---

yaml
---
r: 88850
b: refs/heads/snap-stage3
c: 8be66e2
h: refs/heads/master
v: v3

Author: alexcrichton

[refs]

@@ -1,7 +1,7 @@
 ---
 refs/heads/master: deeca5d586bfaa4aa60246f671a8d611d38f6248
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
-refs/heads/snap-stage3: 14caf00c92b40e3f62094db54f325196c8a05d5a
+refs/heads/snap-stage3: 8be66e212b37045b927138965a76abe3608325ca
 refs/heads/try: b160761e35efcd1207112b3b782c06633cf441a8
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b

branches/snap-stage3/src/libstd/comm/mod.rs

@@ -238,7 +238,6 @@ use rt::local::Local;
 use rt::task::{Task, BlockedTask};
 use rt::thread::Thread;
 use sync::atomics::{AtomicInt, AtomicBool, SeqCst, Relaxed};
-use task;
 use vec::{ImmutableVector, OwnedVector};
 
 use spsc = sync::spsc_queue;
@@ -346,6 +345,7 @@ struct Packet {
     selection_id: uint,
     select_next: *mut Packet,
     select_prev: *mut Packet,
+    recv_cnt: int,
 }
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -367,6 +367,7 @@ impl Packet {
             selection_id: 0,
             select_next: 0 as *mut Packet,
             select_prev: 0 as *mut Packet,
+            recv_cnt: 0,
         }
     }
 
@@ -611,8 +612,9 @@ impl<T: Send> Chan<T> {
                 // the TLS overhead can be a bit much.
                 n => {
                     assert!(n >= 0);
-                    if can_resched && n > 0 && n % RESCHED_FREQ == 0 {
-                        task::deschedule();
+                    if n > 0 && n % RESCHED_FREQ == 0 {
+                        let task: ~Task = Local::take();
+                        task.maybe_yield();
                     }
                     true
                 }
@@ -704,8 +706,9 @@ impl<T: Send> SharedChan<T> {
                 DISCONNECTED => {} // oh well, we tried
                 -1 => { (*packet).wakeup(can_resched); }
                 n => {
-                    if can_resched && n > 0 && n % RESCHED_FREQ == 0 {
-                        task::deschedule();
+                    if n > 0 && n % RESCHED_FREQ == 0 {
+                        let task: ~Task = Local::take();
+                        task.maybe_yield();
                     }
                 }
             }
@@ -773,6 +776,18 @@ impl<T: Send> Port<T> {
         // This is a "best effort" situation, so if a queue is inconsistent just
         // don't worry about it.
         let this = unsafe { cast::transmute_mut(self) };
+
+        // See the comment about yielding on sends, but the same applies here.
+        // If a thread is spinning in try_recv we should try
+        unsafe {
+            let packet = this.queue.packet();
+            (*packet).recv_cnt += 1;
+            if (*packet).recv_cnt % RESCHED_FREQ == 0 {
+                let task: ~Task = Local::take();
+                task.maybe_yield();
+            }
+        }
+
         let ret = match this.queue {
             SPSC(ref mut queue) => queue.pop(),
             MPSC(ref mut queue) => match queue.pop() {