SetEvent/ResetEvent

　　在自动重置事件对象中，当WaitSingleObject/WaitForMultipleObjects接收到SetEvent发送过来的信号后则返回WAIT_OBJECT_0，此时操作系统（待定）自动重置等待的事件对象（即自动将其设置为无信号状态。无论何时通过SetEvent发送过来的信号，只要未被接收到均不会被自动重置。但在未被接收之前可以调用ResetEvent手动重置等待的事件对象，此时等待的事件对象为无信号状态）。在手动重置事件对象中，当WaitSingleObject/WaitForMultipleObjects接收到SetEvent发送过来的信号后则返回WAIT_OBJECT_0，此时需要调用ResetEvent手动重置等待的事件对象（即手动将其设置为无信号状态）。

#include <windows.h>
#include <iostream>
using namespace std;

DWORD WINAPI ThreadProc(LPVOID lpParam);
DWORD WINAPI ThreadProc2(LPVOID lpParam);

DWORD g_dwThreadID;
DWORD g_dwThreadID2;

UINT g_nTickets = 300;
HANDLE g_hEvent = NULL;

int main(int argc, char* argv[])
{
 cout << "Main thread is running." << endl;
 
 HANDLE hHandle = CreateThread(NULL, 0, ThreadProc, NULL, 0, &g_dwThreadID);
 HANDLE hHandle2 = CreateThread(NULL, 0, ThreadProc2, NULL, 0, &g_dwThreadID2);
 CloseHandle(hHandle); 
 CloseHandle(hHandle2);

 g_hEvent = CreateEvent(NULL, FALSE,  TRUE, NULL);

 Sleep(4000);
 system("pause");
 return 0;
}

DWORD WINAPI ThreadProc(LPVOID lpParam)
{ 
 // cout << "No." << g_dwThreadID << " thread is running." << endl;
 while (TRUE)
 {
  WaitForSingleObject(g_hEvent, INFINITE);
  if (g_nTickets > 0)
  {
   Sleep(1);
   cout << "No.1-" << g_dwThreadID << " sell ticket : " << g_nTickets << endl;
   g_nTickets--;
   SetEvent(g_hEvent); 
  }
  else
  {
   break;
  }
 }
 return 0;
}

DWORD WINAPI ThreadProc2(LPVOID lpParam)
{
 // cout << "No." << g_dwThreadID2 << " thread is running." << endl;
 while (TRUE)
 {
  WaitForSingleObject(g_hEvent, INFINITE);
  if (g_nTickets > 0)
  {
   Sleep(1);
   cout << "No.2-" << g_dwThreadID2 << " sell ticket : " << g_nTickets << endl;
   g_nTickets--;
   SetEvent(g_hEvent);
  }
  else
  {
   break;
  }
 }
 return 0;
}