C++中如何实现对象池模式 重复利用对象的内存管理技巧

#include <iostream>
#include <queue>
#include <mutex>

template <typename T>
class ObjectPool {
public:
    ObjectPool(size_t size) {
        for (size_t i = 0; i < size; ++i) {
            free_objects_.push(new T());
        }
    }

    T* acquireObject() {
        std::lock_guard<std::mutex> lock(mutex_);
        if (free_objects_.empty()) {
            // 如果对象池为空，可以创建新的对象，或者返回nullptr
            return new T(); // 简单起见，直接创建新的对象
        }
        T* obj = free_objects_.front();
        free_objects_.pop();
        return obj;
    }

    void releaseObject(T* obj) {
        std::lock_guard<std::mutex> lock(mutex_);
        // 重置对象状态，确保下次使用时是干净的
        //obj->reset(); // 假设T类型有reset方法
        free_objects_.push(obj);
    }

    ~ObjectPool() {
        std::lock_guard<std::mutex> lock(mutex_);
        while (!free_objects_.empty()) {
            T* obj = free_objects_.front();
            free_objects_.pop();
            delete obj;
        }
    }

private:
    std::queue<T*> free_objects_;
    std::mutex mutex_;
};

// 示例用法
class MyObject {
public:
    MyObject() {
        std::cout << "MyObject created" << std::endl;
    }
    ~MyObject() {
        std::cout << "MyObject destroyed" << std::endl;
    }

    void doSomething() {
        std::cout << "MyObject doing something" << std::endl;
    }
};

int main() {
    ObjectPool<MyObject> pool(5);

    MyObject* obj1 = pool.acquireObject();
    obj1->doSomething();
    pool.releaseObject(obj1);

    MyObject* obj2 = pool.acquireObject();
    obj2->doSomething();
    pool.releaseObject(obj2);

    return 0;
}