text: /*
   * Copyright 2020 Google LLC
   *
   * 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.
   */
  
  #include "Firestore/core/src/util/background_queue.h"
  
  #include "Firestore/core/src/util/executor.h"
  
  namespace firebase {
  namespace firestore {
  namespace util {
  
  BackgroundQueue::BackgroundQueue(Executor* executor) : executor_(executor) {
  }
  
  void BackgroundQueue::Execute(std::function<void()>&& operation) {
    {
      std::lock_guard<std::mutex> lock(mutex_);
      pending_tasks_ += 1;
    }
  
    executor_->Execute([this, operation]() {
      operation();
  
      std::lock_guard<std::mutex> lock(mutex_);
      pending_tasks_ -= 1;
      if (pending_tasks_ == 0) {
        done_.notify_all();
      }
    });
  }
  
  void BackgroundQueue::AwaitAll() {
    std::unique_lock<std::mutex> lock(mutex_);
    done_.wait(lock, [this] { return pending_tasks_ == 0; });
  }
  
  }  // namespace util
  }  // namespace firestore
  }  // namespace firebase
  