cout多线程输出混乱???

[火星大能猫]

int index = 50;
DWORD WINAPI ThreadA(LPVOID lparm)
{
	while(TRUE)
	{
		if(index > 0)
		{
			//cout<<"1剩余:"<< index-- <<endl;
			printf("1剩余%d\n", index --);
		}
		else
		{
			break;
		}
		/*Sleep(1);*/
	}
	return 0;
}
DWORD WINAPI ThreadB(LPVOID lparm)
{
	while(TRUE)
	{
		if(index > 0)
		{
		//	cout<<"2剩余:"<< index-- <<endl;
			printf("2剩余%d\n", index --);
		}
		else
		{
			break;
		}
		/*Sleep(1);*/
	}
	return 0;
}
int main(void)
{
	HANDLE hdlA = CreateThread(NULL, 0, ThreadA, NULL, 0, NULL);
	HANDLE hdlB = CreateThread(NULL, 0, ThreadB, NULL, 0, NULL);
	CloseHandle(hdlA);
	CloseHandle(hdlB);
	Sleep(3000);
	return 0;

代码很简单,如上
使用cout,输出会变乱
1剩余:2剩余:5049

1剩余:2剩余:4847

1剩余:2剩余:4645

1剩余:2剩余:4443

而使用printf正常.
1剩余50
2剩余49
1剩余48
2剩余47
1剩余46
2剩余45
1剩余44
2剩余43
1剩余42
2剩余41


cout如果取消注释sleep
则输出结果如下,还是比较混乱?
为何?
2剩余:1剩余:4443

1剩余:2剩余:4241

1剩余:2剩余:4039

2剩余:1剩余:3837

2剩余:1剩余:3635

2剩余:1剩余:3433

1剩余:2剩余:3231

2剩余:1剩余:3029

2剩余:1剩余:2827

2剩余:1剩余:2625

2剩余:24
1剩余:23
2剩余:1剩余:2221

2剩余:20
1剩余:19
2剩余:18
1剩余:2剩余:1716

1剩余:15
2剩余:14
1剩余:13
2剩余:12
1剩余40

[珍惜生命远离CPP]

改用_beginthreadex创建线程

[转角天边]

你应该给这两个线程加锁

[ForestDB]

最终还是要通过同步来达到预期的效果。