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当锁定在新范围内完成时，编译器是否可以重新排序锁定之前和之后的操作？

例如：

std::cout << "started from ...
std::cout << "exited from ...
locking

或者：

locking
std::cout << "started from ...
std::cout << "exited from ...

完整示例代码：

#include <iostream>
#include <thread>
#include <mutex>

std::mutex mtx;
int counter = 0;
bool updated = false;

void foo()
{    
    std::cout << "started from : " << std::this_thread::get_id() << std::endl;
    //or any other operation before locking

    {
    //explicit scope
    std::scoped_lock lk{mtx};
        if(counter++)
            updated = true;

    std::cout << "ctr: " << counter << std::endl;        
    std::cout << "upd: " << updated << std::endl;
    std::cout << "performed from : " << std::this_thread::get_id() << std::endl;
    }

    std::cout << "exited from : " << std::this_thread::get_id() << std::endl;
    //or any other operation after releasing lock
}

int main()
{
    std::thread t1(foo);
    std::thread t2(foo);

    t1.join();
    t2.join();
}

到目前为止输出稳定：

started from : 140096075392768
ctr: 1
upd: 0
performed from : 140096075392768
exited from : 140096075392768
started from : 140096083785472
ctr: 2
upd: 1
performed from : 140096083785472
exited from : 140096083785472

但是有没有保证它会保持稳定？

是否可以获得以下输出：

started from : 140096075392768 
exited from : 140096075392768
ctr: 1 
upd: 0 
performed from : 140096075392768 
ctr: 2 
upd: 1 
performed from : 140096083785472 
started from : 140096083785472 
exited from : 140096083785472

这样在两个线程中，锁下的操作都会与非同步操作重新排序。

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