PaperMC/patches/api/0197-Make-JavaPluginLoader-thread-safe.patch
2021-06-21 09:57:15 -07:00

53 lines
2.7 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Trigary <trigary0@gmail.com>
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 f26303315c9c93356f0b04440136855dd54d32b7..ce751577623eaad0f31e2eb7bf0842d1ab73e845 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<String, java.util.concurrent.locks.ReentrantReadWriteLock> classLoadLock = new java.util.HashMap<String, java.util.concurrent.locks.ReentrantReadWriteLock>(); // Paper
+ private final Map<String, Integer> classLoadLockCount = new java.util.HashMap<String, Integer>(); // Paper
private final List<PluginClassLoader> loaders = new CopyOnWriteArrayList<PluginClassLoader>();
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;
}