Support ModuleHolder-based lazy init of C++ modules with C++ bridge on android

Reviewed By: AaaChiuuu

Differential Revision: D4614479

fbshipit-source-id: 109ac34b8688f0113675e4a4479d1ddcc6169ed4

React/CxxBridge/RCTCxxBridge.mm

@@ -553,7 +553,8 @@ struct RCTInstanceCallback : public InstanceCallback {
       }
       modules.emplace_back(
         new QueueNativeModule(self, std::make_unique<CxxNativeModule>(
-          _reactInstance, [(RCTCxxModule *)(moduleData.instance) move])));
+                                  _reactInstance, [moduleData.name UTF8String],
+                                  [moduleData] { return [(RCTCxxModule *)(moduleData.instance) move]; })));
     } else {
       modules.emplace_back(new RCTNativeModule(self, moduleData));
     }

ReactAndroid/src/main/java/com/facebook/react/cxxbridge/CatalystInstanceImpl.java

@@ -110,7 +110,7 @@ public class CatalystInstanceImpl implements CatalystInstance {
       final JavaScriptModuleRegistry jsModuleRegistry,
       final JSBundleLoader jsBundleLoader,
       NativeModuleCallExceptionHandler nativeModuleCallExceptionHandler) {
-    FLog.d(ReactConstants.TAG, "Initializing React Xplat Bridge.");
+    FLog.w(ReactConstants.TAG, "Initializing React Xplat Bridge.");
     mHybridData = initHybrid();
 
     mReactQueueConfiguration = ReactQueueConfigurationImpl.create(
@@ -123,6 +123,7 @@ public class CatalystInstanceImpl implements CatalystInstance {
     mNativeModuleCallExceptionHandler = nativeModuleCallExceptionHandler;
     mTraceListener = new JSProfilerTraceListener(this);
 
+    FLog.w(ReactConstants.TAG, "Initializing React Xplat Bridge before initializeBridge");
     initializeBridge(
       new BridgeCallback(this),
       jsExecutor,
@@ -130,6 +131,7 @@ public class CatalystInstanceImpl implements CatalystInstance {
       mReactQueueConfiguration.getNativeModulesQueueThread(),
       mJavaRegistry.getJavaModules(this),
       mJavaRegistry.getCxxModules());
+    FLog.w(ReactConstants.TAG, "Initializing React Xplat Bridge after initializeBridge");
     mMainExecutorToken = getMainExecutorToken();
   }
 
@@ -182,7 +184,7 @@ public class CatalystInstanceImpl implements CatalystInstance {
       MessageQueueThread jsQueue,
       MessageQueueThread moduleQueue,
       Collection<JavaModuleWrapper> javaModules,
-      Collection<CxxModuleWrapper> cxxModules);
+      Collection<ModuleHolder> cxxModules);
 
   /**
    * This API is used in situations where the JS bundle is being executed not on

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

@@ -53,12 +53,12 @@ public class NativeModuleRegistry {
     return javaModules;
   }
 
-  /* package */ Collection<CxxModuleWrapper> getCxxModules() {
-    ArrayList<CxxModuleWrapper> cxxModules = new ArrayList<>();
+  /* package */ Collection<ModuleHolder> getCxxModules() {
+    ArrayList<ModuleHolder> cxxModules = new ArrayList<>();
     for (Map.Entry<Class<? extends NativeModule>, ModuleHolder> entry : mModules.entrySet()) {
       Class<?> type = entry.getKey();
       if (CxxModuleWrapper.class.isAssignableFrom(type)) {
-        cxxModules.add((CxxModuleWrapper) entry.getValue().getModule());
+        cxxModules.add(entry.getValue());
       }
     }
     return cxxModules;

ReactAndroid/src/main/jni/xreact/jni/Android.mk

@@ -15,6 +15,7 @@ LOCAL_SRC_FILES := \
   JSLogging.cpp \
   JniJSModulesUnbundle.cpp \
   MethodInvoker.cpp \
+  ModuleRegistryBuilder.cpp \
   NativeArray.cpp \
   NativeCommon.cpp \
   NativeMap.cpp \

ReactAndroid/src/main/jni/xreact/jni/BUCK

@@ -6,6 +6,7 @@ EXPORTED_HEADERS = [
     "JExecutorToken.h",
     "JSLoader.h",
     "MethodInvoker.h",
+    "ModuleRegistryBuilder.h",
     "NativeArray.h",
     "NativeCommon.h",
     "NativeMap.h",

ReactAndroid/src/main/jni/xreact/jni/CatalystInstanceImpl.cpp

@@ -20,6 +20,7 @@
 #include <cxxreact/ModuleRegistry.h>
 #include <cxxreact/CxxNativeModule.h>
 
+#include "CxxModuleWrapper.h"
 #include "JavaScriptExecutorHolder.h"
 #include "JniJSModulesUnbundle.h"
 #include "JNativeRunnable.h"
@@ -128,21 +129,10 @@ void CatalystInstanceImpl::initializeBridge(
     jni::alias_ref<JavaMessageQueueThread::javaobject> jsQueue,
     jni::alias_ref<JavaMessageQueueThread::javaobject> moduleQueue,
     jni::alias_ref<jni::JCollection<JavaModuleWrapper::javaobject>::javaobject> javaModules,
-    jni::alias_ref<jni::JCollection<CxxModuleWrapper::javaobject>::javaobject> cxxModules) {
+    jni::alias_ref<jni::JCollection<ModuleHolder::javaobject>::javaobject> cxxModules) {
   // TODO mhorowitz: how to assert here?
   // Assertions.assertCondition(mBridge == null, "initializeBridge should be called once");
 
-  std::vector<std::unique_ptr<NativeModule>> modules;
-  std::weak_ptr<Instance> winstance(instance_);
-  for (const auto& jm : *javaModules) {
-    modules.emplace_back(folly::make_unique<JavaNativeModule>(winstance, jm));
-  }
-  for (const auto& cm : *cxxModules) {
-    modules.emplace_back(
-      folly::make_unique<CxxNativeModule>(winstance, std::move(cthis(cm)->getModule())));
-  }
-  auto moduleRegistry = std::make_shared<ModuleRegistry>(std::move(modules));
-
   // This used to be:
   //
   // Java CatalystInstanceImpl -> C++ CatalystInstanceImpl -> Bridge -> Bridge::Callback
@@ -163,7 +153,8 @@ void CatalystInstanceImpl::initializeBridge(
                               jseh->getExecutorFactory(),
                               folly::make_unique<JMessageQueueThread>(jsQueue),
                               folly::make_unique<JMessageQueueThread>(moduleQueue),
-                              moduleRegistry);
+                              buildModuleRegistry(std::weak_ptr<Instance>(instance_),
+                                                  javaModules, cxxModules));
 }
 
 void CatalystInstanceImpl::jniSetSourceURL(const std::string& sourceURL) {

ReactAndroid/src/main/jni/xreact/jni/CatalystInstanceImpl.h

@@ -10,6 +10,7 @@
 #include "JMessageQueueThread.h"
 #include "JSLoader.h"
 #include "JavaModuleWrapper.h"
+#include "ModuleRegistryBuilder.h"
 
 namespace facebook {
 namespace react {
@@ -48,7 +49,7 @@ class CatalystInstanceImpl : public jni::HybridClass<CatalystInstanceImpl> {
       jni::alias_ref<JavaMessageQueueThread::javaobject> jsQueue,
       jni::alias_ref<JavaMessageQueueThread::javaobject> moduleQueue,
       jni::alias_ref<jni::JCollection<JavaModuleWrapper::javaobject>::javaobject> javaModules,
-      jni::alias_ref<jni::JCollection<CxxModuleWrapper::javaobject>::javaobject> cxxModules);
+      jni::alias_ref<jni::JCollection<ModuleHolder::javaobject>::javaobject> cxxModules);
 
   /**
    * Sets the source URL of the underlying bridge without loading any JS code.

ReactAndroid/src/main/jni/xreact/jni/CxxModuleWrapper.h

@@ -12,7 +12,13 @@
 namespace facebook {
 namespace react {
 
-class CxxModuleWrapper : public jni::HybridClass<CxxModuleWrapper> {
+struct JNativeModule : jni::JavaClass<JNativeModule> {
+  constexpr static const char *const kJavaDescriptor =
+    "Lcom/facebook/react/bridge/NativeModule;";
+};
+
+class CxxModuleWrapper :
+    public jni::HybridClass<CxxModuleWrapper, JNativeModule> {
 public:
   constexpr static const char *const kJavaDescriptor =
     "Lcom/facebook/react/cxxbridge/CxxModuleWrapper;";

ReactAndroid/src/main/jni/xreact/jni/JavaModuleWrapper.h

@@ -27,6 +27,8 @@ struct JavaModuleWrapper : jni::JavaClass<JavaModuleWrapper> {
   static constexpr auto kJavaDescriptor = "Lcom/facebook/react/cxxbridge/JavaModuleWrapper;";
 
   jni::local_ref<JBaseJavaModule::javaobject> getModule() {
+    // This is the call which causes a lazy Java module to actually be
+    // created.
     static auto getModule = javaClassStatic()->getMethod<JBaseJavaModule::javaobject()>("getModule");
     return getModule(self());
   }

ReactAndroid/src/main/jni/xreact/jni/ModuleRegistryBuilder.cpp

@@ -0,0 +1,51 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+#include "ModuleRegistryBuilder.h"
+
+#include <cxxreact/CxxNativeModule.h>
+#include <folly/Memory.h>
+
+namespace facebook {
+namespace react {
+
+std::string ModuleHolder::getName() const {
+  static auto method = getClass()->getMethod<jstring()>("getName");
+  return method(self())->toStdString();
+}
+
+xplat::module::CxxModule::Provider ModuleHolder::getProvider() const {
+  return [self=jni::make_global(self())] {
+    static auto method =
+      ModuleHolder::javaClassStatic()->getMethod<JNativeModule::javaobject()>(
+        "getModule");
+    // This is the call which uses the lazy Java Provider to instantiate the
+    // Java CxxModuleWrapper which contains the CxxModule.
+    auto module = method(self);
+    CHECK(module->isInstanceOf(CxxModuleWrapper::javaClassStatic()))
+      << "module isn't a C++ module";
+    auto cxxModule = jni::static_ref_cast<CxxModuleWrapper::javaobject>(module);
+    // Then, we grab the CxxModule from the wrapper, which is no longer needed.
+    return cxxModule->cthis()->getModule();
+  };
+}
+
+std::unique_ptr<ModuleRegistry> buildModuleRegistry(
+    std::weak_ptr<Instance> winstance,
+    jni::alias_ref<jni::JCollection<JavaModuleWrapper::javaobject>::javaobject> javaModules,
+    jni::alias_ref<jni::JCollection<ModuleHolder::javaobject>::javaobject> cxxModules) {
+  std::vector<std::unique_ptr<NativeModule>> modules;
+  for (const auto& jm : *javaModules) {
+    modules.emplace_back(folly::make_unique<JavaNativeModule>(winstance, jm));
+  }
+  for (const auto& cm : *cxxModules) {
+    modules.emplace_back(
+      folly::make_unique<CxxNativeModule>(winstance, cm->getName(), cm->getProvider()));
+  }
+  if (modules.empty()) {
+    return nullptr;
+  } else {
+    return folly::make_unique<ModuleRegistry>(std::move(modules));
+  }
+}
+
+}}

ReactAndroid/src/main/jni/xreact/jni/ModuleRegistryBuilder.h

@@ -0,0 +1,30 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+#include <string>
+
+#include <cxxreact/CxxModule.h>
+#include <cxxreact/ModuleRegistry.h>
+#include <fb/fbjni.h>
+
+#include "CxxModuleWrapper.h"
+#include "JavaModuleWrapper.h"
+
+namespace facebook {
+namespace react {
+
+class ModuleHolder : public jni::JavaClass<ModuleHolder> {
+ public:
+  static auto constexpr kJavaDescriptor =
+    "Lcom/facebook/react/cxxbridge/ModuleHolder;";
+
+  std::string getName() const;
+  xplat::module::CxxModule::Provider getProvider() const;
+};
+
+std::unique_ptr<ModuleRegistry> buildModuleRegistry(
+  std::weak_ptr<Instance> winstance,
+  jni::alias_ref<jni::JCollection<JavaModuleWrapper::javaobject>::javaobject> javaModules,
+  jni::alias_ref<jni::JCollection<ModuleHolder::javaobject>::javaobject> cxxModules);
+
+}
+}

ReactCommon/cxxreact/Android.mk

@@ -5,6 +5,7 @@ include $(CLEAR_VARS)
 LOCAL_MODULE := libreactnativefb
 
 LOCAL_SRC_FILES := \
+  CxxMessageQueue.cpp \
   CxxNativeModule.cpp \
   Instance.cpp \
   JSCExecutor.cpp \

ReactCommon/cxxreact/CxxModule.h

@@ -50,6 +50,8 @@ class CxxModule {
   class SyncTagType {};
 
 public:
+  typedef std::function<std::unique_ptr<CxxModule>()> Provider;
+
   typedef std::function<void(std::vector<folly::dynamic>)> Callback;
 
   constexpr static AsyncTagType AsyncTag = AsyncTagType();

ReactCommon/cxxreact/CxxNativeModule.cpp

@@ -47,18 +47,19 @@ CxxModule::Callback convertCallback(
 }
 
 CxxNativeModule::CxxNativeModule(std::weak_ptr<Instance> instance,
-                                 std::unique_ptr<CxxModule> module)
+                                 std::string name,
+                                 CxxModule::Provider provider)
   : instance_(instance)
-  , module_(std::move(module))
-  , methods_(module_->getMethods()) {
-    module_->setInstance(instance);
-  }
+  , name_(std::move(name))
+  , provider_(provider) {}
 
 std::string CxxNativeModule::getName() {
-  return module_->getName();
+  return name_;
 }
 
 std::vector<MethodDescriptor> CxxNativeModule::getMethods() {
+  lazyInit();
+
   std::vector<MethodDescriptor> descs;
   for (auto& method : methods_) {
     assert(method.func || method.syncFunc);
@@ -68,6 +69,8 @@ std::vector<MethodDescriptor> CxxNativeModule::getMethods() {
 }
 
 folly::dynamic CxxNativeModule::getConstants() {
+  lazyInit();
+
   folly::dynamic constants = folly::dynamic::object();
   for (auto& pair : module_->getConstants()) {
     constants.insert(std::move(pair.first), std::move(pair.second));
@@ -168,5 +171,15 @@ MethodCallResult CxxNativeModule::callSerializableNativeHook(
   return method.syncFunc(std::move(args));
 }
 
+void CxxNativeModule::lazyInit() {
+  if (module_) {
+    return;
+  }
+
+  module_ = provider_();
+  methods_ = module_->getMethods();
+  module_->setInstance(instance_);
+}
+
 }
 }

ReactCommon/cxxreact/CxxNativeModule.h

@@ -15,8 +15,8 @@ std::function<void(folly::dynamic)> makeCallback(
 
 class CxxNativeModule : public NativeModule {
 public:
-  CxxNativeModule(std::weak_ptr<Instance> instance,
-                  std::unique_ptr<xplat::module::CxxModule> module);
+  CxxNativeModule(std::weak_ptr<Instance> instance, std::string name,
+                  xplat::module::CxxModule::Provider provider);
 
   std::string getName() override;
   std::vector<MethodDescriptor> getMethods() override;
@@ -27,7 +27,11 @@ public:
     ExecutorToken token, unsigned int hookId, folly::dynamic&& args) override;
 
 private:
+  void lazyInit();
+
   std::weak_ptr<Instance> instance_;
+  std::string name_;
+  xplat::module::CxxModule::Provider provider_;
   std::unique_ptr<xplat::module::CxxModule> module_;
   std::vector<xplat::module::CxxModule::Method> methods_;
 };

ReactCommon/cxxreact/Instance.cpp

@@ -40,7 +40,7 @@ void Instance::initializeBridge(
   if (!nativeQueue) {
     // TODO pass down a thread/queue from java, instead of creating our own.
 
-    auto queue = std::make_unique<CxxMessageQueue>();
+    auto queue = folly::make_unique<CxxMessageQueue>();
     std::thread t(queue->getUnregisteredRunLoop());
     t.detach();
     nativeQueue = std::move(queue);

ReactCommon/cxxreact/JSCExecutor.cpp

@@ -361,12 +361,8 @@ void JSCExecutor::loadApplicationScript(std::unique_ptr<const JSBigString> scrip
 
       evaluateSourceCode(m_context, bcSourceCode, jsSourceURL);
 
-      // TODO(luk): t13903306 Remove this check once we make native modules
-      // working for java2js
-      if (m_delegate) {
       bindBridge();
       flush();
-      }
 
       ReactMarker::logMarker("CREATE_REACT_CONTEXT_END");
       ReactMarker::logMarker("RUN_JS_BUNDLE_END");
@@ -416,11 +412,8 @@ void JSCExecutor::loadApplicationScript(std::unique_ptr<const JSBigString> scrip
     evaluateScript(m_context, jsScript, jsSourceURL);
   }
 
-  // TODO(luk): t13903306 Remove this check once we make native modules working for java2js
-  if (m_delegate) {
   bindBridge();
   flush();
-  }
 
   ReactMarker::logMarker("CREATE_REACT_CONTEXT_END");
   ReactMarker::logMarker("RUN_JS_BUNDLE_END");
@@ -435,6 +428,9 @@ void JSCExecutor::setJSModulesUnbundle(std::unique_ptr<JSModulesUnbundle> unbund
 
 void JSCExecutor::bindBridge() throw(JSException) {
   SystraceSection s("JSCExecutor::bindBridge");
+  if (!m_delegate || !m_delegate->getModuleRegistry()) {
+    return;
+  }
   auto global = Object::getGlobalObject(m_context);
   auto batchedBridgeValue = global.getProperty("__fbBatchedBridge");
   if (batchedBridgeValue.isUndefined()) {
@@ -466,7 +462,18 @@ void JSCExecutor::callNativeModules(Value&& value) {
 
 void JSCExecutor::flush() {
   SystraceSection s("JSCExecutor::flush");
+  if (!m_delegate) {
+    // do nothing
+  } else if (!m_delegate->getModuleRegistry()) {
+    callNativeModules(Value::makeNull(m_context));
+  } else {
+    // If this is failing, chances are you have provided a delegate with a
+    // module registry, but haven't loaded the JS which enables native function
+    // queueing.  Add BatchedBridge.js to your bundle, pass a nullptr delegate,
+    // or make delegate->getModuleRegistry() return nullptr.
+    CHECK(m_flushedQueueJS) << "Attempting to use native methods without loading BatchedBridge.js";
     callNativeModules(m_flushedQueueJS->callAsFunction({}));
+  }
 }
 
 void JSCExecutor::callFunction(const std::string& moduleId, const std::string& methodId, const folly::dynamic& arguments) {
@@ -476,6 +483,9 @@ void JSCExecutor::callFunction(const std::string& moduleId, const std::string& m
 
   auto result = [&] {
     try {
+      // See flush()
+      CHECK(m_callFunctionReturnFlushedQueueJS)
+        << "Attempting to call native methods without loading BatchedBridge.js";
       return m_callFunctionReturnFlushedQueueJS->callAsFunction({
         Value(m_context, String::createExpectingAscii(m_context, moduleId)),
         Value(m_context, String::createExpectingAscii(m_context, methodId)),
@@ -511,6 +521,8 @@ Value JSCExecutor::callFunctionSyncWithValue(
     const std::string& module, const std::string& method, Value args) {
   SystraceSection s("JSCExecutor::callFunction");
 
+  // See flush()
+  CHECK(m_callFunctionReturnResultAndFlushedQueueJS);
   Object result = m_callFunctionReturnResultAndFlushedQueueJS->callAsFunction({
     Value(m_context, String::createExpectingAscii(m_context, module)),
     Value(m_context, String::createExpectingAscii(m_context, method)),

ReactCommon/cxxreact/JSCNativeModules.cpp

@@ -11,6 +11,10 @@ JSCNativeModules::JSCNativeModules(std::shared_ptr<ModuleRegistry> moduleRegistr
   m_moduleRegistry(std::move(moduleRegistry)) {}
 
 JSValueRef JSCNativeModules::getModule(JSContextRef context, JSStringRef jsName) {
+  if (!m_moduleRegistry) {
+    return Value::makeUndefined(context);
+  }
+
   std::string moduleName = String::ref(context, jsName).str();
 
   const auto it = m_objects.find(moduleName);

ReactCommon/cxxreact/NativeToJsBridge.cpp

@@ -47,6 +47,9 @@ public:
 
   void callNativeModules(
       JSExecutor& executor, folly::dynamic&& calls, bool isEndOfBatch) override {
+
+    CHECK(m_registry || calls.empty()) <<
+      "native module calls cannot be completed with no native modules";
     ExecutorToken token = m_nativeToJs->getTokenForExecutor(executor);
     m_nativeQueue->runOnQueue([this, token, calls=std::move(calls), isEndOfBatch] () mutable {
       // An exception anywhere in here stops processing of the batch.  This
@@ -95,13 +98,8 @@ NativeToJsBridge::NativeToJsBridge(
     std::shared_ptr<InstanceCallback> callback)
     : m_destroyed(std::make_shared<bool>(false))
     , m_mainExecutorToken(callback->createExecutorToken())
-    , m_delegate(registry
-                 ? std::make_shared<JsToNativeBridge>(
-                     this, registry, std::move(nativeQueue), callback)
-                 : nullptr) {
-  if (!m_delegate) {
-    nativeQueue->quitSynchronous();
-  }
+    , m_delegate(std::make_shared<JsToNativeBridge>(
+                   this, registry, std::move(nativeQueue), callback)) {
   std::unique_ptr<JSExecutor> mainExecutor =
     jsExecutorFactory->createJSExecutor(m_delegate, jsQueue);
   // cached to avoid locked map lookup in the common case
@@ -318,9 +316,7 @@ ExecutorToken NativeToJsBridge::getTokenForExecutor(JSExecutor& executor) {
 }
 
 void NativeToJsBridge::destroy() {
-  if (m_delegate) {
   m_delegate->quitQueueSynchronous();
-  }
   auto* executorMessageQueueThread = getMessageQueueThread(m_mainExecutorToken);
   // All calls made through runOnExecutorQueue have an early exit if
   // m_destroyed is true. Setting this before the runOnQueueSync will cause

ReactCommon/jschelpers/Value.h

@@ -305,6 +305,10 @@ public:
     return Value(ctx, JSC_JSValueMakeUndefined(ctx));
   }
 
+  static Value makeNull(JSContextRef ctx) {
+    return Value(ctx, JSC_JSValueMakeNull(ctx));
+  }
+
   std::string toJSONString(unsigned indent = 0) const;
   static Value fromJSON(JSContextRef ctx, const String& json);
   static JSValueRef fromDynamic(JSContextRef ctx, const folly::dynamic& value);