+/*
+ * Copyright 2017-present Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#pragma once
+
+#include <folly/ExceptionString.h>
+#include <folly/Function.h>
+#include <folly/futures/DrivableExecutor.h>
+#include <folly/io/async/NotificationQueue.h>
+
+namespace folly {
+
+class NotificationQueueExecutor : public folly::DrivableExecutor {
+ public:
+ using Func = folly::Func;
+
+ void add(Func func) override {
+ queue_.putMessage(std::move(func));
+ }
+
+ int fileno() const {
+ return consumer_.getFd();
+ }
+
+ void drive() noexcept override {
+ Func func;
+ while (queue_.tryConsume(func)) {
+ try {
+ func();
+ } catch (const std::exception& ex) {
+ LOG(ERROR) << "Exception thrown by NotificationQueueExecutor task."
+ << "Exception message: " << folly::exceptionStr(ex);
+ } catch (...) {
+ LOG(ERROR) << "Unknown Exception thrown "
+ << "by NotificationQueueExecutor task.";
+ }
+ }
+ }
+
+ private:
+ folly::NotificationQueue<Func> queue_;
+ folly::NotificationQueue<Func>::SimpleConsumer consumer_{queue_};
+}; // NotificationQueueExecutor
+
+} // namespace folly