Introduce MessageQueueThreadCallInvoker

Summary: This abstraction will be used by TurboModules to schedule work on the NativeModules thread.

Reviewed By: PeteTheHeat

Differential Revision: D17422165

fbshipit-source-id: d5ca7837a0ecbcc2118813e1bafa6d445ba2ef3b

ReactCommon/callinvoker/ReactCommon/MessageQueueThreadCallInvoker.cpp

@@ -0,0 +1,22 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include "MessageQueueThreadCallInvoker.h"
+
+namespace facebook {
+namespace react {
+
+MessageQueueThreadCallInvoker::MessageQueueThreadCallInvoker(
+    std::shared_ptr<MessageQueueThread> moduleMessageQueue)
+    : moduleMessageQueue_(moduleMessageQueue) {}
+
+void MessageQueueThreadCallInvoker::invokeAsync(std::function<void()> &&func) {
+  moduleMessageQueue_->runOnQueue(std::move(func));
+}
+
+} // namespace react
+} // namespace facebook

ReactCommon/callinvoker/ReactCommon/MessageQueueThreadCallInvoker.h

@@ -0,0 +1,35 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#pragma once
+
+#include <functional>
+#include <memory>
+
+#include <ReactCommon/CallInvoker.h>
+#include <cxxreact/MessageQueueThread.h>
+
+namespace facebook {
+namespace react {
+
+/**
+ * Used to schedule async calls on the NativeModuels thread.
+ */
+class MessageQueueThreadCallInvoker : public CallInvoker {
+ public:
+  MessageQueueThreadCallInvoker(
+      std::shared_ptr<MessageQueueThread> moduleMessageQueue);
+
+  void invokeAsync(std::function<void()> &&func) override;
+  // TODO: add sync support
+
+ private:
+  std::shared_ptr<MessageQueueThread> moduleMessageQueue_;
+};
+
+} // namespace react
+} // namespace facebook