Merge pull request #21 from LabyMod/develop

Make Javascript context provider async

Author: Janrupf

README.md

@@ -27,7 +27,7 @@ Moreover, the databind API is capable of translating Java objects directly to Ja
 calls directly from within your JavaScript code, making integration with the UI even easier.
 
 # Licensing
-For Ultralight Java [GPLv3](https://www.gnu.org/licenses/gpl-3.0.en.html) is being used, however, Ultralight itself is
+For Ultralight Java [LGPLv3](https://www.gnu.org/licenses/lgpl-3.0.en.html) is being used, however, Ultralight itself is
 licensed under a custom proprietary license. See
 [Ultralight licensing](https://github.com/ultralight-ux/Ultralight/blob/master/README.md#licensing) for further 
 information.

VERSION

@@ -1 +1 @@
-0.3.0
+0.3.1

ultralight-java-databind/src/main/java/com/labymedia/ultralight/context/ContextProvider.java

@@ -21,15 +21,16 @@
 
 import com.labymedia.ultralight.javascript.JavascriptContextLock;
 
+import java.util.function.Consumer;
+
 /**
  * Interface to be implemented by the user.
  */
 public interface ContextProvider {
     /**
-     * Retrieves the bound Javascript context with a lock. The lock will be unlocked by the consumer automatically
-     * after it finished using it.
+     * Executes the callback later on a thread which is synchronized with the Javascript engine.
      *
-     * @return The bound Javascript context lock, or {@code null}, if the context is not available anymore
+     * @param callback The callback to execute
      */
-    JavascriptContextLock getContext();
+    void syncWithJavascript(Consumer<JavascriptContextLock> callback);
 }

ultralight-java-databind/src/main/java/com/labymedia/ultralight/utils/FunctionalInvocationHandler.java

@@ -28,6 +28,8 @@
 import java.lang.invoke.MethodHandles;
 import java.lang.reflect.InvocationHandler;
 import java.lang.reflect.Method;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.atomic.AtomicReference;
 
 /**
  * Invocation handler for Javascript functions bound to functional interfaces.
@@ -90,16 +92,15 @@ public Object invoke(Object proxy, Method method, Object[] args) throws Throwabl
 
         Class<?>[] methodParameterTypes = method.getParameterTypes();
 
-        synchronized (lock) {
-            try (JavascriptContextLock lock = contextProvider.getContext()) {
-                if (lock == null) {
-                    throw new IllegalStateException("Context required for callback does not exist anymore");
-                }
+        CountDownLatch awaiter = new CountDownLatch(1);
+        AtomicReference<Object> out = new AtomicReference<>();
 
-                JavascriptContext context = lock.getContext();
+        contextProvider.syncWithJavascript((contextLock) -> {
+            synchronized (lock) {
+                JavascriptContext context = contextLock.getContext();
 
                 // Revive the Javascript value, this will effectively invalidate the protected value
-                JavascriptObject object = protectedValue.get().value.revive(lock).toObject();
+                JavascriptObject object = protectedValue.get().value.revive(contextLock).toObject();
 
                 // Convert all Java arguments to Javascript values
                 JavascriptValue[] arguments = new JavascriptValue[args.length];
@@ -112,9 +113,15 @@ public Object invoke(Object proxy, Method method, Object[] args) throws Throwabl
                 protectedValue.get().value = object.protect();
 
                 JavascriptValue returnValue = object.callAsFunction(null, arguments);
-                return databind.getConversionUtils().fromJavascript(returnValue, method.getReturnType());
+                Object ret = databind.getConversionUtils().fromJavascript(returnValue, method.getReturnType());
+                out.set(ret);
+                awaiter.countDown();
             }
-        }
+        });
+
+        awaiter.await();
+
+        return out.get();
     }
 
     /**
@@ -142,8 +149,8 @@ private ValueWrapper(ContextProvider contextProvider, JavascriptProtectedValue v
      * @param valueWrapper The wrapper to delete
      */
     private static void delete(ValueWrapper valueWrapper) {
-        try (JavascriptContextLock lock = valueWrapper.contextProvider.getContext()) {
-            valueWrapper.value.revive(lock);
-        }
+        valueWrapper.contextProvider.syncWithJavascript((contextLock) -> {
+            valueWrapper.value.revive(contextLock);
+        });
     }
 }

ultralight-java-lwjgl3-opengl/src/test/java/com/labymedia/ultralight/lwjgl3/opengl/TestContextProvider.java

@@ -22,9 +22,12 @@
 import com.labymedia.ultralight.UltralightView;
 import com.labymedia.ultralight.context.ContextProviderFactory;
 import com.labymedia.ultralight.context.ContextProvider;
+import com.labymedia.ultralight.javascript.JavascriptContext;
 import com.labymedia.ultralight.javascript.JavascriptContextLock;
 import com.labymedia.ultralight.javascript.JavascriptValue;
 
+import java.util.function.Consumer;
+
 public class TestContextProvider implements ContextProvider {
     private final UltralightView view;
 
@@ -33,8 +36,10 @@ private TestContextProvider(UltralightView view) {
     }
 
     @Override
-    public JavascriptContextLock getContext() {
-        return view.lockJavascriptContext();
+    public void syncWithJavascript(Consumer<JavascriptContextLock> callback) {
+        try(JavascriptContextLock lock = view.lockJavascriptContext()) {
+            callback.accept(lock);
+        }
     }
 
     public static class Factory implements ContextProviderFactory {