Thunk::new(f));
 }
 
@@ -154,5 +162,8 @@ pub fn at_exit<F: FnOnce() + Send>(f: F) {
 pub unsafe fn cleanup() {
     args::cleanup();
     sys::stack_overflow::cleanup();
-    at_exit_imp::cleanup();
+    // FIXME: (#20012): the resources being cleaned up by at_exit
+    // currently are not prepared for cleanup to happen asynchronously
+    // with detached threads using the resources; for now, we leak.
+    // at_exit_imp::cleanup();
 }

src/libstd/rt/unwind.rs

@@ -68,7 +68,7 @@
 use libc::c_void;
 use mem;
 use sync::atomic;
-use sys_common::mutex::{Mutex, MUTEX_INIT};
+use sync::{Once, ONCE_INIT};
 
 use rt::libunwind as uw;
 
@@ -540,20 +540,11 @@ pub fn begin_unwind<M: Any + Send>(msg: M, file_line: &(&'static str, uint)) ->
 /// Doing this split took the LLVM IR line counts of `fn main() { panic!()
 /// }` from ~1900/3700 (-O/no opts) to 180/590.
 #[inline(never)] #[cold] // this is the slow path, please never inline this
-fn begin_unwind_inner(msg: Box<Any + Send>,
-                      file_line: &(&'static str, uint)) -> ! {
+fn begin_unwind_inner(msg: Box<Any + Send>, file_line: &(&'static str, uint)) -> ! {
     // Make sure the default failure handler is registered before we look at the
     // callbacks.
-    unsafe {
-        static LOCK: Mutex = MUTEX_INIT;
-        static mut INIT: bool = false;
-        LOCK.lock();
-        if !INIT {
-            register(failure::on_fail);
-            INIT = true;
-        }
-        LOCK.unlock();
-    }
+    static INIT: Once = ONCE_INIT;
+    INIT.doit(|| unsafe { register(failure::on_fail); });
 
     // First, invoke call the user-defined callbacks triggered on thread panic.
     //

src/libstd/sys/common/helper_thread.rs

@@ -20,8 +20,6 @@
 //! can be created in the future and there must be no active timers at that
 //! time.
 
-#![macro_escape]
-
 use prelude::*;
 
 use cell::UnsafeCell;
@@ -70,17 +68,6 @@ unsafe impl<M:Send> Sync for Helper<M> { }
 unsafe impl Send for RaceBox {}
 unsafe impl Sync for RaceBox {}
 
-macro_rules! helper_init { (static $name:ident: Helper<$m:ty>) => (
-    static $name: Helper<$m> = Helper {
-        lock: ::sync::MUTEX_INIT,
-        cond: ::sync::CONDVAR_INIT,
-        chan: ::cell::UnsafeCell { value: 0 as *mut Sender<$m> },
-        signal: ::cell::UnsafeCell { value: 0 },
-        initialized: ::cell::UnsafeCell { value: false },
-        shutdown: ::cell::UnsafeCell { value: false },
-    };
-) }
-
 impl<M: Send> Helper<M> {
     /// Lazily boots a helper thread, becoming a no-op if the helper has already
     /// been spawned.
@@ -97,7 +84,7 @@ pub fn boot<T, F>(&'static self, f: F, helper: fn(helper_signal::signal, Receive
     {
         unsafe {
             let _guard = self.lock.lock().unwrap();
-            if *self.chan.get() as uint == 0 {
+            if !*self.initialized.get() {
                 let (tx, rx) = channel();
                 *self.chan.get() = mem::transmute(box tx);
                 let (receive, send) = helper_signal::new();
@@ -106,17 +93,15 @@ pub fn boot<T, F>(&'static self, f: F, helper: fn(helper_signal::signal, Receive
                 let receive = RaceBox(receive);
 
                 let t = f();
-                Thread::spawn(move || {
+                Thread::spawn(move |:| {
                     helper(receive.0, rx, t);
                     let _g = self.lock.lock().unwrap();
                     *self.shutdown.get() = true;
                     self.cond.notify_one()
                 }).detach();
 
-                rt::at_exit(move || { self.shutdown() });
+                rt::at_exit(move|:| { self.shutdown() });
                 *self.initialized.get() = true;
-            } else if *self.chan.get() as uint == 1 {
-                panic!("cannot continue usage after shutdown");
             }
         }
     }
@@ -131,9 +116,7 @@ pub fn send(&'static self, msg: M) {
             // Must send and *then* signal to ensure that the child receives the
             // message. Otherwise it could wake up and go to sleep before we
             // send the message.
-            assert!(*self.chan.get() as uint != 0);
-            assert!(*self.chan.get() as uint != 1,
-                    "cannot continue usage after shutdown");
+            assert!(!self.chan.get().is_null());
             (**self.chan.get()).send(msg);
             helper_signal::signal(*self.signal.get() as helper_signal::signal);
         }
@@ -146,13 +129,9 @@ fn shutdown(&'static self) {
             // returns.
             let mut guard = self.lock.lock().unwrap();
 
-            let ptr = *self.chan.get();
-            if ptr as uint == 1 {
-                panic!("cannot continue usage after shutdown");
-            }
             // Close the channel by destroying it
             let chan: Box<Sender<M>> = mem::transmute(*self.chan.get());
-            *self.chan.get() = 1 as *mut Sender<M>;
+            *self.chan.get() = 0 as *mut Sender<M>;
             drop(chan);
             helper_signal::signal(*self.signal.get() as helper_signal::signal);
 

src/libstd/sys/common/mod.rs

@@ -9,7 +9,7 @@
 // except according to those terms.
 
 #![allow(missing_docs)]
-#![macro_escape]
+#![allow(dead_code)]
 
 use io::{mod, IoError, IoResult};
 use prelude::*;

src/libstd/sys/common/mutex.rs

@@ -29,7 +29,6 @@ impl Mutex {
     /// Behavior is undefined if the mutex is moved after the first method is
     /// called on the mutex.
     #[inline]
-    #[allow(dead_code)] // sys is not exported yet
     pub unsafe fn new() -> Mutex { Mutex(imp::Mutex::new()) }
 
     /// Lock the mutex blocking the current thread until it is available.

src/libstd/sys/common/net.rs

@@ -23,9 +23,7 @@
 use sys::{mod, retry, c, sock_t, last_error, last_net_error, last_gai_error, close_sock,
           wrlen, msglen_t, os, wouldblock, set_nonblocking, timer, ms_to_timeval,
           decode_error_detailed};
-use sync::Mutex;
-#[cfg(not(target_os = "linux"))]
-use sync::MutexGuard;
+use sync::{Mutex, MutexGuard};
 use sys_common::{mod, keep_going, short_write, timeout};
 use prelude::*;
 use cmp;
@@ -613,13 +611,11 @@ impl Drop for Inner {
     fn drop(&mut self) { unsafe { close_sock(self.fd); } }
 }
 
-#[cfg(not(target_os = "linux"))]
 pub struct Guard<'a> {
     pub fd: sock_t,
     pub guard: MutexGuard<'a, ()>,
 }
 
-#[cfg(not(target_os = "linux"))]
 #[unsafe_destructor]
 impl<'a> Drop for Guard<'a> {
     fn drop(&mut self) {

src/libstd/sys/common/rwlock.rs

@@ -26,7 +26,6 @@ impl RWLock {
     /// Usage of an RWLock is undefined if it is moved after its first use (any
     /// function calls below).
     #[inline]
-    #[allow(dead_code)] // sys is not exported yet
     pub unsafe fn new() -> RWLock { RWLock(imp::RWLock::new()) }
 
     /// Acquire shared access to the underlying lock, blocking the current

src/libstd/sys/common/stack.rs

@@ -121,6 +121,37 @@ pub unsafe fn record_os_managed_stack_bounds(stack_lo: uint, _stack_hi: uint) {
     record_sp_limit(stack_lo + RED_ZONE);
 }
 
+#[inline(always)]
+pub unsafe fn record_rust_managed_stack_bounds(stack_lo: uint, stack_hi: uint) {
+    // When the old runtime had segmented stacks, it used a calculation that was
+    // "limit + RED_ZONE + FUDGE". The red zone was for things like dynamic
+    // symbol resolution, llvm function calls, etc. In theory this red zone
+    // value is 0, but it matters far less when we have gigantic stacks because
+    // we don't need to be so exact about our stack budget. The "fudge factor"
+    // was because LLVM doesn't emit a stack check for functions < 256 bytes in
+    // size. Again though, we have giant stacks, so we round all these
+    // calculations up to the nice round number of 20k.
+    record_sp_limit(stack_lo + RED_ZONE);
+
+    return target_record_stack_bounds(stack_lo, stack_hi);
+
+    #[cfg(not(windows))] #[inline(always)]
+    unsafe fn target_record_stack_bounds(_stack_lo: uint, _stack_hi: uint) {}
+
+    #[cfg(all(windows, target_arch = "x86"))] #[inline(always)]
+    unsafe fn target_record_stack_bounds(stack_lo: uint, stack_hi: uint) {
+        // stack range is at TIB: %fs:0x04 (top) and %fs:0x08 (bottom)
+        asm!("mov $0, %fs:0x04" :: "r"(stack_hi) :: "volatile");
+        asm!("mov $0, %fs:0x08" :: "r"(stack_lo) :: "volatile");
+    }
+    #[cfg(all(windows, target_arch = "x86_64"))] #[inline(always)]
+    unsafe fn target_record_stack_bounds(stack_lo: uint, stack_hi: uint) {
+        // stack range is at TIB: %gs:0x08 (top) and %gs:0x10 (bottom)
+        asm!("mov $0, %gs:0x08" :: "r"(stack_hi) :: "volatile");
+        asm!("mov $0, %gs:0x10" :: "r"(stack_lo) :: "volatile");
+    }
+}
+
 /// Records the current limit of the stack as specified by `end`.
 ///
 /// This is stored in an OS-dependent location, likely inside of the thread

src/libstd/sys/common/thread_info.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(dead_code)] // stack_guard isn't used right now on all platforms
-
 use core::prelude::*;
 
 use thread::Thread;
@@ -17,6 +15,10 @@
 use string::String;
 
 struct ThreadInfo {
+    // This field holds the known bounds of the stack in (lo, hi)
+    // form. Not all threads necessarily know their precise bounds,
+    // hence this is optional.
+    stack_bounds: (uint, uint),
     stack_guard: uint,
     thread: Thread,
 }
@@ -33,6 +35,7 @@ fn with<R>(f: |&mut ThreadInfo| -> R) -> R {
         THREAD_INFO.with(|c| {
             if c.borrow().is_none() {
                 *c.borrow_mut() = Some(ThreadInfo {
+                    stack_bounds: (0, 0),
                     stack_guard: 0,
                     thread: NewThread::new(None),
                 })
@@ -50,9 +53,10 @@ pub fn stack_guard() -> uint {
     ThreadInfo::with(|info| info.stack_guard)
 }
 
-pub fn set(stack_guard: uint, thread: Thread) {
+pub fn set(stack_bounds: (uint, uint), stack_guard: uint, thread: Thread) {
     THREAD_INFO.with(|c| assert!(c.borrow().is_none()));
     THREAD_INFO.with(move |c| *c.borrow_mut() = Some(ThreadInfo{
+        stack_bounds: stack_bounds,
         stack_guard: stack_guard,
         thread: thread,
     }));

src/libstd/sys/common/thread_local.rs

@@ -55,11 +55,11 @@
 //! ```
 
 #![allow(non_camel_case_types)]
-#![allow(dead_code)] // sys isn't exported yet
 
 use prelude::*;
 
 use sync::atomic::{mod, AtomicUint};
+use sync::{Mutex, Once, ONCE_INIT};
 
 use sys::thread_local as imp;
 
@@ -140,6 +140,9 @@ pub struct Key {
     key: atomic::INIT_ATOMIC_UINT,
 };
 
+static INIT_KEYS: Once = ONCE_INIT;
+static mut KEYS: *mut Mutex<Vec<imp::Key>> = 0 as *mut _;
+
 impl StaticKey {
     /// Gets the value associated with this TLS key
     ///

src/libstd/sys/unix/backtrace.rs

@@ -83,12 +83,12 @@
 /// to symbols. This is a bit of a hokey implementation as-is, but it works for
 /// all unix platforms we support right now, so it at least gets the job done.
 
-use prelude::*;
-
 use c_str::CString;
-use io::IoResult;
+use io::{IoResult, Writer};
 use libc;
 use mem;
+use option::Option::{mod, Some, None};
+use result::Result::{Ok, Err};
 use sync::{StaticMutex, MUTEX_INIT};
 
 use sys_common::backtrace::*;
@@ -151,7 +151,7 @@ struct Context<'a> {
     // I/O done here is blocking I/O, not green I/O, so we don't have to
     // worry about this being a native vs green mutex.
     static LOCK: StaticMutex = MUTEX_INIT;
-    let _g = LOCK.lock();
+    let _g = unsafe { LOCK.lock() };
 
     try!(writeln!(w, "stack backtrace:"));
 
@@ -241,8 +241,12 @@ fn dladdr(addr: *const libc::c_void,
 
 #[cfg(not(any(target_os = "macos", target_os = "ios")))]
 fn print(w: &mut Writer, idx: int, addr: *mut libc::c_void) -> IoResult<()> {
+    use iter::{Iterator, IteratorExt};
     use os;
+    use path::GenericPath;
+    use ptr::PtrExt;
     use ptr;
+    use slice::SliceExt;
 
     ////////////////////////////////////////////////////////////////////////
     // libbacktrace.h API

src/libstd/sys/unix/mod.rs

@@ -10,14 +10,30 @@
 
 #![allow(missing_docs)]
 #![allow(non_camel_case_types)]
+#![allow(unused_imports)]
+#![allow(dead_code)]
+#![allow(unused_unsafe)]
+#![allow(unused_mut)]
 
 extern crate libc;
 
+use num;
 use num::{Int, SignedInt};
 use prelude::*;
 use io::{mod, IoResult, IoError};
 use sys_common::mkerr_libc;
 
+macro_rules! helper_init { (static $name:ident: Helper<$m:ty>) => (
+    static $name: Helper<$m> = Helper {
+        lock: ::sync::MUTEX_INIT,
+        cond: ::sync::CONDVAR_INIT,
+        chan: ::cell::UnsafeCell { value: 0 as *mut Sender<$m> },
+        signal: ::cell::UnsafeCell { value: 0 },
+        initialized: ::cell::UnsafeCell { value: false },
+        shutdown: ::cell::UnsafeCell { value: false },
+    };
+) }
+
 pub mod backtrace;
 pub mod c;
 pub mod ext;

src/libstd/sys/unix/mutex.rs

@@ -11,6 +11,7 @@
 use cell::UnsafeCell;
 use kinds::Sync;
 use sys::sync as ffi;
+use sys_common::mutex;
 
 pub struct Mutex { inner: UnsafeCell<ffi::pthread_mutex_t> }
 
@@ -25,7 +26,6 @@ pub unsafe fn raw(m: &Mutex) -> *mut ffi::pthread_mutex_t {
 
 unsafe impl Sync for Mutex {}
 
-#[allow(dead_code)] // sys isn't exported yet
 impl Mutex {
     #[inline]
     pub unsafe fn new() -> Mutex {

src/libstd/sys/unix/os.rs

@@ -10,16 +10,17 @@
 
 //! Implementation of `std::os` functionality for unix systems
 
-#![allow(unused_imports)] // lots of cfg code here
-
 use prelude::*;
 
+use error::{FromError, Error};
+use fmt;
 use io::{IoError, IoResult};
-use libc::{mod, c_int, c_char};
-use os;
+use libc::{mod, c_int, c_char, c_void};
 use path::BytesContainer;
 use ptr;
+use sync::atomic::{AtomicInt, INIT_ATOMIC_INT, SeqCst};
 use sys::fs::FileDesc;
+use os;
 
 use os::TMPBUF_SZ;
 

src/libstd/sys/unix/pipe.rs

@@ -145,7 +145,7 @@ fn lock_nonblocking(&self) {}
     fn lock_nonblocking<'a>(&'a self) -> Guard<'a> {
         let ret = Guard {
             fd: self.fd(),
-            guard: self.inner.lock.lock().unwrap(),
+            guard: unsafe { self.inner.lock.lock().unwrap() },
         };
         assert!(set_nonblocking(self.fd(), true).is_ok());
         ret

src/libstd/sys/unix/process.rs

@@ -11,7 +11,7 @@
 
 use libc::{mod, pid_t, c_void, c_int};
 use c_str::CString;
-use io::{IoResult, EndOfFile};
+use io::{mod, IoResult, IoError, EndOfFile};
 use mem;
 use os;
 use ptr;
@@ -327,7 +327,7 @@ pub fn wait(&self, deadline: u64) -> IoResult<ProcessExit> {
         // The actual communication between the helper thread and this thread is
         // quite simple, just a channel moving data around.
 
-        HELPER.boot(register_sigchld, waitpid_helper);
+        unsafe { HELPER.boot(register_sigchld, waitpid_helper) }
 
         match self.try_wait() {
             Some(ret) => return Ok(ret),
@@ -335,7 +335,7 @@ pub fn wait(&self, deadline: u64) -> IoResult<ProcessExit> {
         }
 
         let (tx, rx) = channel();
-        HELPER.send(NewChild(self.pid, tx, deadline));
+        unsafe { HELPER.send(NewChild(self.pid, tx, deadline)); }
         return match rx.recv_opt() {
             Ok(e) => Ok(e),
             Err(()) => Err(timeout("wait timed out")),
@@ -419,15 +419,8 @@ fn waitpid_helper(input: libc::c_int,
                             Ok(NewChild(pid, tx, deadline)) => {
                                 active.push((pid, tx, deadline));
                             }
-                            // Once we've been disconnected it means the main
-                            // thread is exiting (at_exit has run). We could
-                            // still have active waiter for other threads, so
-                            // we're just going to drop them all on the floor.
-                            // This means that they won't receive a "you're
-                            // done" message in which case they'll be considered
-                            // as timed out, but more generally errors will
-                            // start propagating.
                             Err(comm::Disconnected) => {
+                                assert!(active.len() == 0);
                                 break 'outer;
                             }
                             Err(comm::Empty) => break,

src/libstd/sys/unix/rwlock.rs

@@ -17,7 +17,6 @@ pub struct RWLock { inner: UnsafeCell<ffi::pthread_rwlock_t> }
     inner: UnsafeCell { value: ffi::PTHREAD_RWLOCK_INITIALIZER },
 };
 
-#[allow(dead_code)] // sys isn't exported yet
 impl RWLock {
     #[inline]
     pub unsafe fn new() -> RWLock {

src/libstd/sys/unix/stack_overflow.rs

@@ -34,6 +34,7 @@ fn drop(&mut self) {
 
 #[cfg(any(target_os = "linux", target_os = "macos"))]
 mod imp {
+    use core::prelude::*;
     use sys_common::stack;
 
     use super::Handler;

src/libstd/sys/unix/tcp.rs

@@ -135,6 +135,10 @@ pub fn accept(&mut self) -> IoResult<TcpStream> {
         Err(sys_common::eof())
     }
 
+    pub fn socket_name(&mut self) -> IoResult<ip::SocketAddr> {
+        net::sockname(self.fd(), libc::getsockname)
+    }
+
     pub fn set_timeout(&mut self, timeout: Option<u64>) {
         self.deadline = timeout.map(|a| sys::timer::now() + a).unwrap_or(0);
     }

src/libstd/sys/unix/timer.rs

@@ -100,7 +100,7 @@ pub fn now() -> u64 {
 fn helper(input: libc::c_int, messages: Receiver<Req>, _: ()) {
     let mut set: c::fd_set = unsafe { mem::zeroed() };
 
-    let fd = FileDesc::new(input, true);
+    let mut fd = FileDesc::new(input, true);
     let mut timeout: libc::timeval = unsafe { mem::zeroed() };
 
     // active timers are those which are able to be selected upon (and it's a
@@ -168,15 +168,8 @@ fn signal(active: &mut Vec<Box<Inner>>,
             1 => {
                 loop {
                     match messages.try_recv() {
-                        // Once we've been disconnected it means the main thread
-                        // is exiting (at_exit has run). We could still have
-                        // active timers for other threads, so we're just going
-                        // to drop them all on the floor. This is all we can
-                        // really do, however, to prevent resource leakage. The
-                        // remaining timers will likely start panicking quickly
-                        // as they attempt to re-use this thread but are
-                        // disallowed to do so.
                         Err(comm::Disconnected) => {
+                            assert!(active.len() == 0);
                             break 'outer;
                         }
 

src/libstd/sys/unix/tty.rs

@@ -43,4 +43,5 @@ pub fn set_raw(&mut self, _raw: bool) -> IoResult<()> {
     pub fn get_winsize(&mut self) -> IoResult<(int, int)> {
         Err(sys_common::unimpl())
     }
+    pub fn isatty(&self) -> bool { false }
 }

src/libstd/sys/windows/backtrace.rs

@@ -7,22 +7,19 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
-
-//! As always, windows has something very different than unix, we mainly want
-//! to avoid having to depend too much on libunwind for windows.
-//!
-//! If you google around, you'll find a fair bit of references to built-in
-//! functions to get backtraces on windows. It turns out that most of these are
-//! in an external library called dbghelp. I was unable to find this library
-//! via `-ldbghelp`, but it is apparently normal to do the `dlopen` equivalent
-//! of it.
-//!
-//! You'll also find that there's a function called CaptureStackBackTrace
-//! mentioned frequently (which is also easy to use), but sadly I didn't have a
-//! copy of that function in my mingw install (maybe it was broken?). Instead,
-//! this takes the route of using StackWalk64 in order to walk the stack.
-
-#![allow(dead_code)] // constants/fields aren't always used on all platforms
+/// As always, windows has something very different than unix, we mainly want
+/// to avoid having to depend too much on libunwind for windows.
+///
+/// If you google around, you'll find a fair bit of references to built-in
+/// functions to get backtraces on windows. It turns out that most of these are
+/// in an external library called dbghelp. I was unable to find this library
+/// via `-ldbghelp`, but it is apparently normal to do the `dlopen` equivalent
+/// of it.
+///
+/// You'll also find that there's a function called CaptureStackBackTrace
+/// mentioned frequently (which is also easy to use), but sadly I didn't have a
+/// copy of that function in my mingw install (maybe it was broken?). Instead,
+/// this takes the route of using StackWalk64 in order to walk the stack.
 
 use c_str::CString;
 use intrinsics;
@@ -297,7 +294,7 @@ pub fn write(w: &mut Writer) -> IoResult<()> {
     // According to windows documentation, all dbghelp functions are
     // single-threaded.
     static LOCK: StaticMutex = MUTEX_INIT;
-    let _g = LOCK.lock();
+    let _g = unsafe { LOCK.lock() };
 
     // Open up dbghelp.dll, we don't link to it explicitly because it can't
     // always be found. Additionally, it's nice having fewer dependencies.

src/libstd/sys/windows/c.rs

@@ -15,6 +15,7 @@
 #![allow(non_camel_case_types)]
 
 use libc;
+use prelude::*;
 
 pub const WSADESCRIPTION_LEN: uint = 256;
 pub const WSASYS_STATUS_LEN: uint = 128;

src/libstd/sys/windows/fs.rs

@@ -10,17 +10,21 @@
 
 //! Blocking Windows-based file I/O
 
+use alloc::arc::Arc;
 use libc::{mod, c_int};
 
-use io;
+use c_str::CString;
 use mem;
-use ptr;
 use sys::os::fill_utf16_buf_and_decode;
+use path;
+use ptr;
+use str;
+use io;
 
 use prelude::*;
 use sys;
 use sys::os;
-use sys_common::{unimpl, mkerr_libc};
+use sys_common::{keep_going, eof, mkerr_libc};
 
 use io::{FilePermission, Write, UnstableFileStat, Open, FileAccess, FileMode};
 use io::{IoResult, IoError, FileStat, SeekStyle};
@@ -441,7 +445,7 @@ pub fn stat(p: &Path) -> IoResult<FileStat> {
 // FIXME: move this to platform-specific modules (for now)?
 pub fn lstat(_p: &Path) -> IoResult<FileStat> {
     // FIXME: implementation is missing
-    Err(unimpl())
+    Err(super::unimpl())
 }
 
 pub fn utime(p: &Path, atime: u64, mtime: u64) -> IoResult<()> {

src/libstd/sys/windows/mod.rs

@@ -11,14 +11,30 @@
 #![allow(missing_docs)]
 #![allow(non_camel_case_types)]
 #![allow(non_snake_case)]
+#![allow(unused_imports)]
+#![allow(dead_code)]
+#![allow(unused_unsafe)]
+#![allow(unused_mut)]
 
 extern crate libc;
 
+use num;
 use mem;
 use prelude::*;
 use io::{mod, IoResult, IoError};
 use sync::{Once, ONCE_INIT};
 
+macro_rules! helper_init { (static $name:ident: Helper<$m:ty>) => (
+    static $name: Helper<$m> = Helper {
+        lock: ::sync::MUTEX_INIT,
+        cond: ::sync::CONDVAR_INIT,
+        chan: ::cell::UnsafeCell { value: 0 as *mut Sender<$m> },
+        signal: ::cell::UnsafeCell { value: 0 },
+        initialized: ::cell::UnsafeCell { value: false },
+        shutdown: ::cell::UnsafeCell { value: false },
+    };
+) }
+
 pub mod backtrace;
 pub mod c;
 pub mod ext;
@@ -164,6 +180,14 @@ pub fn init_net() {
     }
 }
 
+pub fn unimpl() -> IoError {
+    IoError {
+        kind: io::IoUnavailable,
+        desc: "operation is not implemented",
+        detail: None,
+    }
+}
+
 pub fn to_utf16(s: Option<&str>) -> IoResult<Vec<u16>> {
     match s {
         Some(s) => Ok({

src/libstd/sys/windows/os.rs

@@ -15,6 +15,7 @@
 
 use prelude::*;
 
+use fmt;
 use io::{IoResult, IoError};
 use iter::repeat;
 use libc::{c_int, c_void};

src/libstd/sys/windows/pipe.rs

@@ -365,7 +365,7 @@ pub fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> {
         // acquire the lock.
         //
         // See comments in close_read() about why this lock is necessary.
-        let guard = self.inner.lock.lock();
+        let guard = unsafe { self.inner.lock.lock() };
         if self.read_closed() {
             return Err(eof())
         }
@@ -441,7 +441,7 @@ pub fn write(&mut self, buf: &[u8]) -> IoResult<()> {
             // going after we woke up.
             //
             // See comments in close_read() about why this lock is necessary.
-            let guard = self.inner.lock.lock();
+            let guard = unsafe { self.inner.lock.lock() };
             if self.write_closed() {
                 return Err(epipe())
             }
@@ -516,14 +516,14 @@ pub fn close_read(&mut self) -> IoResult<()> {
         // close_read() between steps 1 and 2. By atomically executing steps 1
         // and 2 with a lock with respect to close_read(), we're guaranteed that
         // no thread will erroneously sit in a read forever.
-        let _guard = self.inner.lock.lock();
+        let _guard = unsafe { self.inner.lock.lock() };
         self.inner.read_closed.store(true, atomic::SeqCst);
         self.cancel_io()
     }
 
     pub fn close_write(&mut self) -> IoResult<()> {
         // see comments in close_read() for why this lock is necessary
-        let _guard = self.inner.lock.lock();
+        let _guard = unsafe { self.inner.lock.lock() };
         self.inner.write_closed.store(true, atomic::SeqCst);
         self.cancel_io()
     }

src/libstd/sys/windows/process.rs

@@ -8,24 +8,25 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use prelude::*;
-
-use libc::{pid_t, c_void};
+use libc::{pid_t, c_void, c_int};
 use libc;
 use c_str::CString;
 use io;
 use mem;
 use os;
 use ptr;
-use io::process::{ProcessExit, ExitStatus};
+use prelude::*;
+use io::process::{ProcessExit, ExitStatus, ExitSignal};
 use collections;
 use path::BytesContainer;
 use hash::Hash;
 use io::{IoResult, IoError};
 
-use sys::timer;
+use sys::fs;
+use sys::{mod, retry, c, wouldblock, set_nonblocking, ms_to_timeval, timer};
 use sys::fs::FileDesc;
-use sys_common::{AsInner, timeout};
+use sys_common::helper_thread::Helper;
+use sys_common::{AsInner, mkerr_libc, timeout};
 
 use io::fs::PathExtensions;
 
@@ -120,6 +121,8 @@ pub fn spawn<K, V, C, P>(cfg: &C, in_fd: Option<P>,
         use libc::funcs::extra::msvcrt::get_osfhandle;
 
         use mem;
+        use iter::{Iterator, IteratorExt};
+        use str::StrExt;
 
         if cfg.gid().is_some() || cfg.uid().is_some() {
             return Err(IoError {

src/libstd/sys/windows/stack_overflow.rs

@@ -14,7 +14,7 @@
 use mem;
 use libc;
 use libc::types::os::arch::extra::{LPVOID, DWORD, LONG, BOOL};
-use sys_common::stack;
+use sys_common::{stack, thread_info};
 
 pub struct Handler {
     _data: *mut libc::c_void
@@ -30,6 +30,14 @@ impl Drop for Handler {
     fn drop(&mut self) {}
 }
 
+// get_task_info is called from an exception / signal handler.
+// It returns the guard page of the current task or 0 if that
+// guard page doesn't exist. None is returned if there's currently
+// no local task.
+unsafe fn get_task_guard_page() -> uint {
+    thread_info::stack_guard()
+}
+
 // This is initialized in init() and only read from after
 static mut PAGE_SIZE: uint = 0;
 

src/libstd/sys/windows/tcp.rs

@@ -14,10 +14,11 @@
 use mem;
 use ptr;
 use prelude::*;
-use super::{last_error, last_net_error, sock_t};
+use super::{last_error, last_net_error, retry, sock_t};
 use sync::{Arc, atomic};
+use sys::fs::FileDesc;
 use sys::{mod, c, set_nonblocking, wouldblock, timer};
-use sys_common::{timeout, eof, net};
+use sys_common::{mod, timeout, eof, net};
 
 pub use sys_common::net::TcpStream;
 
@@ -204,6 +205,10 @@ pub fn accept(&mut self) -> IoResult<TcpStream> {
         Err(eof())
     }
 
+    pub fn socket_name(&mut self) -> IoResult<ip::SocketAddr> {
+        net::sockname(self.socket(), libc::getsockname)
+    }
+
     pub fn set_timeout(&mut self, timeout: Option<u64>) {
         self.deadline = timeout.map(|a| timer::now() + a).unwrap_or(0);
     }

src/libstd/sys/windows/thread.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+use core::prelude::*;
+
 use boxed::Box;
 use cmp;
 use mem;

src/libstd/sys/windows/thread_local.rs

@@ -137,9 +137,9 @@ unsafe fn init_dtors() {
     rt::at_exit(move|| {
         DTOR_LOCK.lock();
         let dtors = DTORS;
-        DTORS = 1 as *mut _;
+        DTORS = 0 as *mut _;
         mem::transmute::<_, Box<Vec<(Key, Dtor)>>>(dtors);
-        assert!(DTORS as uint == 1); // can't re-init after destructing
+        assert!(DTORS.is_null()); // can't re-init after destructing
         DTOR_LOCK.unlock();
     });
 }
@@ -147,9 +147,6 @@ unsafe fn init_dtors() {
 unsafe fn register_dtor(key: Key, dtor: Dtor) {
     DTOR_LOCK.lock();
     init_dtors();
-    assert!(DTORS as uint != 0);
-    assert!(DTORS as uint != 1,
-            "cannot create new TLS keys after the main thread has exited");
     (*DTORS).push((key, dtor));
     DTOR_LOCK.unlock();
 }
@@ -157,9 +154,6 @@ unsafe fn register_dtor(key: Key, dtor: Dtor) {
 unsafe fn unregister_dtor(key: Key) -> bool {
     DTOR_LOCK.lock();
     init_dtors();
-    assert!(DTORS as uint != 0);
-    assert!(DTORS as uint != 1,
-            "cannot unregister destructors after the main thread has exited");
     let ret = {
         let dtors = &mut *DTORS;
         let before = dtors.len();
@@ -238,7 +232,6 @@ unsafe fn unregister_dtor(key: Key) -> bool {
     }
 }
 
-#[allow(dead_code)] // not actually dead
 unsafe fn run_dtors() {
     let mut any_run = true;
     for _ in range(0, 5i) {

src/libstd/sys/windows/timer.rs

@@ -26,6 +26,8 @@
 use ptr;
 use comm;
 
+use sys::c;
+use sys::fs::FileDesc;
 use sys_common::helper_thread::Helper;
 use prelude::*;
 use io::IoResult;
@@ -78,10 +80,9 @@ fn helper(input: libc::HANDLE, messages: Receiver<Req>, _: ()) {
                             None => {}
                         }
                     }
-                    // See the comment in unix::timer for why we don't have any
-                    // asserts here and why we're likely just leaving timers on
-                    // the floor as we exit.
                     Err(comm::Disconnected) => {
+                        assert_eq!(objs.len(), 1);
+                        assert_eq!(chans.len(), 0);
                         break 'outer;
                     }
                     Err(..) => break

src/libstd/sys/windows/tty.rs

@@ -26,6 +26,7 @@
 //! to working in raw UTF-16, with such a wrapper around it.
 
 use super::c::{ReadConsoleW, WriteConsoleW, GetConsoleMode, SetConsoleMode};
+use super::c::{ERROR_ILLEGAL_CHARACTER};
 use super::c::{ENABLE_ECHO_INPUT, ENABLE_EXTENDED_FLAGS};
 use super::c::{ENABLE_INSERT_MODE, ENABLE_LINE_INPUT};
 use super::c::{ENABLE_PROCESSED_INPUT, ENABLE_QUICK_EDIT_MODE};
@@ -38,8 +39,6 @@
 use ptr;
 use str::from_utf8;
 
-use sys_common::unimpl;
-
 fn invalid_encoding() -> IoError {
     IoError {
         kind: io::InvalidInput,
@@ -151,8 +150,11 @@ pub fn get_winsize(&mut self) -> IoResult<(int, int)> {
         // Make a CONSOLE_SCREEN_BUFFER_INFO
         // Call GetConsoleScreenBufferInfo
         // Maybe call GetLargestConsoleWindowSize instead?
-        Err(unimpl())
+        Err(super::unimpl())
     }
+
+    // Let us magically declare this as a TTY
+    pub fn isatty(&self) -> bool { true }
 }
 
 impl Drop for TTY {

src/libstd/thread.rs

@@ -232,10 +232,13 @@ fn spawn_inner<T: Send>(self, f: Thunk<(), T>) -> JoinGuard<T> {
             let my_stack_top = addr as uint;
             let my_stack_bottom = my_stack_top - stack_size + 1024;
             unsafe {
-                stack::record_os_managed_stack_bounds(my_stack_bottom,
-                                                      my_stack_top);
-                thread_info::set(imp::guard::current(), their_thread);
+                stack::record_os_managed_stack_bounds(my_stack_bottom, my_stack_top);
             }
+            thread_info::set(
+                (my_stack_bottom, my_stack_top),
+                unsafe { imp::guard::current() },
+                their_thread
+            );
 
             let mut output = None;
             let f: Thunk<(), T> = if stdout.is_some() || stderr.is_some() {