WebWorkers: Allow web worker owner to inject globals into worker, supply modified __fbBatchedBridgeConfig

Summary: Now that web workers are just JSCExecutors, we can move forward with adding native module support. The means we need to supply the worker with a correct __fbBatchedBridgeConfig global so it can appropriately set up its JS MessageQueue. Unfortunately, native modules can't support multiple JS execution contexts out-of-the-box, so we need to whitelist those modules that actually can be referenced from a webworker. In order to do that, we add the supportsWebWorkers call in NativeModule and the SupportsWebWorkers annotation for JS modules. These add metadata to __fbBatchedBridgeConfig which allows us to create a new config with only those modules that support web workers.

Reviewed By: lexs

Differential Revision: D2927091

fb-gh-sync-id: 9b47331253b277940b552e7d899198b5f0a3ed8c
shipit-source-id: 9b47331253b277940b552e7d899198b5f0a3ed8c

ReactAndroid/src/main/java/com/facebook/react/bridge/BaseJavaModule.java

@@ -341,4 +341,9 @@ public abstract class BaseJavaModule implements NativeModule {
   public void onCatalystInstanceDestroy() {
     // do nothing
   }
+
+  @Override
+  public boolean supportsWebWorkers() {
+    return false;
+  }
 }

ReactAndroid/src/main/java/com/facebook/react/bridge/JavaScriptModulesConfig.java

@@ -52,6 +52,9 @@ public class JavaScriptModulesConfig {
       jg.writeEndObject();
     }
     jg.writeEndObject();
+    if (registration.getModuleInterface().isAnnotationPresent(SupportsWebWorkers.class)) {
+      jg.writeBooleanField("supportsWebWorkers", true);
+    }
   }
 
   public static class Builder {

ReactAndroid/src/main/java/com/facebook/react/bridge/NativeModule.java

@@ -72,4 +72,9 @@ public interface NativeModule {
    * Called before {CatalystInstance#onHostDestroy}
    */
   void onCatalystInstanceDestroy();
+
+  /**
+   * Whether this native module supports calls from web workers. Ignored for now.
+   */
+  boolean supportsWebWorkers();
 }

ReactAndroid/src/main/java/com/facebook/react/bridge/NativeModuleRegistry.java

@@ -65,6 +65,7 @@ public class NativeModuleRegistry {
       for (ModuleDefinition moduleDef : mModuleTable) {
         jg.writeObjectFieldStart(moduleDef.name);
         jg.writeNumberField("moduleID", moduleDef.id);
+        jg.writeBooleanField("supportsWebWorkers", moduleDef.target.supportsWebWorkers());
         jg.writeObjectFieldStart("methods");
         for (int i = 0; i < moduleDef.methods.size(); i++) {
           MethodRegistration method = moduleDef.methods.get(i);

ReactAndroid/src/main/java/com/facebook/react/bridge/SupportsWebWorkers.java

@@ -0,0 +1,15 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+package com.facebook.react.bridge;
+
+import java.lang.annotation.Retention;
+
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+/**
+ * Annotation indicating that a JS module should be made available to web
+ * workers spawned by the main JS executor.
+ */
+@Retention(RUNTIME)
+public @interface SupportsWebWorkers {
+}