add graceful shutdown system

examples/signals/Cargo.toml

@@ -11,7 +11,4 @@ path = "src/main.rs"
 env_logger = "*"
 futures = "0.1"
 actix = "^0.3.5"
-
-#actix-web = { git = "https://github.com/actix/actix-web.git" }
-
-actix-web = { path="../../", features=["signal"] }
+actix-web = { git = "https://github.com/actix/actix-web.git", features=["signal"] }

examples/signals/src/main.rs

@@ -3,10 +3,22 @@ extern crate actix_web;
 extern crate futures;
 extern crate env_logger;
 
+use actix::*;
 use actix_web::*;
-use actix::Arbiter;
 use actix::actors::signal::{ProcessSignals, Subscribe};
 
+struct MyWebSocket;
+
+impl Actor for MyWebSocket {
+    type Context = HttpContext<Self>;
+}
+
+impl StreamHandler<ws::Message> for MyWebSocket {}
+impl Handler<ws::Message> for MyWebSocket {
+    fn handle(&mut self, _: ws::Message, _: &mut Self::Context) -> Response<Self, ws::Message> {
+        Self::empty()
+    }
+}
 
 fn main() {
     ::std::env::set_var("RUST_LOG", "actix_web=info");
@@ -17,6 +29,7 @@ fn main() {
         Application::new()
             // enable logger
             .middleware(middleware::Logger::default())
+            .resource("/ws/", |r| r.f(|req| ws::start(req, MyWebSocket)))
             .resource("/", |r| r.h(httpcodes::HTTPOk))})
         .bind("127.0.0.1:8080").unwrap()
         .start();

guide/src/qs_3_5.md

@@ -164,3 +164,73 @@ fn index(req: HttpRequest) -> HttpResponse {
 }
 # fn main() {}
 ```
+
+## Graceful shutdown
+
+Actix http server support graceful shutdown. After receiving a stop signal, workers
+have specific amount of time to finish serving requests. Workers still alive after the
+timeout are force dropped. By default shutdown timeout sets to 30 seconds.
+You can change this parameter with `HttpServer::shutdown_timeout()` method.
+
+You can send stop message to server with server address and specify if you what 
+graceful shutdown or not. `start()` or `spawn()` methods return address of the server.
+
+```rust
+# extern crate futures;
+# extern crate actix;
+# extern crate actix_web;
+# use futures::Future;
+use actix_web::*;
+
+fn main() {
+    let addr = HttpServer::new(
+        || Application::new()
+             .resource("/", |r| r.h(httpcodes::HTTPOk)))
+        .bind("127.0.0.1:0").expect("Can not bind to 127.0.0.1:0")
+        .shutdown_timeout(60)    // <- Set shutdown timeout to 60 seconds
+        .spawn();
+
+    let _ = addr.call_fut(
+         dev::StopServer{graceful:true}).wait(); // <- Send `StopServer` message to server.
+}
+```
+
+It is possible to use unix signals on compatible OSs. "signal" feature needs to be enabled
+in *Cargo.toml* for *actix-web* dependency.
+
+```toml
+[dependencies]
+actix-web = { git = "https://github.com/actix/actix-web", features=["signal"] }
+```
+
+Then you can subscribe your server to unix signals. Http server handles three signals:
+
+* *SIGINT* - Force shutdown workers
+* *SIGTERM* - Graceful shutdown workers
+* *SIGQUIT* - Force shutdown workers
+
+```rust,ignore
+# extern crate futures;
+# extern crate actix;
+# extern crate actix_web;
+use actix_web::*;
+use actix::actors::signal::{ProcessSignals, Subscribe};
+
+fn main() {
+    let sys = actix::System::new("signals");
+
+    let addr = HttpServer::new(|| {
+        Application::new()
+            .resource("/", |r| r.h(httpcodes::HTTPOk))})
+        .bind("127.0.0.1:8080").unwrap()
+        .start();
+
+    // Subscribe to unix signals
+    let signals = Arbiter::system_registry().get::<ProcessSignals>();
+    signals.send(Subscribe(addr.subscriber()));
+
+    println!("Started http server: 127.0.0.1:8080");
+    #     actix::Arbiter::system().send(actix::msgs::SystemExit(0));
+    let _ = sys.run();
+}
+```

src/channel.rs

@@ -1,7 +1,6 @@
 use std::rc::Rc;
 use std::net::SocketAddr;
 
-use actix::dev::*;
 use bytes::Bytes;
 use futures::{Future, Poll, Async};
 use tokio_io::{AsyncRead, AsyncWrite};
@@ -71,6 +70,7 @@ impl<T, H> HttpChannel<T, H>
     pub(crate) fn new(h: Rc<WorkerSettings<H>>,
                io: T, peer: Option<SocketAddr>, http2: bool) -> HttpChannel<T, H>
     {
+        h.add_channel();
         if http2 {
             HttpChannel {
                 proto: Some(HttpProtocol::H2(
@@ -89,12 +89,6 @@ impl<T, H> HttpChannel<T, H>
     }
 }*/
 
-impl<T, H> Actor for HttpChannel<T, H>
-    where T: AsyncRead + AsyncWrite + 'static, H: HttpHandler + 'static
-{
-    type Context = Context<Self>;
-}
-
 impl<T, H> Future for HttpChannel<T, H>
     where T: AsyncRead + AsyncWrite + 'static, H: HttpHandler + 'static
 {
@@ -105,16 +99,27 @@ impl<T, H> Future for HttpChannel<T, H>
         match self.proto {
             Some(HttpProtocol::H1(ref mut h1)) => {
                 match h1.poll() {
-                    Ok(Async::Ready(h1::Http1Result::Done)) =>
-                        return Ok(Async::Ready(())),
+                    Ok(Async::Ready(h1::Http1Result::Done)) => {
+                        h1.settings().remove_channel();
+                        return Ok(Async::Ready(()))
+                    }
                     Ok(Async::Ready(h1::Http1Result::Switch)) => (),
                     Ok(Async::NotReady) =>
                         return Ok(Async::NotReady),
-                    Err(_) =>
-                        return Err(()),
+                    Err(_) => {
+                        h1.settings().remove_channel();
+                        return Err(())
                     }
                 }
-            Some(HttpProtocol::H2(ref mut h2)) => return h2.poll(),
+            }
+            Some(HttpProtocol::H2(ref mut h2)) => {
+                let result = h2.poll();
+                match result {
+                    Ok(Async::Ready(())) | Err(_) => h2.settings().remove_channel(),
+                    _ => (),
+                }
+                return result
+            }
             None => unreachable!(),
         }
 

src/h1.rs

@@ -89,6 +89,10 @@ impl<T, H> Http1<T, H>
                keepalive_timer: None }
     }
 
+    pub fn settings(&self) -> &WorkerSettings<H> {
+        self.settings.as_ref()
+    }
+
     pub fn into_inner(self) -> (Rc<WorkerSettings<H>>, T, Option<SocketAddr>, Bytes) {
         (self.settings, self.stream.into_inner(), self.addr, self.read_buf.freeze())
     }

src/h2.rs

@@ -64,6 +64,10 @@ impl<T, H> Http2<T, H>
         }
     }
 
+    pub fn settings(&self) -> &WorkerSettings<H> {
+        self.settings.as_ref()
+    }
+
     pub fn poll(&mut self) -> Poll<(), ()> {
         // server
         if let State::Server(ref mut server) = self.state {

src/server.rs

@@ -7,7 +7,7 @@ use std::collections::HashMap;
 
 use actix::dev::*;
 use actix::System;
-use futures::Stream;
+use futures::{Future, Sink, Stream};
 use futures::sync::mpsc;
 use tokio_io::{AsyncRead, AsyncWrite};
 use tokio_core::net::TcpStream;
@@ -107,6 +107,7 @@ pub struct HttpServer<T, A, H, U>
     sockets: HashMap<net::SocketAddr, net::TcpListener>,
     accept: Vec<(mio::SetReadiness, sync_mpsc::Sender<Command>)>,
     exit: bool,
+    shutdown_timeout: u16,
 }
 
 unsafe impl<T, A, H, U> Sync for HttpServer<T, A, H, U> where H: 'static {}
@@ -151,6 +152,7 @@ impl<T, A, H, U, V> HttpServer<T, A, H, U>
                     sockets: HashMap::new(),
                     accept: Vec::new(),
                     exit: false,
+                    shutdown_timeout: 30,
         }
     }
 
@@ -210,6 +212,17 @@ impl<T, A, H, U, V> HttpServer<T, A, H, U>
         self
     }
 
+    /// Timeout for graceful workers shutdown.
+    ///
+    /// After receiving a stop signal, workers have this much time to finish serving requests.
+    /// Workers still alive after the timeout are force dropped.
+    ///
+    /// By default shutdown timeout sets to 30 seconds.
+    pub fn shutdown_timeout(mut self, sec: u16) -> Self {
+        self.shutdown_timeout = sec;
+        self
+    }
+
     /// Get addresses of bound sockets.
     pub fn addrs(&self) -> Vec<net::SocketAddr> {
         self.sockets.keys().cloned().collect()
@@ -607,14 +620,36 @@ impl<T, A, H, U> Handler<StopServer> for HttpServer<T, A, H, U>
             let _ = item.1.send(Command::Stop);
             let _ = item.0.set_readiness(mio::Ready::readable());
         }
-        ctx.stop();
 
         // stop workers
-        let dur = if msg.graceful { Some(Duration::new(30, 0)) } else { None };
+        let (tx, rx) = mpsc::channel(1);
+
+        let dur = if msg.graceful {
+            Some(Duration::new(u64::from(self.shutdown_timeout), 0))
+        } else {
+            None
+        };
         for worker in &self.workers {
-            worker.send(StopWorker{graceful: dur})
+            let tx2 = tx.clone();
+            let fut = worker.call(self, StopWorker{graceful: dur});
+            ActorFuture::then(fut, move |_, slf, _| {
+                slf.workers.pop();
+                if slf.workers.is_empty() {
+                    let _ = tx2.send(());
+
+                    // we need to stop system if server was spawned
+                    if slf.exit {
+                        Arbiter::system().send(msgs::SystemExit(0))
+                    }
+                }
+                fut::ok(())
+            }).spawn(ctx);
         }
 
+        if !self.workers.is_empty() {
+            Self::async_reply(
+                rx.into_future().map(|_| ()).map_err(|_| ()).actfuture())
+        } else {
             // we need to stop system if server was spawned
             if self.exit {
                 Arbiter::system().send(msgs::SystemExit(0))
@@ -622,6 +657,7 @@ impl<T, A, H, U> Handler<StopServer> for HttpServer<T, A, H, U>
             Self::empty()
         }
     }
+}
 
 enum Command {
     Pause,

src/worker.rs

@@ -1,25 +1,27 @@
 use std::{net, time};
 use std::rc::Rc;
-use std::cell::{RefCell, RefMut};
+use std::cell::{Cell, RefCell, RefMut};
+use futures::Future;
+use futures::unsync::oneshot;
 use tokio_core::net::TcpStream;
 use tokio_core::reactor::Handle;
 use net2::TcpStreamExt;
 
 #[cfg(feature="tls")]
-use futures::{future, Future};
+use futures::future;
 #[cfg(feature="tls")]
 use native_tls::TlsAcceptor;
 #[cfg(feature="tls")]
 use tokio_tls::TlsAcceptorExt;
 
 #[cfg(feature="alpn")]
-use futures::{future, Future};
+use futures::future;
 #[cfg(feature="alpn")]
 use openssl::ssl::SslAcceptor;
 #[cfg(feature="alpn")]
 use tokio_openssl::SslAcceptorExt;
 
-use actix::{Actor, Arbiter, AsyncContext, Context, Handler, Response, StreamHandler};
+use actix::*;
 use actix::msgs::StopArbiter;
 
 use helpers;
@@ -33,8 +35,10 @@ pub(crate) struct Conn<T> {
     pub http2: bool,
 }
 
-/// Stop worker
+/// Stop worker message. Returns `true` on successful shutdown
+/// and `false` if some connections still alive.
 #[derive(Message)]
+#[rtype(bool)]
 pub(crate) struct StopWorker {
     pub graceful: Option<time::Duration>,
 }
@@ -45,6 +49,7 @@ pub(crate) struct WorkerSettings<H> {
     keep_alive: u64,
     bytes: Rc<helpers::SharedBytesPool>,
     messages: Rc<helpers::SharedMessagePool>,
+    channels: Cell<usize>,
 }
 
 impl<H> WorkerSettings<H> {
@@ -55,6 +60,7 @@ impl<H> WorkerSettings<H> {
             keep_alive: keep_alive.unwrap_or(0),
             bytes: Rc::new(helpers::SharedBytesPool::new()),
             messages: Rc::new(helpers::SharedMessagePool::new()),
+            channels: Cell::new(0),
         }
     }
 
@@ -73,6 +79,17 @@ impl<H> WorkerSettings<H> {
     pub fn get_http_message(&self) -> helpers::SharedHttpMessage {
         helpers::SharedHttpMessage::new(self.messages.get(), Rc::clone(&self.messages))
     }
+    pub fn add_channel(&self) {
+        self.channels.set(self.channels.get()+1);
+    }
+    pub fn remove_channel(&self) {
+        let num = self.channels.get();
+        if num > 0 {
+            self.channels.set(num-1);
+        } else {
+            error!("Number of removed channels is bigger than added channel. Bug in actix-web");
+        }
+    }
 }
 
 /// Http worker
@@ -100,6 +117,24 @@ impl<H: 'static> Worker<H> {
         helpers::update_date();
         ctx.run_later(time::Duration::new(1, 0), |slf, ctx| slf.update_time(ctx));
     }
+
+    fn shutdown_timeout(&self, ctx: &mut Context<Self>,
+                        tx: oneshot::Sender<bool>, dur: time::Duration) {
+        // sleep for 1 second and then check again
+        ctx.run_later(time::Duration::new(1, 0), move |slf, ctx| {
+            let num = slf.h.channels.get();
+            if num == 0 {
+                let _ = tx.send(true);
+                Arbiter::arbiter().send(StopArbiter(0));
+            } else if let Some(d) = dur.checked_sub(time::Duration::new(1, 0)) {
+                slf.shutdown_timeout(ctx, tx, d);
+            } else {
+                info!("Force shutdown http worker, {} connections", num);
+                let _ = tx.send(false);
+                Arbiter::arbiter().send(StopArbiter(0));
+            }
+        });
+    }
 }
 
 impl<H: 'static> Actor for Worker<H> {
@@ -133,10 +168,21 @@ impl<H> Handler<Conn<net::TcpStream>> for Worker<H>
 impl<H> Handler<StopWorker> for Worker<H>
     where H: HttpHandler + 'static,
 {
-    fn handle(&mut self, _: StopWorker, _: &mut Context<Self>) -> Response<Self, StopWorker>
+    fn handle(&mut self, msg: StopWorker, ctx: &mut Context<Self>) -> Response<Self, StopWorker>
     {
-        Arbiter::arbiter().send(StopArbiter(0));
-        Self::empty()
+        let num = self.h.channels.get();
+        if num == 0 {
+            info!("Shutting down http worker, 0 connections");
+            Self::reply(true)
+        } else if let Some(dur) = msg.graceful {
+            info!("Graceful http worker shutdown, {} connections", num);
+            let (tx, rx) = oneshot::channel();
+            self.shutdown_timeout(ctx, tx, dur);
+            Self::async_reply(rx.map_err(|_| ()).actfuture())
+        } else {
+            info!("Force shutdown http worker, {} connections", num);
+            Self::reply(false)
+        }
     }
 }