Compartmentalise the parent loader.

Author: Moderocky

src/main/java/org/byteskript/skript/compiler/SimpleSkriptCompiler.java

@@ -263,8 +263,9 @@ public ElementTree assembleExpression(String expression, final Type expected, fi
     }
 
     @Override
+    @Deprecated
     public Class<?> load(byte[] bytecode, String name) {
-        return Skript.LOADER.loadClass(name, bytecode);
+        return Skript.currentLoader().loadClass(name, bytecode);
     }
 
     @Override

src/main/java/org/byteskript/skript/lang/syntax/script/UnloadScriptEffect.java

@@ -44,7 +44,7 @@ public static void unloadScript(Object object) throws IOException {
         else if (object instanceof Script script)
             Skript.localInstance().unloadScript(script);
         else if (object instanceof String name)
-            Skript.localInstance().unloadScript(Skript.LOADER.findClass(name.replace('/', '.')));
+            Skript.localInstance().unloadScript(Skript.localLoader().findClass(name.replace('/', '.')));
     }
 
 }

src/main/java/org/byteskript/skript/lang/syntax/type/property/PropertyMember.java

@@ -11,7 +11,6 @@
 import org.byteskript.skript.api.syntax.Member;
 import org.byteskript.skript.compiler.*;
 import org.byteskript.skript.compiler.structure.SectionMeta;
-import org.byteskript.skript.error.ScriptError;
 import org.byteskript.skript.lang.element.StandardElements;
 import org.byteskript.skript.runtime.data.SourceData;
 import org.byteskript.skript.runtime.internal.ConsoleColour;

src/main/java/org/byteskript/skript/runtime/Skript.java

@@ -41,8 +41,8 @@ public final class Skript {
 
     public static final ThreadGroup THREAD_GROUP = new ThreadGroup("skript");
     public static final int JAVA_VERSION = 61;
-    public static final RuntimeClassLoader LOADER = new RuntimeClassLoader(Skript.class.getClassLoader());
     static final GlobalVariableMap VARIABLES = new GlobalVariableMap();
+    private static final RuntimeClassLoader LOADER = new RuntimeClassLoader(Skript.class.getClassLoader());
     private static Skript skript;
     final ExecutorService executor;
     final SkriptThreadProvider factory;
@@ -51,12 +51,10 @@ public final class Skript {
     final ModifiableCompiler compiler;
     final List<OperationController> processes;
     final Map<Class<? extends Event>, EventHandler> events;
-    final SkriptMirror mirror = new SkriptMirror(LOADER);
+    final RuntimeClassLoader parent = new RuntimeClassLoader(LOADER);
     final WeakList<ScriptClassLoader> loaders = new WeakList<>();
     final List<Script> scripts = new ArrayList<>(); // the only strong reference, be careful!
 
-    //region Class Loaders
-    
     /**
      * Create a Skript runtime with a custom (non-default) Skript compiler.
      * This is used by the Jar-form script loader, which has no compiler.
@@ -101,6 +99,47 @@ public Skript() {
         this(new SkriptThreadProvider(), SkriptCompiler.createBasic(), Thread.currentThread());
     }
 
+    /**
+     * Gets the parent class-loader local to this thread.
+     * This is only usable from a script thread.
+     *
+     * @return the local runtime loader
+     */
+    @ThreadSpecific
+    public static RuntimeClassLoader localLoader() {
+        final Thread current = Thread.currentThread();
+        if (!(current instanceof ScriptThread thread))
+            throw new ScriptRuntimeError("Not running on a script thread.");
+        return thread.skript.parent;
+    }
+    
+    /**
+     * Finds an arbitrary parent class-loader.
+     * This will use the most recently-created Skript runtime.
+     * This is unsafe, since it is unlikely to be the required loader.
+     *
+     * @return potentially null class-loader
+     */
+    @Deprecated
+    public static RuntimeClassLoader currentLoader() {
+        return skript.parent;
+    }
+    
+    /**
+     * Attempts to find the parent class-loader.
+     * This will look for a local loader but default to the most-recently-created.
+     * This is designed for internal use.
+     *
+     * @return an arbitrary class-loader
+     */
+    @ThreadSpecific
+    public static RuntimeClassLoader findLoader() {
+        final Thread current = Thread.currentThread();
+        if (current instanceof ScriptThread thread)
+            return thread.skript.parent;
+        return skript.parent;
+    }
+    
     /**
      * This is the map of global `{!var}` variables.
      * This is a modifiable and atomic map.
@@ -114,7 +153,6 @@ public Skript() {
     public static GlobalVariableMap getVariables() {
         return VARIABLES;
     }
-    //endregion
 
     /**
      * This returns the Skript instance that launched the current thread.
@@ -157,8 +195,6 @@ private static String createClassName(String name, String path) {
         return path.substring(0, index).replace(File.separatorChar, '.');
     }
 
-    //region Runtime Instances
-    
     private static List<File> getFiles(List<File> files, Path root) {
         try (DirectoryStream<Path> stream = Files.newDirectoryStream(root)) {
             for (Path path : stream) {
@@ -175,6 +211,16 @@ private static List<File> getFiles(List<File> files, Path root) {
         return files;
     }
 
+    /**
+     * Gets the parent class-loader attached to this Skript runtime.
+     * This is used to search available libraries and scripts for classes.
+     *
+     * @return this runtime loader
+     */
+    public RuntimeClassLoader getLoader() {
+        return parent;
+    }
+    
     /**
      * Submits this instruction to a background thread.
      * Background threads are safe for blocking.
@@ -195,9 +241,6 @@ public void runOnAsyncThread(final Instruction<?> runnable) {
     public Future<?> getOnAsyncThread(final Instruction<?> runnable) {
         return executor.submit(runnable::get);
     }
-    //endregion
-    
-    //region Thread Control
 
     /**
      * Submits this instruction to a background thread.
@@ -232,9 +275,6 @@ public Script[] getScripts() {
     public Collection<OperationController> getProcesses() {
         return processes;
     }
-    //endregion
-    
-    //region Script Control
 
     /**
      * Runs a script with a completing future.
@@ -353,9 +393,6 @@ private static Class<?> getClass(String name, Class<?> owner) {
             return null;
         }
     }
-    //endregion
-    
-    //region Libraries
 
     /**
      * Registers a single class library, typically compiled from a script to load
@@ -378,7 +415,6 @@ public Class<?> defineClass(String name, byte[] bytes) {
         compiler.addLibrary(library);
     }
 
-    //region File Utilities
     private static String getClassName(InputStream is)
         throws IOException {
         final DataInputStream stream = new DataInputStream(is);
@@ -428,9 +464,6 @@ public boolean unregisterLibrary(Library library) {
     public ModifiableCompiler getCompiler() {
         return compiler;
     }
-    //endregion
-    
-    //region Script Compiling
 
     /**
      * Returns an array of all registered libraries.
@@ -598,9 +631,6 @@ public void unloadScript(Class<?> main) {
             if (script.mainClass() == main) this.unloadScript(script);
         }
     }
-    //endregion
-    
-    //region Script Loading
 
     /**
      * Unloads a script. This is a destructive operation.
@@ -845,9 +875,6 @@ public Script loadScript(final InputStream stream, final String name)
         throws IOException {
         return loadScript(this.loadClass(name, stream.readAllBytes()));
     }
-    //endregion
-    
-    //region Timings
 
     /**
      * Loads a script from its compiled class file.
@@ -904,7 +931,6 @@ public ScheduledExecutorService getScheduler() {
     public ExecutorService getExecutor() {
         return executor;
     }
-    //endregion
 
     /**
      * Schedules a task to be run at some point in the future.
@@ -919,7 +945,7 @@ public Future<?> schedule(Runnable runnable, long millis) {
 
     /**
      * This class handles the class-loading delegation for libraries and scripts.
-     * It should not be interacted with directly, see {@link Skript#LOADER} for an instance.
+     * It should not be interacted with directly, see {@link Skript#getLoader()} for an instance.
      */
     public static class RuntimeClassLoader extends ClassLoader implements ClassProvider {
         protected RuntimeClassLoader(ClassLoader parent) {
@@ -987,6 +1013,5 @@ public Class<?> loadClass(String name, byte[] bytecode) {
             return super.loadClass(name, bytecode);
         }
     }
-    //endregion
 
 }

src/main/java/org/byteskript/skript/runtime/internal/Member.java

@@ -31,7 +31,7 @@ public Member(Script script, Method method, boolean async) {
         this.script = script;
         this.async = async;
         this.parameters = method.getParameterCount();
-        final Mirror<?> mirror = Mirror.of(script.mainClass()).useProvider(Skript.LOADER);
+        final Mirror<?> mirror = Mirror.of(script.mainClass()).useProvider(script.skriptInstance().getLoader());
         this.invoker = mirror.method(method);
         this.verifier = mirror.method(method.getName() + "_verify", method.getParameterTypes());
     }
@@ -79,7 +79,7 @@ else if (thing instanceof Future future)
     }
 
     public static MethodAccessor<Object> findFunction(Object owner, String name) {
-        return Mirror.of(owner).useProvider(Skript.LOADER).method(name);
+        return Mirror.of(owner).useProvider(Skript.findLoader()).method(name);
     }
 
     public static MethodAccessor<Object> getFunction(Object source, String pattern) {
@@ -120,7 +120,7 @@ private static int count(String pattern) {
     public static MethodAccessor<Object> findFunction(Object owner, String name, Number arguments) {
         final Class<?>[] parameters = new Class[arguments.intValue()];
         Arrays.fill(parameters, Object.class);
-        return Mirror.of(owner).useProvider(Skript.LOADER).method(name, parameters);
+        return Mirror.of(owner).useProvider(Skript.findLoader()).method(name, parameters);
     }
 
     public Script getScript() {

src/main/java/org/byteskript/skript/runtime/internal/Metafactory.java

@@ -53,7 +53,8 @@ private static Method findTarget(MethodHandles.Lookup caller, String name, Class
     }
 
     public static Object callFunction(String name, Object target, Object[] parameters) {
-        final MethodAccessor<Object> accessor = Mirror.of(target).useProvider(Skript.LOADER).method(name, parameters);
+        final MethodAccessor<Object> accessor = Mirror.of(target).useProvider(Skript.findLoader())
+            .method(name, parameters);
         if (accessor == null) throw new ScriptRuntimeError("Unable to find function '" + name + "' from " + target);
         return accessor.invoke(parameters);
     }

src/main/java/org/byteskript/skript/runtime/internal/ScriptClassLoader.java

@@ -17,7 +17,7 @@ public class ScriptClassLoader extends ClassLoader implements ClassProvider {
     final List<Class<?>> loaded = new ArrayList<>();
 
     public ScriptClassLoader() {
-        super(Skript.LOADER);
+        super(Skript.findLoader());
     }
 
     public Class<?> loadClass0(String name) throws ClassNotFoundException {
@@ -32,15 +32,15 @@ public Class<?> loadClass(String name) throws ClassNotFoundException {
         for (final Class<?> thing : loaded) {
             if (thing.getName().equals(name)) return thing;
         }
-        return Skript.LOADER.loadClass(name);
+        return Skript.findLoader().loadClass(name);
     }
 
     @Override
     public Class<?> findClass(String name) throws ClassNotFoundException {
         for (final Class<?> thing : loaded) {
             if (thing.getName().equals(name)) return thing;
         }
-        return Skript.LOADER.findClass(name);
+        return Skript.findLoader().findClass(name);
     }
 
     public Class<?> findClass0(String name) throws ClassNotFoundException {

src/main/java/skript.java

@@ -192,10 +192,11 @@ public static MethodAccessor<Object> get_java_method(Object owner, Object name,
     private static Mirror<?> mirror(Object owner) {
         if (owner == null) return null;
         if (owner instanceof Class<?> type) {
-            if (type.getName().startsWith("skript")) return Mirror.of(type).useProvider(Skript.LOADER);
+            if (type.getName().startsWith("skript")) return Mirror.of(type).useProvider(Skript.findLoader());
             return Mirror.of(type);
         } else {
-            if (owner.getClass().getName().startsWith("skript")) return Mirror.of(owner).useProvider(Skript.LOADER);
+            if (owner.getClass().getName().startsWith("skript"))
+                return Mirror.of(owner).useProvider(Skript.findLoader());
             return Mirror.of(owner);
         }
     }