From d19a5e1ea1d373f5cc8591bb2a0d5d80d4742abe Mon Sep 17 00:00:00 2001
From: Josh Leeb-du Toit <mail@joshleeb.com>
Date: Thu, 16 May 2019 19:17:18 +1000
Subject: [PATCH] Add ServerCommand::Restart and Command::Restart

This PR creates a new `ServerCommand` and corresponding `Command` to restart
server workers.

Related to actix/actix-web#280
---
 actix-server/src/accept.rs  | 21 +++++++++++++++++++++
 actix-server/src/builder.rs |  4 ++++
 actix-server/src/server.rs  |  8 ++++++++
 3 files changed, 33 insertions(+)

diff --git a/actix-server/src/accept.rs b/actix-server/src/accept.rs
index e02fb05f..f152e608 100644
--- a/actix-server/src/accept.rs
+++ b/actix-server/src/accept.rs
@@ -16,6 +16,7 @@ use super::Token;
 pub(crate) enum Command {
     Pause,
     Resume,
+    Restart,
     Stop,
     Worker(WorkerClient),
 }
@@ -315,6 +316,26 @@ impl Accept {
                             }
                         }
                     }
+                    Command::Restart => {
+                        for (token, info) in self.sockets.iter_mut() {
+                            if let Err(err) = self.poll.deregister(&info.sock) {
+                                error!("Can not restart server socket {}", err);
+                            }
+                            if let Err(err) = self.poll.reregister(
+                                &info.sock,
+                                mio::Token(token + DELTA),
+                                mio::Ready::readable(),
+                                mio::PollOpt::edge(),
+                            ) {
+                                error!("Can not restart socket accept process: {}", err);
+                            } else {
+                                info!(
+                                    "Accepting connections on {} has been restarted",
+                                    info.addr
+                                );
+                            }
+                        }
+                    }
                     Command::Stop => {
                         for (_, info) in self.sockets.iter() {
                             let _ = self.poll.deregister(&info.sock);
diff --git a/actix-server/src/builder.rs b/actix-server/src/builder.rs
index 7cd8bfab..bd70404e 100644
--- a/actix-server/src/builder.rs
+++ b/actix-server/src/builder.rs
@@ -287,6 +287,10 @@ impl ServerBuilder {
                 self.accept.send(Command::Resume);
                 let _ = tx.send(());
             }
+            ServerCommand::Restart(tx) => {
+                self.accept.send(Command::Restart);
+                let _ = tx.send(());
+            }
             ServerCommand::Signal(sig) => {
                 // Signals support
                 // Handle `SIGINT`, `SIGTERM`, `SIGQUIT` signals and stop actix system
diff --git a/actix-server/src/server.rs b/actix-server/src/server.rs
index f1d862c9..82219331 100644
--- a/actix-server/src/server.rs
+++ b/actix-server/src/server.rs
@@ -10,6 +10,7 @@ pub(crate) enum ServerCommand {
     WorkerDied(usize),
     Pause(oneshot::Sender<()>),
     Resume(oneshot::Sender<()>),
+    Restart(oneshot::Sender<()>),
     Signal(Signal),
     /// Whether to try and shut down gracefully
     Stop {
@@ -56,6 +57,13 @@ impl Server {
         rx.map_err(|_| ())
     }
 
+    /// Restart server
+    pub fn restart(&self) -> impl Future<Item = (), Error = ()> {
+        let (tx, rx) = oneshot::channel();
+        let _ = self.0.unbounded_send(ServerCommand::Restart(tx));
+        rx.map_err(|_| ())
+    }
+
     /// Stop incoming connection processing, stop all workers and exit.
     ///
     /// If server starts with `spawn()` method, then spawned thread get terminated.