Cleanup timer wheel on driver drop

ntex/CHANGES.md

@@ -1,5 +1,9 @@
 # Changes
 
+## [0.4.0-b.5] - 2021-08-28
+
+* Cleanup timer wheel on driver drop
+
 ## [0.4.0-b.4] - 2021-08-28
 
 * Reduce timer resolution

ntex/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ntex"
-version = "0.4.0-b.4"
+version = "0.4.0-b.5"
 authors = ["ntex contributors <team@ntex.rs>"]
 description = "Framework for composable network services"
 readme = "README.md"

ntex/src/time/wheel.rs

@@ -2,7 +2,9 @@
 //!
 //! Inspired by linux kernel timers system
 #![allow(arithmetic_overflow)]
-use std::{cell::RefCell, future::Future, pin::Pin, rc::Rc, task, task::Poll, time};
+use std::{
+    cell::RefCell, future::Future, mem, pin::Pin, rc::Rc, task, task::Poll, time,
+};
 
 use slab::Slab;
 
@@ -147,15 +149,8 @@ impl Timer {
 
 impl TimerInner {
     fn new() -> Self {
-        let mut buckets = Vec::with_capacity(WHEEL_SIZE);
-        for idx in 0..WHEEL_SIZE {
-            let lvl = idx / (LVL_SIZE as usize);
-            let offs = idx % (LVL_SIZE as usize);
-            buckets.push(Bucket::new(lvl, offs))
-        }
-
         TimerInner {
-            buckets,
+            buckets: Self::create_buckets(),
             timers: Slab::default(),
             elapsed: 0,
             elapsed_instant: time::Instant::now(),
@@ -166,9 +161,32 @@ impl TimerInner {
         }
     }
 
+    fn create_buckets() -> Vec<Bucket> {
+        let mut buckets = Vec::with_capacity(WHEEL_SIZE);
+        for idx in 0..WHEEL_SIZE {
+            let lvl = idx / (LVL_SIZE as usize);
+            let offs = idx % (LVL_SIZE as usize);
+            buckets.push(Bucket::new(lvl, offs))
+        }
+        buckets
+    }
+
     // Add the timer into the hash bucket
     fn add_timer(inner: &Rc<RefCell<Self>>, millis: u64) -> TimerHandle {
         let mut slf = inner.borrow_mut();
+        if millis == 0 {
+            let entry = slf.timers.vacant_entry();
+            let no = entry.key();
+
+            entry.insert(TimerEntry {
+                bucket_entry: 0,
+                bucket: 0,
+                task: LocalWaker::new(),
+                flags: TimerEntryFlags::ELAPSED,
+            });
+            return TimerHandle(no);
+        }
+
         let delta = to_units(
             (time::Instant::now() + time::Duration::from_millis(millis)
                 - slf.elapsed_instant)
@@ -213,6 +231,11 @@ impl TimerInner {
 
     fn update_timer(inner: &Rc<RefCell<Self>>, hnd: usize, millis: u64) {
         let mut slf = inner.borrow_mut();
+        if millis == 0 {
+            slf.timers[hnd].flags = TimerEntryFlags::ELAPSED;
+            return;
+        }
+
         let delta = to_units(
             (time::Instant::now() + time::Duration::from_millis(millis)
                 - slf.elapsed_instant)
@@ -449,12 +472,9 @@ impl TimerEntry {
     }
 }
 
-pin_project_lite::pin_project! {
-    struct TimerDriver {
-        inner: Rc<RefCell<TimerInner>>,
-        #[pin]
-        sleep: Sleep,
-    }
+struct TimerDriver {
+    inner: Rc<RefCell<TimerInner>>,
+    sleep: Pin<Box<Sleep>>,
 }
 
 impl TimerDriver {
@@ -464,46 +484,105 @@ impl TimerDriver {
 
         crate::rt::spawn(TimerDriver {
             inner: cell.clone(),
-            sleep: sleep_until(inner.next_expiry()),
+            sleep: Box::pin(sleep_until(inner.next_expiry())),
         });
     }
 }
 
+impl Drop for TimerDriver {
+    fn drop(&mut self) {
+        let mut inner = self.inner.borrow_mut();
+
+        // mark all old timers as elapsed
+        let mut buckets = mem::take(&mut inner.buckets);
+        for b in &mut buckets {
+            for no in b.entries.drain() {
+                inner.timers[no].flags.insert(TimerEntryFlags::ELAPSED);
+            }
+        }
+
+        // cleanup info
+        inner.flags = Flags::empty();
+        inner.buckets = buckets;
+        inner.occupied = [0; WHEEL_SIZE];
+    }
+}
+
 impl Future for TimerDriver {
     type Output = ();
 
     fn poll(mut self: Pin<&mut Self>, cx: &mut task::Context<'_>) -> Poll<Self::Output> {
-        let mut this = self.as_mut().project();
-        let mut inner = this.inner.borrow_mut();
+        let mut inner = self.inner.borrow_mut();
         inner.driver.register(cx.waker());
 
         if inner.flags.contains(Flags::NEEDS_RECALC) {
             inner.flags.remove(Flags::NEEDS_RECALC);
             inner.flags.insert(Flags::TIMER_ACTIVE);
-            this.sleep.reset(inner.next_expiry());
+            let exp = inner.next_expiry();
             drop(inner);
+            Pin::as_mut(&mut self.sleep).reset(exp);
             return self.poll(cx);
-        } else if inner.flags.contains(Flags::TIMER_ACTIVE)
-            && this.sleep.poll(cx).is_ready()
-        {
+        } else if inner.flags.contains(Flags::TIMER_ACTIVE) {
             drop(inner);
-            this = self.as_mut().project();
-            let mut inner = this.inner.borrow_mut();
-            let instant = this.sleep.deadline();
-            inner.execute_expired_timers(instant);
+            let result = Pin::as_mut(&mut self.sleep).poll(cx).is_ready();
+            if result {
+                let instant = self.sleep.deadline();
+                let mut inner = self.inner.borrow_mut();
+                inner.execute_expired_timers(instant);
 
-            if let Some(next_expiry) = inner.next_pending_bucket() {
-                inner.next_expiry = next_expiry;
-                inner.flags.insert(Flags::TIMER_ACTIVE);
-                this.sleep.reset(inner.next_expiry());
-                drop(inner);
-                return self.poll(cx);
-            } else {
-                inner.next_expiry = u64::MAX;
-                inner.flags.remove(Flags::TIMER_ACTIVE);
+                if let Some(next_expiry) = inner.next_pending_bucket() {
+                    inner.next_expiry = next_expiry;
+                    inner.flags.insert(Flags::TIMER_ACTIVE);
+                    let exp = inner.next_expiry();
+                    drop(inner);
+                    Pin::as_mut(&mut self.sleep).reset(exp);
+                    return self.poll(cx);
+                } else {
+                    inner.next_expiry = u64::MAX;
+                    inner.flags.remove(Flags::TIMER_ACTIVE);
+                }
             }
         }
-
         Poll::Pending
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use std::time::{Duration, Instant};
+
+    use crate::time::*;
+
+    #[crate::rt_test]
+    async fn test_timer() {
+        crate::rt::spawn(async {
+            let s = interval(25);
+            loop {
+                s.tick().await;
+            }
+        });
+        let time = Instant::now();
+        let fut1 = sleep(Millis(1000));
+        let fut2 = sleep(Millis(200));
+
+        fut2.await;
+        let elapsed = Instant::now() - time;
+        assert!(
+            elapsed > Duration::from_millis(200) && elapsed < Duration::from_millis(250)
+        );
+
+        fut1.await;
+        let elapsed = Instant::now() - time;
+        assert!(
+            elapsed > Duration::from_millis(1000)
+                && elapsed < Duration::from_millis(1200)
+        );
+
+        let time = Instant::now();
+        sleep(Millis(25)).await;
+        let elapsed = Instant::now() - time;
+        assert!(
+            elapsed > Duration::from_millis(20) && elapsed < Duration::from_millis(45)
+        );
+    }
+}