--- a/src/jdk.internal.vm.compiler/share/classes/jdk.internal.vm.compiler.libgraal/src/jdk/internal/vm/compiler/libgraal/LibGraal.java	Thu Jun 27 03:10:52 2019 +0200
+++ b/src/jdk.internal.vm.compiler/share/classes/jdk.internal.vm.compiler.libgraal/src/jdk/internal/vm/compiler/libgraal/LibGraal.java	Thu Jun 27 03:33:44 2019 +0200
@@ -33,67 +33,43 @@
 public class LibGraal {
 
     public static boolean isAvailable() {
-        return isCurrentRuntime() || libgraalIsolate != 0L;
+        return inLibGraal() || isolate != 0L;
     }
 
-    public static boolean isCurrentRuntime() {
+    public static boolean inLibGraal() {
         return Services.IS_IN_NATIVE_IMAGE;
     }
 
-    public static long getIsolate() {
-        if (isCurrentRuntime() || !isAvailable()) {
-            throw new IllegalStateException();
-        }
-        return libgraalIsolate;
-    }
-
-    public static long getIsolateThread() {
-        if (isCurrentRuntime()) {
-            throw new IllegalStateException();
-        }
-        return CURRENT_ISOLATE_THREAD.get();
-    }
-
-    @SuppressWarnings("unused")
-    public static long[] registerNativeMethods(HotSpotJVMCIRuntime runtime, Class<?> clazz) {
+    public static void registerNativeMethods(HotSpotJVMCIRuntime runtime, Class<?> clazz) {
         if (clazz.isPrimitive()) {
             throw new IllegalArgumentException();
         }
-        if (isCurrentRuntime() || !isAvailable()) {
+        if (inLibGraal() || !isAvailable()) {
             throw new IllegalStateException();
         }
-        // Waiting for https://bugs.openjdk.java.net/browse/JDK-8220623
-        // return runtime.registerNativeMethods(clazz);
-        throw new IllegalStateException("Requires JDK-8220623");
+        runtime.registerNativeMethods(clazz);
     }
 
-    @SuppressWarnings("unused")
     public static long translate(HotSpotJVMCIRuntime runtime, Object obj) {
         if (!isAvailable()) {
             throw new IllegalStateException();
         }
-        // return runtime.translate(obj);
-        throw new IllegalStateException("Requires JDK-8220623");
+        if (!inLibGraal() && LibGraalScope.currentScope.get() == null) {
+            throw new IllegalStateException("Not within a " + LibGraalScope.class.getName());
+        }
+        return runtime.translate(obj);
     }
 
-    @SuppressWarnings("unused")
     public static <T> T unhand(HotSpotJVMCIRuntime runtime, Class<T> type, long handle) {
         if (!isAvailable()) {
             throw new IllegalStateException();
         }
-        // return runtime.unhand(type, handle);
-        throw new IllegalStateException("Requires JDK-8220623");
+        if (!inLibGraal() && LibGraalScope.currentScope.get() == null) {
+            throw new IllegalStateException("Not within a " + LibGraalScope.class.getName());
+        }
+        return runtime.unhand(type, handle);
     }
 
-    private static final ThreadLocal<Long> CURRENT_ISOLATE_THREAD = new ThreadLocal<>() {
-        @Override
-        protected Long initialValue() {
-            return attachThread(libgraalIsolate);
-        }
-    };
-
-    private static final long libgraalIsolate = Services.IS_BUILDING_NATIVE_IMAGE ? 0L : initializeLibgraal();
-
     private static long initializeLibgraal() {
         try {
             // Initialize JVMCI to ensure JVMCI opens its packages to
@@ -101,20 +77,27 @@
             // below will fail on JDK13+.
             Services.initializeJVMCI();
 
-            // Waiting for https://bugs.openjdk.java.net/browse/JDK-8220623
-            // HotSpotJVMCIRuntime runtime = HotSpotJVMCIRuntime.runtime();
-            // long[] nativeInterface = runtime.registerNativeMethods(LibGraal.class);
-            // return nativeInterface[1];
-            return 0L;
+            HotSpotJVMCIRuntime runtime = HotSpotJVMCIRuntime.runtime();
+            long[] nativeInterface = runtime.registerNativeMethods(LibGraal.class);
+            return nativeInterface[1];
         } catch (UnsupportedOperationException e) {
             return 0L;
         }
     }
 
-    /**
-     * Attaches the current thread to a thread in {@code isolate}.
-     *
-     * @param isolate
-     */
-    private static native long attachThread(long isolate);
+    static final long isolate = Services.IS_BUILDING_NATIVE_IMAGE ? 0L : initializeLibgraal();
+
+    static boolean isCurrentThreadAttached(HotSpotJVMCIRuntime runtime) {
+        return runtime.isCurrentThreadAttached();
+    }
+
+    static boolean attachCurrentThread(HotSpotJVMCIRuntime runtime) {
+        return runtime.attachCurrentThread(false);
+    }
+
+    static void detachCurrentThread(HotSpotJVMCIRuntime runtime) {
+        runtime.detachCurrentThread();
+    }
+
+    static native long getCurrentIsolateThread(long iso);
 }