内存池模板参考Poco库简单易懂

最新推荐文章于 2025-05-31 09:00:07 发布

原创最新推荐文章于 2025-05-31 09:00:07 发布 · 1k 阅读

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#c++ #内存

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本文介绍如何使用C++实现一个简单的内存池，参考了Poco库的设计，旨在提供一种理解和实现内存池的简洁方法。通过内存池管理内存，可以提高分配和释放效率，减少碎片。

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#pragma once
#include <vector>
#include "Poco\Mutex.h"

template<class T>
class CFramePool
{
public:
	CFramePool(int preAlloc, int maxAlloc = 0);

	~CFramePool();

	/**
	@des 
	申请一个T
	*/
	T* get();

	/**
	@des 
	释放一个T
	*/
	void release(T* ptr);

	/**
	@des
	获取池的大小
	*/
	int allocated() const;

	/**
	@des
	可用个数
	*/
	int available() const;

private:
	CFramePool();	//缺省构造？？
	CFramePool(CFramePool&); //默认复制构造
	CFramePool& operator =(const CFramePool&); //默认赋值

	Poco::FastMutex m_MtxBlocks;
	std::vector<T*>	m_vecBlocks;
	int	m_nAllocated;
	int m_nMaxAlloc;
};

//函数定义

template<class T>
CFramePool<T>::CFramePool(int preAlloc, int maxAlloc/* = 0*/) :
m_nMaxAlloc(maxAlloc),
m_nAllocated(preAlloc)
{
	m_vecBlocks.clear();

	for (int i = 0; i < preAlloc; i++)
	{
		T* ptr = new T;
		m_vecBlocks.push_back(ptr);
	}
}

template<class T>
CFramePool<T>::~CFramePool()
{
	std::vector<T*>::iterator it = m_vecBlocks.begin();
	for (; it != m_vecBlocks.end(); it++)
	{
		T* ptr = *it;
		delete ptr;
	}
}

template<class T>
T* CFramePool<T>::get()
{
	Poco::FastMutex::ScopedLock lock(m_MtxBlocks);

	if (m_vecBlocks.empty())
	{
		if (m_nAllocated < m_nMaxAlloc)
		{
			++m_nAllocated;
			T* ptr = new T;
			return ptr;
		}
		else
		{
			//throw OutOfMemoryException("MemoryPool exhausted");
			return NULL;
		}
	}
	else
	{
		T* ptr = m_vecBlocks.back();
		m_vecBlocks.pop_back();
		return ptr;
	}
}

template<class T>
void CFramePool<T>::release(T* ptr)
{
	Poco::FastMutex::ScopedLock lock(m_MtxBlocks);

	m_vecBlocks.push_back(ptr);
}

template<class T>
int CFramePool<T>::allocated() const
{
	Poco::FastMutex::ScopedLock lock(m_MtxBlocks);

	return m_nAllocated;
}

template<class T>
int CFramePool<T>::available() const
{
	Poco::FastMutex::ScopedLock lock(m_MtxBlocks);

	return m_vecBlocks.size();
}