Windows、Linux中std::this_thread::get_id()导致的Qt中sql执行报Driver not loaded错误

Windows、Linux中std::this_thread::get_id()导致的Qt中sql执行报Driver not loaded错误

抽象代码：

void dosomework()
{
    std::ostringstream oss;
    oss << std::this_thread::get_id();
    std::string stid = oss.str();
    std::string dbname = "m_"+stid;
    QSqlDatabase db;
    {
        //mutex locked
        if(QSqlDatabase::connectionNames().contains(dbName.c_str())){
            db = QSqlDatabase::database(dbName.c_str());
        }else{
            db = QSqlDatabase::addDatabase("QSQLITE",dbName.c_str());
            db.setDatabaseName(dbpath);// 创建数据库
            db.open();
        }
    }
    /*
    这之间最好有一个db的判断
    if(db.isOpen())
    {
        // continue run;
    
    }else{
        // error
    }
    */
    QSqlQuery query(db);
    //下面是query执行语句
}

void handleLoop(Msg &msg)
{
    std::thread demothread([](){
        dosomework();
    });
    demothread.join();
    #linux
    sleep(1);
    #windows
    Sleep(1000);
}

上面示例代码中使用std::this_thread::get_id()作为db连接的名字，主要目的是可以同一个线程保证只有一个db连接。

但是。。。。。

Windows环境下std::this_thread::get_id()返回的都是不同的值，每次线程结束db的连接也会随之关闭。但是，但是，但是，linux上返回的尽然是一样的值，导致第二个线程再次连接db的时候，由于连接已经被第一个线程关闭了，执行query时直接报driver not loaded错误。

下面是测试代码

/// Linux
#include <unistd.h>
#include <iostream>
#include <thread>

void dosomework()
{
	std::cout << std::this_thread::get_id() << std::endl;
}

int main()
{
	for (int i = 0; i < 10; ++i){
		std::thread connectthread([](){
			dosomework();
		});
		std::cout << "connectthread:" << connectthread.get_id() << std::endl;
		connectthread.join(); 
		sleep(1000);
	}
	return 0;
}

结果：

120364298702360
connectthread:120364298702360
120364298702360
connectthread:120364298702360
120364298702360
connectthread:120364298702360
。。。

/// windows
#include <Windows.h>
#include <iostream>
#include <thread>

void dosomework()
{
	std::cout << std::this_thread::get_id() << std::endl;
}

int main()
{
	for (int i = 0; i < 10; ++i){
		std::thread connectthread([](){
			dosomework();
		});
		std::cout << "connectthread:" << connectthread.get_id() << std::endl;
		connectthread.join(); 
		Sleep(1000);
	}
	return 0;
}

结果

22360
connectthread:22360
4400
connectthread:4400
20852
connectthread:20852
23104
connectthread:23104
20152
connectthread:20152
4760
connectthread:4760
19496
connectthread:19496
400
connectthread:400
21152
connectthread:21152
23276
connectthread:23276