fix(poll): cancel in the fd queue (#346)

* fix(poll): cancel in the fd queue

* fix(poll): use retain instead of position - remove

* fix(poll): make renew safe

compio-driver/src/poll/mod.rs

@@ -4,7 +4,7 @@ pub use std::os::fd::{AsRawFd, OwnedFd, RawFd};
 #[cfg(aio)]
 use std::ptr::NonNull;
 use std::{
-    collections::{HashMap, HashSet, VecDeque},
+    collections::{HashMap, VecDeque},
     io,
     num::NonZeroUsize,
     os::fd::BorrowedFd,
@@ -123,6 +123,11 @@ impl FdQueue {
         }
     }
 
+    pub fn remove(&mut self, user_data: usize) {
+        self.read_queue.retain(|&k| k != user_data);
+        self.write_queue.retain(|&k| k != user_data);
+    }
+
     pub fn event(&self) -> Event {
         let mut event = Event::none(0);
         if let Some(&key) = self.read_queue.front() {
@@ -167,7 +172,6 @@ pub(crate) struct Driver {
     events: Events,
     poll: Arc<Poller>,
     registry: HashMap<RawFd, FdQueue>,
-    cancelled: HashSet<usize>,
     pool: AsyncifyPool,
     pool_completed: Arc<SegQueue<Entry>>,
 }
@@ -189,7 +193,6 @@ impl Driver {
             events,
             poll,
             registry: HashMap::new(),
-            cancelled: HashSet::new(),
             pool: builder.create_or_get_thread_pool(),
             pool_completed: Arc::new(SegQueue::new()),
         })
@@ -215,16 +218,49 @@ impl Driver {
         Ok(())
     }
 
+    fn renew(
+        poll: &Poller,
+        registry: &mut HashMap<RawFd, FdQueue>,
+        fd: BorrowedFd,
+        renew_event: Event,
+    ) -> io::Result<()> {
+        if !renew_event.readable && !renew_event.writable {
+            poll.delete(fd)?;
+            registry.remove(&fd.as_raw_fd());
+        } else {
+            poll.modify(fd, renew_event)?;
+        }
+        Ok(())
+    }
+
     pub fn attach(&mut self, _fd: RawFd) -> io::Result<()> {
         Ok(())
     }
 
     pub fn cancel(&mut self, op: &mut Key<dyn crate::sys::OpCode>) {
-        self.cancelled.insert(op.user_data());
-        #[cfg(aio)]
-        {
-            let op = op.as_op_pin();
-            if let Some(OpType::Aio(aiocbp)) = op.op_type() {
+        let op_pin = op.as_op_pin();
+        match op_pin.op_type() {
+            None => {}
+            Some(OpType::Fd(fd)) => {
+                let queue = self
+                    .registry
+                    .get_mut(&fd)
+                    .expect("the fd should be attached");
+                queue.remove(op.user_data());
+                let renew_event = queue.event();
+                if Self::renew(
+                    &self.poll,
+                    &mut self.registry,
+                    unsafe { BorrowedFd::borrow_raw(fd) },
+                    renew_event,
+                )
+                .is_ok()
+                {
+                    self.pool_completed.push(entry_cancelled(op.user_data()));
+                }
+            }
+            #[cfg(aio)]
+            Some(OpType::Aio(aiocbp)) => {
                 let aiocb = unsafe { aiocbp.as_ref() };
                 let fd = aiocb.aio_fildes;
                 syscall!(libc::aio_cancel(fd, aiocbp.as_ptr())).ok();
@@ -314,21 +350,27 @@ impl Driver {
         }
     }
 
-    fn poll_blocking(&mut self) {
+    fn poll_blocking(&mut self) -> bool {
+        if self.pool_completed.is_empty() {
+            return false;
+        }
         while let Some(entry) = self.pool_completed.pop() {
             unsafe {
                 entry.notify();
             }
         }
+        true
     }
 
     pub unsafe fn poll(&mut self, timeout: Option<Duration>) -> io::Result<()> {
         instrument!(compio_log::Level::TRACE, "poll", ?timeout);
+        if self.poll_blocking() {
+            return Ok(());
+        }
         self.poll.wait(&mut self.events, timeout)?;
-        if self.events.is_empty() && self.pool_completed.is_empty() && timeout.is_some() {
+        if self.events.is_empty() && timeout.is_some() {
             return Err(io::Error::from_raw_os_error(libc::ETIMEDOUT));
         }
-        self.poll_blocking();
         for event in self.events.iter() {
             let user_data = event.key;
             trace!("receive {} for {:?}", user_data, event);
@@ -348,32 +390,27 @@ impl Driver {
                         .get_mut(&fd)
                         .expect("the fd should be attached");
                     if let Some((user_data, interest)) = queue.pop_interest(&event) {
-                        if self.cancelled.remove(&user_data) {
-                            entry_cancelled(user_data).notify();
-                        } else {
-                            let mut op = Key::<dyn crate::sys::OpCode>::new_unchecked(user_data);
-                            let op = op.as_op_pin();
-                            let res = match op.operate() {
-                                Poll::Pending => {
-                                    // The operation should go back to the front.
-                                    queue.push_front_interest(user_data, interest);
-                                    None
-                                }
-                                Poll::Ready(res) => Some(res),
-                            };
-                            if let Some(res) = res {
-                                Entry::new(user_data, res).notify();
+                        let mut op = Key::<dyn crate::sys::OpCode>::new_unchecked(user_data);
+                        let op = op.as_op_pin();
+                        let res = match op.operate() {
+                            Poll::Pending => {
+                                // The operation should go back to the front.
+                                queue.push_front_interest(user_data, interest);
+                                None
                             }
+                            Poll::Ready(res) => Some(res),
+                        };
+                        if let Some(res) = res {
+                            Entry::new(user_data, res).notify();
                         }
                     }
                     let renew_event = queue.event();
-                    let borrowed_fd = BorrowedFd::borrow_raw(fd);
-                    if !renew_event.readable && !renew_event.writable {
-                        self.poll.delete(borrowed_fd)?;
-                        self.registry.remove(&fd);
-                    } else {
-                        self.poll.modify(borrowed_fd, renew_event)?;
-                    }
+                    Self::renew(
+                        &self.poll,
+                        &mut self.registry,
+                        BorrowedFd::borrow_raw(fd),
+                        renew_event,
+                    )?;
                 }
                 #[cfg(aio)]
                 Some(OpType::Aio(aiocbp)) => {
@@ -388,7 +425,6 @@ impl Driver {
                             continue;
                         }
                         libc::ECANCELED => {
-                            self.cancelled.remove(&user_data);
                             // Remove the aiocb from kqueue.
                             libc::aio_return(aiocbp.as_ptr());
                             Err(io::Error::from_raw_os_error(libc::ETIMEDOUT))