m: Use try-iter for processing timers

Cargo.toml

@@ -25,7 +25,7 @@ harness = false
 [dependencies]
 async-lock = "2.6"
 cfg-if = "1"
-concurrent-queue = "2"
+concurrent-queue = "2.2.0"
 futures-lite = "1.11.0"
 log = "0.4.11"
 parking = "2.0.0"

src/reactor.rs

@@ -222,17 +222,17 @@ impl Reactor {
     fn process_timer_ops(&self, timers: &mut MutexGuard<'_, BTreeMap<(Instant, usize), Waker>>) {
         // Process only as much as fits into the queue, or else this loop could in theory run
         // forever.
-        for _ in 0..self.timer_ops.capacity().unwrap() {
-            match self.timer_ops.pop() {
-                Ok(TimerOp::Insert(when, id, waker)) => {
+        self.timer_ops
+            .try_iter()
+            .take(self.timer_ops.capacity().unwrap())
+            .for_each(|op| match op {
+                TimerOp::Insert(when, id, waker) => {
                     timers.insert((when, id), waker);
                 }
-                Ok(TimerOp::Remove(when, id)) => {
+                TimerOp::Remove(when, id) => {
                     timers.remove(&(when, id));
                 }
-                Err(_) => break,
-            }
-        }
+            });
     }
 }