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papermc/Spigot-API-Patches/0022-Use-ASM-for-event-executors.patch
Aikar 17b58d00d8
Unwrap Event Exceptions 
This was a useless exception wrapper that ends up making
stack traces harder to read as well as the JVM cutting off
the important parts

Nothing catches this exception, so its safe to just get rid
of it and let the REAL exception bubble down
2019-02-23 12:17:41 -05:00

426 lines
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From c3ff7d3fbb2e568bfc8c25a3c3f0857e73c2c184 Mon Sep 17 00:00:00 2001
From: Techcable <Techcable@outlook.com>
Date: Thu, 3 Mar 2016 13:20:33 -0700
Subject: [PATCH] Use ASM for event executors.
Uses method handles for private or static methods.
diff --git a/pom.xml b/pom.xml
index f8f12595..84ba2076 100644
--- a/pom.xml
+++ b/pom.xml
@@ -116,6 +116,17 @@
<version>1.3</version>
<scope>test</scope>
</dependency>
+ <!-- ASM -->
+ <dependency>
+ <groupId>org.ow2.asm</groupId>
+ <artifactId>asm</artifactId>
+ <version>6.1.1</version>
+ </dependency>
+ <dependency>
+ <groupId>org.ow2.asm</groupId>
+ <artifactId>asm-commons</artifactId>
+ <version>6.1.1</version>
+ </dependency>
</dependencies>
<build>
diff --git a/src/main/java/com/destroystokyo/paper/event/executor/MethodHandleEventExecutor.java b/src/main/java/com/destroystokyo/paper/event/executor/MethodHandleEventExecutor.java
new file mode 100644
index 00000000..9ff99e3b
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/event/executor/MethodHandleEventExecutor.java
@@ -0,0 +1,40 @@
+package com.destroystokyo.paper.event.executor;
+
+import java.lang.invoke.MethodHandle;
+import java.lang.invoke.MethodHandles;
+import java.lang.reflect.Method;
+
+import org.bukkit.event.Event;
+import org.bukkit.event.EventException;
+import org.bukkit.event.Listener;
+import org.bukkit.plugin.EventExecutor;
+
+public class MethodHandleEventExecutor implements EventExecutor {
+ private final Class<? extends Event> eventClass;
+ private final MethodHandle handle;
+
+ public MethodHandleEventExecutor(Class<? extends Event> eventClass, MethodHandle handle) {
+ this.eventClass = eventClass;
+ this.handle = handle;
+ }
+
+ public MethodHandleEventExecutor(Class<? extends Event> eventClass, Method m) {
+ this.eventClass = eventClass;
+ try {
+ m.setAccessible(true);
+ this.handle = MethodHandles.lookup().unreflect(m);
+ } catch (IllegalAccessException e) {
+ throw new AssertionError("Unable to set accessible", e);
+ }
+ }
+
+ @Override
+ public void execute(Listener listener, Event event) throws EventException {
+ if (!eventClass.isInstance(event)) return;
+ try {
+ handle.invoke(listener, event);
+ } catch (Throwable t) {
+ throw new EventException(t);
+ }
+ }
+}
diff --git a/src/main/java/com/destroystokyo/paper/event/executor/StaticMethodHandleEventExecutor.java b/src/main/java/com/destroystokyo/paper/event/executor/StaticMethodHandleEventExecutor.java
new file mode 100644
index 00000000..bac04fd8
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/event/executor/StaticMethodHandleEventExecutor.java
@@ -0,0 +1,41 @@
+package com.destroystokyo.paper.event.executor;
+
+import java.lang.invoke.MethodHandle;
+import java.lang.invoke.MethodHandles;
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+
+import com.destroystokyo.paper.util.SneakyThrow;
+import com.google.common.base.Preconditions;
+
+import org.bukkit.Bukkit;
+import org.bukkit.event.Event;
+import org.bukkit.event.EventException;
+import org.bukkit.event.Listener;
+import org.bukkit.plugin.EventExecutor;
+
+public class StaticMethodHandleEventExecutor implements EventExecutor {
+ private final Class<? extends Event> eventClass;
+ private final MethodHandle handle;
+
+ public StaticMethodHandleEventExecutor(Class<? extends Event> eventClass, Method m) {
+ Preconditions.checkArgument(Modifier.isStatic(m.getModifiers()), "Not a static method: %s", m);
+ this.eventClass = eventClass;
+ try {
+ m.setAccessible(true);
+ this.handle = MethodHandles.lookup().unreflect(m);
+ } catch (IllegalAccessException e) {
+ throw new AssertionError("Unable to set accessible", e);
+ }
+ }
+
+ @Override
+ public void execute(Listener listener, Event event) throws EventException {
+ if (!eventClass.isInstance(event)) return;
+ try {
+ handle.invoke(event);
+ } catch (Throwable throwable) {
+ SneakyThrow.sneaky(throwable);
+ }
+ }
+}
diff --git a/src/main/java/com/destroystokyo/paper/event/executor/asm/ASMEventExecutorGenerator.java b/src/main/java/com/destroystokyo/paper/event/executor/asm/ASMEventExecutorGenerator.java
new file mode 100644
index 00000000..140cf0ad
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/event/executor/asm/ASMEventExecutorGenerator.java
@@ -0,0 +1,44 @@
+package com.destroystokyo.paper.event.executor.asm;
+
+import java.lang.reflect.Method;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import org.bukkit.plugin.EventExecutor;
+import org.objectweb.asm.ClassWriter;
+import org.objectweb.asm.Type;
+import org.objectweb.asm.commons.GeneratorAdapter;
+
+import static org.objectweb.asm.Opcodes.*;
+
+public class ASMEventExecutorGenerator {
+ public static byte[] generateEventExecutor(Method m, String name) {
+ ClassWriter writer = new ClassWriter(ClassWriter.COMPUTE_FRAMES | ClassWriter.COMPUTE_MAXS);
+ writer.visit(V1_8, ACC_PUBLIC, name.replace('.', '/'), null, Type.getInternalName(Object.class), new String[] {Type.getInternalName(EventExecutor.class)});
+ // Generate constructor
+ GeneratorAdapter methodGenerator = new GeneratorAdapter(writer.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null), ACC_PUBLIC, "<init>", "()V");
+ methodGenerator.loadThis();
+ methodGenerator.visitMethodInsn(INVOKESPECIAL, Type.getInternalName(Object.class), "<init>", "()V", false); // Invoke the super class (Object) constructor
+ methodGenerator.returnValue();
+ methodGenerator.endMethod();
+ // Generate the execute method
+ methodGenerator = new GeneratorAdapter(writer.visitMethod(ACC_PUBLIC, "execute", "(Lorg/bukkit/event/Listener;Lorg/bukkit/event/Event;)V", null, null), ACC_PUBLIC, "execute", "(Lorg/bukkit/event/Listener;Lorg/bukkit/event/Listener;)V");;
+ methodGenerator.loadArg(0);
+ methodGenerator.checkCast(Type.getType(m.getDeclaringClass()));
+ methodGenerator.loadArg(1);
+ methodGenerator.checkCast(Type.getType(m.getParameterTypes()[0]));
+ methodGenerator.visitMethodInsn(m.getDeclaringClass().isInterface() ? INVOKEINTERFACE : INVOKEVIRTUAL, Type.getInternalName(m.getDeclaringClass()), m.getName(), Type.getMethodDescriptor(m), m.getDeclaringClass().isInterface());
+ if (m.getReturnType() != void.class) {
+ methodGenerator.pop();
+ }
+ methodGenerator.returnValue();
+ methodGenerator.endMethod();
+ writer.visitEnd();
+ return writer.toByteArray();
+ }
+
+ public static AtomicInteger NEXT_ID = new AtomicInteger(1);
+ public static String generateName() {
+ int id = NEXT_ID.getAndIncrement();
+ return "com.destroystokyo.paper.event.executor.asm.generated.GeneratedEventExecutor" + id;
+ }
+}
diff --git a/src/main/java/com/destroystokyo/paper/event/executor/asm/ClassDefiner.java b/src/main/java/com/destroystokyo/paper/event/executor/asm/ClassDefiner.java
new file mode 100644
index 00000000..6941d9fb
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/event/executor/asm/ClassDefiner.java
@@ -0,0 +1,32 @@
+package com.destroystokyo.paper.event.executor.asm;
+
+import com.destroystokyo.paper.utils.UnsafeUtils;
+
+public interface ClassDefiner {
+
+ /**
+ * Returns if the defined classes can bypass access checks
+ *
+ * @return if classes bypass access checks
+ */
+ public default boolean isBypassAccessChecks() {
+ return false;
+ }
+
+ /**
+ * Define a class
+ *
+ * @param parentLoader the parent classloader
+ * @param name the name of the class
+ * @param data the class data to load
+ * @return the defined class
+ * @throws ClassFormatError if the class data is invalid
+ * @throws NullPointerException if any of the arguments are null
+ */
+ public Class<?> defineClass(ClassLoader parentLoader, String name, byte[] data);
+
+ public static ClassDefiner getInstance() {
+ return SafeClassDefiner.INSTANCE;
+ }
+
+}
diff --git a/src/main/java/com/destroystokyo/paper/event/executor/asm/SafeClassDefiner.java b/src/main/java/com/destroystokyo/paper/event/executor/asm/SafeClassDefiner.java
new file mode 100644
index 00000000..1473ff8c
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/event/executor/asm/SafeClassDefiner.java
@@ -0,0 +1,63 @@
+package com.destroystokyo.paper.event.executor.asm;
+
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+
+import com.google.common.base.Preconditions;
+
+import com.google.common.collect.MapMaker;
+import org.objectweb.asm.Type;
+
+public class SafeClassDefiner implements ClassDefiner {
+ /* default */ static final SafeClassDefiner INSTANCE = new SafeClassDefiner();
+
+ private SafeClassDefiner() {}
+
+ private final ConcurrentMap<ClassLoader, GeneratedClassLoader> loaders = new MapMaker().weakKeys().makeMap();
+
+ @Override
+ public Class<?> defineClass(ClassLoader parentLoader, String name, byte[] data) {
+ GeneratedClassLoader loader = loaders.computeIfAbsent(parentLoader, GeneratedClassLoader::new);
+ synchronized (loader.getClassLoadingLock(name)) {
+ Preconditions.checkState(!loader.hasClass(name), "%s already defined", name);
+ Class<?> c = loader.define(name, data);
+ assert c.getName().equals(name);
+ return c;
+ }
+ }
+
+ private static class GeneratedClassLoader extends ClassLoader {
+ static {
+ ClassLoader.registerAsParallelCapable();
+ }
+
+ protected GeneratedClassLoader(ClassLoader parent) {
+ super(parent);
+ }
+
+ private Class<?> define(String name, byte[] data) {
+ synchronized (getClassLoadingLock(name)) {
+ assert !hasClass(name);
+ Class<?> c = defineClass(name, data, 0, data.length);
+ resolveClass(c);
+ return c;
+ }
+ }
+
+ @Override
+ public Object getClassLoadingLock(String name) {
+ return super.getClassLoadingLock(name);
+ }
+
+ public boolean hasClass(String name) {
+ synchronized (getClassLoadingLock(name)) {
+ try {
+ Class.forName(name);
+ return true;
+ } catch (ClassNotFoundException e) {
+ return false;
+ }
+ }
+ }
+ }
+}
diff --git a/src/main/java/com/destroystokyo/paper/utils/UnsafeUtils.java b/src/main/java/com/destroystokyo/paper/utils/UnsafeUtils.java
new file mode 100644
index 00000000..62acbf82
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/utils/UnsafeUtils.java
@@ -0,0 +1,33 @@
+package com.destroystokyo.paper.utils;
+
+import sun.misc.Unsafe;
+
+import java.lang.reflect.Field;
+
+public class UnsafeUtils {
+ private UnsafeUtils() {}
+
+ private static final Unsafe UNSAFE;
+ static {
+ Unsafe unsafe;
+ try {
+ Class c = Class.forName("sun.misc.Unsafe");
+ Field f = c.getDeclaredField("theUnsafe");
+ f.setAccessible(true);
+ unsafe = (Unsafe) f.get(null);
+ } catch (ClassNotFoundException | NoSuchFieldException | SecurityException e) {
+ unsafe = null;
+ } catch (IllegalAccessException e) {
+ throw new AssertionError(e);
+ }
+ UNSAFE = unsafe;
+ }
+
+ public static boolean isUnsafeSupported() {
+ return UNSAFE != null;
+ }
+
+ public static Unsafe getUnsafe() {
+ return UNSAFE;
+ }
+}
diff --git a/src/main/java/org/bukkit/plugin/EventExecutor.java b/src/main/java/org/bukkit/plugin/EventExecutor.java
index 3b2c99ea..b11c6ce6 100644
--- a/src/main/java/org/bukkit/plugin/EventExecutor.java
+++ b/src/main/java/org/bukkit/plugin/EventExecutor.java
@@ -4,9 +4,74 @@ import org.bukkit.event.Event;
import org.bukkit.event.EventException;
import org.bukkit.event.Listener;
+// Paper start
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+import java.util.HashMap;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+import java.util.function.Function;
+
+import com.destroystokyo.paper.event.executor.MethodHandleEventExecutor;
+import com.destroystokyo.paper.event.executor.StaticMethodHandleEventExecutor;
+import com.destroystokyo.paper.event.executor.asm.ASMEventExecutorGenerator;
+import com.destroystokyo.paper.event.executor.asm.ClassDefiner;
+import com.google.common.base.Preconditions;
+// Paper end
+
/**
* Interface which defines the class for event call backs to plugins
*/
public interface EventExecutor {
public void execute(Listener listener, Event event) throws EventException;
+
+ // Paper start
+ ConcurrentMap<Method, Class<? extends EventExecutor>> eventExecutorMap = new ConcurrentHashMap<Method, Class<? extends EventExecutor>>() {
+ @Override
+ public Class<? extends EventExecutor> computeIfAbsent(Method key, Function<? super Method, ? extends Class<? extends EventExecutor>> mappingFunction) {
+ Class<? extends EventExecutor> executorClass = get(key);
+ if (executorClass != null)
+ return executorClass;
+
+ //noinspection SynchronizationOnLocalVariableOrMethodParameter
+ synchronized (key) {
+ executorClass = get(key);
+ if (executorClass != null)
+ return executorClass;
+
+ return super.computeIfAbsent(key, mappingFunction);
+ }
+ }
+ };
+
+ public static EventExecutor create(Method m, Class<? extends Event> eventClass) {
+ Preconditions.checkNotNull(m, "Null method");
+ Preconditions.checkArgument(m.getParameterCount() != 0, "Incorrect number of arguments %s", m.getParameterCount());
+ Preconditions.checkArgument(m.getParameterTypes()[0] == eventClass, "First parameter %s doesn't match event class %s", m.getParameterTypes()[0], eventClass);
+ ClassDefiner definer = ClassDefiner.getInstance();
+ if (Modifier.isStatic(m.getModifiers())) {
+ return new StaticMethodHandleEventExecutor(eventClass, m);
+ } else if (definer.isBypassAccessChecks() || Modifier.isPublic(m.getDeclaringClass().getModifiers()) && Modifier.isPublic(m.getModifiers())) {
+ // get the existing generated EventExecutor class for the Method or generate one
+ Class<? extends EventExecutor> executorClass = eventExecutorMap.computeIfAbsent(m, (__) -> {
+ String name = ASMEventExecutorGenerator.generateName();
+ byte[] classData = ASMEventExecutorGenerator.generateEventExecutor(m, name);
+ return definer.defineClass(m.getDeclaringClass().getClassLoader(), name, classData).asSubclass(EventExecutor.class);
+ });
+
+ try {
+ EventExecutor asmExecutor = executorClass.newInstance();
+ // Define a wrapper to conform to bukkit stupidity (passing in events that don't match and wrapper exception)
+ return (listener, event) -> {
+ if (!eventClass.isInstance(event)) return;
+ asmExecutor.execute(listener, event);
+ };
+ } catch (InstantiationException | IllegalAccessException e) {
+ throw new AssertionError("Unable to initialize generated event executor", e);
+ }
+ } else {
+ return new MethodHandleEventExecutor(eventClass, m);
+ }
+ }
+ // Paper end
}
diff --git a/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java b/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java
index bf972302..77207f14 100644
--- a/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java
+++ b/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java
@@ -290,20 +290,7 @@ public final class JavaPluginLoader implements PluginLoader {
}
}
- EventExecutor executor = new co.aikar.timings.TimedEventExecutor(new EventExecutor() { // Spigot
- public void execute(Listener listener, Event event) throws EventException {
- try {
- if (!eventClass.isAssignableFrom(event.getClass())) {
- return;
- }
- method.invoke(listener, event);
- } catch (InvocationTargetException ex) {
- throw new EventException(ex.getCause());
- } catch (Throwable t) {
- throw new EventException(t);
- }
- }
- }, plugin, method, eventClass); // Spigot
+ EventExecutor executor = new co.aikar.timings.TimedEventExecutor(EventExecutor.create(method, eventClass), plugin, method, eventClass); // Spigot // Paper - Use factory method `EventExecutor.create()`
if (false) { // Spigot - RL handles useTimings check now
eventSet.add(new TimedRegisteredListener(listener, executor, eh.priority(), plugin, eh.ignoreCancelled()));
} else {
--
2.20.1
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