孙鑫 VC++深入详解第16课——线程同步与异步套接字编程

1.通过事件对象实现同步

①创建事件对象CreateEvent

②设置为激活常态SetEvent

③等待信号量WaitForSingleObject

④关闭事件句柄CloseHandle

代码：

#include <Windows.h>
#include <iostream>

using namespace std;
int tickets = 100;

HANDLE g_Event;//事件对象句柄
DWORD WINAPI OneSellTickets(LPVOID lpParam);
DWORD WINAPI TwoSellTickets(LPVOID lpParam);
void main()
{
//创建事件句柄，
g_Event = CreateEvent(NULL,              //安全性，默认是NULL
FALSE,			 //FALSE表示线程释放后自动复位为无信号，TRUE要手动复位
FALSE,			 //TRUE表示有信号状态，FALSE表示无信号状态
TEXT("tickets"));
if (g_Event)
{
if (ERROR_ALREADY_EXISTS == GetLastError())
{
cout<<"only one instance can run"<<endl;
return ;
}
}
SetEvent(g_Event);
HANDLE handleOne = CreateThread(NULL,0,OneSellTickets,NULL,0,NULL);
HANDLE handleTwo = CreateThread(NULL,0,TwoSellTickets,NULL,0,NULL);
CloseHandle(handleOne);
CloseHandle(handleTwo);

Sleep(1000);

CloseHandle(g_Event);

cin.get();
cin.get();
}

DWORD WINAPI OneSellTickets(LPVOID lpParam)
{
while (TRUE)
{
WaitForSingleObject(g_Event,INFINITE);
if (tickets > 0)
{
cout<<"One Sell Tickets"<<tickets--<<endl;
SetEvent(g_Event);
}
else
{
SetEvent(g_Event);
break;
}
}
return 0;
}

DWORD WINAPI TwoSellTickets(LPVOID lpParam)
{
while (TRUE)
{
WaitForSingleObject(g_Event,INFINITE);
if (tickets > 0)
{
cout<<"Two Sell Tickets"<<tickets-- <<endl;
SetEvent(g_Event);
}
else
{
SetEvent(g_Event);
break;
}
}
return 0;
}

2.临界区：

①设置临界区结构体 CRITICAL_SECTION

②初始化临界区 InitializeCriticalSection

③进入临界区 EnterCriticalSection

④离开临界区 LeaveCriticalSection

⑤销毁临界区 DeleteCriticalSection

#include <Windows.h>
#include <iostream>

using namespace std;
int tickets = 100;

CRITICAL_SECTION g_cs;//设置临界区结构体的全局变量

DWORD WINAPI OneSellTickets(LPVOID lpParam);
DWORD WINAPI TwoSellTickets(LPVOID lpParam);
void main()
{

InitializeCriticalSection(&g_cs);
HANDLE handleOne = CreateThread(NULL,0,OneSellTickets,NULL,0,NULL);
HANDLE handleTwo = CreateThread(NULL,0,TwoSellTickets,NULL,0,NULL);
CloseHandle(handleOne);
CloseHandle(handleTwo);

Sleep(1000);
DeleteCriticalSection(&g_cs);
cin.get();
cin.get();
}

DWORD WINAPI OneSellTickets(LPVOID lpParam)
{
while (TRUE)
{
EnterCriticalSection(&g_cs);
if (tickets > 0)
{
cout<<"One Sell Tickets"<<tickets--<<endl;
LeaveCriticalSection(&g_cs);
}
else
{
LeaveCriticalSection(&g_cs);
break;
}
}
return 0;
}

DWORD WINAPI TwoSellTickets(LPVOID lpParam)
{
while (TRUE)
{
EnterCriticalSection(&g_cs);
if (tickets > 0)
{
cout<<"Two Sell Tickets"<<tickets-- <<endl;
LeaveCriticalSection(&g_cs);
}
else
{
LeaveCriticalSection(&g_cs);
break;
}
}
return 0;
}