auto merge of #6577 : brson/rust/io-upstream, r=pcwalton

r?

This is all of my scheduler work on #4419 from the last 3 weeks or so. I've had a few failed pull requests so far but I think the problems are ironed out.

* TCP
* The beginnings of runtime embedding APIs
* Porting various corners of core to be compatible with both schedulers
* libuv timer bindings
* Further refinement of I/O error handling, including a new, incomplete, `read_error` condition
* Incomplete refactoring to make tasks work without coroutines and user-space scheduling
* Implementations of Reader/Writer extension methods
* Implementations of the most important part of core::comm

I'm particularly happy with how easy the [comm types on top of the scheduler](https://github.com/brson/rust/blob/io-upstream/src/libcore/rt/comm.rs). Note that these implementations do not use pipes. If anything here needs careful review though it's this code.

This branch passes 95% of the run-pass tests (with `TESTARGS=--newrt`)

In the next week I'll probably spend some time adding preliminary multithreading and seeing how close we are to removing the old runtime.

Author: bors

src/libcore/comm.rs

@@ -205,8 +205,11 @@ mod unicode;
 #[path = "num/cmath.rs"]
 mod cmath;
 mod stackwalk;
+
+// XXX: This shouldn't be pub, and it should be reexported under 'unstable'
+// but name resolution doesn't work without it being pub.
 #[path = "rt/mod.rs"]
-mod rt;
+pub mod rt;
 
 // A curious inner-module that's not exported that contains the binding
 // 'core' so that macro-expanded references to core::error and such

src/libcore/core.rc

@@ -10,17 +10,16 @@
 
 //! Logging
 
-pub mod rustrt {
-    use libc;
-
-    pub extern {
-        unsafe fn rust_log_console_on();
-        unsafe fn rust_log_console_off();
-        unsafe fn rust_log_str(level: u32,
-                               string: *libc::c_char,
-                               size: libc::size_t);
-    }
-}
+use option::*;
+use either::*;
+use rt;
+use rt::logging::{Logger, StdErrLogger};
+use io;
+use libc;
+use repr;
+use vec;
+use cast;
+use str;
 
 /// Turns on logging to stdout globally
 pub fn console_on() {
@@ -55,8 +54,46 @@ pub fn log_type<T>(level: u32, object: &T) {
     let bytes = do io::with_bytes_writer |writer| {
         repr::write_repr(writer, object);
     };
+
+    match rt::context() {
+        rt::OldTaskContext => {
+            unsafe {
+                let len = bytes.len() as libc::size_t;
+                rustrt::rust_log_str(level, cast::transmute(vec::raw::to_ptr(bytes)), len);
+            }
+        }
+        _ => {
+            // XXX: Bad allocation
+            let msg = str::from_bytes(bytes);
+            newsched_log_str(msg);
+        }
+    }
+}
+
+fn newsched_log_str(msg: ~str) {
     unsafe {
-        let len = bytes.len() as libc::size_t;
-        rustrt::rust_log_str(level, transmute(vec::raw::to_ptr(bytes)), len);
+        match rt::local_services::unsafe_try_borrow_local_services() {
+            Some(local) => {
+                // Use the available logger
+                (*local).logger.log(Left(msg));
+            }
+            None => {
+                // There is no logger anywhere, just write to stderr
+                let mut logger = StdErrLogger;
+                logger.log(Left(msg));
+            }
+        }
+    }
+}
+
+pub mod rustrt {
+    use libc;
+
+    pub extern {
+        unsafe fn rust_log_console_on();
+        unsafe fn rust_log_console_off();
+        unsafe fn rust_log_str(level: u32,
+                               string: *libc::c_char,
+                               size: libc::size_t);
     }
 }

src/libcore/logging.rs

@@ -30,10 +30,24 @@ macro_rules! rtdebug (
     ($( $arg:expr),+) => ( $(let _ = $arg)*; )
 )
 
+macro_rules! rtassert (
+    ( $arg:expr ) => ( {
+        if !$arg {
+            abort!("assertion failed: %s", stringify!($arg));
+        }
+    } )
+)
+
 macro_rules! abort(
     ($( $msg:expr),+) => ( {
         rtdebug!($($msg),+);
 
-        unsafe { ::libc::abort(); }
+        do_abort();
+
+        // NB: This is in a fn to avoid putting the `unsafe` block in a macro,
+        // which causes spurious 'unnecessary unsafe block' warnings.
+        fn do_abort() -> ! {
+            unsafe { ::libc::abort(); }
+        }
     } )
 )

src/libcore/macros.rs

@@ -147,23 +147,25 @@ pub mod win32 {
 
 /*
 Accessing environment variables is not generally threadsafe.
-This uses a per-runtime lock to serialize access.
-FIXME #4726: It would probably be appropriate to make this a real global
+Serialize access through a global lock.
 */
 fn with_env_lock<T>(f: &fn() -> T) -> T {
-    use unstable::global::global_data_clone_create;
-    use unstable::sync::{Exclusive, exclusive};
-
-    struct SharedValue(());
-    type ValueMutex = Exclusive<SharedValue>;
-    fn key(_: ValueMutex) { }
+    use unstable::finally::Finally;
 
     unsafe {
-        let lock: ValueMutex = global_data_clone_create(key, || {
-            ~exclusive(SharedValue(()))
-        });
+        return do (|| {
+            rust_take_env_lock();
+            f()
+        }).finally {
+            rust_drop_env_lock();
+        };
+    }
 
-        lock.with_imm(|_| f() )
+    extern {
+        #[fast_ffi]
+        fn rust_take_env_lock();
+        #[fast_ffi]
+        fn rust_drop_env_lock();
     }
 }
 
@@ -749,7 +751,7 @@ pub fn list_dir(p: &Path) -> ~[~str] {
             use os::win32::{
                 as_utf16_p
             };
-            use unstable::exchange_alloc::{malloc_raw, free_raw};
+            use rt::global_heap::{malloc_raw, free_raw};
             #[nolink]
             extern {
                 unsafe fn rust_list_dir_wfd_size() -> libc::size_t;