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refactor(lib): Use pin-project crate to perform pin projections

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Remove all pin-related `unsafe` code from Hyper, as well as the
now-unused 'pin-utils' dependency.
This commit is contained in:
Aaron Hill
2019-08-22 23:06:12 -04:00
committed by Sean McArthur
parent d406602c5d
commit 4c552a4960
6 changed files with 147 additions and 125 deletions
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3
Cargo.toml
View File

@@ -34,7 +34,8 @@ iovec = "0.1"
itoa = "0.4.1"
log = "0.4"
net2 = { version = "0.2.32", optional = true }
pin-utils = "=0.1.0-alpha.4"
pin-project = { version = "0.4.0-alpha.7", features = ["project_attr"] }
time = "0.1"
tokio = { version = "=0.2.0-alpha.4", optional = true, default-features = false, features = ["rt-full"] }
tower-service = "=0.3.0-alpha.1"

17
src/common/drain.rs
View File

@@ -2,6 +2,7 @@ use std::mem;
use futures_util::FutureExt as _;
use tokio_sync::{mpsc, watch};
use pin_project::pin_project;
use super::{Future, Never, Poll, Pin, task};
@@ -43,7 +44,9 @@ pub struct Watch {
}
#[allow(missing_debug_implementations)]
#[pin_project]
pub struct Watching<F, FN> {
#[pin]
future: F,
state: State<FN>,
watch: Watch,
@@ -95,10 +98,10 @@ where
{
type Output = F::Output;
fn poll(self: Pin<&mut Self>, cx: &mut task::Context<'_>) -> Poll<Self::Output> {
let me = unsafe { self.get_unchecked_mut() };
fn poll(mut self: Pin<&mut Self>, cx: &mut task::Context<'_>) -> Poll<Self::Output> {
loop {
match mem::replace(&mut me.state, State::Draining) {
let me = self.project();
match mem::replace(me.state, State::Draining) {
State::Watch(on_drain) => {
let recv = me.watch.rx.recv_ref();
futures_util::pin_mut!(recv);
@@ -106,17 +109,17 @@ where
match recv.poll_unpin(cx) {
Poll::Ready(None) => {
// Drain has been triggered!
on_drain(unsafe { Pin::new_unchecked(&mut me.future) });
on_drain(me.future);
},
Poll::Ready(Some(_/*State::Open*/)) |
Poll::Pending => {
me.state = State::Watch(on_drain);
return unsafe { Pin::new_unchecked(&mut me.future) }.poll(cx);
*me.state = State::Watch(on_drain);
return me.future.poll(cx);
},
}
},
State::Draining => {
return unsafe { Pin::new_unchecked(&mut me.future) }.poll(cx);
return me.future.poll(cx)
},
}
}

51
src/proto/h2/server.rs
View File

@@ -1,6 +1,7 @@
use std::error::Error as StdError;
use std::marker::Unpin;
use pin_project::{pin_project, project};
use h2::Reason;
use h2::server::{Builder, Connection, Handshake, SendResponse};
use tokio_io::{AsyncRead, AsyncWrite};
@@ -199,19 +200,22 @@ where
}
#[allow(missing_debug_implementations)]
#[pin_project]
pub struct H2Stream<F, B>
where
B: Payload,
{
reply: SendResponse<SendBuf<B::Data>>,
#[pin]
state: H2StreamState<F, B>,
}
#[pin_project]
enum H2StreamState<F, B>
where
B: Payload,
{
Service(F),
Service(#[pin] F),
Body(PipeToSendStream<B>),
}
@@ -229,6 +233,19 @@ where
}
}
macro_rules! reply {
($me:expr, $res:expr, $eos:expr) => ({
match $me.reply.send_response($res, $eos) {
Ok(tx) => tx,
Err(e) => {
debug!("send response error: {}", e);
$me.reply.send_reset(Reason::INTERNAL_ERROR);
return Poll::Ready(Err(crate::Error::new_h2(e)));
}
}
})
}
impl<F, B, E> H2Stream<F, B>
where
F: Future<Output = Result<Response<B>, E>>,
@@ -236,13 +253,14 @@ where
B::Data: Unpin,
E: Into<Box<dyn StdError + Send + Sync>>,
{
fn poll2(self: Pin<&mut Self>, cx: &mut task::Context<'_>) -> Poll<crate::Result<()>> {
// Safety: State::{Service, Body} futures are never moved
let me = unsafe { self.get_unchecked_mut() };
#[project]
fn poll2(mut self: Pin<&mut Self>, cx: &mut task::Context<'_>) -> Poll<crate::Result<()>> {
loop {
let next = match me.state {
H2StreamState::Service(ref mut h) => {
let res = match unsafe { Pin::new_unchecked(h) }.poll(cx) {
let mut me = self.project();
#[project]
let next = match me.state.project() {
H2StreamState::Service(h) => {
let res = match h.poll(cx) {
Poll::Ready(Ok(r)) => r,
Poll::Pending => {
// Response is not yet ready, so we want to check if the client has sent a
@@ -274,18 +292,7 @@ where
.expect("DATE is a valid HeaderName")
.or_insert_with(crate::proto::h1::date::update_and_header_value);
macro_rules! reply {
($eos:expr) => ({
match me.reply.send_response(res, $eos) {
Ok(tx) => tx,
Err(e) => {
debug!("send response error: {}", e);
me.reply.send_reset(Reason::INTERNAL_ERROR);
return Poll::Ready(Err(crate::Error::new_h2(e)));
}
}
})
}
// automatically set Content-Length from body...
if let Some(len) = body.size_hint().exact() {
@@ -293,10 +300,10 @@ where
}
if !body.is_end_stream() {
let body_tx = reply!(false);
let body_tx = reply!(me, res, false);
H2StreamState::Body(PipeToSendStream::new(body, body_tx))
} else {
reply!(true);
reply!(me, res, true);
return Poll::Ready(Ok(()));
}
},
@@ -304,7 +311,7 @@ where
return Pin::new(pipe).poll(cx);
}
};
me.state = next;
me.state.set(next);
}
}
}

88
src/server/conn.rs
View File

@@ -16,8 +16,8 @@ use std::mem;
use bytes::Bytes;
use futures_core::Stream;
use pin_utils::{unsafe_pinned, unsafe_unpinned};
use tokio_io::{AsyncRead, AsyncWrite};
use pin_project::{pin_project, project};
#[cfg(feature = "runtime")] use tokio_net::driver::Handle;
use crate::body::{Body, Payload};
@@ -69,8 +69,10 @@ enum ConnectionMode {
///
/// Yields `Connecting`s that are futures that should be put on a reactor.
#[must_use = "streams do nothing unless polled"]
#[pin_project]
#[derive(Debug)]
pub struct Serve<I, S, E = Exec> {
#[pin]
incoming: I,
make_service: S,
protocol: Http<E>,
@@ -81,16 +83,20 @@ pub struct Serve<I, S, E = Exec> {
/// Wraps the future returned from `MakeService` into one that returns
/// a `Connection`.
#[must_use = "futures do nothing unless polled"]
#[pin_project]
#[derive(Debug)]
pub struct Connecting<I, F, E = Exec> {
#[pin]
future: F,
io: Option<I>,
protocol: Http<E>,
}
#[must_use = "futures do nothing unless polled"]
#[pin_project]
#[derive(Debug)]
pub(super) struct SpawnAll<I, S, E> {
#[pin]
pub(super) serve: Serve<I, S, E>,
}
@@ -98,6 +104,7 @@ pub(super) struct SpawnAll<I, S, E> {
///
/// Polling this future will drive HTTP forward.
#[must_use = "futures do nothing unless polled"]
#[pin_project]
pub struct Connection<T, S, E = Exec>
where
S: Service<Body>,
@@ -119,9 +126,10 @@ where
fallback: Fallback<E>,
}
#[pin_project]
pub(super) enum Either<A, B> {
A(A),
B(B),
A(#[pin] A),
B(#[pin] B),
}
#[derive(Clone, Debug)]
@@ -484,10 +492,8 @@ where
///
/// This `Connection` should continue to be polled until shutdown
/// can finish.
pub fn graceful_shutdown(self: Pin<&mut Self>) {
// Safety: neither h1 nor h2 poll any of the generic futures
// in these methods.
match unsafe { self.get_unchecked_mut() }.conn.as_mut().unwrap() {
pub fn graceful_shutdown(mut self: Pin<&mut Self>) {
match self.project().conn.as_mut().unwrap() {
Either::A(ref mut h1) => {
h1.disable_keep_alive();
},
@@ -672,9 +678,6 @@ where
// ===== impl Serve =====
impl<I, S, E> Serve<I, S, E> {
unsafe_pinned!(incoming: I);
unsafe_unpinned!(make_service: S);
/// Spawn all incoming connections onto the executor in `Http`.
pub(super) fn spawn_all(self) -> SpawnAll<I, S, E> {
SpawnAll {
@@ -709,7 +712,7 @@ where
type Item = crate::Result<Connecting<IO, S::Future, E>>;
fn poll_next(mut self: Pin<&mut Self>, cx: &mut task::Context<'_>) -> Poll<Option<Self::Item>> {
match ready!(self.as_mut().make_service().poll_ready_ref(cx)) {
match ready!(self.project().make_service.poll_ready_ref(cx)) {
Ok(()) => (),
Err(e) => {
trace!("make_service closed");
@@ -717,9 +720,9 @@ where
}
}
if let Some(item) = ready!(self.as_mut().incoming().poll_next(cx)) {
if let Some(item) = ready!(self.project().incoming.poll_next(cx)) {
let io = item.map_err(crate::Error::new_accept)?;
let new_fut = self.as_mut().make_service().make_service_ref(&io);
let new_fut = self.project().make_service.make_service_ref(&io);
Poll::Ready(Some(Ok(Connecting {
future: new_fut,
io: Some(io),
@@ -733,10 +736,6 @@ where
// ===== impl Connecting =====
impl<I, F, E> Connecting<I, F, E> {
unsafe_pinned!(future: F);
unsafe_unpinned!(io: Option<I>);
}
impl<I, F, S, FE, E, B> Future for Connecting<I, F, E>
where
@@ -750,8 +749,8 @@ where
type Output = Result<Connection<I, S, E>, FE>;
fn poll(mut self: Pin<&mut Self>, cx: &mut task::Context<'_>) -> Poll<Self::Output> {
let service = ready!(self.as_mut().future().poll(cx))?;
let io = self.as_mut().io().take().expect("polled after complete");
let service = ready!(self.project().future.poll(cx))?;
let io = self.project().io.take().expect("polled after complete");
Poll::Ready(Ok(self.protocol.serve_connection(io, service)))
}
}
@@ -784,17 +783,15 @@ where
B: Payload,
E: H2Exec<<S::Service as Service<Body>>::Future, B>,
{
pub(super) fn poll_watch<W>(self: Pin<&mut Self>, cx: &mut task::Context<'_>, watcher: &W) -> Poll<crate::Result<()>>
pub(super) fn poll_watch<W>(mut self: Pin<&mut Self>, cx: &mut task::Context<'_>, watcher: &W) -> Poll<crate::Result<()>>
where
E: NewSvcExec<IO, S::Future, S::Service, E, W>,
W: Watcher<IO, S::Service, E>,
{
// Safety: futures are never moved... lolwtf
let me = unsafe { self.get_unchecked_mut() };
loop {
if let Some(connecting) = ready!(unsafe { Pin::new_unchecked(&mut me.serve) }.poll_next(cx)?) {
if let Some(connecting) = ready!(self.project().serve.poll_next(cx)?) {
let fut = NewSvcTask::new(connecting, watcher.clone());
me.serve.protocol.exec.execute_new_svc(fut)?;
self.project().serve.project().protocol.exec.execute_new_svc(fut)?;
} else {
return Poll::Ready(Ok(()));
}
@@ -810,13 +807,13 @@ where
{
type Output = A::Output;
fn poll(self: Pin<&mut Self>, cx: &mut task::Context<'_>) -> Poll<Self::Output> {
#[project]
fn poll(mut self: Pin<&mut Self>, cx: &mut task::Context<'_>) -> Poll<Self::Output> {
// Just simple pin projection to the inner variants
unsafe {
match self.get_unchecked_mut() {
Either::A(a) => Pin::new_unchecked(a).poll(cx),
Either::B(b) => Pin::new_unchecked(b).poll(cx),
}
#[project]
match self.project() {
Either::A(a) => a.poll(cx),
Either::B(b) => b.poll(cx),
}
}
}
@@ -830,6 +827,7 @@ pub(crate) mod spawn_all {
use crate::common::{Future, Pin, Poll, Unpin, task};
use crate::service::Service;
use super::{Connecting, UpgradeableConnection};
use pin_project::{pin_project, project};
// Used by `SpawnAll` to optionally watch a `Connection` future.
//
@@ -872,14 +870,18 @@ pub(crate) mod spawn_all {
//
// Users cannot import this type, nor the associated `NewSvcExec`. Instead,
// a blanket implementation for `Executor<impl Future>` is sufficient.
#[pin_project]
#[allow(missing_debug_implementations)]
pub struct NewSvcTask<I, N, S: Service<Body>, E, W: Watcher<I, S, E>> {
#[pin]
state: State<I, N, S, E, W>,
}
enum State<I, N, S: Service<Body>, E, W: Watcher<I, S, E>> {
Connecting(Connecting<I, N, E>, W),
Connected(W::Future),
#[pin_project]
pub enum State<I, N, S: Service<Body>, E, W: Watcher<I, S, E>> {
Connecting(#[pin] Connecting<I, N, E>, W),
Connected(#[pin] W::Future),
}
impl<I, N, S: Service<Body>, E, W: Watcher<I, S, E>> NewSvcTask<I, N, S, E, W> {
@@ -903,16 +905,19 @@ pub(crate) mod spawn_all {
{
type Output = ();
fn poll(self: Pin<&mut Self>, cx: &mut task::Context<'_>) -> Poll<Self::Output> {
#[project]
fn poll(mut self: Pin<&mut Self>, cx: &mut task::Context<'_>) -> Poll<Self::Output> {
// If it weren't for needing to name this type so the `Send` bounds
// could be projected to the `Serve` executor, this could just be
// an `async fn`, and much safer. Woe is me.
let me = unsafe { self.get_unchecked_mut() };
loop {
let next = match me.state {
State::Connecting(ref mut connecting, ref watcher) => {
let res = ready!(unsafe { Pin::new_unchecked(connecting).poll(cx) });
let mut me = self.project();
let next = {
#[project]
match me.state.project() {
State::Connecting(connecting, watcher) => {
let res = ready!(connecting.poll(cx));
let conn = match res {
Ok(conn) => conn,
Err(err) => {
@@ -924,8 +929,8 @@ pub(crate) mod spawn_all {
let connected = watcher.watch(conn.with_upgrades());
State::Connected(connected)
},
State::Connected(ref mut future) => {
return unsafe { Pin::new_unchecked(future) }
State::Connected(future) => {
return future
.poll(cx)
.map(|res| {
if let Err(err) = res {
@@ -933,9 +938,10 @@ pub(crate) mod spawn_all {
}
});
}
}
};
me.state = next;
me.state.set(next);
}
}
}

13
src/server/mod.rs
View File

@@ -59,8 +59,8 @@ use std::fmt;
#[cfg(feature = "runtime")] use std::time::Duration;
use futures_core::Stream;
use pin_utils::unsafe_pinned;
use tokio_io::{AsyncRead, AsyncWrite};
use pin_project::pin_project;
use crate::body::{Body, Payload};
use crate::common::exec::{Exec, H2Exec, NewSvcExec};
@@ -78,7 +78,9 @@ use self::shutdown::{Graceful, GracefulWatcher};
/// handlers. It is built using the [`Builder`](Builder), and the future
/// completes when the server has been shutdown. It should be run by an
/// `Executor`.
#[pin_project]
pub struct Server<I, S, E = Exec> {
#[pin]
spawn_all: SpawnAll<I, S, E>,
}
@@ -101,11 +103,6 @@ impl<I> Server<I, ()> {
}
}
impl<I, S, E> Server<I, S, E> {
// Never moved, just projected
unsafe_pinned!(spawn_all: SpawnAll<I, S, E>);
}
#[cfg(feature = "runtime")]
impl Server<AddrIncoming, ()> {
/// Binds to the provided address, and returns a [`Builder`](Builder).
@@ -216,8 +213,8 @@ where
{
type Output = crate::Result<()>;
fn poll(self: Pin<&mut Self>, cx: &mut task::Context<'_>) -> Poll<Self::Output> {
self.spawn_all().poll_watch(cx, &NoopWatcher)
fn poll(mut self: Pin<&mut Self>, cx: &mut task::Context<'_>) -> Poll<Self::Output> {
self.project().spawn_all.poll_watch(cx, &NoopWatcher)
}
}

32
src/server/shutdown.rs
View File

@@ -2,6 +2,7 @@ use std::error::Error as StdError;
use futures_core::Stream;
use tokio_io::{AsyncRead, AsyncWrite};
use pin_project::{pin_project, project};
use crate::body::{Body, Payload};
use crate::common::drain::{self, Draining, Signal, Watch, Watching};
@@ -11,14 +12,19 @@ use crate::service::{MakeServiceRef, Service};
use super::conn::{SpawnAll, UpgradeableConnection, Watcher};
#[allow(missing_debug_implementations)]
#[pin_project]
pub struct Graceful<I, S, F, E> {
#[pin]
state: State<I, S, F, E>,
}
enum State<I, S, F, E> {
#[pin_project]
pub(super) enum State<I, S, F, E> {
Running {
drain: Option<(Signal, Watch)>,
#[pin]
spawn_all: SpawnAll<I, S, E>,
#[pin]
signal: F,
},
Draining(Draining),
@@ -54,16 +60,18 @@ where
{
type Output = crate::Result<()>;
fn poll(self: Pin<&mut Self>, cx: &mut task::Context<'_>) -> Poll<Self::Output> {
// Safety: the futures are NEVER moved, self.state is overwritten instead.
let me = unsafe { self.get_unchecked_mut() };
#[project]
fn poll(mut self: Pin<&mut Self>, cx: &mut task::Context<'_>) -> Poll<Self::Output> {
let mut me = self.project();
loop {
let next = match me.state {
let next = {
#[project]
match me.state.project() {
State::Running {
ref mut drain,
ref mut spawn_all,
ref mut signal,
} => match unsafe { Pin::new_unchecked(signal) }.poll(cx) {
drain,
spawn_all,
signal,
} => match signal.poll(cx) {
Poll::Ready(()) => {
debug!("signal received, starting graceful shutdown");
let sig = drain
@@ -78,15 +86,15 @@ where
.expect("drain channel")
.1
.clone();
return unsafe { Pin::new_unchecked(spawn_all) }.poll_watch(cx, &GracefulWatcher(watch));
return spawn_all.poll_watch(cx, &GracefulWatcher(watch));
},
},
State::Draining(ref mut draining) => {
return Pin::new(draining).poll(cx).map(Ok);
}
}
};
// It's important to just assign, not mem::replace or anything.
me.state = next;
me.state.set(next);
}
}
}