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
