Auto merge of #21325 - gterzian:crossbeam_integration, r=SimonSapin,jdm

Replace mpsc with crossbeam-channel

Follow up on https://github.com/servo/servo/pull/19515

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Selecting over multiple channels in `std::sync::mpsc` is not stable and likely never will be:

https://github.com/rust-lang/rust/issues/27800#issuecomment-260136777
> It seems the only thing keeping `mpsc_select` around is Servo.

crossbeam-channel is designed specifically to replace `std::sync::mpsc` and fix many of its shortcomings:
https://github.com/stjepang/rfcs-crossbeam/blob/channel/text/2017-11-09-channel.md

This is to be landed together with https://github.com/servo/ipc-channel/pull/183.

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1 files changed, 7 insertions, 11 deletions

diff --git a/components/script/serviceworker_manager.rs b/components/script/serviceworker_manager.rs
index 2bf19aa25a5..4573a5666c3 100644
--- a/components/script/serviceworker_manager.rs
+++ b/components/script/serviceworker_manager.rs
@@ -13,13 +13,12 @@ use dom::bindings::structuredclone::StructuredCloneData;
 use dom::serviceworkerglobalscope::{ServiceWorkerGlobalScope, ServiceWorkerScriptMsg};
 use dom::serviceworkerregistration::longest_prefix_match;
 use ipc_channel::ipc::{self, IpcSender};
-use ipc_channel::router::ROUTER;
 use net_traits::{CustomResponseMediator, CoreResourceMsg};
 use script_traits::{ServiceWorkerMsg, ScopeThings, SWManagerMsg, SWManagerSenders, DOMMessage};
+use servo_channel::{channel, route_ipc_receiver_to_new_servo_receiver, Sender, Receiver};
 use servo_config::prefs::PREFS;
 use servo_url::ServoUrl;
 use std::collections::HashMap;
-use std::sync::mpsc::{channel, Sender, Receiver, RecvError};
 use std::thread;
 
 enum Message {
@@ -56,8 +55,8 @@ impl ServiceWorkerManager {
     pub fn spawn_manager(sw_senders: SWManagerSenders) {
         let (own_sender, from_constellation_receiver) = ipc::channel().unwrap();
         let (resource_chan, resource_port) = ipc::channel().unwrap();
-        let from_constellation = ROUTER.route_ipc_receiver_to_new_mpsc_receiver(from_constellation_receiver);
-        let resource_port = ROUTER.route_ipc_receiver_to_new_mpsc_receiver(resource_port);
+        let from_constellation = route_ipc_receiver_to_new_servo_receiver(from_constellation_receiver);
+        let resource_port = route_ipc_receiver_to_new_servo_receiver(resource_port);
         let _ = sw_senders.resource_sender.send(CoreResourceMsg::NetworkMediator(resource_chan));
         let _ = sw_senders.swmanager_sender.send(SWManagerMsg::OwnSender(own_sender.clone()));
         thread::Builder::new().name("ServiceWorkerManager".to_owned()).spawn(move || {
@@ -108,7 +107,7 @@ impl ServiceWorkerManager {
     }
 
     fn handle_message(&mut self) {
-        while let Ok(message) = self.receive_message() {
+        while let Some(message) = self.receive_message() {
             let should_continue = match message {
                 Message::FromConstellation(msg) => {
                     self.handle_message_from_constellation(msg)
@@ -184,13 +183,10 @@ impl ServiceWorkerManager {
         true
     }
 
-    #[allow(unsafe_code)]
-    fn receive_message(&mut self) -> Result<Message, RecvError> {
-        let msg_from_constellation = &self.own_port;
-        let msg_from_resource = &self.resource_receiver;
+    fn receive_message(&mut self) -> Option<Message> {
         select! {
-            msg = msg_from_constellation.recv() => msg.map(Message::FromConstellation),
-            msg = msg_from_resource.recv() => msg.map(Message::FromResource)
+            recv(self.own_port.select(), msg) => msg.map(Message::FromConstellation),
+            recv(self.resource_receiver.select(), msg) => msg.map(Message::FromResource),
         }
     }
 }