host_mode_ctrl.h

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/*
 * Copyright (C) 2021 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 <cstdint>
#include <functional>
#include <mutex>
 
#include <fruit/fruit.h>
 
#include "cuttlefish/common/libs/confui/confui.h"
#include "cuttlefish/host/libs/confui/host_utils.h"
 
namespace cuttlefish {
class HostModeCtrl {
 public:
  enum class ModeType : std::uint8_t { kAndroidMode = 55, kConfUI_Mode = 77 };
  INJECT(HostModeCtrl()) : atomic_mode_(ModeType::kAndroidMode) {}
  void WaitAndroidMode() {
    ConfUiLog(DEBUG) << cuttlefish::confui::thread::GetName()
                     << "checking atomic Android mode";
    if (atomic_mode_ == ModeType::kAndroidMode) {
      ConfUiLog(DEBUG) << cuttlefish::confui::thread::GetName()
                       << "returns as it is already Android mode";
      return;
    }
    auto check = [this]() -> bool {
      return atomic_mode_ == ModeType::kAndroidMode;
    };
    std::unique_lock<std::mutex> lock(mode_mtx_);
    and_mode_cv_.wait(lock, check);
    ConfUiLog(DEBUG) << cuttlefish::confui::thread::GetName()
                     << "awakes from cond var waiting for Android mode";
  }
 
  void SetMode(const ModeType mode) {
    ConfUiLog(DEBUG) << cuttlefish::confui::thread::GetName()
                     << " tries to acquire the lock in SetMode";
    std::lock_guard<std::mutex> lock(mode_mtx_);
    ConfUiLog(DEBUG) << cuttlefish::confui::thread::GetName()
                     << " acquired the lock in SetMode";
    atomic_mode_ = mode;
    if (atomic_mode_ == ModeType::kAndroidMode) {
      ConfUiLog(DEBUG) << cuttlefish::confui::thread::GetName()
                       << " signals kAndroidMode in SetMode";
      and_mode_cv_.notify_all();
      return;
    }
    ConfUiLog(DEBUG) << cuttlefish::confui::thread::GetName()
                     << "signals kConfUI_Mode in SetMode";
    confui_mode_cv_.notify_all();
  }
 
  auto GetMode() {
    ModeType ret_val = atomic_mode_;
    return ret_val;
  }
 
  auto IsConfirmatioUiMode() {
    return (atomic_mode_ == ModeType::kConfUI_Mode);
  }
 
  auto IsAndroidMode() { return (atomic_mode_ == ModeType::kAndroidMode); }
 
  static HostModeCtrl& Get() {
    static HostModeCtrl host_mode_controller;
    return host_mode_controller;
  }
 
 private:
  std::mutex mode_mtx_;
  std::condition_variable and_mode_cv_;
  std::condition_variable confui_mode_cv_;
  std::atomic<ModeType> atomic_mode_;
};
}  // end of namespace cuttlefish