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[原创]线程之内核对象与事件操作

发表于: 2022-2-9 21:39 4212

[原创]线程之内核对象与事件操作

呓语。

2022-2-9 21:39

4212

1.内核对象：

1	`进程、线程、文件、文件映射、事件、互斥体等等`

2、事件内核对象的创建

HANDLE CreateEvent(                
  LPSECURITY_ATTRIBUTES lpEventAttributes, // 安全属性 NULL时为系统默认                
  BOOL bManualReset,                       // TRUE 通过调ResetEvent将事件对象标记为未通知                
  BOOL bInitialState,                      // TRUE 已通知状态  FALSE未通知状态                
  LPCTSTR lpName                           // 对象名称 以NULL结尾的字符串                
);                

3、事件对象的控制

1	`BOOL` `SetEvent(HANDLE hEvent);` `//将对象设置为已通知`

4、事件内核对象的获取//跨进程时使用

HANDLE OpenEvent(                        
  DWORD dwDesiredAccess,  // access                        
  BOOL bInheritHandle,    // inheritance option                        
  LPCTSTR lpName          // object name                        
);                        
 
HANDLE g_hEvent = OpenEvent(EVENT_ALL_ACCESS, FALSE, "XYZ");        

5、内核对象的销毁

1	`BOOL` `CloseHandle(HANDLE hobj);`

(1)、当没有其他程序引用时，系统会销毁内核对象(使用数量).
(2)、内核对象的生命周期，可能比创建它的对象要长.

6.示例:线程同步

HANDLE g_hSet, g_hClear;        
int g_Max = 10;        
int g_Number = 0;        
 
//生产者线程函数          
DWORD WINAPI ThreadProduct(LPVOID pM)          
{          
    for (int i = 0; i < g_Max; i++)        
    {          
        WaitForSingleObject(g_hSet, INFINITE);          
        g_Number = 1; 
        DWORD id = GetCurrentThreadId();
        printf("生产者%d将数据%d放入缓冲区\n",id, g_Number); 
        SetEvent(g_hClear);           
    }          
    return 0;          
}          
//消费者线程函数        
DWORD WINAPI ThreadConsumer(LPVOID pM)          
{          
    for (int i = 0; i < g_Max; i++)        
    {          
        WaitForSingleObject(g_hClear, INFINITE);          
        g_Number = 0; 
        DWORD id = GetCurrentThreadId();
        printf("----消费者%d将数据%d放入缓冲区\n",id, g_Number); 
        SetEvent(g_hSet);           
    }          
    return 0;          
}          
 
int main(int argc, char* argv[])        
{        
 
    HANDLE hThread[2];         
 
    g_hSet = CreateEvent(NULL, FALSE, TRUE, NULL);      
    g_hClear = CreateEvent(NULL, FALSE, FALSE, NULL);         
 
    hThread[0] = ::CreateThread(NULL, 0, ThreadProduct, NULL, 0, NULL);         
    hThread[1] = ::CreateThread(NULL, 0, ThreadConsumer, NULL, 0, NULL);    
 
    WaitForMultipleObjects(2, hThread, TRUE, INFINITE);          
    CloseHandle(hThread[0]);          
    CloseHandle(hThread[1]);        
 
    //销毁     
    CloseHandle(g_hSet);      
    CloseHandle(g_hClear);          
 
    return 0;    
}        