adding support if connect failed

examples/tcp_client.rs

@@ -9,7 +9,7 @@ fn main() -> io::Result<()> {
     unsafe {
         poller.add(&socket, Event::new(0, true, true))?;
     }
-    let addr = net::SocketAddr::new(net::Ipv4Addr::LOCALHOST.into(), 8080);
+    let addr = net::SocketAddr::new(net::Ipv4Addr::LOCALHOST.into(), 12345); // some address with no server listening
     socket.set_nonblocking(true)?;
     let _ = socket.connect(&addr.into());
 
@@ -19,9 +19,12 @@ fn main() -> io::Result<()> {
     poller.wait(&mut events, None)?;
 
     let event = events.iter().next();
-    let Some(event) = event else {
-        println!("no event");
-        return Ok(());
+    let event = match event {
+        Some(event) => event,
+        None => {
+            println!("no event");
+            return Ok(());
+        }
     };
 
     println!("event: {:?}", event);

src/epoll.rs

@@ -86,6 +86,11 @@ impl Poller {
         true
     }
 
+    /// Whether this poller supports checking for the tcp connection failure.
+    pub fn supports_is_connect_failed(&self) -> bool {
+        true
+    }
+
     /// Adds a new file descriptor.
     ///
     /// # Safety

src/iocp/mod.rs

@@ -164,6 +164,11 @@ impl Poller {
         false
     }
 
+    /// Whether this poller supports checking for the tcp connection failure.
+    pub fn supports_is_connect_failed(&self) -> bool {
+        true
+    }
+
     /// Add a new source to the poller.
     ///
     /// # Safety

src/kqueue.rs

@@ -79,6 +79,11 @@ impl Poller {
         true
     }
 
+    /// Whether this poller supports checking for the tcp connection failure.
+    pub fn supports_is_connect_failed(&self) -> bool {
+        false
+    }
+
     /// Adds a new file descriptor.
     ///
     /// # Safety
@@ -372,9 +377,10 @@ impl EventExtra {
         false
     }
 
+    /// is the tcp connection failed?
     #[inline]
     pub fn is_connect_failed(&self) -> bool {
-        unimplemented!("is connect failed is not supported on kqueue");
+        false
     }
 }
 

src/lib.rs

@@ -337,7 +337,45 @@ impl Event {
     /// This indicates a tcp connection has failed, it corresponds to the `EPOLLERR` along with `EPOLLHUP` event in linux
     /// and `CONNECT_FAILED` event in windows IOCP.
     ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::{io, net};
+    /// use polling::Event;
+    /// use socket2::Type;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///      let socket = socket2::Socket::new(socket2::Domain::IPV4, Type::STREAM, None)?;
+    /// let poller = polling::Poller::new()?;
+    /// unsafe {
+    ///     poller.add(&socket, Event::new(0, true, true))?;
+    /// }
+    /// let addr = net::SocketAddr::new(net::Ipv4Addr::LOCALHOST.into(), 12345); // some address with no server listening
+    /// socket.set_nonblocking(true)?;
+    /// let _ = socket.connect(&addr.into());
 
+    /// let mut events = polling::Events::new();
+
+    /// events.clear();
+    /// poller.wait(&mut events, None)?;
+
+    /// let event = events.iter().next();
+    /// let event = match event {
+    ///     Some(event) => event,
+    ///     None => {
+    ///         println!("no event");
+    ///         return Ok(());
+    ///     }
+    /// };
+
+    /// println!("event: {:?}", event);
+    /// if event.is_connect_failed() {
+    ///     println!("connect failed");
+    /// }
+
+    /// Ok(())
+    /// }
+    /// ```
     #[inline]
     pub fn is_connect_failed(&self) -> bool {
         self.extra.is_connect_failed()
@@ -395,6 +433,11 @@ impl Poller {
         self.poller.supports_edge()
     }
 
+    /// Whether this poller supports checking for the tcp connection failure.
+    pub fn supports_is_connect_failed(&self) -> bool {
+        self.poller.supports_is_connect_failed()
+    }
+
     /// Adds a file descriptor or socket to the poller.
     ///
     /// A file descriptor or socket is considered readable or writable when a read or write

src/poll.rs

@@ -94,6 +94,11 @@ impl Poller {
         false
     }
 
+    /// Whether this poller supports checking for the tcp connection failure.
+    pub fn supports_is_connect_failed(&self) -> bool {
+        true
+    }
+
     /// Adds a new file descriptor.
     pub fn add(&self, fd: RawFd, ev: Event, mode: PollMode) -> io::Result<()> {
         if self.notify.has_fd(fd) {

src/port.rs

@@ -42,6 +42,11 @@ impl Poller {
         false
     }
 
+    /// Whether this poller supports checking for the tcp connection failure.
+    pub fn supports_is_connect_failed(&self) -> bool {
+        true
+    }
+
     /// Adds a file descriptor.
     ///
     /// # Safety