Support passing native modules to JSContext

Reviewed By: amnn

Differential Revision: D4561036

fbshipit-source-id: b096a222103e895b14cba1ec5b2bb6e72dd72c37

ReactCommon/cxxreact/BUCK

@@ -55,7 +55,6 @@ if THIS_IS_FBANDROID:
           # `initOnJSVMThread` to be called before the platform-specific hooks
           # have been properly initialised. Bad Times(TM).
           #     -- @ashokmenon (2017/01/03)
-          '//java/com/facebook/java2js:jni',
           react_native_target('jni/xreact/jni:jni'),
           react_native_xplat_target('cxxreact/...'),
         ],

ReactCommon/cxxreact/Instance.cpp

@@ -2,6 +2,7 @@
 
 #include "Instance.h"
 
+#include "CxxMessageQueue.h"
 #include "Executor.h"
 #include "MethodCall.h"
 #include "RecoverableError.h"
@@ -36,6 +37,15 @@ void Instance::initializeBridge(
     std::shared_ptr<ModuleRegistry> moduleRegistry) {
   callback_ = std::move(callback);
 
+  if (!nativeQueue) {
+    // TODO pass down a thread/queue from java, instead of creating our own.
+
+    auto queue = std::make_unique<CxxMessageQueue>();
+    std::thread t(queue->getUnregisteredRunLoop());
+    t.detach();
+    nativeQueue = std::move(queue);
+  }
+
   jsQueue->runOnQueueSync(
     [this, &jsef, moduleRegistry, jsQueue,
      nativeQueue=folly::makeMoveWrapper(std::move(nativeQueue))] () mutable {

ReactCommon/cxxreact/NativeToJsBridge.cpp

@@ -95,9 +95,13 @@ NativeToJsBridge::NativeToJsBridge(
     std::shared_ptr<InstanceCallback> callback)
     : m_destroyed(std::make_shared<bool>(false))
     , m_mainExecutorToken(callback->createExecutorToken())
-    , m_delegate(
-      std::make_shared<JsToNativeBridge>(
-        this, registry, std::move(nativeQueue), callback)) {
+    , m_delegate(registry
+                 ? std::make_shared<JsToNativeBridge>(
+                     this, registry, std::move(nativeQueue), callback)
+                 : nullptr) {
+  if (!m_delegate) {
+    nativeQueue->quitSynchronous();
+  }
   std::unique_ptr<JSExecutor> mainExecutor =
     jsExecutorFactory->createJSExecutor(m_delegate, jsQueue);
   // cached to avoid locked map lookup in the common case
@@ -314,7 +318,9 @@ ExecutorToken NativeToJsBridge::getTokenForExecutor(JSExecutor& executor) {
 }
 
 void NativeToJsBridge::destroy() {
-  m_delegate->quitQueueSynchronous();
+  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