From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Trigary Date: Wed, 15 Apr 2020 01:24:55 -0400 Subject: [PATCH] Make JavaPluginLoader thread-safe diff --git a/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java b/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java index e98934d32b8dac88b3c3fd14ea5d726872212807..cf809eda2a3feb6abccf7286068280f430452135 100644 --- a/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java +++ b/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java @@ -52,6 +52,8 @@ import org.yaml.snakeyaml.error.YAMLException; public final class JavaPluginLoader implements PluginLoader { final Server server; private final Pattern[] fileFilters = new Pattern[]{Pattern.compile("\\.jar$")}; + private final Map classLoadLock = new java.util.HashMap(); // Paper + private final Map classLoadLockCount = new java.util.HashMap(); // Paper private final List loaders = new CopyOnWriteArrayList(); private final LibraryLoader libraryLoader; @@ -201,12 +203,33 @@ public final class JavaPluginLoader implements PluginLoader { @Nullable Class getClassByName(final String name, boolean resolve, PluginDescriptionFile description) { + // Paper start - make MT safe + java.util.concurrent.locks.ReentrantReadWriteLock lock; + synchronized (classLoadLock) { + lock = classLoadLock.computeIfAbsent(name, (x) -> new java.util.concurrent.locks.ReentrantReadWriteLock()); + classLoadLockCount.compute(name, (x, prev) -> prev != null ? prev + 1 : 1); + } + lock.writeLock().lock();try { + // Paper end for (PluginClassLoader loader : loaders) { try { return loader.loadClass0(name, resolve, false, ((SimplePluginManager) server.getPluginManager()).isTransitiveDepend(description, loader.plugin.getDescription())); } catch (ClassNotFoundException cnfe) { } } + // Paper start - make MT safe + } finally { + synchronized (classLoadLock) { + lock.writeLock().unlock(); + if (classLoadLockCount.get(name) == 1) { + classLoadLock.remove(name); + classLoadLockCount.remove(name); + } else { + classLoadLockCount.compute(name, (x, prev) -> prev - 1); + } + } + } + // Paper end return null; }