From 1beea5967f1fdcebb9fd414eae3e1dce5d8e2c4e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marcel=20M=C3=A4rtens?= <marcel.cochem@googlemail.com>
Date: Mon, 17 Aug 2020 14:21:36 +0200
Subject: [PATCH 1/2] investigate if participant mutex causes server hang

---
 server/src/events/player.rs | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/server/src/events/player.rs b/server/src/events/player.rs
index 439fc613d1..3e5aac94d1 100644
--- a/server/src/events/player.rs
+++ b/server/src/events/player.rs
@@ -80,7 +80,13 @@ pub fn handle_exit_ingame(server: &mut Server, entity: EcsEntity) {
 pub fn handle_client_disconnect(server: &mut Server, entity: EcsEntity) -> Event {
     if let Some(client) = server.state().read_storage::<Client>().get(entity) {
         trace!("Closing participant of client");
-        let participant = client.participant.lock().unwrap().take().unwrap();
+        let participant = match client.participant.try_lock() {
+            Ok(mut p) => p.take().unwrap(),
+            Err(e) => {
+                error!(?e, "coudln't lock participant for removal");
+                panic!("coudlnt lock participant, not good!");
+            },
+        };
         if let Err(e) = block_on(participant.disconnect()) {
             debug!(
                 ?e,

From 08e7063a3666dcd15b8021df94fd635b638bdb35 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marcel=20M=C3=A4rtens?= <marcel.cochem@googlemail.com>
Date: Mon, 17 Aug 2020 16:34:02 +0200
Subject: [PATCH 2/2] no longer block when disconnecting a player

---
 server/src/events/player.rs | 28 ++++++++++++++++++++--------
 1 file changed, 20 insertions(+), 8 deletions(-)

diff --git a/server/src/events/player.rs b/server/src/events/player.rs
index 3e5aac94d1..306300605e 100644
--- a/server/src/events/player.rs
+++ b/server/src/events/player.rs
@@ -10,7 +10,7 @@ use common::{
 };
 use futures_executor::block_on;
 use specs::{saveload::MarkerAllocator, Builder, Entity as EcsEntity, WorldExt};
-use tracing::{debug, error, trace};
+use tracing::{debug, error, trace, warn};
 
 pub fn handle_exit_ingame(server: &mut Server, entity: EcsEntity) {
     let state = server.state_mut();
@@ -84,15 +84,27 @@ pub fn handle_client_disconnect(server: &mut Server, entity: EcsEntity) -> Event
             Ok(mut p) => p.take().unwrap(),
             Err(e) => {
                 error!(?e, "coudln't lock participant for removal");
-                panic!("coudlnt lock participant, not good!");
+                return Event::ClientDisconnected { entity };
             },
         };
-        if let Err(e) = block_on(participant.disconnect()) {
-            debug!(
-                ?e,
-                "Error when disconnecting client, maybe the pipe already broke"
-            );
-        };
+        std::thread::spawn(|| {
+            let pid = participant.remote_pid();
+            let now = std::time::Instant::now();
+            trace!(?pid, "start disconnect");
+            if let Err(e) = block_on(participant.disconnect()) {
+                debug!(
+                    ?e,
+                    "Error when disconnecting client, maybe the pipe already broke"
+                );
+            };
+            trace!(?pid, "finished disconnect");
+            let elapsed = now.elapsed();
+            if elapsed.as_millis() > 100 {
+                warn!(?elapsed, "disconecting took quite long");
+            } else {
+                debug!(?elapsed, "disconecting took");
+            }
+        });
     }
 
     let state = server.state_mut();