Paper/Spigot-API-Patches/0104-Close-Plugin-Class-Loaders-on-Disable.patch

From 9825cddc7fa38c5ec7a8446b9d8c7332b6b07fac Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Tue, 1 May 2018 21:33:35 -0400
Subject: [PATCH] Close Plugin Class Loaders on Disable

This should close more memory leaks from /reload and disabling plugins,
by closing the class loader and the jar file.

diff --git a/src/main/java/org/bukkit/plugin/PluginLoader.java b/src/main/java/org/bukkit/plugin/PluginLoader.java
index e7981a1d..541f85bc 100644
--- a/src/main/java/org/bukkit/plugin/PluginLoader.java
+++ b/src/main/java/org/bukkit/plugin/PluginLoader.java
@@ -73,4 +73,16 @@ public interface PluginLoader {
      * @param plugin Plugin to disable
      */
     public void disablePlugin(Plugin plugin);
+
+    // Paper start - close Classloader on disable
+    /**
+     * Disables the specified plugin
+     * <p>
+     * Attempting to disable a plugin that is not enabled will have no effect
+     *
+     * @param plugin Plugin to disable
+     * @param closeClassloader if the classloader for the Plugin should be closed
+     */
+    public void disablePlugin(Plugin plugin, boolean closeClassloader);
+    // Paper end - close Classloader on disable
 }
diff --git a/src/main/java/org/bukkit/plugin/PluginManager.java b/src/main/java/org/bukkit/plugin/PluginManager.java
index e5638d56..b72d5a9b 100644
--- a/src/main/java/org/bukkit/plugin/PluginManager.java
+++ b/src/main/java/org/bukkit/plugin/PluginManager.java
@@ -154,6 +154,18 @@ public interface PluginManager {
      */
     public void disablePlugin(Plugin plugin);
 
+    // Paper start - close Classloader on disable
+    /**
+     * Disables the specified plugin
+     * <p>
+     * Attempting to disable a plugin that is not enabled will have no effect
+     *
+     * @param plugin Plugin to disable
+     * @param closeClassloader if the classloader for the Plugin should be closed
+     */
+    public void disablePlugin(Plugin plugin, boolean closeClassloader);
+    // Paper end - close Classloader on disable
+
     /**
      * Gets a {@link Permission} from its fully qualified name
      *
diff --git a/src/main/java/org/bukkit/plugin/SimplePluginManager.java b/src/main/java/org/bukkit/plugin/SimplePluginManager.java
index bd0588a2..cb2b0b9c 100644
--- a/src/main/java/org/bukkit/plugin/SimplePluginManager.java
+++ b/src/main/java/org/bukkit/plugin/SimplePluginManager.java
@@ -412,17 +412,29 @@ public final class SimplePluginManager implements PluginManager {
         }
     }
 
+    // Paper start - close Classloader on disable
     public void disablePlugins() {
+        disablePlugins(false);
+    }
+
+    public void disablePlugins(boolean closeClassloaders) {
+        // Paper end - close Classloader on disable
         Plugin[] plugins = getPlugins();
         for (int i = plugins.length - 1; i >= 0; i--) {
-            disablePlugin(plugins[i]);
+            disablePlugin(plugins[i], closeClassloaders); // Paper - close Classloader on disable
         }
     }
 
-    public void disablePlugin(final Plugin plugin) {
+    // Paper start - close Classloader on disable
+    public void disablePlugin(Plugin plugin) {
+        disablePlugin(plugin, false);
+    }
+
+    public void disablePlugin(final Plugin plugin, boolean closeClassloader) {
+        // Paper end - close Classloader on disable
         if (plugin.isEnabled()) {
             try {
-                plugin.getPluginLoader().disablePlugin(plugin);
+                plugin.getPluginLoader().disablePlugin(plugin, closeClassloader); // Paper - close Classloader on disable
             } catch (Throwable ex) {
                 handlePluginException("Error occurred (in the plugin loader) while disabling "
                         + plugin.getDescription().getFullName() + " (Is it up to date?)", ex, plugin); // Paper
@@ -468,7 +480,7 @@ public final class SimplePluginManager implements PluginManager {
 
     public void clearPlugins() {
         synchronized (this) {
-            disablePlugins();
+            disablePlugins(true); // Paper - close Classloader on disable
             plugins.clear();
             lookupNames.clear();
             HandlerList.unregisterAll();
diff --git a/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java b/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java
index 40fd71dc..d2c538b2 100644
--- a/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java
+++ b/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java
@@ -1,23 +1,5 @@
 package org.bukkit.plugin.java;
 
-import java.io.File;
-import java.io.FileNotFoundException;
-import java.io.IOException;
-import java.io.InputStream;
-import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Method;
-import java.util.Arrays;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import java.util.concurrent.CopyOnWriteArrayList;
-import java.util.jar.JarEntry;
-import java.util.jar.JarFile;
-import java.util.logging.Level;
-import java.util.regex.Pattern;
-
 import org.apache.commons.lang.Validate;
 import org.bukkit.Server;
 import org.bukkit.Warning;
@@ -25,7 +7,6 @@ import org.bukkit.Warning.WarningState;
 import org.bukkit.configuration.serialization.ConfigurationSerializable;
 import org.bukkit.configuration.serialization.ConfigurationSerialization;
 import org.bukkit.event.Event;
-import org.bukkit.event.EventException;
 import org.bukkit.event.EventHandler;
 import org.bukkit.event.Listener;
 import org.bukkit.event.server.PluginDisableEvent;
@@ -42,18 +23,35 @@ import org.bukkit.plugin.TimedRegisteredListener;
 import org.bukkit.plugin.UnknownDependencyException;
 import org.yaml.snakeyaml.error.YAMLException;
 
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.lang.reflect.Method;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.jar.JarEntry;
+import java.util.jar.JarFile;
+import java.util.logging.Level;
+import java.util.regex.Pattern;
+
 /**
  * Represents a Java plugin loader, allowing plugins in the form of .jar
  */
 public final class JavaPluginLoader implements PluginLoader {
     final Server server;
-    private final Pattern[] fileFilters = new Pattern[] { Pattern.compile("\\.jar$"), };
+    private final Pattern[] fileFilters = new Pattern[]{Pattern.compile("\\.jar$"),};
     private final Map<String, Class<?>> classes = new java.util.concurrent.ConcurrentHashMap<String, Class<?>>(); // Spigot
     private final List<PluginClassLoader> loaders = new CopyOnWriteArrayList<PluginClassLoader>();
 
     /**
      * This class was not meant to be constructed explicitly
-     * 
+     *
      * @param instance the server instance
      */
     @Deprecated
@@ -78,39 +76,38 @@ public final class JavaPluginLoader implements PluginLoader {
 
         final File parentFile = file.getParentFile();
         final File dataFolder = new File(parentFile, description.getName());
-        @SuppressWarnings("deprecation")
-        final File oldDataFolder = new File(parentFile, description.getRawName());
+        @SuppressWarnings("deprecation") final File oldDataFolder = new File(parentFile, description.getRawName());
 
         // Found old data folder
         if (dataFolder.equals(oldDataFolder)) {
             // They are equal -- nothing needs to be done!
         } else if (dataFolder.isDirectory() && oldDataFolder.isDirectory()) {
             server.getLogger().warning(String.format(
-                "While loading %s (%s) found old-data folder: `%s' next to the new one `%s'",
-                description.getFullName(),
-                file,
-                oldDataFolder,
-                dataFolder
+                    "While loading %s (%s) found old-data folder: `%s' next to the new one `%s'",
+                    description.getFullName(),
+                    file,
+                    oldDataFolder,
+                    dataFolder
             ));
         } else if (oldDataFolder.isDirectory() && !dataFolder.exists()) {
             if (!oldDataFolder.renameTo(dataFolder)) {
                 throw new InvalidPluginException("Unable to rename old data folder: `" + oldDataFolder + "' to: `" + dataFolder + "'");
             }
             server.getLogger().log(Level.INFO, String.format(
-                "While loading %s (%s) renamed data folder: `%s' to `%s'",
-                description.getFullName(),
-                file,
-                oldDataFolder,
-                dataFolder
+                    "While loading %s (%s) renamed data folder: `%s' to `%s'",
+                    description.getFullName(),
+                    file,
+                    oldDataFolder,
+                    dataFolder
             ));
         }
 
         if (dataFolder.exists() && !dataFolder.isDirectory()) {
             throw new InvalidPluginException(String.format(
-                "Projected datafolder: `%s' for %s (%s) exists and is not a directory",
-                dataFolder,
-                description.getFullName(),
-                file
+                    "Projected datafolder: `%s' for %s (%s) exists and is not a directory",
+                    dataFolder,
+                    description.getFullName(),
+                    file
             ));
         }
 
@@ -187,7 +184,8 @@ public final class JavaPluginLoader implements PluginLoader {
             for (PluginClassLoader loader : loaders) {
                 try {
                     cachedClass = loader.findClass(name, false);
-                } catch (ClassNotFoundException cnfe) {}
+                } catch (ClassNotFoundException cnfe) {
+                }
                 if (cachedClass != null) {
                     return cachedClass;
                 }
@@ -276,7 +274,7 @@ public final class JavaPluginLoader implements PluginLoader {
                             Level.WARNING,
                             String.format(
                                     "\"%s\" has registered a listener for %s on method \"%s\", but the event is Deprecated." +
-                                    " \"%s\"; please notify the authors %s.",
+                                            " \"%s\"; please notify the authors %s.",
                                     plugin.getDescription().getFullName(),
                                     clazz.getName(),
                                     method.toGenericString(),
@@ -317,7 +315,7 @@ public final class JavaPluginLoader implements PluginLoader {
             } catch (Throwable ex) {
                 server.getLogger().log(Level.SEVERE, "Error occurred while enabling " + plugin.getDescription().getFullName() + " (Is it up to date?)", ex);
                 // Paper start - Disable plugins that fail to load
-                disablePlugin(jPlugin);
+                disablePlugin(jPlugin, true); // Paper - close Classloader on disable - She's dead jim
                 return;
                 // Paper end
             }
@@ -328,7 +326,13 @@ public final class JavaPluginLoader implements PluginLoader {
         }
     }
 
+    // Paper start - close Classloader on disable
     public void disablePlugin(Plugin plugin) {
+        disablePlugin(plugin, false); // Retain old behavior unless requested
+    }
+
+    public void disablePlugin(Plugin plugin, boolean closeClassloader) {
+        // Paper end - close Class Loader on disable
         Validate.isTrue(plugin instanceof JavaPlugin, "Plugin is not associated with this PluginLoader");
 
         if (plugin.isEnabled()) {
@@ -355,6 +359,16 @@ public final class JavaPluginLoader implements PluginLoader {
                 for (String name : names) {
                     removeClass(name);
                 }
+                // Paper start - close Class Loader on disable
+                try {
+                    if (closeClassloader) {
+                        loader.close();
+                    }
+                } catch (IOException e) {
+                    server.getLogger().log(Level.WARNING, "Error closing the Plugin Class Loader for " + plugin.getDescription().getFullName());
+                    e.printStackTrace();
+                }
+                // Paper end
             }
         }
     }
-- 
2.17.1