thermal_watcher.h

/*
 * Copyright (C) 2018 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 <chrono>
#include <condition_variable>
#include <future>
#include <list>
#include <mutex>
#include <set>
#include <string>
#include <thread>
#include <unordered_map>
#include <vector>

#include <android-base/unique_fd.h>
#include <utils/Looper.h>
#include <utils/Thread.h>

namespace android {
namespace hardware {
namespace thermal {
namespace V2_0 {
namespace implementation {

using android::base::unique_fd;
using WatcherCallback = std::function<bool(const std::set<std::string> &name)>;

// A helper class for monitoring thermal files changes.
class ThermalWatcher : public ::android::Thread {
  public:
	ThermalWatcher(const WatcherCallback &cb)
		: Thread(false), cb_(cb), looper_(new Looper(true)) {}
	~ThermalWatcher() = default;

	// Disallow copy and assign.
	ThermalWatcher(const ThermalWatcher &) = delete;
	void operator=(const ThermalWatcher &) = delete;

	// Start the thread and return true if it succeeds.
	bool startThermalWatcher();
	// init uevent socket
	void initThermalWatcher(int tz_version);
	// Wake up the looper thus the worker thread, immediately. This can be called
	// in any thread.
	void wake();

  private:
	// The work done by the watcher thread. This will use inotify to check for
	// modifications to the files to watch. If any modification is seen this
	// will callback the registered function with the new data read from the
	// modified file.
	bool threadLoop() override;

	// Parse uevent message or socket message
	void parseUevent(std::set<std::string> *sensors_set);
	void parseMsg(std::set<std::string> *sensors_set);

	// The callback function. Called whenever thermal uevent is seen.
	// The function passed in should expect a string in the form (type).
	// Where type is the name of the thermal zone that trigger a uevent notification.
	// Callback will return thermal trigger status for next polling decision.
	const WatcherCallback cb_;

	sp<Looper> looper_;

	// listen thermal info from theraml core via thermal hal socket
	// uevent socket registration for legancy tz map
	android::base::unique_fd event_fd_;
	// Flag to point out if any sensor across the first threshold.
	bool thermal_triggered_;
	// Flag to point out if device can support uevent notify.
	bool is_polling_;
	int tz_map_version;
};

}  // namespace implementation
}  // namespace V2_0
}  // namespace thermal
}  // namespace hardware
}  // namespace android