screen_connector_ctrl.h

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/*
 * Copyright (C) 2020 The Android Open Source Project
 *
 * 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 <atomic>
#include <condition_variable>
#include <functional>
#include <memory>
#include <mutex>
#include <thread>
 
#include "cuttlefish/common/libs/concurrency/semaphore.h"
 
namespace cuttlefish {
class ScreenConnectorCtrl {
 public:
  enum class ModeType { kAndroidMode, kConfUI_Mode };
 
  ScreenConnectorCtrl() : atomic_mode_(ModeType::kAndroidMode) {}
 
  void WaitAndroidMode() {
    if (atomic_mode_ == ModeType::kAndroidMode) {
      return;
    }
    auto check = [this]() -> bool {
      return atomic_mode_ == ModeType::kAndroidMode;
    };
    std::unique_lock<std::mutex> lock(mode_mtx_);
    and_mode_cv_.wait(lock, check);
  }
 
  void SetMode(const ModeType mode) {
    std::lock_guard<std::mutex> lock(mode_mtx_);
    atomic_mode_ = mode;
    if (atomic_mode_ == ModeType::kAndroidMode) {
      and_mode_cv_.notify_all();
    }
  }
 
  auto GetMode() {
    std::lock_guard<std::mutex> lock(mode_mtx_);
    ModeType ret_val = atomic_mode_;
    return ret_val;
  }
 
  void SemWait() { sem_.SemWait(); }
 
  // Only called by the producers
  void SemPost() { sem_.SemPost(); }
 
 private:
  std::mutex mode_mtx_;
  std::condition_variable and_mode_cv_;
  std::atomic<ModeType> atomic_mode_;
 
  // track the total number of items in all queues
  Semaphore sem_;
};
 
}  // namespace cuttlefish