Reserve 'yield' keyword

Rename task::yield() to task::deschedule().

Fixes #8494.

Author: lilyball

src/libextra/arc.rs

@@ -762,7 +762,7 @@ mod tests {
                 do 10.times {
                     let tmp = *num;
                     *num = -1;
-                    task::yield();
+                    task::deschedule();
                     *num = tmp + 1;
                 }
                 c.send(());
@@ -913,17 +913,17 @@ mod tests {
             do read_mode.read |state| {
                 // if writer mistakenly got in, make sure it mutates state
                 // before we assert on it
-                do 5.times { task::yield(); }
+                do 5.times { task::deschedule(); }
                 // make sure writer didn't get in.
                 assert!(*state);
             }
         }
     }
     #[test]
     fn test_rw_write_cond_downgrade_read_race() {
-        // Ideally the above test case would have yield statements in it that
+        // Ideally the above test case would have deschedule statements in it that
         // helped to expose the race nearly 100% of the time... but adding
-        // yields in the intuitively-right locations made it even less likely,
+        // deschedules in the intuitively-right locations made it even less likely,
         // and I wasn't sure why :( . This is a mediocre "next best" option.
         do 8.times { test_rw_write_cond_downgrade_read_race_helper() }
     }

src/libextra/sync.rs

@@ -112,7 +112,7 @@ impl<Q:Send> Sem<Q> {
                 }
             }
             // Uncomment if you wish to test for sem races. Not valgrind-friendly.
-            /* do 1000.times { task::yield(); } */
+            /* do 1000.times { task::deschedule(); } */
             // Need to wait outside the exclusive.
             if waiter_nobe.is_some() {
                 let _ = waiter_nobe.unwrap().recv();
@@ -225,7 +225,7 @@ impl<'self> Condvar<'self> {
                 }
             }
 
-            // If yield checks start getting inserted anywhere, we can be
+            // If deschedule checks start getting inserted anywhere, we can be
             // killed before or after enqueueing. Deciding whether to
             // unkillably reacquire the lock needs to happen atomically
             // wrt enqueuing.
@@ -731,11 +731,11 @@ mod tests {
         let s2 = ~s.clone();
         do task::spawn || {
             do s2.access {
-                do 5.times { task::yield(); }
+                do 5.times { task::deschedule(); }
             }
         }
         do s.access {
-            do 5.times { task::yield(); }
+            do 5.times { task::deschedule(); }
         }
     }
     #[test]
@@ -748,7 +748,7 @@ mod tests {
             s2.acquire();
             c.send(());
         }
-        do 5.times { task::yield(); }
+        do 5.times { task::deschedule(); }
         s.release();
         let _ = p.recv();
 
@@ -757,7 +757,7 @@ mod tests {
         let s = ~Semaphore::new(0);
         let s2 = ~s.clone();
         do task::spawn || {
-            do 5.times { task::yield(); }
+            do 5.times { task::deschedule(); }
             s2.release();
             let _ = p.recv();
         }
@@ -800,7 +800,7 @@ mod tests {
                     c.send(());
                 }
                 let _ = p.recv(); // wait for child to come alive
-                do 5.times { task::yield(); } // let the child contend
+                do 5.times { task::deschedule(); } // let the child contend
             }
             let _ = p.recv(); // wait for child to be done
         }
@@ -837,7 +837,7 @@ mod tests {
             do n.times {
                 do m.lock {
                     let oldval = *sharedstate;
-                    task::yield();
+                    task::deschedule();
                     *sharedstate = oldval + 1;
                 }
             }
@@ -948,7 +948,7 @@ mod tests {
             let (p,c) = comm::stream();
             do task::spawn || { // linked
                 let _ = p.recv(); // wait for sibling to get in the mutex
-                task::yield();
+                task::deschedule();
                 fail!();
             }
             do m2.lock_cond |cond| {
@@ -1114,7 +1114,7 @@ mod tests {
             do n.times {
                 do lock_rwlock_in_mode(x, mode) {
                     let oldval = *sharedstate;
-                    task::yield();
+                    task::deschedule();
                     *sharedstate = oldval + 1;
                 }
             }

src/libstd/rt/kill.rs

@@ -141,7 +141,7 @@ pub struct Death {
     on_exit:         Option<~fn(bool)>,
     // nesting level counter for task::unkillable calls (0 == killable).
     unkillable:      int,
-    // nesting level counter for unstable::atomically calls (0 == can yield).
+    // nesting level counter for unstable::atomically calls (0 == can deschedule).
     wont_sleep:      int,
     // A "spare" handle to the kill flag inside the kill handle. Used during
     // blocking/waking as an optimization to avoid two xadds on the refcount.
@@ -572,16 +572,16 @@ impl Death {
     }
 
     /// Enter a possibly-nested "atomic" section of code. Just for assertions.
-    /// All calls must be paired with a subsequent call to allow_yield.
+    /// All calls must be paired with a subsequent call to allow_deschedule.
     #[inline]
-    pub fn inhibit_yield(&mut self) {
+    pub fn inhibit_deschedule(&mut self) {
         self.wont_sleep += 1;
     }
 
     /// Exit a possibly-nested "atomic" section of code. Just for assertions.
-    /// All calls must be paired with a preceding call to inhibit_yield.
+    /// All calls must be paired with a preceding call to inhibit_deschedule.
     #[inline]
-    pub fn allow_yield(&mut self) {
+    pub fn allow_deschedule(&mut self) {
         rtassert!(self.wont_sleep != 0);
         self.wont_sleep -= 1;
     }

src/libstd/select.rs

@@ -250,7 +250,7 @@ mod test {
                     let (c2, p3, c4) = x.take();
                     p3.recv();   // handshake parent
                     c4.send(()); // normal receive
-                    task::yield();
+                    task::deschedule();
                     c2.send(()); // select receive
                 }
 
@@ -294,7 +294,7 @@ mod test {
                             if send_on_chans.contains(&i) {
                                 let c = Cell::new(c);
                                 do spawntask_random {
-                                    task::yield();
+                                    task::deschedule();
                                     c.take().send(());
                                 }
                             }

src/libstd/task/mod.rs

@@ -537,7 +537,7 @@ pub fn with_task_name<U>(blk: &fn(Option<&str>) -> U) -> U {
     }
 }
 
-pub fn yield() {
+pub fn deschedule() {
     //! Yield control to the task scheduler
 
     use rt::local::Local;
@@ -568,10 +568,10 @@ pub fn failing() -> bool {
  *
  * ~~~
  * do task::unkillable {
- *     // detach / yield / destroy must all be called together
+ *     // detach / deschedule / destroy must all be called together
  *     rustrt::rust_port_detach(po);
  *     // This must not result in the current task being killed
- *     task::yield();
+ *     task::deschedule();
  *     rustrt::rust_port_destroy(po);
  * }
  * ~~~
@@ -689,7 +689,7 @@ fn test_spawn_unlinked_unsup_no_fail_down() { // grandchild sends on a port
             let ch = ch.clone();
             do spawn_unlinked {
                 // Give middle task a chance to fail-but-not-kill-us.
-                do 16.times { task::yield(); }
+                do 16.times { task::deschedule(); }
                 ch.send(()); // If killed first, grandparent hangs.
             }
             fail!(); // Shouldn't kill either (grand)parent or (grand)child.
@@ -712,7 +712,7 @@ fn test_spawn_unlinked_sup_no_fail_up() { // child unlinked fails
     do run_in_newsched_task {
         do spawn_supervised { fail!(); }
         // Give child a chance to fail-but-not-kill-us.
-        do 16.times { task::yield(); }
+        do 16.times { task::deschedule(); }
     }
 }
 #[ignore(reason = "linked failure")]
@@ -821,7 +821,7 @@ fn test_spawn_failure_propagate_grandchild() {
             do spawn_supervised {
                 do spawn_supervised { block_forever(); }
             }
-            do 16.times { task::yield(); }
+            do 16.times { task::deschedule(); }
             fail!();
         };
         assert!(result.is_err());
@@ -838,7 +838,7 @@ fn test_spawn_failure_propagate_secondborn() {
             do spawn_supervised {
                 do spawn { block_forever(); } // linked
             }
-            do 16.times { task::yield(); }
+            do 16.times { task::deschedule(); }
             fail!();
         };
         assert!(result.is_err());
@@ -855,7 +855,7 @@ fn test_spawn_failure_propagate_nephew_or_niece() {
             do spawn { // linked
                 do spawn_supervised { block_forever(); }
             }
-            do 16.times { task::yield(); }
+            do 16.times { task::deschedule(); }
             fail!();
         };
         assert!(result.is_err());
@@ -872,7 +872,7 @@ fn test_spawn_linked_sup_propagate_sibling() {
             do spawn { // linked
                 do spawn { block_forever(); } // linked
             }
-            do 16.times { task::yield(); }
+            do 16.times { task::deschedule(); }
             fail!();
         };
         assert!(result.is_err());
@@ -1169,12 +1169,12 @@ fn test_unkillable() {
 
     // We want to do this after failing
     do spawn_unlinked {
-        do 10.times { yield() }
+        do 10.times { deschedule() }
         ch.send(());
     }
 
     do spawn {
-        yield();
+        deschedule();
         // We want to fail after the unkillable task
         // blocks on recv
         fail!();
@@ -1205,12 +1205,12 @@ fn test_unkillable_nested() {
 
     // We want to do this after failing
     do spawn_unlinked || {
-        do 10.times { yield() }
+        do 10.times { deschedule() }
         ch.send(());
     }
 
     do spawn {
-        yield();
+        deschedule();
         // We want to fail after the unkillable task
         // blocks on recv
         fail!();
@@ -1277,7 +1277,7 @@ fn test_spawn_watched() {
                 t.unlinked();
                 t.watched();
                 do t.spawn {
-                    task::yield();
+                    task::deschedule();
                     fail!();
                 }
             }
@@ -1313,7 +1313,7 @@ fn test_indestructible() {
                 t.unwatched();
                 do t.spawn {
                     p3.recv();
-                    task::yield();
+                    task::deschedule();
                     fail!();
                 }
                 c3.send(());

src/libstd/unstable/sync.rs

@@ -272,9 +272,9 @@ impl<T> Drop for UnsafeAtomicRcBox<T>{
 
 /**
  * Enables a runtime assertion that no operation in the argument closure shall
- * use scheduler operations (yield, recv, spawn, etc). This is for use with
+ * use scheduler operations (deschedule, recv, spawn, etc). This is for use with
  * pthread mutexes, which may block the entire scheduler thread, rather than
- * just one task, and is hence prone to deadlocks if mixed with yielding.
+ * just one task, and is hence prone to deadlocks if mixed with descheduling.
  *
  * NOTE: THIS DOES NOT PROVIDE LOCKING, or any sort of critical-section
  * synchronization whatsoever. It only makes sense to use for CPU-local issues.
@@ -288,10 +288,10 @@ pub unsafe fn atomically<U>(f: &fn() -> U) -> U {
     if in_green_task_context() {
         let t = Local::unsafe_borrow::<Task>();
         do (|| {
-            (*t).death.inhibit_yield();
+            (*t).death.inhibit_deschedule();
             f()
         }).finally {
-            (*t).death.allow_yield();
+            (*t).death.allow_deschedule();
         }
     } else {
         f()
@@ -349,7 +349,7 @@ struct ExData<T> {
  * This uses a pthread mutex, not one that's aware of the userspace scheduler.
  * The user of an Exclusive must be careful not to invoke any functions that may
  * reschedule the task while holding the lock, or deadlock may result. If you
- * need to block or yield while accessing shared state, use extra::sync::RWArc.
+ * need to block or deschedule while accessing shared state, use extra::sync::RWArc.
  */
 pub struct Exclusive<T> {
     x: UnsafeAtomicRcBox<ExData<T>>
@@ -377,7 +377,7 @@ impl<T:Send> Exclusive<T> {
     // Exactly like std::arc::MutexArc,access(), but with the LittleLock
     // instead of a proper mutex. Same reason for being unsafe.
     //
-    // Currently, scheduling operations (i.e., yielding, receiving on a pipe,
+    // Currently, scheduling operations (i.e., descheduling, receiving on a pipe,
     // accessing the provided condition variable) are prohibited while inside
     // the Exclusive. Supporting that is a work in progress.
     #[inline]
@@ -431,7 +431,7 @@ mod tests {
     fn test_atomically() {
         // NB. The whole runtime will abort on an 'atomic-sleep' violation,
         // so we can't really test for the converse behaviour.
-        unsafe { do atomically { } } task::yield(); // oughtn't fail
+        unsafe { do atomically { } } task::deschedule(); // oughtn't fail
     }
 
     #[test]
@@ -545,7 +545,7 @@ mod tests {
             c.send(());
         }
         p.recv();
-        task::yield(); // Try to make the unwrapper get blocked first.
+        task::deschedule(); // Try to make the unwrapper get blocked first.
         let left_x = x.try_unwrap();
         assert!(left_x.is_left());
         util::ignore(left_x);
@@ -566,7 +566,7 @@ mod tests {
         do task::spawn {
             let x2 = x2.take();
             unsafe { do x2.with |_hello| { } }
-            task::yield();
+            task::deschedule();
         }
         assert!(x.unwrap() == ~~"hello");
 
@@ -612,7 +612,7 @@ mod tests {
             let x = Exclusive::new(~~"hello");
             let x2 = x.clone();
             do task::spawn {
-                do 10.times { task::yield(); } // try to let the unwrapper go
+                do 10.times { task::deschedule(); } // try to let the unwrapper go
                 fail!(); // punt it awake from its deadlock
             }
             let _z = x.unwrap();