Auto merge of #25136 - alexcrichton:drop-the-two, r=aturon

* Remove the 2-suffix from some modules
* Remove some unused files
* Remove double-boxing for `ReentrantMutex`

4 files changed, 12 insertions, 178 deletions

diff --git a/src/libstd/sys/common/helper_thread.rs b/src/libstd/sys/common/helper_thread.rs
deleted file mode 100644
index 34a58f6c83a..00000000000
--- a/src/libstd/sys/common/helper_thread.rs
+++ /dev/null
@@ -1,170 +0,0 @@
-// Copyright 2013-2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-//! Implementation of the helper thread for the timer module
-//!
-//! This module contains the management necessary for the timer worker thread.
-//! This thread is responsible for performing the send()s on channels for timers
-//! that are using channels instead of a blocking call.
-//!
-//! The timer thread is lazily initialized, and it's shut down via the
-//! `shutdown` function provided. It must be maintained as an invariant that
-//! `shutdown` is only called when the entire program is finished. No new timers
-//! can be created in the future and there must be no active timers at that
-//! time.
-
-use prelude::v1::*;
-
-use boxed;
-use cell::UnsafeCell;
-use rt;
-use sync::{StaticMutex, StaticCondvar};
-use sync::mpsc::{channel, Sender, Receiver};
-use sys::helper_signal;
-
-use thread;
-
-/// A structure for management of a helper thread.
-///
-/// This is generally a static structure which tracks the lifetime of a helper
-/// thread.
-///
-/// The fields of this helper are all public, but they should not be used, this
-/// is for static initialization.
-pub struct Helper<M:Send> {
-    /// Internal lock which protects the remaining fields
-    pub lock: StaticMutex,
-    pub cond: StaticCondvar,
-
-    // You'll notice that the remaining fields are UnsafeCell<T>, and this is
-    // because all helper thread operations are done through &self, but we need
-    // these to be mutable (once `lock` is held).
-
-    /// Lazily allocated channel to send messages to the helper thread.
-    pub chan: UnsafeCell<*mut Sender<M>>,
-
-    /// OS handle used to wake up a blocked helper thread
-    pub signal: UnsafeCell<usize>,
-
-    /// Flag if this helper thread has booted and been initialized yet.
-    pub initialized: UnsafeCell<bool>,
-
-    /// Flag if this helper thread has shut down
-    pub shutdown: UnsafeCell<bool>,
-}
-
-unsafe impl<M:Send> Send for Helper<M> { }
-
-unsafe impl<M:Send> Sync for Helper<M> { }
-
-struct RaceBox(helper_signal::signal);
-
-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.
-    ///
-    /// This function will check to see if the thread has been initialized, and
-    /// if it has it returns quickly. If initialization has not happened yet,
-    /// the closure `f` will be run (inside of the initialization lock) and
-    /// passed to the helper thread in a separate task.
-    ///
-    /// This function is safe to be called many times.
-    pub fn boot<T, F>(&'static self, f: F, helper: fn(helper_signal::signal, Receiver<M>, T)) where
-        T: Send + 'static,
-        F: FnOnce() -> T,
-    {
-        unsafe {
-            let _guard = self.lock.lock().unwrap();
-            if *self.chan.get() as usize == 0 {
-                let (tx, rx) = channel();
-                *self.chan.get() = boxed::into_raw(box tx);
-                let (receive, send) = helper_signal::new();
-                *self.signal.get() = send as usize;
-
-                let receive = RaceBox(receive);
-
-                let t = f();
-                thread::spawn(move || {
-                    helper(receive.0, rx, t);
-                    let _g = self.lock.lock().unwrap();
-                    *self.shutdown.get() = true;
-                    self.cond.notify_one()
-                });
-
-                let _ = rt::at_exit(move || { self.shutdown() });
-                *self.initialized.get() = true;
-            } else if *self.chan.get() as usize == 1 {
-                panic!("cannot continue usage after shutdown");
-            }
-        }
-    }
-
-    /// Sends a message to a spawned worker thread.
-    ///
-    /// This is only valid if the worker thread has previously booted
-    pub fn send(&'static self, msg: M) {
-        unsafe {
-            let _guard = self.lock.lock().unwrap();
-
-            // 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 usize != 0);
-            assert!(*self.chan.get() as usize != 1,
-                    "cannot continue usage after shutdown");
-            (**self.chan.get()).send(msg).unwrap();
-            helper_signal::signal(*self.signal.get() as helper_signal::signal);
-        }
-    }
-
-    fn shutdown(&'static self) {
-        unsafe {
-            // Shut down, but make sure this is done inside our lock to ensure
-            // that we'll always receive the exit signal when the thread
-            // returns.
-            let mut guard = self.lock.lock().unwrap();
-
-            let ptr = *self.chan.get();
-            if ptr as usize == 1 {
-                panic!("cannot continue usage after shutdown");
-            }
-            // Close the channel by destroying it
-            let chan = Box::from_raw(*self.chan.get());
-            *self.chan.get() = 1 as *mut Sender<M>;
-            drop(chan);
-            helper_signal::signal(*self.signal.get() as helper_signal::signal);
-
-            // Wait for the child to exit
-            while !*self.shutdown.get() {
-                guard = self.cond.wait(guard).unwrap();
-            }
-            drop(guard);
-
-            // Clean up after ourselves
-            self.lock.destroy();
-            helper_signal::close(*self.signal.get() as helper_signal::signal);
-            *self.signal.get() = 0;
-        }
-    }
-}
diff --git a/src/libstd/sys/common/mod.rs b/src/libstd/sys/common/mod.rs
index 95294b813ea..b528575bbed 100644
--- a/src/libstd/sys/common/mod.rs
+++ b/src/libstd/sys/common/mod.rs
@@ -15,7 +15,7 @@ use prelude::v1::*;
 pub mod backtrace;
 pub mod condvar;
 pub mod mutex;
-pub mod net2;
+pub mod net;
 pub mod poison;
 pub mod remutex;
 pub mod rwlock;
diff --git a/src/libstd/sys/common/net2.rs b/src/libstd/sys/common/net.rs
index 7da7071670a..7da7071670a 100644
--- a/src/libstd/sys/common/net2.rs
+++ b/src/libstd/sys/common/net.rs
diff --git a/src/libstd/sys/common/remutex.rs b/src/libstd/sys/common/remutex.rs
index 48c74b8d89e..1a467580672 100644
--- a/src/libstd/sys/common/remutex.rs
+++ b/src/libstd/sys/common/remutex.rs
@@ -19,9 +19,9 @@ use sys::mutex as sys;
 
 /// A re-entrant mutual exclusion
 ///
-/// This mutex will block *other* threads waiting for the lock to become available. The thread
-/// which has already locked the mutex can lock it multiple times without blocking, preventing a
-/// common source of deadlocks.
+/// This mutex will block *other* threads waiting for the lock to become
+/// available. The thread which has already locked the mutex can lock it
+/// multiple times without blocking, preventing a common source of deadlocks.
 pub struct ReentrantMutex<T> {
     inner: Box<sys::ReentrantMutex>,
     poison: poison::Flag,
@@ -51,10 +51,14 @@ impl<'a, T> !marker::Send for ReentrantMutexGuard<'a, T> {}
 impl<T> ReentrantMutex<T> {
     /// Creates a new reentrant mutex in an unlocked state.
     pub fn new(t: T) -> ReentrantMutex<T> {
-        ReentrantMutex {
-            inner: box unsafe { sys::ReentrantMutex::new() },
-            poison: poison::FLAG_INIT,
-            data: t,
+        unsafe {
+            let mut mutex = ReentrantMutex {
+                inner: box sys::ReentrantMutex::uninitialized(),
+                poison: poison::FLAG_INIT,
+                data: t,
+            };
+            mutex.inner.init();
+            return mutex
         }
     }