Add wstd::main and wstd::test macros for WASIp3

examples/macro_main.rs

@@ -0,0 +1,9 @@
+#![cfg_attr(not(target_os = "wasi"), no_main)]
+#![cfg(target_os = "wasi")]
+
+//! Verifies that the `main` macro is compiling.
+
+#[wstd::main]
+async fn main() {
+    println!("Hello world");
+}

examples/tcp_echo_server.rs

@@ -7,7 +7,7 @@ use wstd::net::TcpListener;
 
 #[wstd::main]
 async fn main() -> io::Result<()> {
-    let listener = TcpListener::bind("127.0.0.1:8080").await?;
+    let mut listener = TcpListener::bind("127.0.0.1:8080").await?;
     println!("Listening on {}", listener.local_addr()?);
     println!("type `nc localhost 8080` to create a TCP client");
 
@@ -17,7 +17,9 @@ async fn main() -> io::Result<()> {
         println!("Accepted from: {}", stream.peer_addr()?);
         wstd::runtime::spawn(async move {
             // If echo copy fails, we can ignore it.
-            let _ = io::copy(&stream, &stream).await;
+            let mut stream = stream;
+            let (mut read_half, mut write_half) = stream.split();
+            let _ = io::copy(&mut read_half, &mut write_half).await;
         })
         .detach();
     }

src/http/body.rs

@@ -3,7 +3,7 @@ use crate::http::{
     error::Context as _,
     fields::{header_map_from_wasi, header_map_to_wasi},
 };
-use crate::io::{AsyncInputStream, AsyncOutputStream};
+use crate::io::{AsyncInputStream, AsyncOutputStream, AsyncWrite};
 use crate::runtime::{AsyncPollable, Reactor, WaitFor};
 
 pub use ::http_body::{Body as HttpBody, Frame, SizeHint};
@@ -77,7 +77,7 @@ impl Body {
         match self.0 {
             BodyInner::Incoming(incoming) => incoming.send(outgoing_body).await,
             BodyInner::Boxed(box_body) => {
-                let out_stream = AsyncOutputStream::new(
+                let mut out_stream = AsyncOutputStream::new(
                     outgoing_body
                         .write()
                         .expect("outgoing body already written"),
@@ -108,7 +108,7 @@ impl Body {
                 }
             }
             BodyInner::Complete { data, trailers } => {
-                let out_stream = AsyncOutputStream::new(
+                let mut out_stream = AsyncOutputStream::new(
                     outgoing_body
                         .write()
                         .expect("outgoing body already written"),
@@ -348,14 +348,14 @@ impl Incoming {
     }
     async fn send(self, outgoing_body: WasiOutgoingBody) -> Result<(), Error> {
         let in_body = self.body;
-        let in_stream =
+        let mut in_stream =
             AsyncInputStream::new(in_body.stream().expect("incoming body already read"));
-        let out_stream = AsyncOutputStream::new(
+        let mut out_stream = AsyncOutputStream::new(
             outgoing_body
                 .write()
                 .expect("outgoing body already written"),
         );
-        in_stream.copy_to(&out_stream).await.map_err(|e| {
+        in_stream.copy_to(&mut out_stream).await.map_err(|e| {
             Error::from(e).context("copying incoming body stream to outgoing body stream")
         })?;
         drop(in_stream);

src/io/read.rs

@@ -28,7 +28,7 @@ pub trait AsyncRead {
     // If the `AsyncRead` implementation is an unbuffered wrapper around an
     // `AsyncInputStream`, some I/O operations can be more efficient.
     #[inline]
-    fn as_async_input_stream(&self) -> Option<&io::AsyncInputStream> {
+    fn as_async_input_stream(&mut self) -> Option<&mut io::AsyncInputStream> {
         None
     }
 }
@@ -45,7 +45,7 @@ impl<R: AsyncRead + ?Sized> AsyncRead for &mut R {
     }
 
     #[inline]
-    fn as_async_input_stream(&self) -> Option<&io::AsyncInputStream> {
+    fn as_async_input_stream(&mut self) -> Option<&mut io::AsyncInputStream> {
         (**self).as_async_input_stream()
     }
 }

src/io/stdio.rs

@@ -43,8 +43,8 @@ impl AsyncRead for Stdin {
     }
 
     #[inline]
-    fn as_async_input_stream(&self) -> Option<&AsyncInputStream> {
-        Some(&self.stream)
+    fn as_async_input_stream(&mut self) -> Option<&mut AsyncInputStream> {
+        Some(&mut self.stream)
     }
 }
 
@@ -93,7 +93,7 @@ impl AsyncWrite for Stdout {
     }
 
     #[inline]
-    fn as_async_output_stream(&self) -> Option<&AsyncOutputStream> {
+    fn as_async_output_stream(&mut self) -> Option<&mut AsyncOutputStream> {
         self.stream.as_async_output_stream()
     }
 }
@@ -143,7 +143,7 @@ impl AsyncWrite for Stderr {
     }
 
     #[inline]
-    fn as_async_output_stream(&self) -> Option<&AsyncOutputStream> {
+    fn as_async_output_stream(&mut self) -> Option<&mut AsyncOutputStream> {
         self.stream.as_async_output_stream()
     }
 }

src/io/streams.rs

@@ -26,7 +26,7 @@ impl AsyncInputStream {
             stream,
         }
     }
-    fn poll_ready(&self, cx: &mut Context<'_>) -> Poll<()> {
+    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<()> {
         // Lazily initialize the AsyncPollable
         let subscription = self
             .subscription
@@ -43,40 +43,13 @@ impl AsyncInputStream {
         }
     }
     /// Await for read readiness.
-    async fn ready(&self) {
+    async fn ready(&mut self) {
         poll_fn(|cx| self.poll_ready(cx)).await
     }
-    /// Asynchronously read from the input stream.
-    /// This method is the same as [`AsyncRead::read`], but doesn't require a `&mut self`.
-    pub async fn read(&self, buf: &mut [u8]) -> std::io::Result<usize> {
-        let read = loop {
-            self.ready().await;
-            // Ideally, the ABI would be able to read directly into buf.
-            // However, with the default generated bindings, it returns a
-            // newly allocated vec, which we need to copy into buf.
-            match self.stream.read(buf.len() as u64) {
-                // A read of 0 bytes from WASI's `read` doesn't mean
-                // end-of-stream as it does in Rust. However, `self.ready()`
-                // cannot guarantee that at least one byte is ready for
-                // reading, so in this case we try again.
-                Ok(r) if r.is_empty() => continue,
-                Ok(r) => break r,
-                // 0 bytes from Rust's `read` means end-of-stream.
-                Err(StreamError::Closed) => return Ok(0),
-                Err(StreamError::LastOperationFailed(err)) => {
-                    return Err(std::io::Error::other(err.to_debug_string()));
-                }
-            }
-        };
-        let len = read.len();
-        buf[0..len].copy_from_slice(&read);
-        Ok(len)
-    }
-
     /// Move the entire contents of an input stream directly into an output
     /// stream, until the input stream has closed. This operation is optimized
     /// to avoid copying stream contents into and out of memory.
-    pub async fn copy_to(&self, writer: &AsyncOutputStream) -> std::io::Result<u64> {
+    pub async fn copy_to(&mut self, writer: &mut AsyncOutputStream) -> std::io::Result<u64> {
         let mut written = 0;
         loop {
             self.ready().await;
@@ -124,11 +97,32 @@ impl AsyncInputStream {
 
 impl AsyncRead for AsyncInputStream {
     async fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
-        Self::read(self, buf).await
+        let read = loop {
+            self.ready().await;
+            // Ideally, the ABI would be able to read directly into buf.
+            // However, with the default generated bindings, it returns a
+            // newly allocated vec, which we need to copy into buf.
+            match self.stream.read(buf.len() as u64) {
+                // A read of 0 bytes from WASI's `read` doesn't mean
+                // end-of-stream as it does in Rust. However, `self.ready()`
+                // cannot guarantee that at least one byte is ready for
+                // reading, so in this case we try again.
+                Ok(r) if r.is_empty() => continue,
+                Ok(r) => break r,
+                // 0 bytes from Rust's `read` means end-of-stream.
+                Err(StreamError::Closed) => return Ok(0),
+                Err(StreamError::LastOperationFailed(err)) => {
+                    return Err(std::io::Error::other(err.to_debug_string()));
+                }
+            }
+        };
+        let len = read.len();
+        buf[0..len].copy_from_slice(&read);
+        Ok(len)
     }
 
     #[inline]
-    fn as_async_input_stream(&self) -> Option<&AsyncInputStream> {
+    fn as_async_input_stream(&mut self) -> Option<&mut AsyncInputStream> {
         Some(self)
     }
 }
@@ -150,9 +144,10 @@ impl AsyncInputChunkStream {
 impl futures_lite::stream::Stream for AsyncInputChunkStream {
     type Item = Result<Vec<u8>, std::io::Error>;
     fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
-        match self.stream.poll_ready(cx) {
+        let this = self.get_mut();
+        match this.stream.poll_ready(cx) {
             Poll::Pending => Poll::Pending,
-            Poll::Ready(()) => match self.stream.stream.read(self.chunk_size as u64) {
+            Poll::Ready(()) => match this.stream.stream.read(this.chunk_size as u64) {
                 Ok(r) if r.is_empty() => Poll::Pending,
                 Ok(r) => Poll::Ready(Some(Ok(r))),
                 Err(StreamError::LastOperationFailed(err)) => {
@@ -233,23 +228,19 @@ impl AsyncOutputStream {
         }
     }
     /// Await write readiness.
-    async fn ready(&self) {
+    async fn ready(&mut self) {
         // Lazily initialize the AsyncPollable
         let subscription = self
             .subscription
             .get_or_init(|| AsyncPollable::new(self.stream.subscribe()));
         // Wait on readiness
         subscription.wait_for().await;
     }
-    /// Asynchronously write to the output stream. This method is the same as
-    /// [`AsyncWrite::write`], but doesn't require a `&mut self`.
-    ///
-    /// Awaits for write readiness, and then performs at most one write to the
-    /// output stream. Returns how much of the argument `buf` was written, or
-    /// a `std::io::Error` indicating either an error returned by the stream write
-    /// using the debug string provided by the WASI error, or else that the,
-    /// indicated by `std::io::ErrorKind::ConnectionReset`.
-    pub async fn write(&self, buf: &[u8]) -> std::io::Result<usize> {
+}
+
+impl AsyncWrite for AsyncOutputStream {
+    // Required methods
+    async fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
         // Loops at most twice.
         loop {
             match self.stream.check_write() {
@@ -279,32 +270,7 @@ impl AsyncOutputStream {
             }
         }
     }
-
-    /// Asynchronously write to the output stream. This method is the same as
-    /// [`AsyncWrite::write_all`], but doesn't require a `&mut self`.
-    pub async fn write_all(&self, buf: &[u8]) -> std::io::Result<()> {
-        let mut to_write = &buf[0..];
-        loop {
-            let bytes_written = self.write(to_write).await?;
-            to_write = &to_write[bytes_written..];
-            if to_write.is_empty() {
-                return Ok(());
-            }
-        }
-    }
-
-    /// Asyncronously flush the output stream. Initiates a flush, and then
-    /// awaits until the flush is complete and the output stream is ready for
-    /// writing again.
-    ///
-    /// This method is the same as [`AsyncWrite::flush`], but doesn't require
-    /// a `&mut self`.
-    ///
-    /// Fails with a `std::io::Error` indicating either an error returned by
-    /// the stream flush, using the debug string provided by the WASI error,
-    /// or else that the stream is closed, indicated by
-    /// `std::io::ErrorKind::ConnectionReset`.
-    pub async fn flush(&self) -> std::io::Result<()> {
+    async fn flush(&mut self) -> std::io::Result<()> {
         match self.stream.flush() {
             Ok(()) => {
                 self.ready().await;
@@ -318,19 +284,9 @@ impl AsyncOutputStream {
             }
         }
     }
-}
-
-impl AsyncWrite for AsyncOutputStream {
-    // Required methods
-    async fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
-        Self::write(self, buf).await
-    }
-    async fn flush(&mut self) -> std::io::Result<()> {
-        Self::flush(self).await
-    }
 
     #[inline]
-    fn as_async_output_stream(&self) -> Option<&AsyncOutputStream> {
+    fn as_async_output_stream(&mut self) -> Option<&mut AsyncOutputStream> {
         Some(self)
     }
 }

src/io/write.rs

@@ -20,7 +20,7 @@ pub trait AsyncWrite {
     // If the `AsyncWrite` implementation is an unbuffered wrapper around an
     // `AsyncOutputStream`, some I/O operations can be more efficient.
     #[inline]
-    fn as_async_output_stream(&self) -> Option<&io::AsyncOutputStream> {
+    fn as_async_output_stream(&mut self) -> Option<&mut io::AsyncOutputStream> {
         None
     }
 }
@@ -42,7 +42,7 @@ impl<W: AsyncWrite + ?Sized> AsyncWrite for &mut W {
     }
 
     #[inline]
-    fn as_async_output_stream(&self) -> Option<&io::AsyncOutputStream> {
+    fn as_async_output_stream(&mut self) -> Option<&mut io::AsyncOutputStream> {
         (**self).as_async_output_stream()
     }
 }

src/lib.rs

@@ -69,15 +69,25 @@ pub mod net;
 pub mod rand;
 #[cfg(all(target_os = "wasi", target_env = "p2"))]
 pub mod runtime;
+#[cfg(all(target_os = "wasi", target_env = "p3"))]
+pub mod runtime {
+    pub fn block_on<F, T>(fut: F) -> F::Output
+    where
+        F: Future<Output = T>,
+        T: 'static,
+    {
+        wasip3::wit_bindgen::block_on(fut)
+    }
+}
 #[cfg(all(target_os = "wasi", target_env = "p2"))]
 pub mod task;
 #[cfg(all(target_os = "wasi", target_env = "p2"))]
 pub mod time;
 
 #[cfg(all(target_os = "wasi", target_env = "p2"))]
-pub use wstd_macro::{
-    attr_macro_http_server as http_server, attr_macro_main as main, attr_macro_test as test,
-};
+pub use wstd_macro::attr_macro_http_server as http_server;
+
+pub use wstd_macro::{attr_macro_main as main, attr_macro_test as test};
 
 // Re-export the active WASI backend crate for use only by `wstd-macro` macros.
 // The proc macros need to generate code that uses these definitions, but we

src/net/tcp_listener.rs

@@ -55,15 +55,15 @@ impl TcpListener {
     }
 
     /// Returns an iterator over the connections being received on this listener.
-    pub fn incoming(&self) -> Incoming<'_> {
+    pub fn incoming(&mut self) -> Incoming<'_> {
         Incoming { listener: self }
     }
 }
 
 /// An iterator that infinitely accepts connections on a TcpListener.
 #[derive(Debug)]
 pub struct Incoming<'a> {
-    listener: &'a TcpListener,
+    listener: &'a mut TcpListener,
 }
 
 impl<'a> AsyncIterator for Incoming<'a> {