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libasync: replace TcpStream::listen() with accept(), make accept() return earlier

This commit is contained in:
Astro 2020-04-16 20:28:40 +02:00
parent be35be8d38
commit c3fc948714
2 changed files with 55 additions and 45 deletions
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18
experiments/src/main.rs
View File

@ -241,10 +241,20 @@ pub fn main_core0() {
Ok(())
}
TcpStream::listen(TCP_PORT, 2048, 2048, 8, |stream| async {
handle_connection(stream)
.await
.map_err(|e| println!("Connection: {:?}", e));
let mut counter = alloc::rc::Rc::new(core::cell::RefCell::new(0));
task::spawn(async move {
while let stream = TcpStream::accept(TCP_PORT, 2048, 2408).await.unwrap() {
let counter = counter.clone();
task::spawn(async move {
*counter.borrow_mut() += 1;
println!("Serving {} connections", *counter.borrow());
handle_connection(stream)
.await
.map_err(|e| println!("Connection: {:?}", e));
*counter.borrow_mut() -= 1;
println!("Now serving {} connections", *counter.borrow());
});
}
});
let mut time = 0u32;

82
libasync/src/smoltcp/tcp_stream.rs
View File

@ -9,9 +9,10 @@ use core::{
};
use alloc::vec::Vec;
use smoltcp::{
Error, Result,
socket::{
SocketHandle, SocketRef,
TcpSocketBuffer, TcpSocket,
TcpSocketBuffer, TcpSocket, TcpState,
},
};
use crate::task;
@ -77,47 +78,26 @@ impl TcpStream {
f(socket_ref)
}
/// Spawns `backlog` tasks with listening sockets so that more
/// connections can be accepted while some are still
/// handshaking. Spawns additional tasks for each connection.
pub fn listen<F, R, T>(port: u16, rx_bufsize: usize, tx_bufsize: usize, backlog: usize, f: F)
where
F: Fn(Self) -> R + Clone + 'static,
R: Future<Output = T> + 'static,
{
for _ in 0..backlog {
let f = f.clone();
task::spawn(async move {
loop {
// Wait for new connection
let stream = TcpStream::accept(port, rx_bufsize, tx_bufsize).await;
// Spawn async task for new connection
task::spawn(f(stream));
}
});
}
}
/// Listen for the next incoming connection on a TCP
/// port. Succeeds on connection attempt.
///
/// Calling this serially in a loop will cause slow/botched
/// connection attempts stall any more new connections. Use
/// `listen()` with a backlog instead.
pub async fn accept(port: u16, rx_bufsize: usize, tx_bufsize: usize) -> Self {
pub async fn accept(port: u16, rx_bufsize: usize, tx_bufsize: usize) -> Result<Self> {
let stream = Self::new(rx_bufsize, tx_bufsize);
// Set socket to listen
stream.with_socket(|mut s| s.listen(port))
.expect("listen");
stream.with_socket(|mut s| s.listen(port))?;
// Wait for a connection
poll_stream!(&stream, (), |socket| {
if socket.is_active() {
if socket.state() != TcpState::Listen {
Poll::Ready(())
} else {
Poll::Pending
}
}).await;
stream
Ok(stream)
}
/// Probe the receive buffer
@ -127,7 +107,7 @@ impl TcpStream {
/// just return `Poll::Pending` if there is not enough data
/// yet. Likewise, return the amount of bytes consumed from the
/// buffer in the `Poll::Ready` result.
pub async fn recv<F, R>(&self, f: F) -> smoltcp::Result<R>
pub async fn recv<F, R>(&self, f: F) -> Result<R>
where
F: Fn(&[u8]) -> Poll<(usize, R)>,
{
@ -137,10 +117,14 @@ impl TcpStream {
}
impl<'a, F: Fn(&[u8]) -> Poll<(usize, R)>, R> Future for Recv<'a, F, R> {
type Output = smoltcp::Result<R>;
type Output = Result<R>;
fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
let result = self.stream.with_socket(|mut socket| {
if socket_is_handhshaking(&socket) {
return Ok(Poll::Pending);
}
socket.recv(|buf| {
if buf.len() > 0 {
match (self.f)(buf) {
@ -156,10 +140,11 @@ impl TcpStream {
})
});
match result {
Ok(Poll::Pending) => {
Sockets::register_waker(cx.waker().clone());
Poll::Pending
}
Ok(result) => {
if !result.is_ready() {
Sockets::register_waker(cx.waker().clone());
}
result
}
Err(e) =>
@ -175,12 +160,14 @@ impl TcpStream {
}
/// Wait until there is any space in the socket's send queue
async fn wait_can_send(&self) -> smoltcp::Result<()> {
poll_stream!(self, smoltcp::Result<()>, |socket| {
if !socket.is_active() {
Poll::Ready(Err(smoltcp::Error::Illegal))
async fn wait_can_send(&self) -> Result<()> {
poll_stream!(self, Result<()>, |socket| {
if socket_is_handhshaking(&socket) {
Poll::Pending
} else if socket.can_send() {
Poll::Ready(Ok(()))
} else if ! socket.may_send() {
Poll::Ready(Err(Error::Truncated))
} else {
Poll::Pending
}
@ -188,7 +175,7 @@ impl TcpStream {
}
/// Yields to wait for more buffer space
pub async fn send<I: IntoIterator<Item = u8>>(&self, data: I) -> Result<(), smoltcp::Error> {
pub async fn send<I: IntoIterator<Item = u8>>(&self, data: I) -> Result<()> {
let mut data = data.into_iter();
let mut done = false;
while !done {
@ -217,12 +204,16 @@ impl TcpStream {
/// **Warning:** this may not work as immediately as expected! The
/// other side may wait until it sends packets to you for
/// piggybacking the ACKs.
pub async fn flush(&self) {
poll_stream!(self, (), |socket| {
if socket.may_send() && socket.send_queue() > 0 {
pub async fn flush(&self) -> Result<()> {
poll_stream!(self, Result<()>, |socket| {
if socket_is_handhshaking(&socket) {
Poll::Pending
} else if socket.may_send() && socket.send_queue() > 0 {
Poll::Pending
} else if socket.may_send() {
Poll::Ready(Ok(()))
} else {
Poll::Ready(())
Poll::Ready(Err(Error::Truncated))
}
}).await
}
@ -236,3 +227,12 @@ impl Drop for TcpStream {
.remove(self.handle);
}
}
fn socket_is_handhshaking(socket: &SocketRef<TcpSocket>) -> bool {
match socket.state() {
TcpState::SynSent | TcpState::SynReceived =>
true,
_ =>
false,
}
}