Paper/Bukkit-Patches/0004-Make-the-plugin-class-loader-thread-safe.patch

From a62dabb02fe7405059ceb42495ed5dbc9704c1ea Mon Sep 17 00:00:00 2001
From: snowleo <schneeleo@gmail.com>
Date: Wed, 17 Oct 2012 22:30:45 +0200
Subject: [PATCH] Make the plugin class loader thread safe

---
 .../org/bukkit/plugin/java/JavaPluginLoader.java    | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java b/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java
index 10fc26a..f9a09ef 100644
--- a/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java
+++ b/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java
@@ -45,6 +45,7 @@ import org.bukkit.plugin.UnknownDependencyException;
 import org.yaml.snakeyaml.error.YAMLException;
 
 import com.google.common.collect.ImmutableList;
+import java.util.concurrent.ConcurrentHashMap;
 
 /**
  * Represents a Java plugin loader, allowing plugins in the form of .jar
@@ -61,14 +62,14 @@ public class JavaPluginLoader implements PluginLoader {
     @Deprecated
     protected final Pattern[] fileFilters = fileFilters0;
 
-    private final Map<String, Class<?>> classes0 = new HashMap<String, Class<?>>();
+    private final Map<String, Class<?>> classes0 = new ConcurrentHashMap<String, Class<?>>();
     /**
      * @deprecated Internal field that wasn't intended to be exposed
      */
     @Deprecated
     protected final Map<String, Class<?>> classes = classes0;
 
-    private final Map<String, PluginClassLoader> loaders0 = new LinkedHashMap<String, PluginClassLoader>();
+    private final Map<String, PluginClassLoader> loaders0 = new ConcurrentHashMap<String, PluginClassLoader>();
     /**
      * @deprecated Internal field that wasn't intended to be exposed
      */
@@ -293,14 +294,16 @@ public class JavaPluginLoader implements PluginLoader {
         if (cachedClass != null) {
             return cachedClass;
         } else {
-            for (String current : loaders0.keySet()) {
-                PluginClassLoader loader = loaders0.get(current);
+            synchronized (loaders) {
+                for (String current : loaders0.keySet()) {
+                    PluginClassLoader loader = loaders0.get(current);
 
-                try {
-                    cachedClass = loader.extended ? loader.findClass(name, false) : loader.findClass0(name, false); // Don't warn on deprecation, but maintain overridability
-                } catch (ClassNotFoundException cnfe) {}
-                if (cachedClass != null) {
-                    return cachedClass;
+                    try {
+                        cachedClass = loader.extended ? loader.findClass(name, false) : loader.findClass0(name, false); // Don't warn on deprecation, but maintain overridability
+                    } catch (ClassNotFoundException cnfe) {}
+                    if (cachedClass != null) {
+                        return cachedClass;
+                    }
                 }
             }
         }
-- 
1.8.1-rc2