Do not require &mut self in AsyncUdpSocket::poll_send

quinn-udp/src/fallback.rs

@@ -1,5 +1,6 @@
 use std::{
     io::{self, IoSliceMut},
+    sync::Mutex,
     time::Instant,
 };
 
@@ -13,14 +14,14 @@ use super::{log_sendmsg_error, RecvMeta, UdpSockRef, UdpState, IO_ERROR_LOG_INTE
 /// reduced performance compared to that enabled by some target-specific interfaces.
 #[derive(Debug)]
 pub struct UdpSocketState {
-    last_send_error: Instant,
+    last_send_error: Mutex<Instant>,
 }
 
 impl UdpSocketState {
     pub fn new() -> Self {
         let now = Instant::now();
         Self {
-            last_send_error: now.checked_sub(2 * IO_ERROR_LOG_INTERVAL).unwrap_or(now),
+            last_send_error: Mutex::new(now.checked_sub(2 * IO_ERROR_LOG_INTERVAL).unwrap_or(now)),
         }
     }
 
@@ -29,7 +30,7 @@ impl UdpSocketState {
     }
 
     pub fn send(
-        &mut self,
+        &self,
         socket: UdpSockRef<'_>,
         _state: &UdpState,
         transmits: &[Transmit],
@@ -58,7 +59,7 @@ impl UdpSocketState {
                     //   Those are not fatal errors, since the
                     //   configuration can be dynamically changed.
                     // - Destination unreachable errors have been observed for other
-                    log_sendmsg_error(&mut self.last_send_error, e, transmit);
+                    log_sendmsg_error(&self.last_send_error, e, transmit);
                     sent += 1;
                 }
             }

quinn-udp/src/lib.rs

@@ -5,7 +5,10 @@ use std::os::unix::io::AsRawFd;
 use std::os::windows::io::AsRawSocket;
 use std::{
     net::{IpAddr, Ipv6Addr, SocketAddr},
-    sync::atomic::{AtomicBool, AtomicUsize, Ordering},
+    sync::{
+        atomic::{AtomicBool, AtomicUsize, Ordering},
+        Mutex,
+    },
     time::{Duration, Instant},
 };
 
@@ -123,11 +126,12 @@ const IO_ERROR_LOG_INTERVAL: Duration = std::time::Duration::from_secs(60);
 /// Logging will only be performed if at least [`IO_ERROR_LOG_INTERVAL`]
 /// has elapsed since the last error was logged.
 fn log_sendmsg_error(
-    last_send_error: &mut Instant,
+    last_send_error: &Mutex<Instant>,
     err: impl core::fmt::Debug,
     transmit: &Transmit,
 ) {
     let now = Instant::now();
+    let last_send_error = &mut *last_send_error.lock().expect("poisend lock");
     if now.saturating_duration_since(*last_send_error) > IO_ERROR_LOG_INTERVAL {
         *last_send_error = now;
         warn!(

quinn-udp/src/unix.rs

@@ -6,7 +6,10 @@ use std::{
     mem::{self, MaybeUninit},
     net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV4, SocketAddrV6},
     os::unix::io::AsRawFd,
-    sync::atomic::{AtomicBool, AtomicUsize},
+    sync::{
+        atomic::{AtomicBool, AtomicUsize},
+        Mutex,
+    },
     time::Instant,
 };
 
@@ -26,14 +29,14 @@ type IpTosTy = libc::c_int;
 /// platforms.
 #[derive(Debug)]
 pub struct UdpSocketState {
-    last_send_error: Instant,
+    last_send_error: Mutex<Instant>,
 }
 
 impl UdpSocketState {
     pub fn new() -> Self {
         let now = Instant::now();
         Self {
-            last_send_error: now.checked_sub(2 * IO_ERROR_LOG_INTERVAL).unwrap_or(now),
+            last_send_error: Mutex::new(now.checked_sub(2 * IO_ERROR_LOG_INTERVAL).unwrap_or(now)),
         }
     }
 
@@ -42,12 +45,12 @@ impl UdpSocketState {
     }
 
     pub fn send(
-        &mut self,
+        &self,
         socket: UdpSockRef<'_>,
         state: &UdpState,
         transmits: &[Transmit],
     ) -> Result<usize, io::Error> {
-        send(state, socket.0, &mut self.last_send_error, transmits)
+        send(state, socket.0, &self.last_send_error, transmits)
     }
 
     pub fn recv(
@@ -148,7 +151,7 @@ fn send(
     #[allow(unused_variables)] // only used on Linux
     state: &UdpState,
     io: SockRef<'_>,
-    last_send_error: &mut Instant,
+    last_send_error: &Mutex<Instant>,
     transmits: &[Transmit],
 ) -> io::Result<usize> {
     #[allow(unused_mut)] // only mutable on FeeBSD
@@ -252,7 +255,7 @@ fn send(
 fn send(
     state: &UdpState,
     io: SockRef<'_>,
-    last_send_error: &mut Instant,
+    last_send_error: &Mutex<Instant>,
     transmits: &[Transmit],
 ) -> io::Result<usize> {
     let mut hdr: libc::msghdr = unsafe { mem::zeroed() };

quinn-udp/src/windows.rs

@@ -2,6 +2,7 @@ use std::{
     io::{self, IoSliceMut},
     mem,
     os::windows::io::AsRawSocket,
+    sync::Mutex,
     time::Instant,
 };
 
@@ -13,14 +14,14 @@ use super::{log_sendmsg_error, RecvMeta, UdpSockRef, UdpState, IO_ERROR_LOG_INTE
 /// QUIC-friendly UDP interface for Windows
 #[derive(Debug)]
 pub struct UdpSocketState {
-    last_send_error: Instant,
+    last_send_error: Mutex<Instant>,
 }
 
 impl UdpSocketState {
     pub fn new() -> Self {
         let now = Instant::now();
         Self {
-            last_send_error: now.checked_sub(2 * IO_ERROR_LOG_INTERVAL).unwrap_or(now),
+            last_send_error: Mutex::new(now.checked_sub(2 * IO_ERROR_LOG_INTERVAL).unwrap_or(now)),
         }
     }
 
@@ -81,7 +82,7 @@ impl UdpSocketState {
     }
 
     pub fn send(
-        &mut self,
+        &self,
         socket: UdpSockRef<'_>,
         _state: &UdpState,
         transmits: &[Transmit],
@@ -106,7 +107,7 @@ impl UdpSocketState {
 
                     // Other errors are ignored, since they will ususally be handled
                     // by higher level retransmits and timeouts.
-                    log_sendmsg_error(&mut self.last_send_error, e, transmit);
+                    log_sendmsg_error(&self.last_send_error, e, transmit);
                     sent += 1;
                 }
             }

quinn/src/runtime.rs

@@ -35,7 +35,7 @@ pub trait AsyncUdpSocket: Send + Debug + 'static {
     /// Send UDP datagrams from `transmits`, or register to be woken if sending may succeed in the
     /// future
     fn poll_send(
-        &mut self,
+        &self,
         state: &UdpState,
         cx: &mut Context,
         transmits: &[Transmit],

quinn/src/runtime/async_std.rs

@@ -50,7 +50,7 @@ struct UdpSocket {
 
 impl AsyncUdpSocket for UdpSocket {
     fn poll_send(
-        &mut self,
+        &self,
         state: &udp::UdpState,
         cx: &mut Context,
         transmits: &[proto::Transmit],

quinn/src/runtime/tokio.rs

@@ -52,12 +52,12 @@ struct UdpSocket {
 
 impl AsyncUdpSocket for UdpSocket {
     fn poll_send(
-        &mut self,
+        &self,
         state: &udp::UdpState,
         cx: &mut Context,
         transmits: &[proto::Transmit],
     ) -> Poll<io::Result<usize>> {
-        let inner = &mut self.inner;
+        let inner = &self.inner;
         let io = &self.io;
         loop {
             ready!(io.poll_send_ready(cx))?;