Runtime removal: refactor helper threads

This patch continues the runtime removal by moving
libnative::io::helper_thread into sys::helper_signal and
sys_common::helper_thread

Because this eliminates APIs in `libnative` and `librustrt`, it is a:

[breaking-change]

This functionality is likely to be available publicly, in some form,
from `std` in the future.

src/libnative/io/mod.rs

@@ -32,8 +32,6 @@ use std::num;
 // Local re-exports
 pub use self::process::Process;
 
-mod helper_thread;
-
 // Native I/O implementations
 pub mod process;
 mod util;

src/libstd/sys/common/helper_thread.rs

@@ -22,14 +22,15 @@
 
 #![macro_escape]
 
-use std::cell::UnsafeCell;
-use std::mem;
-use std::rt::bookkeeping;
-use std::rt::mutex::StaticNativeMutex;
-use std::rt;
-use std::task::TaskBuilder;
+use mem;
+use rt::bookkeeping;
+use rt::mutex::StaticNativeMutex;
+use rt;
+use cell::UnsafeCell;
+use sys::helper_signal;
+use prelude::*;
 
-use NativeTaskBuilder;
+use task;
 
 /// A structure for management of a helper thread.
 ///
@@ -77,17 +78,17 @@ impl<M: Send> Helper<M> {
     /// This function is safe to be called many times.
     pub fn boot<T: Send>(&'static self,
                          f: || -> T,
-                         helper: fn(imp::signal, Receiver<M>, T)) {
+                         helper: fn(helper_signal::signal, Receiver<M>, T)) {
         unsafe {
             let _guard = self.lock.lock();
             if !*self.initialized.get() {
                 let (tx, rx) = channel();
                 *self.chan.get() = mem::transmute(box tx);
-                let (receive, send) = imp::new();
+                let (receive, send) = helper_signal::new();
                 *self.signal.get() = send as uint;
 
                 let t = f();
-                TaskBuilder::new().native().spawn(proc() {
+                task::spawn(proc() {
                     bookkeeping::decrement();
                     helper(receive, rx, t);
                     self.lock.lock().signal()
@@ -111,7 +112,7 @@ impl<M: Send> Helper<M> {
             // send the message.
             assert!(!self.chan.get().is_null());
             (**self.chan.get()).send(msg);
-            imp::signal(*self.signal.get() as imp::signal);
+            helper_signal::signal(*self.signal.get() as helper_signal::signal);
         }
     }
 
@@ -126,7 +127,7 @@ impl<M: Send> Helper<M> {
             let chan: Box<Sender<M>> = mem::transmute(*self.chan.get());
             *self.chan.get() = 0 as *mut Sender<M>;
             drop(chan);
-            imp::signal(*self.signal.get() as imp::signal);
+            helper_signal::signal(*self.signal.get() as helper_signal::signal);
 
             // Wait for the child to exit
             guard.wait();
@@ -134,64 +135,8 @@ impl<M: Send> Helper<M> {
 
             // Clean up after ourselves
             self.lock.destroy();
-            imp::close(*self.signal.get() as imp::signal);
+            helper_signal::close(*self.signal.get() as helper_signal::signal);
             *self.signal.get() = 0;
         }
     }
 }
-
-#[cfg(unix)]
-mod imp {
-    use libc;
-    use std::os;
-
-    use io::file::FileDesc;
-
-    pub type signal = libc::c_int;
-
-    pub fn new() -> (signal, signal) {
-        let os::Pipe { reader, writer } = unsafe { os::pipe().unwrap() };
-        (reader, writer)
-    }
-
-    pub fn signal(fd: libc::c_int) {
-        FileDesc::new(fd, false).inner_write([0]).ok().unwrap();
-    }
-
-    pub fn close(fd: libc::c_int) {
-        let _fd = FileDesc::new(fd, true);
-    }
-}
-
-#[cfg(windows)]
-mod imp {
-    use libc::{BOOL, LPCSTR, HANDLE, LPSECURITY_ATTRIBUTES, CloseHandle};
-    use std::ptr;
-    use libc;
-
-    pub type signal = HANDLE;
-
-    pub fn new() -> (HANDLE, HANDLE) {
-        unsafe {
-            let handle = CreateEventA(ptr::null_mut(), libc::FALSE, libc::FALSE,
-                                      ptr::null());
-            (handle, handle)
-        }
-    }
-
-    pub fn signal(handle: HANDLE) {
-        assert!(unsafe { SetEvent(handle) != 0 });
-    }
-
-    pub fn close(handle: HANDLE) {
-        assert!(unsafe { CloseHandle(handle) != 0 });
-    }
-
-    extern "system" {
-        fn CreateEventA(lpSecurityAttributes: LPSECURITY_ATTRIBUTES,
-                        bManualReset: BOOL,
-                        bInitialState: BOOL,
-                        lpName: LPCSTR) -> HANDLE;
-        fn SetEvent(hEvent: HANDLE) -> BOOL;
-    }
-}

src/libstd/sys/common/mod.rs

@@ -20,6 +20,7 @@ use path::BytesContainer;
 use collections;
 
 pub mod net;
+pub mod helper_thread;
 
 // common error constructors
 

src/libstd/sys/common/net.rs

@@ -24,6 +24,8 @@ use prelude::*;
 use cmp;
 use io;
 
+// FIXME: move uses of Arc and deadline tracking to std::io
+
 #[deriving(Show)]
 pub enum SocketStatus {
     Readable,

src/libstd/sys/unix/helper_signal.rs

@@ -0,0 +1,29 @@
+// Copyright 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.
+
+use libc;
+use os;
+
+use sys::fs::FileDesc;
+
+pub type signal = libc::c_int;
+
+pub fn new() -> (signal, signal) {
+    let os::Pipe { reader, writer } = unsafe { os::pipe().unwrap() };
+    (reader, writer)
+}
+
+pub fn signal(fd: libc::c_int) {
+    FileDesc::new(fd, false).write([0]).ok().unwrap();
+}
+
+pub fn close(fd: libc::c_int) {
+    let _fd = FileDesc::new(fd, true);
+}

src/libstd/sys/unix/mod.rs

@@ -17,12 +17,23 @@ 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: ::rt::mutex::NATIVE_MUTEX_INIT,
+        chan: ::cell::UnsafeCell { value: 0 as *mut Sender<$m> },
+        signal: ::cell::UnsafeCell { value: 0 },
+        initialized: ::cell::UnsafeCell { value: false },
+    };
+) )
+
 pub mod c;
 pub mod fs;
 pub mod os;
 pub mod tcp;
 pub mod udp;
 pub mod pipe;
+pub mod helper_signal;
 
 pub mod addrinfo {
     pub use sys_common::net::get_host_addresses;

src/libstd/sys/windows/helper_signal.rs

@@ -0,0 +1,38 @@
+// Copyright 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.
+
+use libc::{mod, BOOL, LPCSTR, HANDLE, LPSECURITY_ATTRIBUTES, CloseHandle};
+use ptr;
+
+pub type signal = HANDLE;
+
+pub fn new() -> (HANDLE, HANDLE) {
+    unsafe {
+        let handle = CreateEventA(ptr::null_mut(), libc::FALSE, libc::FALSE,
+                                  ptr::null());
+        (handle, handle)
+    }
+}
+
+pub fn signal(handle: HANDLE) {
+    assert!(unsafe { SetEvent(handle) != 0 });
+}
+
+pub fn close(handle: HANDLE) {
+    assert!(unsafe { CloseHandle(handle) != 0 });
+}
+
+extern "system" {
+    fn CreateEventA(lpSecurityAttributes: LPSECURITY_ATTRIBUTES,
+                    bManualReset: BOOL,
+                    bInitialState: BOOL,
+                    lpName: LPCSTR) -> HANDLE;
+    fn SetEvent(hEvent: HANDLE) -> BOOL;
+}

src/libstd/sys/windows/mod.rs

@@ -39,6 +39,7 @@ pub mod os;
 pub mod tcp;
 pub mod udp;
 pub mod pipe;
+pub mod helper_signal;
 
 pub mod addrinfo {
     pub use sys_common::net::get_host_addresses;