/***************************************************************
function: connect pool template for mysql, redis, memcached ...
author: liuyi
date: 2016.04.13
version: 1.0
***************************************************************/
#ifndef CONNECT_POOL_H
#define COMMECT_POOL_H
#include <stdlib.h>
#include <iostream>
#include <vector>
#include <pthread.h>
using namespace std;
template<class T>
class connect_pool
{
public:
static connect_pool<T> * get_instance()
{
static connect_pool<T> s_instance;
return &s_instance;
}
bool init(vector<T*> connect_ptrs)
{
if(connect_ptrs.empty())
return false;
pthread_mutex_lock(m_mutex);
for(size_t i = 0; i < connect_ptrs.size(); i++)
{
m_used_index_vect.push_back(0);
m_connect_vect.push_back(connect_ptrs[i]);
}
pthread_mutex_unlock(m_mutex);
return true;
}
int get_connect_index()
{
int index = -1;
int rand_index = 0;
pthread_mutex_lock(m_mutex);
if(0 != m_used_index_vect.size())
{
rand_index = rand() % m_used_index_vect.size();
}
for(int j = rand_index; j < m_used_index_vect.size(); j++)
{
if(0 == m_used_index_vect[j])
{
m_used_index_vect[j] = 1;
index = j;
break;
}
}
if(index == -1)
{
for(int i = 0; i < rand_index; i++)
{
if(0 == m_used_index_vect[i])
{
m_used_index_vect[i] = 1;
index = i;
break;
}
}
}
pthread_mutex_unlock(m_mutex);
return index;
}
T* get_connect(int index)const
{
pthread_mutex_lock(m_mutex);
if(index >= 0 && index < m_connect_vect.size())
{
T* p = m_connect_vect[index];
pthread_mutex_unlock(m_mutex);
return p;
}
return NULL;
}
bool return_connect_2_pool(int index)
{
if(index < 0)
return false;
pthread_mutex_lock(m_mutex);
if(index < m_used_index_vect.size())
{
m_used_index_vect[index] = 0;
pthread_mutex_unlock(m_mutex);
return true;
}
pthread_mutex_unlock(m_mutex);
return false;
}
void remove_connect_from_pool(int index)
{
pthread_mutex_lock(m_mutex);
if(index >= 0 && index < m_used_index_vect.size())
{
m_used_index_vect[index] = 1;
}
pthread_mutex_unlock(m_mutex);
}
bool replace_alive_connect(T* new_connect, int index)
{
bool ret = false;
pthread_mutex_lock(m_mutex);
if(index >= 0 && index < m_used_index_vect.size())
{
m_used_index_vect[index] = 0;
m_connect_vect[index] = new_connect;
ret = true;
}
pthread_mutex_unlock(m_mutex);
return ret;
}
private:
connect_pool()
{
m_mutex = new pthread_mutex_t;
pthread_mutex_init(m_mutex, NULL);
srand(time(NULL));
}
~connect_pool()
{
if(NULL != m_mutex)
{
delete m_mutex;
m_mutex = NULL;
}
}
private:
pthread_mutex_t *m_mutex;
vector<int> m_used_index_vect;
vector<T*> m_connect_vect;
};
#endif
连接池模板
原文：https://www.cnblogs.com/henryliublog/p/9222003.html
