From 72795f24992711b90de1db3fa337de1ffbbe06d8 Mon Sep 17 00:00:00 2001 From: Techcable Date: Thu, 3 Mar 2016 13:20:33 -0700 Subject: [PATCH] Use ASM for event executors. Uses method handles for private methods. diff --git a/pom.xml b/pom.xml index 0b615b4..1ad108e 100644 --- a/pom.xml +++ b/pom.xml @@ -112,6 +112,12 @@ 1.3 test + + + org.ow2.asm + asm-all + 5.0.4 + 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 0000000..9ff99e3 --- /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 eventClass; + private final MethodHandle handle; + + public MethodHandleEventExecutor(Class eventClass, MethodHandle handle) { + this.eventClass = eventClass; + this.handle = handle; + } + + public MethodHandleEventExecutor(Class 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/asm/ASMEventExecutorGenerator.java b/src/main/java/com/destroystokyo/paper/event/executor/asm/ASMEventExecutorGenerator.java new file mode 100644 index 0000000..45c2330 --- /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, "", "()V", null, null), ACC_PUBLIC, "", "()V"); + methodGenerator.loadThis(); + methodGenerator.visitMethodInsn(INVOKESPECIAL, Type.getInternalName(Object.class), "", "()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(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 0000000..6941d9f --- /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 0000000..776a9a0 --- /dev/null +++ b/src/main/java/com/destroystokyo/paper/event/executor/asm/SafeClassDefiner.java @@ -0,0 +1,62 @@ +package com.destroystokyo.paper.event.executor.asm; + +import java.util.concurrent.ConcurrentHashMap; +import java.util.concurrent.ConcurrentMap; + +import com.google.common.base.Preconditions; + +import org.objectweb.asm.Type; + +public class SafeClassDefiner implements ClassDefiner { + /* default */ static final SafeClassDefiner INSTANCE = new SafeClassDefiner(); + + private SafeClassDefiner() {} + + private final ConcurrentMap loaders = new ConcurrentHashMap<>(); + + @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 0000000..62acbf8 --- /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 3b2c99e..7b92ce0 100644 --- a/src/main/java/org/bukkit/plugin/EventExecutor.java +++ b/src/main/java/org/bukkit/plugin/EventExecutor.java @@ -4,9 +4,53 @@ 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 com.destroystokyo.paper.event.executor.MethodHandleEventExecutor; +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 + public static EventExecutor create(Method m, Class 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); + Preconditions.checkArgument(!Modifier.isStatic(m.getModifiers()), "Static method %s", m.getName()); + ClassDefiner definer = ClassDefiner.getInstance(); + if (definer.isBypassAccessChecks() || Modifier.isPublic(m.getDeclaringClass().getModifiers()) && Modifier.isPublic(m.getModifiers())) { + String name = ASMEventExecutorGenerator.generateName(); + byte[] classData = ASMEventExecutorGenerator.generateEventExecutor(m, name); + Class c = definer.defineClass(m.getDeclaringClass().getClassLoader(), name, classData).asSubclass(EventExecutor.class); + try { + EventExecutor asmExecutor = c.newInstance(); + // Define a wrapper to conform to bukkit stupidity (passing in events that don't match and wrapper exception) + return new EventExecutor() { + @Override + public void execute(Listener listener, Event event) throws EventException { + if (!eventClass.isInstance(event)) return; + try { + asmExecutor.execute(listener, event); + } catch (Exception e) { + throw new EventException(e); + } + } + }; + } 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 93a43dd..7229b25 100644 --- a/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java +++ b/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java @@ -291,20 +291,7 @@ 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 { -- 2.7.2