servo: Merge #4220 - devtools: handle script task panics gracefully in ConsoleActor (from eddyb:devtools-panic); r=jdm

r? @jdm

Source-Repo: https://github.com/servo/servo
Source-Revision: b8444f96f82791d7bbac456dfe23b71b2b09fea3

servo/components/devtools/actor.rs

@@ -21,7 +21,7 @@ pub trait Actor : Any {
                       registry: &ActorRegistry,
                       msg_type: &String,
                       msg: &json::JsonObject,
-                      stream: &mut TcpStream) -> bool;
+                      stream: &mut TcpStream) -> Result<bool, ()>;
     fn name(&self) -> String;
 }
 
@@ -148,13 +148,16 @@ impl ActorRegistry {
 
     /// Attempt to process a message as directed by its `to` property. If the actor is not
     /// found or does not indicate that it knew how to process the message, ignore the failure.
-    pub fn handle_message(&mut self, msg: &json::JsonObject, stream: &mut TcpStream) {
+    pub fn handle_message(&mut self,
+                          msg: &json::JsonObject,
+                          stream: &mut TcpStream)
+                          -> Result<(), ()> {
         let to = msg.get(&"to".to_string()).unwrap().as_string().unwrap();
         match self.actors.get(&to.to_string()) {
             None => println!("message received for unknown actor \"{:s}\"", to),
             Some(actor) => {
                 let msg_type = msg.get(&"type".to_string()).unwrap().as_string().unwrap();
-                if !actor.handle_message(self, &msg_type.to_string(), msg, stream) {
+                if !try!(actor.handle_message(self, &msg_type.to_string(), msg, stream)) {
                     println!("unexpected message type \"{:s}\" found for actor \"{:s}\"",
                              msg_type, to);
                 }
@@ -164,5 +167,6 @@ impl ActorRegistry {
         for actor in new_actors.into_iter() {
             self.actors.insert(actor.name().to_string(), actor);
         }
+        Ok(())
     }
 }

servo/components/devtools/actors/console.rs

@@ -118,8 +118,8 @@ impl Actor for ConsoleActor {
                       _registry: &ActorRegistry,
                       msg_type: &String,
                       msg: &json::JsonObject,
-                      stream: &mut TcpStream) -> bool {
-        match msg_type.as_slice() {
+                      stream: &mut TcpStream) -> Result<bool, ()> {
+        Ok(match msg_type.as_slice() {
             "getCachedMessages" => {
                 let types = msg.get(&"messageTypes".to_string()).unwrap().as_list().unwrap();
                 let /*mut*/ messages = vec!();
@@ -223,7 +223,7 @@ impl Actor for ConsoleActor {
                 self.script_chan.send(EvaluateJS(self.pipeline, input.clone(), chan));
 
                 //TODO: extract conversion into protocol module or some other useful place
-                let result = match port.recv() {
+                let result = match try!(port.recv_opt()) {
                     VoidValue => {
                         let mut m = TreeMap::new();
                         m.insert("type".to_string(), "undefined".to_string().to_json());
@@ -285,6 +285,6 @@ impl Actor for ConsoleActor {
             }
 
             _ => false
-        }
+        })
     }
 }

servo/components/devtools/actors/inspector.rs

@@ -66,8 +66,8 @@ impl Actor for HighlighterActor {
                       _registry: &ActorRegistry,
                       msg_type: &String,
                       _msg: &json::JsonObject,
-                      stream: &mut TcpStream) -> bool {
-        match msg_type.as_slice() {
+                      stream: &mut TcpStream) -> Result<bool, ()> {
+        Ok(match msg_type.as_slice() {
             "showBoxModel" => {
                 let msg = ShowBoxModelReply {
                     from: self.name(),
@@ -85,7 +85,7 @@ impl Actor for HighlighterActor {
             }
 
             _ => false,
-        }
+        })
     }
 }
 
@@ -103,8 +103,8 @@ impl Actor for NodeActor {
                       registry: &ActorRegistry,
                       msg_type: &String,
                       msg: &json::JsonObject,
-                      stream: &mut TcpStream) -> bool {
-        match msg_type.as_slice() {
+                      stream: &mut TcpStream) -> Result<bool, ()> {
+        Ok(match msg_type.as_slice() {
             "modifyAttributes" => {
                 let target = msg.get(&"to".to_string()).unwrap().as_string().unwrap();
                 let mods = msg.get(&"modifications".to_string()).unwrap().as_list().unwrap();
@@ -123,7 +123,7 @@ impl Actor for NodeActor {
             }
 
             _ => false,
-        }
+        })
     }
 }
 
@@ -276,8 +276,8 @@ impl Actor for WalkerActor {
                       registry: &ActorRegistry,
                       msg_type: &String,
                       msg: &json::JsonObject,
-                      stream: &mut TcpStream) -> bool {
-        match msg_type.as_slice() {
+                      stream: &mut TcpStream) -> Result<bool, ()> {
+        Ok(match msg_type.as_slice() {
             "querySelector" => {
                 let msg = QuerySelectorReply {
                     from: self.name(),
@@ -329,7 +329,7 @@ impl Actor for WalkerActor {
             }
 
             _ => false,
-        }
+        })
     }
 }
 
@@ -421,8 +421,8 @@ impl Actor for PageStyleActor {
                       registry: &ActorRegistry,
                       msg_type: &String,
                       msg: &json::JsonObject,
-                      stream: &mut TcpStream) -> bool {
-        match msg_type.as_slice() {
+                      stream: &mut TcpStream) -> Result<bool, ()> {
+        Ok(match msg_type.as_slice() {
             "getApplied" => {
                 //TODO: query script for relevant applied styles to node (msg.node)
                 let msg = GetAppliedReply {
@@ -479,7 +479,7 @@ impl Actor for PageStyleActor {
             }
 
             _ => false,
-        }
+        })
     }
 }
 
@@ -492,8 +492,8 @@ impl Actor for InspectorActor {
                       registry: &ActorRegistry,
                       msg_type: &String,
                       _msg: &json::JsonObject,
-                      stream: &mut TcpStream) -> bool {
-        match msg_type.as_slice() {
+                      stream: &mut TcpStream) -> Result<bool, ()> {
+        Ok(match msg_type.as_slice() {
             "getWalker" => {
                 if self.walker.borrow().is_none() {
                     let walker = WalkerActor {
@@ -569,6 +569,6 @@ impl Actor for InspectorActor {
             }
 
             _ => false,
-        }
+        })
     }
 }

servo/components/devtools/actors/root.rs

@@ -54,8 +54,8 @@ impl Actor for RootActor {
                       registry: &ActorRegistry,
                       msg_type: &String,
                       _msg: &json::JsonObject,
-                      stream: &mut TcpStream) -> bool {
-        match msg_type.as_slice() {
+                      stream: &mut TcpStream) -> Result<bool, ()> {
+        Ok(match msg_type.as_slice() {
             "listAddons" => {
                 let actor = ErrorReply {
                     from: "root".to_string(),
@@ -80,7 +80,7 @@ impl Actor for RootActor {
             }
 
             _ => false
-        }
+        })
     }
 }
 

servo/components/devtools/actors/tab.rs

@@ -78,8 +78,8 @@ impl Actor for TabActor {
                       registry: &ActorRegistry,
                       msg_type: &String,
                       _msg: &json::JsonObject,
-                      stream: &mut TcpStream) -> bool {
-        match msg_type.as_slice() {
+                      stream: &mut TcpStream) -> Result<bool, ()> {
+        Ok(match msg_type.as_slice() {
             "reconfigure" => {
                 stream.write_json_packet(&ReconfigureReply { from: self.name() });
                 true
@@ -125,7 +125,7 @@ impl Actor for TabActor {
             }
 
             _ => false
-        }
+        })
     }
 }
 

servo/components/devtools/lib.rs

@@ -101,9 +101,18 @@ fn run_server(receiver: Receiver<DevtoolsControlMsg>, port: u16) {
 
         'outer: loop {
             match stream.read_json_packet() {
-                Ok(json_packet) =>
-                    actors.lock().handle_message(json_packet.as_object().unwrap(),
-                                                                &mut stream),
+                Ok(json_packet) => {
+                    match actors.lock().handle_message(json_packet.as_object().unwrap(),
+                                                       &mut stream) {
+                        Ok(()) => {},
+                        Err(()) => {
+                            println!("error: devtools actor stopped responding");
+                            stream.close_read();
+                            stream.close_write();
+                            break 'outer
+                        }
+                    }
+                }
                 Err(e) => {
                     println!("error: {}", e.desc);
                     break 'outer