tlbmc/hal/shared_mem/sensors.h

#ifndef THIRD_PARTY_MILOTIC_EXTERNAL_CC_TLBMC_HAL_SHARED_MEM_SENSORS_H_
#define THIRD_PARTY_MILOTIC_EXTERNAL_CC_TLBMC_HAL_SHARED_MEM_SENSORS_H_

#include <atomic>
#include <chrono>  // NOLINT
#include <cstdint>
#include <limits>
#include <utility>

namespace milotic_tlbmc {

class IpcSensor {
 public:
  IpcSensor() : value_(std::numeric_limits<float>::infinity()), timestamp_(0) {
    static_assert(std::atomic<float>::is_always_lock_free);
    static_assert(std::atomic<uint64_t>::is_always_lock_free);
  }
  std::pair<float, uint64_t> GetValue() const { return {value_, timestamp_}; }
  void SetValue(float value) {
    value_ = value;
    timestamp_ = static_cast<uint64_t>(
        std::chrono::duration_cast<std::chrono::milliseconds>(
            std::chrono::system_clock::now().time_since_epoch())
            .count());
  }
  void SetValue(float value, uint64_t timestamp) {
    value_ = value;
    timestamp_ = timestamp;
  }

 private:
  // Our application does not need strong consistency but collect time serials
  // data. It's fine that timestamp is not updated atomically with the value.
  std::atomic<float> value_;
  // The timestamp is in milliseconds.
  std::atomic<uint64_t> timestamp_;
};

}  // namespace milotic_tlbmc

#endif  // THIRD_PARTY_MILOTIC_EXTERNAL_CC_TLBMC_HAL_SHARED_MEM_SENSORS_H_