From 317d9ffdca6e48cd81ea164af30436ebbd5ce4f8 Mon Sep 17 00:00:00 2001
From: spr-equinox <66425054+spr-equinox@users.noreply.github.com>
Date: Sun, 15 Jun 2025 21:37:31 +0800
Subject: [PATCH] Fix deadlock when throwing items (#865) (#902)

* Fix deadlock when throwing items

try test again

* remove unnecessary async
---
 pumpkin-inventory/src/screen_handler.rs |  6 +++---
 pumpkin/src/entity/player.rs            | 15 ++++++---------
 pumpkin/src/net/packet/play.rs          |  4 +---
 3 files changed, 10 insertions(+), 15 deletions(-)

diff --git a/pumpkin-inventory/src/screen_handler.rs b/pumpkin-inventory/src/screen_handler.rs
index 814f36a32..d7303f288 100644
--- a/pumpkin-inventory/src/screen_handler.rs
+++ b/pumpkin-inventory/src/screen_handler.rs
@@ -165,7 +165,7 @@ pub trait ScreenHandler: Send + Sync {
         }
     }
 
-    async fn set_received_hash(&mut self, slot: usize, hash: OptionalItemStackHash) {
+    fn set_received_hash(&mut self, slot: usize, hash: OptionalItemStackHash) {
         let behaviour = self.get_behaviour_mut();
         if slot < behaviour.previous_tracked_stacks.len() {
             behaviour.previous_tracked_stacks[slot].set_received_hash(hash);
@@ -178,12 +178,12 @@ pub trait ScreenHandler: Send + Sync {
         }
     }
 
-    async fn set_received_stack(&mut self, slot: usize, stack: ItemStack) {
+    fn set_received_stack(&mut self, slot: usize, stack: ItemStack) {
         let behaviour = self.get_behaviour_mut();
         behaviour.previous_tracked_stacks[slot].set_received_stack(stack);
     }
 
-    async fn set_received_cursor_hash(&mut self, hash: OptionalItemStackHash) {
+    fn set_received_cursor_hash(&mut self, hash: OptionalItemStackHash) {
         let behaviour = self.get_behaviour_mut();
         behaviour.previous_cursor_stack.set_received_hash(hash);
     }
diff --git a/pumpkin/src/entity/player.rs b/pumpkin/src/entity/player.rs
index c4c637efd..2f4203a76 100644
--- a/pumpkin/src/entity/player.rs
+++ b/pumpkin/src/entity/player.rs
@@ -1454,6 +1454,8 @@ impl Player {
     }
 
     pub async fn drop_held_item(&self, drop_stack: bool) {
+        // should be locked first otherwise cause deadlock in tick() (this thread lock stack, that thread lock screen_handler)
+        let screen_binding = self.current_screen_handler.lock().await;
         let binding = self.inventory.held_item();
         let mut item_stack = binding.lock().await;
 
@@ -1464,16 +1466,13 @@ impl Player {
             item_stack.decrement(drop_amount);
             let selected_slot = self.inventory.get_selected_slot();
             let inv: Arc<dyn Inventory> = self.inventory.clone();
-            let binding = self.current_screen_handler.lock().await;
-            let mut screen_handler = binding.lock().await;
+            let mut screen_handler = screen_binding.lock().await;
             let slot_index = screen_handler
                 .get_slot_index(&inv, selected_slot as usize)
                 .await;
 
             if let Some(slot_index) = slot_index {
-                screen_handler
-                    .set_received_stack(slot_index, *item_stack)
-                    .await;
+                screen_handler.set_received_stack(slot_index, *item_stack);
             }
         }
     }
@@ -1821,12 +1820,10 @@ impl Player {
             .await;
 
         for (key, value) in packet.array_of_changed_slots {
-            screen_handler.set_received_hash(key as usize, value).await;
+            screen_handler.set_received_hash(key as usize, value);
         }
 
-        screen_handler
-            .set_received_cursor_hash(packet.carried_item)
-            .await;
+        screen_handler.set_received_cursor_hash(packet.carried_item);
         screen_handler.enable_sync().await;
 
         if not_in_sync {
diff --git a/pumpkin/src/net/packet/play.rs b/pumpkin/src/net/packet/play.rs
index feafbda2a..5afa90668 100644
--- a/pumpkin/src/net/packet/play.rs
+++ b/pumpkin/src/net/packet/play.rs
@@ -1459,9 +1459,7 @@ impl Player {
                 .await
                 .set_stack(item_stack)
                 .await;
-            player_screen_handler
-                .set_received_stack(packet.slot as usize, item_stack)
-                .await;
+            player_screen_handler.set_received_stack(packet.slot as usize, item_stack);
             player_screen_handler.send_content_updates().await;
         } else if is_negative && is_legal {
             // Item drop