From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: wangxyper <wangxyper@163.com>
Date: Tue, 24 Jan 2023 09:32:37 +0800
Subject: [PATCH] Hearse: Fix some threading issue in bukkit event system

Original license: MIT
Original project: https://github.com/Era4FunMC/Hearse

diff --git a/src/main/java/org/bukkit/Server.java b/src/main/java/org/bukkit/Server.java
index 236aa2c1841eef6ca723a809b1632894bebf0b67..6065bc202d3a5d7efb32ccdd1e7a3131a1a36b4c 100644
--- a/src/main/java/org/bukkit/Server.java
+++ b/src/main/java/org/bukkit/Server.java
@@ -1489,6 +1489,12 @@ public interface Server extends PluginMessageRecipient, net.kyori.adventure.audi
      */
     boolean isPrimaryThread();
 
+    //Hearse start
+    /**
+     * Get current thread is worker or other
+     */
+    boolean isWorkerThread();
+
     // Paper start
     /**
      * Gets the message that is displayed on the server list.
diff --git a/src/main/java/org/bukkit/plugin/SimplePluginManager.java b/src/main/java/org/bukkit/plugin/SimplePluginManager.java
index 17b8d42f8e2897eb019ef12ad772ed0d505f7e84..df42a02c80931e234ca1ca1cfb3a2a83c1453870 100644
--- a/src/main/java/org/bukkit/plugin/SimplePluginManager.java
+++ b/src/main/java/org/bukkit/plugin/SimplePluginManager.java
@@ -646,8 +646,11 @@ public final class SimplePluginManager implements PluginManager {
             defaultPerms.get(false).clear();
         }
     }
+
     private void fireEvent(Event event) { callEvent(event); } // Paper - support old method incase plugin uses reflection
 
+    private final Object eventLock = new Object();//Hearse ensure event system thread safe
+
     /**
      * Calls an event with the given details.
      *
@@ -655,6 +658,20 @@ public final class SimplePluginManager implements PluginManager {
      */
     @Override
     public void callEvent(@NotNull Event event) {
+        // Hearse start
+        if (server.isWorkerThread()) {
+            synchronized (this.eventLock) {
+                this.fireCallEvent(event);
+            }
+            return;
+        }
+
+        this.fireCallEvent(event);
+        // Hearse end
+    }
+
+    // Hearse start - split to a new method
+    private void fireCallEvent(Event event) {
         // Gale start - JettPack - skip events without listeners
         HandlerList handlers = event.getHandlers();
         RegisteredListener[] listeners = handlers.getRegisteredListeners();
@@ -692,7 +709,7 @@ public final class SimplePluginManager implements PluginManager {
                             plugin.getDescription().getAuthors(),
                             plugin.getDescription().getFullName(),
                             ex.getMessage()
-                            ));
+                    ));
                 }
             } catch (Throwable ex) {
                 gg.pufferfish.pufferfish.sentry.SentryContext.setEventContext(event, registration); // Pufferfish
@@ -707,6 +724,7 @@ public final class SimplePluginManager implements PluginManager {
             }
         }
     }
+    // Hearse end
 
     @Override
     public void registerEvents(@NotNull Listener listener, @NotNull Plugin plugin) {