diff --git a/src/connmgr/client.rs b/src/connmgr/client.rs
index 667c02ea..093be72f 100644
--- a/src/connmgr/client.rs
+++ b/src/connmgr/client.rs
@@ -634,7 +634,7 @@ impl Worker {
 
         let instance_id = Rc::new(instance_id);
 
-        let ka_batch = (stream_maxconn + (KEEP_ALIVE_BATCHES - 1)) / KEEP_ALIVE_BATCHES;
+        let ka_batch = stream_maxconn.div_ceil(KEEP_ALIVE_BATCHES);
 
         let batch = Batch::new(ka_batch);
 
diff --git a/src/connmgr/connection.rs b/src/connmgr/connection.rs
index 3209f7d5..8f344592 100644
--- a/src/connmgr/connection.rs
+++ b/src/connmgr/connection.rs
@@ -527,7 +527,7 @@ pub struct AddrRef<'a> {
     s: Ref<'a, Option<ArrayVec<u8, 64>>>,
 }
 
-impl<'a> AddrRef<'a> {
+impl AddrRef<'_> {
     pub fn get(&self) -> Option<&[u8]> {
         match &*self.s {
             Some(s) => Some(s.as_slice()),
@@ -701,8 +701,8 @@ struct SendMessageContentFuture<'a, 'b, W: AsyncWrite, M> {
     done: bool,
 }
 
-impl<'a, 'b, W: AsyncWrite, M: AsRef<[u8]> + AsMut<[u8]>> Future
-    for SendMessageContentFuture<'a, 'b, W, M>
+impl<W: AsyncWrite, M: AsRef<[u8]> + AsMut<[u8]>> Future
+    for SendMessageContentFuture<'_, '_, W, M>
 {
     type Output = Result<(usize, bool), Error>;
 
@@ -4210,7 +4210,7 @@ enum AsyncStream<'a> {
     Tls(AsyncTlsStream<'a>),
 }
 
-impl<'a> AsyncStream<'a> {
+impl AsyncStream<'_> {
     fn into_inner(self) -> Stream {
         match self {
             Self::Plain(stream) => Stream::Plain(stream.into_std()),
diff --git a/src/connmgr/server.rs b/src/connmgr/server.rs
index a86466ce..180f2cc0 100644
--- a/src/connmgr/server.rs
+++ b/src/connmgr/server.rs
@@ -777,7 +777,7 @@ impl Worker {
 
         let instance_id = Rc::new(instance_id);
 
-        let ka_batch = (stream_maxconn + (KEEP_ALIVE_BATCHES - 1)) / KEEP_ALIVE_BATCHES;
+        let ka_batch = stream_maxconn.div_ceil(KEEP_ALIVE_BATCHES);
 
         let batch = Batch::new(ka_batch);
 
diff --git a/src/connmgr/tls.rs b/src/connmgr/tls.rs
index 12be3594..84d50869 100644
--- a/src/connmgr/tls.rs
+++ b/src/connmgr/tls.rs
@@ -1085,7 +1085,7 @@ impl<'a: 'b, 'b> AsyncTlsStream<'a> {
     }
 }
 
-impl<'a> Drop for AsyncTlsStream<'a> {
+impl Drop for AsyncTlsStream<'_> {
     fn drop(&mut self) {
         let registration = self.waker.take_registration();
 
diff --git a/src/connmgr/track.rs b/src/connmgr/track.rs
index e2e6db2a..edebbf8d 100644
--- a/src/connmgr/track.rs
+++ b/src/connmgr/track.rs
@@ -70,7 +70,7 @@ impl<'a, A, B> Track<'a, (A, B)> {
     }
 }
 
-impl<'a, T> Drop for Track<'a, T> {
+impl<T> Drop for Track<'_, T> {
     fn drop(&mut self) {
         if let Some(inner) = &self.inner {
             inner.active.set(false);
@@ -78,7 +78,7 @@ impl<'a, T> Drop for Track<'a, T> {
     }
 }
 
-impl<'a, T> Deref for Track<'a, T> {
+impl<T> Deref for Track<'_, T> {
     type Target = T;
 
     fn deref(&self) -> &Self::Target {
@@ -134,7 +134,7 @@ pub struct TrackFuture<'a, F> {
     value_active: &'a TrackFlag,
 }
 
-impl<'a, F, T, E> Future for TrackFuture<'a, F>
+impl<F, T, E> Future for TrackFuture<'_, F>
 where
     F: Future<Output = Result<T, E>>,
     E: From<ValueActiveError>,
diff --git a/src/core/http1/client.rs b/src/core/http1/client.rs
index ff1a56bb..8bf8592b 100644
--- a/src/core/http1/client.rs
+++ b/src/core/http1/client.rs
@@ -647,7 +647,7 @@ pub struct FinishedKeepHeader<'a> {
     wbuf: &'a mut VecRingBuffer,
 }
 
-impl<'a> FinishedKeepHeader<'a> {
+impl FinishedKeepHeader<'_> {
     pub fn discard_header<const N: usize>(self, resp: protocol::OwnedResponse<N>) -> Finished {
         self.wbuf.set_inner(resp.into_buf());
         self.wbuf.clear();
diff --git a/src/core/http1/protocol.rs b/src/core/http1/protocol.rs
index e70f3c57..18f53ce0 100644
--- a/src/core/http1/protocol.rs
+++ b/src/core/http1/protocol.rs
@@ -605,7 +605,7 @@ pub struct OwnedRequest<'s, const N: usize> {
     expect_100: bool,
 }
 
-impl<'s, const N: usize> OwnedRequest<'s, N> {
+impl<const N: usize> OwnedRequest<'_, N> {
     pub fn get(&self) -> Request {
         let req = self.req.get();
 
@@ -640,7 +640,7 @@ pub struct OwnedResponse<'s, const N: usize> {
     body_size: BodySize,
 }
 
-impl<'s, const N: usize> OwnedResponse<'s, N> {
+impl<const N: usize> OwnedResponse<'_, N> {
     pub fn get(&self) -> Response {
         let resp = self.resp.get();
 
diff --git a/src/core/http1/server.rs b/src/core/http1/server.rs
index 2d149d63..e65e3785 100644
--- a/src/core/http1/server.rs
+++ b/src/core/http1/server.rs
@@ -469,7 +469,7 @@ pub struct ResponseState<'a, R: AsyncRead, W: AsyncWrite> {
     inner: RefCell<Option<ResponseStateInner<'a, R, W>>>,
 }
 
-impl<'a, R: AsyncRead, W: AsyncWrite> Default for ResponseState<'a, R, W> {
+impl<R: AsyncRead, W: AsyncWrite> Default for ResponseState<'_, R, W> {
     fn default() -> Self {
         Self {
             inner: RefCell::new(None),
@@ -517,7 +517,7 @@ pub struct ResponsePrepareBody<'a, 'b, R: AsyncRead, W: AsyncWrite> {
     state: &'b RefCell<Option<ResponseStateInner<'a, R, W>>>,
 }
 
-impl<'a, 'b, R: AsyncRead, W: AsyncWrite> ResponsePrepareBody<'a, 'b, R, W> {
+impl<R: AsyncRead, W: AsyncWrite> ResponsePrepareBody<'_, '_, R, W> {
     // only returns an error on invalid input
     pub fn prepare(&mut self, src: &[u8], end: bool) -> Result<(usize, usize), Error> {
         let state = self.state.borrow();
diff --git a/src/core/io.rs b/src/core/io.rs
index 073c8252..a74b9eba 100644
--- a/src/core/io.rs
+++ b/src/core/io.rs
@@ -155,7 +155,7 @@ impl<'a, 'b, W: AsyncWrite> StdWriteWrapper<'a, 'b, W> {
     }
 }
 
-impl<'a, 'b, W: AsyncWrite> Write for StdWriteWrapper<'a, 'b, W> {
+impl<W: AsyncWrite> Write for StdWriteWrapper<'_, '_, W> {
     fn write(&mut self, buf: &[u8]) -> Result<usize, io::Error> {
         match self.w.as_mut().poll_write(self.cx, buf) {
             Poll::Ready(ret) => ret,
@@ -244,7 +244,7 @@ pub struct ReadFuture<'a, R: AsyncRead + ?Sized> {
     buf: &'a mut [u8],
 }
 
-impl<'a, R: AsyncRead + ?Sized> Future for ReadFuture<'a, R> {
+impl<R: AsyncRead + ?Sized> Future for ReadFuture<'_, R> {
     type Output = Result<usize, io::Error>;
 
     fn poll(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
@@ -256,7 +256,7 @@ impl<'a, R: AsyncRead + ?Sized> Future for ReadFuture<'a, R> {
     }
 }
 
-impl<'a, R: AsyncRead + ?Sized> Drop for ReadFuture<'a, R> {
+impl<R: AsyncRead + ?Sized> Drop for ReadFuture<'_, R> {
     fn drop(&mut self) {
         self.r.cancel();
     }
@@ -268,7 +268,7 @@ pub struct WriteFuture<'a, W: AsyncWrite + ?Sized + Unpin> {
     pos: usize,
 }
 
-impl<'a, W: AsyncWrite + ?Sized> Future for WriteFuture<'a, W> {
+impl<W: AsyncWrite + ?Sized> Future for WriteFuture<'_, W> {
     type Output = Result<usize, io::Error>;
 
     fn poll(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
@@ -291,7 +291,7 @@ impl<'a, W: AsyncWrite + ?Sized> Future for WriteFuture<'a, W> {
     }
 }
 
-impl<'a, W: AsyncWrite + ?Sized> Drop for WriteFuture<'a, W> {
+impl<W: AsyncWrite + ?Sized> Drop for WriteFuture<'_, W> {
     fn drop(&mut self) {
         self.w.cancel();
     }
@@ -301,7 +301,7 @@ pub struct CloseFuture<'a, W: AsyncWrite + ?Sized> {
     w: &'a mut W,
 }
 
-impl<'a, W: AsyncWrite + ?Sized> Future for CloseFuture<'a, W> {
+impl<W: AsyncWrite + ?Sized> Future for CloseFuture<'_, W> {
     type Output = Result<(), io::Error>;
 
     fn poll(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
@@ -313,7 +313,7 @@ impl<'a, W: AsyncWrite + ?Sized> Future for CloseFuture<'a, W> {
     }
 }
 
-impl<'a, W: AsyncWrite + ?Sized> Drop for CloseFuture<'a, W> {
+impl<W: AsyncWrite + ?Sized> Drop for CloseFuture<'_, W> {
     fn drop(&mut self) {
         self.w.cancel();
     }
@@ -341,7 +341,7 @@ pub struct WriteVectoredFuture<'a, W: AsyncWrite + ?Sized + Unpin> {
     pos: usize,
 }
 
-impl<'a, W: AsyncWrite + ?Sized> Future for WriteVectoredFuture<'a, W> {
+impl<W: AsyncWrite + ?Sized> Future for WriteVectoredFuture<'_, W> {
     type Output = Result<usize, io::Error>;
 
     fn poll(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
@@ -380,7 +380,7 @@ impl<'a, W: AsyncWrite + ?Sized> Future for WriteVectoredFuture<'a, W> {
     }
 }
 
-impl<'a, W: AsyncWrite + ?Sized> Drop for WriteVectoredFuture<'a, W> {
+impl<W: AsyncWrite + ?Sized> Drop for WriteVectoredFuture<'_, W> {
     fn drop(&mut self) {
         self.w.cancel();
     }
@@ -391,7 +391,7 @@ pub struct WriteSharedFuture<'a, W: AsyncWrite + ?Sized + Unpin, B: AsRef<[u8]>>
     buf: &'a RefCell<B>,
 }
 
-impl<'a, W: AsyncWrite + ?Sized, B: AsRef<[u8]>> Future for WriteSharedFuture<'a, W, B> {
+impl<W: AsyncWrite + ?Sized, B: AsRef<[u8]>> Future for WriteSharedFuture<'_, W, B> {
     type Output = Result<usize, io::Error>;
 
     fn poll(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
@@ -403,7 +403,7 @@ impl<'a, W: AsyncWrite + ?Sized, B: AsRef<[u8]>> Future for WriteSharedFuture<'a
     }
 }
 
-impl<'a, W: AsyncWrite + ?Sized, B: AsRef<[u8]>> Drop for WriteSharedFuture<'a, W, B> {
+impl<W: AsyncWrite + ?Sized, B: AsRef<[u8]>> Drop for WriteSharedFuture<'_, W, B> {
     fn drop(&mut self) {
         self.w.cancel();
     }
diff --git a/src/core/reactor.rs b/src/core/reactor.rs
index 1a0f2309..68cc3b4b 100644
--- a/src/core/reactor.rs
+++ b/src/core/reactor.rs
@@ -39,7 +39,7 @@ fn duration_to_ticks_round_down(d: Duration) -> u64 {
 }
 
 fn duration_to_ticks_round_up(d: Duration) -> u64 {
-    ((d.as_millis() + (TICK_DURATION_MS as u128) - 1) / (TICK_DURATION_MS as u128)) as u64
+    d.as_millis().div_ceil(TICK_DURATION_MS as u128) as u64
 }
 
 fn ticks_to_duration(t: u64) -> Duration {