more conditional compilation

tokio/src/io/async_fd.rs

@@ -201,6 +201,10 @@ pub struct AsyncFdReadyMutGuard<'a, T: AsRawFd> {
     event: Option<ReadyEvent>,
 }
 
+#[cfg(not(any(target_os = "linux", target_os = "android")))]
+const ALL_INTEREST: Interest = Interest::READABLE.add(Interest::WRITABLE);
+
+#[cfg(any(target_os = "linux", target_os = "android"))]
 const ALL_INTEREST: Interest = Interest::READABLE
     .add(Interest::WRITABLE)
     .add(Interest::PRIORITY);

tokio/src/io/interest.rs

@@ -96,6 +96,8 @@ impl Interest {
     /// let both = Interest::READABLE | Interest::PRIORITY;
     /// assert!(both.is_priority());
     /// ```
+    #[cfg(any(target_os = "linux", target_os = "android"))]
+    #[cfg_attr(docsrs, doc(cfg(any(target_os = "linux", target_os = "android"))))]
     pub const fn is_priority(self) -> bool {
         self.0.is_priority()
     }
@@ -126,6 +128,7 @@ impl Interest {
         match self {
             Interest::READABLE => Ready::READABLE | Ready::READ_CLOSED,
             Interest::WRITABLE => Ready::WRITABLE | Ready::WRITE_CLOSED,
+            #[cfg(any(target_os = "linux", target_os = "android"))]
             Interest::PRIORITY => Ready::PRIORITY,
             _ => Ready::EMPTY,
         }

tokio/src/io/poll_evented.rs

@@ -70,6 +70,14 @@ cfg_io_driver! {
 
 // ===== impl PollEvented =====
 
+#[cfg(not(any(target_os = "linux", target_os = "android")))]
+const ALL_INTEREST: Interest = Interest::READABLE.add(Interest::WRITABLE);
+
+#[cfg(any(target_os = "linux", target_os = "android"))]
+const ALL_INTEREST: Interest = Interest::READABLE
+    .add(Interest::WRITABLE)
+    .add(Interest::PRIORITY);
+
 impl<E: Source> PollEvented<E> {
     /// Creates a new `PollEvented` associated with the default reactor.
     ///
@@ -83,10 +91,7 @@ impl<E: Source> PollEvented<E> {
     #[track_caller]
     #[cfg_attr(feature = "signal", allow(unused))]
     pub(crate) fn new(io: E) -> io::Result<Self> {
-        PollEvented::new_with_interest(
-            io,
-            Interest::READABLE | Interest::WRITABLE | Interest::PRIORITY,
-        )
+        PollEvented::new_with_interest(io, ALL_INTEREST)
     }
 
     /// Creates a new `PollEvented` associated with the default reactor, for

tokio/src/io/ready.rs

@@ -7,6 +7,7 @@ const READABLE: usize = 0b0_01;
 const WRITABLE: usize = 0b0_10;
 const READ_CLOSED: usize = 0b0_0100;
 const WRITE_CLOSED: usize = 0b0_1000;
+#[cfg(any(target_os = "linux", target_os = "android"))]
 const PRIORITY: usize = 0b1_0000;
 
 /// Describes the readiness state of an I/O resources.
@@ -33,11 +34,18 @@ impl Ready {
     pub const WRITE_CLOSED: Ready = Ready(WRITE_CLOSED);
 
     /// Returns a `Ready` representing priority readiness.
+    #[cfg(any(target_os = "linux", target_os = "android"))]
+    #[cfg_attr(docsrs, doc(cfg(any(target_os = "linux", target_os = "android"))))]
     pub const PRIORITY: Ready = Ready(PRIORITY);
 
     /// Returns a `Ready` representing readiness for all operations.
+    #[cfg(any(target_os = "linux", target_os = "android"))]
     pub const ALL: Ready = Ready(READABLE | WRITABLE | READ_CLOSED | WRITE_CLOSED | PRIORITY);
 
+    /// Returns a `Ready` representing readiness for all operations.
+    #[cfg(not(any(target_os = "linux", target_os = "android")))]
+    pub const ALL: Ready = Ready(READABLE | WRITABLE | READ_CLOSED | WRITE_CLOSED);
+
     // Must remain crate-private to avoid adding a public dependency on Mio.
     pub(crate) fn from_mio(event: &mio::event::Event) -> Ready {
         let mut ready = Ready::EMPTY;
@@ -69,8 +77,11 @@ impl Ready {
             ready |= Ready::WRITE_CLOSED;
         }
 
-        if event.is_priority() {
-            ready |= Ready::PRIORITY;
+        #[cfg(any(target_os = "linux", target_os = "android"))]
+        {
+            if event.is_priority() {
+                ready |= Ready::PRIORITY;
+            }
         }
 
         ready
@@ -216,6 +227,7 @@ cfg_io_readiness! {
                 ready |= Ready::WRITE_CLOSED;
             }
 
+            #[cfg(any(target_os = "linux", target_os = "android"))]
             if interest.is_priority() {
                 ready |= Ready::PRIORITY;
             }
@@ -269,12 +281,25 @@ impl ops::Sub<Ready> for Ready {
 
 impl fmt::Debug for Ready {
     fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
-        fmt.debug_struct("Ready")
-            .field("is_readable", &self.is_readable())
-            .field("is_writable", &self.is_writable())
-            .field("is_read_closed", &self.is_read_closed())
-            .field("is_write_closed", &self.is_write_closed())
-            .field("is_priority", &self.is_priority())
-            .finish()
+        #[cfg(any(target_os = "linux", target_os = "android"))]
+        {
+            fmt.debug_struct("Ready")
+                .field("is_readable", &self.is_readable())
+                .field("is_writable", &self.is_writable())
+                .field("is_read_closed", &self.is_read_closed())
+                .field("is_write_closed", &self.is_write_closed())
+                .field("is_priority", &self.is_priority())
+                .finish()
+        }
+
+        #[cfg(not(any(target_os = "linux", target_os = "android")))]
+        {
+            fmt.debug_struct("Ready")
+                .field("is_readable", &self.is_readable())
+                .field("is_writable", &self.is_writable())
+                .field("is_read_closed", &self.is_read_closed())
+                .field("is_write_closed", &self.is_write_closed())
+                .finish()
+        }
     }
 }

tokio/tests/tcp_priority.rs

@@ -1,12 +1,11 @@
 #![warn(rust_2018_idioms)]
-#![cfg(all(feature = "full", not(tokio_wasi)))] // Wasi doesn't support bind
+#![cfg(all(feature = "full", any(target_os = "linux", target_os = "android")))]
 
 use std::os::unix::io::AsRawFd;
 use tokio::io::{self, Interest};
 use tokio::net::{TcpListener, TcpStream};
 
 #[tokio::test]
-#[cfg(any(target_os = "linux", target_os = "android"))]
 async fn await_priority() {
     use std::net::SocketAddr;
 
@@ -25,7 +24,6 @@ async fn await_priority() {
     let _ = client.ready(Interest::PRIORITY).await.unwrap();
 }
 
-#[cfg(any(target_os = "linux", target_os = "android"))]
 fn send_oob_data<S: AsRawFd>(stream: &S, data: &[u8]) -> io::Result<usize> {
     unsafe {
         let res = libc::send(