Make async.

Cargo.toml

@@ -8,5 +8,16 @@ keywords = ["asynchronous", "routing"]
 [dependencies]
 libc = "0.2.66"
 
+[target.'cfg(unix)'.dependencies]
+async-io = "1.2.0"
+
 [target.'cfg(windows)'.dependencies]
-winapi = { version = "0.3.8", features = ["netioapi", "ntdef", "ws2def"] }
+futures-lite = "1.11.2"
+if-addrs = "0.6.5"
+winapi = { version = "0.3.8", features = ["netioapi", "ntdef", "winerror", "ws2def"] }
+
+[target.'cfg(windows)'.dev-dependencies]
+winapi = { version = "0.3.8", features = ["processthreadsapi", "synchapi"] }
+
+[dev-dependencies]
+futures-lite = "1.11.2"

examples/ip_watch.rs

@@ -0,0 +1,10 @@
+use ip_watch::AddrSet;
+
+fn main() {
+    futures_lite::future::block_on(async {
+        let mut set = AddrSet::new().await.unwrap();
+        loop {
+            println!("Got event {:?}", set.next().await);
+        }
+    });
+}

src/lib.rs

@@ -2,7 +2,7 @@
 //! limited to synchronous operation.
 
 #![deny(
-    exceeding_bitshifts,
+    arithmetic_overflow,
     invalid_type_param_default,
     missing_fragment_specifier,
     mutable_transmutes,
@@ -72,15 +72,36 @@ pub enum Event {
     Delete(std::net::IpAddr),
 }
 
-#[cfg(all(test, not(windows)))]
+#[cfg(test)]
 mod tests {
     use super::*;
+    use futures_lite::future::poll_fn;
+    use std::{future::Future, pin::Pin, task::Poll};
+
+    #[test]
+    fn test_ip_watch() {
+        futures_lite::future::block_on(async {
+            let mut set = AddrSet::new().await.unwrap();
+            poll_fn(|cx| loop {
+                let next = set.next();
+                futures_lite::pin!(next);
+                if let Poll::Ready(Ok(ev)) = Pin::new(&mut next).poll(cx) {
+                    println!("Got event {:?}", ev);
+                    continue
+                }
+                return Poll::Ready(())
+            })
+            .await;
+        });
+    }
+
     #[test]
-    fn it_works() {
-        let set = AddrSet::new();
-        println!("Got event {:?}", set);
-        for i in set.unwrap() {
-            println!("Got event {:?}", i.unwrap())
-        }
+    fn test_is_send() {
+        futures_lite::future::block_on(async {
+            fn is_send<T: Send>(_: T) {}
+            is_send(AddrSet::new());
+            is_send(AddrSet::new().await.unwrap());
+            is_send(AddrSet::new().await.unwrap().next());
+        });
     }
 }

src/unix.rs

@@ -44,48 +44,45 @@ pub struct AddrSet {
 
 impl AddrSet {
     /// Create a watcher
-    pub fn new() -> std::io::Result<Self> {
+    pub async fn new() -> std::io::Result<Self> {
         let mut hash = HashSet::new();
         let mut watcher = Watcher::new()?;
         let mut buf = Vec::with_capacity(1 << 16);
         let mut queue = VecDeque::new();
-        watcher.resync(&mut buf, &mut queue, &mut hash)?;
+        watcher.resync(&mut buf, &mut queue, &mut hash).await?;
         Ok(Self {
             hash,
             watcher,
             buf,
             queue,
         })
     }
-}
-
-impl Iterator for AddrSet {
-    type Item = std::io::Result<Event>;
 
-    fn next(&mut self) -> Option<Self::Item> {
+    /// Returns a future for the next event.
+    pub async fn next(&mut self) -> std::io::Result<Event> {
         let Self {
             watcher,
             buf,
             hash,
             queue,
         } = self;
         if let Some(event) = queue.pop_front() {
-            return Some(Ok(event))
+            return Ok(event)
         }
         loop {
-            match watcher.next(buf, queue, hash) {
-                Status::IO(e) => return Some(Err(e)),
+            match watcher.next(buf, queue, hash).await {
+                Status::IO(e) => return Err(e),
                 Status::Desync => {
                     if buf.capacity() < 1 << 19 {
                         buf.reserve(buf.capacity() * 2);
                     }
-                    if watcher.resync(buf, queue, hash).is_err() {
+                    if watcher.resync(buf, queue, hash).await.is_err() {
                         continue
                     }
                 }
                 Status::Data(()) => {
                     if let Some(event) = queue.pop_front() {
-                        return Some(Ok(event))
+                        return Ok(event)
                     }
                 }
             }

src/unix/fd.rs

@@ -19,7 +19,7 @@ impl Fd {
         #[cfg(target_os = "linux")]
         let fd = unsafe { socket(libc::PF_NETLINK, FLAGS, libc::NETLINK_ROUTE) };
         #[cfg(not(target_os = "linux"))]
-        let fd = unsafe { socket(libc::PF_ROUTE, FLAGS | libc::SOCK_NONBLOCK, libc::AF_UNSPEC) };
+        let fd = unsafe { socket(libc::PF_ROUTE, FLAGS, libc::AF_UNSPEC) };
         if fd < 0 {
             Err(std::io::Error::last_os_error())
         } else {