Local::borrow tweak and basic task pinning.

src/libstd/macros.rs

@@ -38,16 +38,18 @@ macro_rules! rtassert (
     } )
 )
 
+
+// The do_abort function was originally inside the abort macro, but
+// this was ICEing the compiler so it has been moved outside. Now this
+// seems to work?
+pub fn do_abort() -> ! {
+    unsafe { ::libc::abort(); }
+}
+
 macro_rules! abort(
     ($( $msg:expr),+) => ( {
         rtdebug!($($msg),+);
-
-        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(); }
-        }
+        ::macros::do_abort();
     } )
 )
+

src/libstd/rt/comm.rs

@@ -120,13 +120,13 @@ impl<T> ChanOne<T> {
             match oldstate {
                 STATE_BOTH => {
                     // Port is not waiting yet. Nothing to do
-                    do Local::borrow::<Scheduler> |sched| {
+                    do Local::borrow::<Scheduler, ()> |sched| {
                         rtdebug!("non-rendezvous send");
                         sched.metrics.non_rendezvous_sends += 1;
                     }
                 }
                 STATE_ONE => {
-                    do Local::borrow::<Scheduler> |sched| {
+                    do Local::borrow::<Scheduler, ()> |sched| {
                         rtdebug!("rendezvous send");
                         sched.metrics.rendezvous_sends += 1;
                     }

src/libstd/rt/local.rs

@@ -18,7 +18,7 @@ pub trait Local {
     fn put(value: ~Self);
     fn take() -> ~Self;
     fn exists() -> bool;
-    fn borrow(f: &fn(&mut Self));
+    fn borrow<T>(f: &fn(&mut Self) -> T) -> T;
     unsafe fn unsafe_borrow() -> *mut Self;
     unsafe fn try_unsafe_borrow() -> Option<*mut Self>;
 }
@@ -27,7 +27,20 @@ impl Local for Scheduler {
     fn put(value: ~Scheduler) { unsafe { local_ptr::put(value) }}
     fn take() -> ~Scheduler { unsafe { local_ptr::take() } }
     fn exists() -> bool { local_ptr::exists() }
-    fn borrow(f: &fn(&mut Scheduler)) { unsafe { local_ptr::borrow(f) } }
+    fn borrow<T>(f: &fn(&mut Scheduler) -> T) -> T {
+        let mut res: Option<T> = None;
+        let res_ptr: *mut Option<T> = &mut res;
+        unsafe {
+            do local_ptr::borrow |sched| {
+                let result = f(sched);
+                *res_ptr = Some(result);
+            }
+        }
+        match res {
+            Some(r) => { r }
+            None => abort!("function failed!")
+        }
+    }
     unsafe fn unsafe_borrow() -> *mut Scheduler { local_ptr::unsafe_borrow() }
     unsafe fn try_unsafe_borrow() -> Option<*mut Scheduler> { abort!("unimpl") }
 }
@@ -36,8 +49,8 @@ impl Local for Task {
     fn put(_value: ~Task) { abort!("unimpl") }
     fn take() -> ~Task { abort!("unimpl") }
     fn exists() -> bool { abort!("unimpl") }
-    fn borrow(f: &fn(&mut Task)) {
-        do Local::borrow::<Scheduler> |sched| {
+    fn borrow<T>(f: &fn(&mut Task) -> T) -> T {
+        do Local::borrow::<Scheduler, T> |sched| {
             match sched.current_task {
                 Some(~ref mut task) => {
                     f(&mut *task.task)
@@ -74,7 +87,7 @@ impl Local for IoFactoryObject {
     fn put(_value: ~IoFactoryObject) { abort!("unimpl") }
     fn take() -> ~IoFactoryObject { abort!("unimpl") }
     fn exists() -> bool { abort!("unimpl") }
-    fn borrow(_f: &fn(&mut IoFactoryObject)) { abort!("unimpl") }
+    fn borrow<T>(_f: &fn(&mut IoFactoryObject) -> T) -> T { abort!("unimpl") }
     unsafe fn unsafe_borrow() -> *mut IoFactoryObject {
         let sched = Local::unsafe_borrow::<Scheduler>();
         let io: *mut IoFactoryObject = (*sched).event_loop.io().unwrap();
@@ -115,4 +128,16 @@ mod test {
         }
         let _scheduler: ~Scheduler = Local::take();
     }
+
+    #[test]
+    fn borrow_with_return() {
+        let scheduler = ~new_test_uv_sched();
+        Local::put(scheduler);
+        let res = do Local::borrow::<Scheduler,bool> |_sched| {
+            true
+        };
+        assert!(res)
+        let _scheduler: ~Scheduler = Local::take();
+    }
+
 }

src/libstd/rt/mod.rs

@@ -208,7 +208,7 @@ pub fn context() -> RuntimeContext {
     } else {
         if Local::exists::<Scheduler>() {
             let context = ::cell::empty_cell();
-            do Local::borrow::<Scheduler> |sched| {
+            do Local::borrow::<Scheduler, ()> |sched| {
                 if sched.in_task_context() {
                     context.put_back(TaskContext);
                 } else {