eis/shm/SingletonTemp.hpp

#pragma once
/**
 * @file SingletonTemp.hpp
 * @brief 单例模式 模板类 加锁
 * @author your name (you@domain.com)
 * @version 0.1
 * @date 2023-12-22
 *
 * Copyright: Baosight Co. Ltd.
 * DO NOT COPY/USE WITHOUT PERMISSION
 *
 */
#include <iostream>
#include <mutex>

// namespace {
// std::mutex local_mutex;
// }
template <class T> class SingletonTemp {
private:
  static std::mutex &get_mutex() {
    static std::mutex instance_mutex; // 每个类型有自己的静态mutex
    return instance_mutex;
  }

protected:
  SingletonTemp();

public:
  virtual ~SingletonTemp(void);

  static T *GetInstancePtr();
  static T &GetInstance();
  static bool release(void);

private:
  static T *mp_singleton;
};

template <class T> T *SingletonTemp<T>::mp_singleton = nullptr;

template <class T> SingletonTemp<T>::SingletonTemp(void) {}

template <class T> SingletonTemp<T>::~SingletonTemp(void) { release(); }

template <class T> T *SingletonTemp<T>::GetInstancePtr() {
  // std::lock_guard<std::mutex> guard(local_mutex);
  std::lock_guard<std::mutex> guard(get_mutex()); // 使用类型特定的锁
  if (mp_singleton == nullptr) {
    mp_singleton = new T();
  }
  return mp_singleton;
}

template <class T> T &SingletonTemp<T>::GetInstance() {
  // std::lock_guard<std::mutex> guard(local_mutex);
  std::lock_guard<std::mutex> guard(get_mutex()); // 使用类型特定的锁
  if (mp_singleton == nullptr) {
    mp_singleton = new T();
  }
  return *mp_singleton;
}

template <class T> bool SingletonTemp<T>::release(void) {
  // std::lock_guard<std::mutex> guard(local_mutex);
  std::lock_guard<std::mutex> guard(get_mutex()); // 使用类型特定的锁
  bool rtc = true;
  if (mp_singleton != nullptr) {
    delete mp_singleton;
    mp_singleton = nullptr;
  }
  return rtc;
}