API patches

patches/api/0026-Use-ASM-for-event-executors.patch

@@ -0,0 +1,394 @@
+From 0000000000000000000000000000000000000000 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/build.gradle.kts b/build.gradle.kts
+index 9b3621a09bd37945877752c801cdd9283017522c..9ec782b00f9f2ac5a38a75667d36de4582a25a03 100644
+--- a/build.gradle.kts
++++ b/build.gradle.kts
+@@ -38,6 +38,9 @@ dependencies {
+     apiAndDocs("net.kyori:adventure-text-serializer-gson")
+     apiAndDocs("net.kyori:adventure-text-serializer-legacy")
+     apiAndDocs("net.kyori:adventure-text-serializer-plain")
++
++    implementation("org.ow2.asm:asm:9.2")
++    implementation("org.ow2.asm:asm-commons:9.2")
+     // Paper end
+ 
+     compileOnly("org.apache.maven:maven-resolver-provider:3.8.4")
+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 0000000000000000000000000000000000000000..5b28e9b1daba7834af67dbc193dd656bedd9a994
+--- /dev/null
++++ b/src/main/java/com/destroystokyo/paper/event/executor/MethodHandleEventExecutor.java
+@@ -0,0 +1,42 @@
++package com.destroystokyo.paper.event.executor;
++
++import java.lang.invoke.MethodHandle;
++import java.lang.invoke.MethodHandles;
++import java.lang.reflect.Method;
++
++import com.destroystokyo.paper.util.SneakyThrow;
++import org.bukkit.event.Event;
++import org.bukkit.event.EventException;
++import org.bukkit.event.Listener;
++import org.bukkit.plugin.EventExecutor;
++import org.jetbrains.annotations.NotNull;
++
++public class MethodHandleEventExecutor implements EventExecutor {
++    private final Class<? extends Event> eventClass;
++    private final MethodHandle handle;
++
++    public MethodHandleEventExecutor(@NotNull Class<? extends Event> eventClass, @NotNull MethodHandle handle) {
++        this.eventClass = eventClass;
++        this.handle = handle;
++    }
++
++    public MethodHandleEventExecutor(@NotNull Class<? extends Event> eventClass, @NotNull 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(@NotNull Listener listener, @NotNull Event event) throws EventException {
++        if (!eventClass.isInstance(event)) return;
++        try {
++            handle.invoke(listener, event);
++        } catch (Throwable t) {
++            SneakyThrow.sneaky(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 0000000000000000000000000000000000000000..c83672427324bd068ed52916f700b68446a226f6
+--- /dev/null
++++ b/src/main/java/com/destroystokyo/paper/event/executor/StaticMethodHandleEventExecutor.java
+@@ -0,0 +1,43 @@
++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;
++import org.jetbrains.annotations.NotNull;
++
++public class StaticMethodHandleEventExecutor implements EventExecutor {
++    private final Class<? extends Event> eventClass;
++    private final MethodHandle handle;
++
++    public StaticMethodHandleEventExecutor(@NotNull Class<? extends Event> eventClass, @NotNull Method m) {
++        Preconditions.checkArgument(Modifier.isStatic(m.getModifiers()), "Not a static method: %s", m);
++        Preconditions.checkArgument(eventClass != null, "eventClass is null");
++        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(@NotNull Listener listener, @NotNull 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 0000000000000000000000000000000000000000..b8d5c13980858dc27fb5383726b7ebcaf14adcb8
+--- /dev/null
++++ b/src/main/java/com/destroystokyo/paper/event/executor/asm/ASMEventExecutorGenerator.java
+@@ -0,0 +1,51 @@
++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.jetbrains.annotations.NotNull;
++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 {
++    @NotNull
++    public static byte[] generateEventExecutor(@NotNull Method m, @NotNull 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());
++        // The only purpose of this switch statement is to generate the correct pop instruction, should the event handler method return something other than void.
++        // Non-void event handlers will be unsupported in a future release.
++        switch (Type.getType(m.getReturnType()).getSize()) {
++            // case 0 is omitted because the only type that has size 0 is void - no pop instruction needed.
++            case 1 -> methodGenerator.pop(); // handles reference types and most primitives
++            case 2 -> methodGenerator.pop2(); // handles long and double
++        }
++        methodGenerator.returnValue();
++        methodGenerator.endMethod();
++        writer.visitEnd();
++        return writer.toByteArray();
++    }
++
++    public static AtomicInteger NEXT_ID = new AtomicInteger(1);
++    @NotNull
++    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 0000000000000000000000000000000000000000..f79685b48bb581277a6891927988b6f7a4389dc4
+--- /dev/null
++++ b/src/main/java/com/destroystokyo/paper/event/executor/asm/ClassDefiner.java
+@@ -0,0 +1,34 @@
++package com.destroystokyo.paper.event.executor.asm;
++
++import org.jetbrains.annotations.NotNull;
++
++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
++     */
++    @NotNull
++    public Class<?> defineClass(@NotNull ClassLoader parentLoader, @NotNull String name, @NotNull byte[] data);
++
++    @NotNull
++    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 0000000000000000000000000000000000000000..ac99477e9f2c08041aeff31abc1d1edee58d0a67
+--- /dev/null
++++ b/src/main/java/com/destroystokyo/paper/event/executor/asm/SafeClassDefiner.java
+@@ -0,0 +1,66 @@
++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.jetbrains.annotations.NotNull;
++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();
++
++    @NotNull
++    @Override
++    public Class<?> defineClass(@NotNull ClassLoader parentLoader, @NotNull String name, @NotNull 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(@NotNull ClassLoader parent) {
++            super(parent);
++        }
++
++        private Class<?> define(@NotNull String name, byte[] data) {
++            synchronized (getClassLoadingLock(name)) {
++                assert !hasClass(name);
++                Class<?> c = defineClass(name, data, 0, data.length);
++                resolveClass(c);
++                return c;
++            }
++        }
++
++        @Override
++        @NotNull
++        public Object getClassLoadingLock(@NotNull String name) {
++            return super.getClassLoadingLock(name);
++        }
++
++        public boolean hasClass(@NotNull String name) {
++            synchronized (getClassLoadingLock(name)) {
++                try {
++                    Class.forName(name);
++                    return true;
++                } catch (ClassNotFoundException e) {
++                    return false;
++                }
++            }
++        }
++    }
++}
+diff --git a/src/main/java/org/bukkit/plugin/EventExecutor.java b/src/main/java/org/bukkit/plugin/EventExecutor.java
+index a850f0780de05463fc0d3f9e15ff7f19d88b2aed..9026e108ccd3a88aee1267ee275137befa646455 100644
+--- a/src/main/java/org/bukkit/plugin/EventExecutor.java
++++ b/src/main/java/org/bukkit/plugin/EventExecutor.java
+@@ -5,9 +5,75 @@ import org.bukkit.event.EventException;
+ import org.bukkit.event.Listener;
+ import org.jetbrains.annotations.NotNull;
+ 
++// Paper start
++import java.lang.reflect.Method;
++import java.lang.reflect.Modifier;
++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(@NotNull Listener listener, @NotNull Event event) throws EventException;
++
++    // Paper start
++    ConcurrentMap<Method, Class<? extends EventExecutor>> eventExecutorMap = new ConcurrentHashMap<Method, Class<? extends EventExecutor>>() {
++        @NotNull
++        @Override
++        public Class<? extends EventExecutor> computeIfAbsent(@NotNull Method key, @NotNull 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);
++            }
++        }
++    };
++
++    @NotNull
++    public static EventExecutor create(@NotNull Method m, @NotNull 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 5eb24f38f158d43fb42836b83c108f808c89512e..5d74fab03a15d7099e5dacb780eade4cdc185797 100644
+--- a/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java
++++ b/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java
+@@ -291,21 +291,7 @@ public final class JavaPluginLoader implements PluginLoader {
+                 }
+             }
+ 
+-            EventExecutor executor = new co.aikar.timings.TimedEventExecutor(new EventExecutor() { // Paper
+-                @Override
+-                public void execute(@NotNull Listener listener, @NotNull Event event) throws EventException { // Paper
+-                    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); // Paper
++            EventExecutor executor = new co.aikar.timings.TimedEventExecutor(EventExecutor.create(method, eventClass), plugin, method, eventClass); // Paper // Paper (Yes.) - 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 {