问题描述

创建线程过多会出现线程不执行问题?

#include "stdafx.h"
#include
#include
#include
#include
using namespace std;

DWORD CALLBACK ThreadFun_02(LPVOID lp);
bool PrintLog(const char * pString);
CRITICAL_SECTION g_Cs;
int g_iTickets = 20;
int main()
{
InitializeCriticalSection(&g_Cs);

  PrintLog("开始创建线程");
  for(int i=0;i<g_iTickets;i++)
  {
        if(!CreateThread(NULL, 0, ThreadFun_02, NULL, 0, NULL))
        {
              PrintLog("创建线程失败!
");
        }
  }

   cin.get();
   cout<<g_iTickets<<endl;
   cin.get();
  return 0;

}

DWORD CALLBACK ThreadFun_02(LPVOID lp)
{
EnterCriticalSection(&g_Cs);
if(g_iTickets > 0)
{
char szChar[20];
sprintf_s(szChar, "Sell ticket: %d", g_iTickets);
cout<<szChar<<endl;
PrintLog(szChar);
g_iTickets--;
}

  LeaveCriticalSection(&g_Cs);

  return 0;

}

bool PrintLog(const char * pString)
{
EnterCriticalSection(&g_Cs);
FILE *cLog = NULL;
cLog = fopen("Test.log", "a");

  if(!cLog)
  {
        return false;
  }

  fputs(pString, cLog);
  fputc('
', cLog);
  fclose(cLog);

  LeaveCriticalSection(&g_Cs);
  return true;

}

代码如上,正常情况下最后输出的g_iTickets应该为0,但是如果g_iTickets过多(如50,100),就会出现最后的g_iTickets不为0的情况.这是什么情况呢?

g_iTickets=20情况下输出:
...
Sell ticket: 9
Sell ticket: 8
Sell ticket: 7
Sell ticket: 6
Sell ticket: 5
Sell ticket: 4
Sell ticket: 3
Sell ticket: 2
Sell ticket: 1

0

g_iTickets=50情况下输出:
...
Sell ticket: 9
Sell ticket: 8
Sell ticket: 7
Sell ticket: 6
Sell ticket: 5
Sell ticket: 4
Sell ticket: 3
Sell ticket: 2

1

g_iTickets=1000情况下输出:
Sell ticket: 45
Sell ticket: 44
Sell ticket: 43
Sell ticket: 42
Sell ticket: 41
Sell ticket: 40
Sell ticket: 39
Sell ticket: 38
Sell ticket: 37

36

解决方案

linux环境下的线程的创建问题
C++创建线程问题 一段可用代码
MFC 线程创建的问题

解决方案二：

http://blog.csdn.net/chen825919148/article/details/7904219

解决方案三：

首先看你线程过多的时候，是否创建成功了这么多线程。
其次就是你的主线程有么有等待其他线程都执行完成，而不是主线程已经先退出了。