多线程的学习，执行情况和显示的效果不一致，求教

[小哥该吃药了]

今天在学习多线程编程时，在vs2010上运行了孙鑫老师深入详解vc里的一段代码。
发现win32控制台显示的结果很奇怪，多线程调用正常，但是cout输出滞后了。以下贴出代码

#include "stdafx.h"
#include "windows.h"
#include "iostream"
using namespace std;
DWORD WINAPI Fun1Proc(LPVOID lpParameter);
DWORD WINAPI Fun2Proc(LPVOID lpParameter);
int t=0;
int tickets=100;
int _tmain(int argc, _TCHAR* argv[])
{
	HANDLE hThread1;
	HANDLE hThread2;
	
	hThread1=CreateThread(NULL,0,Fun1Proc,NULL,0,NULL);
	hThread2=CreateThread(NULL,0,Fun2Proc,NULL,0,NULL);
	CloseHandle(hThread1);
	CloseHandle(hThread2);
	while (t++<1000)
	Sleep(4000);
	system("pause");
	return 0;
}

DWORD WINAPI Fun1Proc(LPVOID lpParameter)
{
	while(TRUE)
	{
		if(tickets>0)
			cout<<"thread1 sell ticket :"<<tickets--<<endl;
		else
			break;
	}
	return 0;
}
DWORD WINAPI Fun2Proc(LPVOID lpParameter)
{
	while(TRUE)
	{
		if(tickets>0)
			cout<<"thread2 sell ticket :"<<tickets--<<endl;
		else
			break;
	}
	return 0;
}

以下是执行结果：
thread1 sell ticket :thread2 sell ticket :99
100
thread1 sell ticket :98
thread1 sell ticket :97
thread2 sell ticket :96
thread1 sell ticket :95
thread2 sell ticket :94
thread2 sell ticket :92thread1 sell ticket :93
thread1 sell ticket :91

thread1 sell ticket :90
thread2 sell ticket :89
thread2 sell ticket :87
thread2 sell ticket :86
thread2 sell ticket :85
thread2 sell ticket :84
thread2 sell ticket :83
thread1 sell ticket :88
thread1 sell ticket :81
thread1 sell ticket :80
thread1 sell ticket :79
thread2 sell ticket :82
thread1 sell ticket :78
thread2 sell ticket :77
thread1 sell ticket :76
thread1 sell ticket :74
thread1 sell ticket :73
thread1 sell ticket :72
thread1 sell ticket :71
thread1 sell ticket :70
thread1 sell ticket :69
thread1 sell ticket :68
thread1 sell ticket :67
thread1 sell ticket :66
thread1 sell ticket :65
thread1 sell ticket :64
thread1 sell ticket :63
thread1 sell ticket :62
thread1 sell ticket :61
thread1 sell ticket :60
thread1 sell ticket :59
thread1 sell ticket :58
thread1 sell ticket :57
thread1 sell ticket :56
thread1 sell ticket :55
thread1 sell ticket :54
thread1 sell ticket :53
thread1 sell ticket :52
thread1 sell ticket :51
thread1 sell ticket :50
thread1 sell ticket :49
thread1 sell ticket :48
thread1 sell ticket :47
thread1 sell ticket :46
thread1 sell ticket :45
thread1 sell ticket :44
thread1 sell ticket :43
thread1 sell ticket :42
thread1 sell ticket :41
thread1 sell ticket :40
thread1 sell ticket :39
thread1 sell ticket :38
thread1 sell ticket :37
thread1 sell ticket :36
thread1 sell ticket :35
thread1 sell ticket :34
thread2 sell ticket :75
thread2 sell ticket :33
thread2 sell ticket :32
thread2 sell ticket :31
thread2 sell ticket :30
thread2 sell ticket :29
thread2 sell ticket :28
thread2 sell ticket :27
thread2 sell ticket :26
thread2 sell ticket :25
thread2 sell ticket :24
thread2 sell ticket :23
thread2 sell ticket :22
thread2 sell ticket :21
thread2 sell ticket :20
thread2 sell ticket :19
thread2 sell ticket :18
thread2 sell ticket :17
thread2 sell ticket :16
thread2 sell ticket :15
thread2 sell ticket :14
thread2 sell ticket :13
thread2 sell ticket :12
thread2 sell ticket :11
thread2 sell ticket :10
thread2 sell ticket :9
thread2 sell ticket :8
thread2 sell ticket :7
thread2 sell ticket :6
thread2 sell ticket :5
thread2 sell ticket :4
thread2 sell ticket :3
thread2 sell ticket :2
thread2 sell ticket :1
————————————————————————————————————
问题来了，93号那张票，既然线程1抢到了，为何不是先输出，而是92号那张票先输出。同样这里面还有82，88号票等，每次运行都有几个这样的情况。

[lx624909677]

给票数加锁，多线程程序运行正常不代表完全正确

[小哥该吃药了]

引用 1 楼 lx624909677 的回复:

给票数加锁，多线程程序运行正常不代表完全正确

我现在不是关心有没有拿到重复的票数，而是这2个线程，拿到了自己的对应票，却没有在拿到票之后打印出票号。票号按理论来讲是要100到1递减，但结果不是这样显示

[boylafong]

引用 2 楼 yang2009001 的回复:

[quote=引用 1 楼 lx624909677 的回复:] 给票数加锁，多线程程序运行正常不代表完全正确

我现在不是关心有没有拿到重复的票数，而是这2个线程，拿到了自己的对应票，却没有在拿到票之后打印出票号。票号按理论来讲是要100到1递减，但结果不是这样显示[/quote] 线程执行是不分先后的，就是说 Fun1Proc在执行tickets--的时候 Fun2Proc可能在执行cout, 这时候Fun2Proc全部执行完了， Fun1Proc才执行完cout

[shenyi0106]

多线程的一个非常重要的概念就是——锁！！！ 不理解锁，就别搞多线程了，这只会使你的思想更混乱

[版主大哥]

问题来了，93号那张票，既然线程1抢到了，为何不是先输出 DWORD WINAPI Fun1Proc(LPVOID lpParameter) { while(TRUE) { if(tickets>0) cout<<"thread1 sell ticket :"<<tickets--<<endl; /./93号线程执行完tickets-- 准备执行cout<< 输出的时候发送线程切换，去执行线程2了，然后又回来就发生这种现象了 else break; } return 0; } DWORD WINAPI Fun2Proc(LPVOID lpParameter) { while(TRUE) { if(tickets>0) cout<<"thread2 sell ticket :"<<tickets--<<endl; else break; } return 0; } 多线程访问共享数据必须加锁

[lx624909677]

引用 2 楼 yang2009001 的回复:

[quote=引用 1 楼 lx624909677 的回复:] 给票数加锁，多线程程序运行正常不代表完全正确

我现在不是关心有没有拿到重复的票数，而是这2个线程，拿到了自己的对应票，却没有在拿到票之后打印出票号。票号按理论来讲是要100到1递减，但结果不是这样显示[/quote] 所以说要你加锁呀！！！

[小哥该吃药了]

引用 4 楼 shenyi0106 的回复:

多线程的一个非常重要的概念就是——锁！！！ 不理解锁，就别搞多线程了，这只会使你的思想更混乱

我刚刚接触，还没看到后面的概念。跟着孙鑫老师的步骤走，发现跟他的结果不一样，又不明白为什么所以贴出来问。